1
|
Yamada R, Tanaka Y, Sugimoto H, Kodama N, Yoshida R, Minagi S. Effect of continuous sweet gustatory stimulation on salivary flow rate over time. Arch Oral Biol 2023; 146:105590. [PMID: 36463789 DOI: 10.1016/j.archoralbio.2022.105590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/20/2022] [Accepted: 11/24/2022] [Indexed: 12/02/2022]
Abstract
OBJECTIVE This study aimed to determine changes in saliva secretion and subjective taste intensity during a sustained period with continuous gustatory stimulation. DESIGN Twenty-two healthy adults participated in this study. The selected taste solutions were aspartame, sucralose, and acesulfame potassium, which are nonnutritive sweeteners. The concentrations of sucralose1 and acesulfame potassium were set to show the same sweetness intensity as aspartame. Sucralose2 was twice the concentration of sucralose1. The solution was continuously fed into the oral cavity at a flow rate of 0.04 mL / min through a neck-worn precise infusion system. The salivary flow rate (g/min) after 10 min of intraoral water supply from the device was used as the baseline. Salivary flow rate, subjective taste intensity evaluated by the visual analog scale (VAS), and salivary flow rate relative to the baseline were recorded at 10, 30, 60, and 120 min after the start of the test. RESULTS In the aspartame, sucralose1, and sucralose2 groups, the salivary flow rate increased significantly from 10 min to 120 min after the start of the test when compared to the rate at baseline (p < 0.05). The relative salivary flow rate increased and the VAS value decreased significantly over time and were affected by the time factor (p < 0.001, p = 0.013, respectively) but not by the sweetener-group factor and the interaction effects. CONCLUSIONS Continuous gustatory stimulation may maintain increased salivary production for a sustained period.
Collapse
Affiliation(s)
- Ranko Yamada
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, 700-8525 Okayama, Japan
| | - Yuki Tanaka
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, 700-8525 Okayama, Japan
| | - Hikaru Sugimoto
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, 700-8525 Okayama, Japan.
| | - Naoki Kodama
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, 700-8525 Okayama, Japan
| | - Ryusuke Yoshida
- Department of Oral Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, 700-8525 Okayama, Japan
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, 700-8525 Okayama, Japan
| |
Collapse
|
2
|
Iwaki M, Kanazawa M, Kodama N, Matsuda K, Minakuchi S, Minagi S, Ikebe K, Nitta H. Current educational settings for the undergraduate curriculum of complete denture prosthodontics in 29 japanese dental schools. J Prosthodont Res 2023; 67:1-3. [PMID: 35370220 DOI: 10.2186/jpr.jpr_d_21_00315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Maiko Iwaki
- Oral Prosthetic Engineering, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Manabu Kanazawa
- Digital Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Naoki Kodama
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Kenichi Matsuda
- Department of Prosthodontics, Gerodontology and Oral Rehabilitation, Osaka University Graduate School of Dentistry, Osaka, Japan
| | - Shunsuke Minakuchi
- Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Kazunori Ikebe
- Department of Prosthodontics, Gerodontology and Oral Rehabilitation, Osaka University Graduate School of Dentistry, Osaka, Japan
| | - Hiroshi Nitta
- General Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| |
Collapse
|
3
|
Maruo Y, Yoshihara K, Irie M, Nagaoka N, Matsumoto T, Minagi S. Does Multifunctional Acrylate's Addition to Methacrylate Improve Its Flexural Properties and Bond Ability to CAD/CAM PMMA Block? Materials (Basel) 2022; 15:7564. [PMID: 36363156 PMCID: PMC9657670 DOI: 10.3390/ma15217564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 10/21/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
This study investigated the effects of a multifunctional acrylate copolymer-Trimethylolpropane Triacrylate (TMPTA) and Di-pentaerythritol Polyacrylate (A-DPH)-on the mechanical properties of chemically polymerized acrylic resin and its bond strength to a CAD/CAM polymethyl methacrylate (PMMA) disk. The methyl methacrylate (MMA) samples were doped with one of the following comonomers: TMPTA, A-DPH, or Trimethylolpropane Trimethacrylate (TMPTMA). The doping ratio ranged from 10 wt% to 50 wt% in 10 wt% increments. The flexural strength (FS) and modulus (FM) of PMMA with and without comonomer doping, as well as the shear bond strength (SBS) between the comonomer-doped PMMA and CAD/CAM PMMA disk, were evaluated. The highest FS (93.2 ± 4.2 MPa) was obtained when doped with 20 wt% of TMPTA. For TMPTMA, the FS decreased with the increase in the doping ratio. For SBS, TMPTA showed almost constant values (ranging from 7.0 to 8.2 MPa) regardless of the doping amount, and A-DPH peaked at 10 wt% doping (8.7 ± 2.2 MPa). TMPTMA showed two peaks at 10 wt% (7.2 ± 2.6 MPa) and 40 wt% (6.5 ± 2.3 MPa). Regarding the failure mode, TMPTMA showed mostly adhesive failure between the CAD/CAM PMMA disk and acrylic resin while TMPTA and A-DPH showed an increased rate of cohesive or mixed failures. Acrylate's addition as a comonomer to PMMA provided improved mechanical properties and bond strength to the CAD/CAM PMMA disk.
Collapse
Affiliation(s)
- Yukinori Maruo
- Department of Prosthodontics, Okayama University, 2-5-1 Shikata-cho, Okayama 700-8525, Japan
| | - Kumiko Yoshihara
- Health Research Institute, National Institute of Advanced Industrial Science and Technology, 2217-14 Hayashi-cho, Takamatsu, Kagawa 761-0395, Japan
| | - Masao Irie
- Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8525, Japan
| | - Noriyuki Nagaoka
- Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Dental School, Okayama 700-8558, Japan
| | - Takuya Matsumoto
- Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8525, Japan
| | - Shogo Minagi
- Department of Prosthodontics, Okayama University, 2-5-1 Shikata-cho, Okayama 700-8525, Japan
| |
Collapse
|
4
|
Ono K, Yoshioka N, Kunisada Y, Nakamura T, Nakamura Y, Obata K, Ibaragi S, Minagi S, Sasaki A. Craniomaxillofacial Fibrous Dysplasia Improved Cosmetic and Occlusal Problem by Comprehensive Treatment: A Case Report and Review of Current Treatments. Diagnostics (Basel) 2022; 12:diagnostics12092146. [PMID: 36140547 PMCID: PMC9497856 DOI: 10.3390/diagnostics12092146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 08/29/2022] [Accepted: 09/01/2022] [Indexed: 11/16/2022] Open
Abstract
Fibrous dysplasia (FD) is a fibrous lesion of immature bone, with an incidence of 10–20% in the head and neck region. Most cases are monostotic, but when a lesion occurs on the maxillofacial region and spreads to the surrounding bone, it is classified as polyostotic, despite its localized occurrence. In some cases, surgical intervention is required to improve the cosmetic or functional disturbance of a FD in the maxillofacial region, but it is necessary to confirm symmetry of the maxillofacial region in real time, and a surgical support system is required to compensate. Furthermore, prosthetic intervention is considered when postoperative acquired defects occur or further cosmetic or occlusal function improvement is needed. A comprehensive approach by an oral surgeon and a maxillofacial prosthodontist is necessary for the successful treatment and rehabilitation of such patients. In this article, we describe the case of a craniomaxillofacial FD patient with facial asymmetry and denture incompatibility with improved quality of life measures by integrating surgical treatment using a navigation system and postoperative prosthetic rehabilitation. We also discuss recent diagnostic methods and treatment strategies for craniomaxillofacial FD in the literature.
Collapse
Affiliation(s)
- Kisho Ono
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8525, Japan
| | - Norie Yoshioka
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8525, Japan
- Correspondence:
| | - Yuki Kunisada
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8525, Japan
| | - Tomoya Nakamura
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8525, Japan
| | - Yuko Nakamura
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8525, Japan
| | - Kyoichi Obata
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8525, Japan
| | - Soichiro Ibaragi
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8525, Japan
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8525, Japan
| | - Akira Sasaki
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8525, Japan
| |
Collapse
|
5
|
Yokoyama T, Mukai T, Kodama N, Takao K, Hiraoka T, Arai N, Yano J, Nagatsuka H, Manda Y, Hanayama K, Minagi S. Efficacy of soft palatal augmentation prosthesis for oral functional rehabilitation in patients with dysarthria and dysphagia: a protocol for a randomised controlled trial. BMJ Open 2022; 12:e060040. [PMID: 35835521 PMCID: PMC9289020 DOI: 10.1136/bmjopen-2021-060040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Palatal augmentation prosthesis (PAP) is used in patients with articulation and swallowing disorders caused by postoperative loss of tongue tissue due to tongue cancer, cerebrovascular disease sequelae and age-related hypofunction. We have previously reported a newly designed soft PAP fabricated using an thermoplastic material that is particularly appropriate for early intervention. However, the effect of soft PAP on oral function improvement remains to be elucidated. The aim of this study is to investigate whether soft PAP can improve dysarthria and dysphagia occurring as cerebrovascular disease sequelae. METHODS AND ANALYSIS This prospective, randomised, controlled trial will compare the immediate and training effects of rehabilitation using soft PAP with those of rehabilitation without using it. Primary outcomes are the single-word intelligibility test score and pharyngeal transit time (PTT). Secondary outcomes are tongue function (evaluated based on maximum tongue pressure, repetitions of tongue pressure and endurance of tongue pressure), articulation function (evaluated based on speech intelligibility, oral diadochokinesis, Voice-Related Quality of Life (V-RQOL)) and swallowing function (evaluated using Eating Assessment Tool-10). The study results will help determine the efficacy of Soft PAP in improving functional outcomes of word intelligibility and PTT. We hypothesised that early rehabilitation using Soft PAP would more effectively improve articulation and swallowing function compared with conventional rehabilitation without using soft PAP. ETHICS AND DISSEMINATION Ethical approval was obtained from the Okayama University Certified Review Board. The study findings will be published in an open access, peer-reviewed journal and presented at relevant conferences and research meetings. TRIAL REGISTRATION NUMBER jRCTs062200054.
Collapse
Affiliation(s)
- Tomonori Yokoyama
- Department of Occlusal & Oral Functional Rehabilitation, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Okayama, Japan
- Division of Speech-Language-Hearing Therapy, Rehabilitation Center, Kawasaki Medical School Hospital, Kurashiki, Japan
| | - Takao Mukai
- Division of Oral Surgery, Kawasaki Medical School Hospital, Kurashiki, Japan
| | - Naoki Kodama
- Department of Occlusal & Oral Functional Rehabilitation, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Kana Takao
- Division of Oral Surgery, Kawasaki Medical School Hospital, Kurashiki, Japan
| | - Takashi Hiraoka
- Department of Rehabilitation Medicine, Kawasaki Medical School, Kurashiki, Japan
| | - Nobuyuki Arai
- Department of Rehabilitation Medicine, Kawasaki Medical School, Kurashiki, Japan
| | - Jitsuro Yano
- Department of Speech-Language Pathology and Audiology, Faculty of Rehabilitation, Kawasaki University of Medical Welfare, Kurashiki, Japan
| | - Hiroaki Nagatsuka
- Department of Occlusal & Oral Functional Rehabilitation, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Okayama, Japan
- Sadamitsu Dental Clinic, Gakuenasahicho, Japan
| | - Yousuke Manda
- Department of Occlusal & Oral Functional Rehabilitation, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Kozo Hanayama
- Department of Rehabilitation Medicine, Kawasaki Medical School, Kurashiki, Japan
| | - Shogo Minagi
- Department of Occlusal & Oral Functional Rehabilitation, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Okayama, Japan
| |
Collapse
|
6
|
Kitagawa K, Kodama N, Manda Y, Mori K, Furutera H, Minagi S. Effect of masseter muscle activity during wakefulness and sleep on tooth wear. J Prosthodont Res 2021; 66:551-556. [PMID: 34955483 DOI: 10.2186/jpr.jpr_d_21_00171] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PURPOSE To investigate the effect of masseter muscle activity during wakefulness and sleep on tooth wear. METHODS Sixteen participants with no or mild tooth wear (NMTW group) and sixteen participants with moderate-to-severe tooth wear (MSTW group) were enrolled. The severity of tooth wear was evaluated using the occlusal and incisal indices of the tooth wear index. Surface electromyography was performed to record the electrical activity of the left masseter muscle during wakefulness and sleep. Electromyographic activity was detected using an electromyographic threshold of 5% and 20% of maximal voluntary clenching (MVC). The total duration of electromyographic activity and bruxism episodes were calculated. RESULTS The mean ages of the NMTW and MSTW groups were 71.75 ± 7.61 years and 71.69 ± 7.49 years, respectively. The mean cumulative duration of electromyographic activity during wakefulness using a threshold of >5% MVC was 6.44 ± 4.52 min/h and 13.62 ± 10.08 min/h for the NMTW and MSTW groups, respectively (p=0.048). The mean total durations of electromyographic activity during wakefulness and sleep using a threshold of >20% MVC were 1.08 ± 1.70 min/h and 1.05 ± 3.02 min/h, respectively, in the NMTW group and 4.78 ± 6.37 min/h and 1.61 ± 1.79 min/h, respectively, in the MSTW group (p=0.048 and p=0.003, respectively). CONCLUSION These results suggest that masseter electromyographic activity during wakefulness and sleep may be related to the severity of tooth wear.
Collapse
Affiliation(s)
- Keisuke Kitagawa
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan
| | - Naoki Kodama
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan
| | - Yousuke Manda
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan
| | - Keitaro Mori
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan
| | - Hiroshi Furutera
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan
| |
Collapse
|
7
|
Abstract
PURPOSE To examine how particle loss affects the evaluation of masticatory ability using the image analysis method. METHODS The subjects were divided into two groups:Y-group (healthy young adults: 10 male, 10 female; mean age 27.6 ± 1.9 years), and D-group (denture wearing older adults: 13 male, 9 female; mean age, 75.1 ± 5.3 years). Raw carrots, peanuts, and a combined test food from 5 daily food materials (mixed foods) were selected as test foods. Images of the boluses were captured and processed after the subjects freely masticated the test foods until the point of swallowing or completed half strokes of total chewing cycles. The median particle size (X50) was calculated from the data for each particle. We compared X50 calculated from all particles obtained from the masticatory bolus (as X50N) with the X50 of only selectively larger particles (as X50R). RESULTS Significant correlations were observed between X50N and X50R (p < 0.01) determined in almost all masticatory conditions. In particular, for particle sizes of 2 mm or more, the correlation coefficient between X50N and X50R was notably strong (r > 0.75). CONCLUSION The method of analyzing only larger particles makes it possible to evaluate masticatory ability without losing the characteristics of the original particle size distribution of the entire bolus. This finding can be applied for the evaluation of masticatory ability, especially among older adults who have difficulty retrieving the total amount of test food due to decreased activities of daily living.
Collapse
Affiliation(s)
- Hikaru Sugimoto
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Yuki Tanaka
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Naoki Kodama
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| |
Collapse
|
8
|
Furutera H, Kawakami S, Kodama N, Manda Y, Kitagawa K, Nakahara R, Minagi S. Detection of muscle fatigue caused by repeated posterior tongue lift movement from neck surface EMG: a pilot study. J Oral Rehabil 2021; 48:1337-1346. [PMID: 34529862 DOI: 10.1111/joor.13258] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 07/24/2021] [Accepted: 09/01/2021] [Indexed: 12/22/2022]
Abstract
BACKGROUND Fatigue is an important factor for muscle strengthening in rehabilitation medicine. Frequency analysis has been regarded as the gold standard for muscle fatigue assessment in surface electromyography (EMG). However, there are no experiments quantifying fatigue with grouped discharge (GD), which is one of the historical phenomena observed in patients having fatigue, by using high sampling rate recording of EMG. OBJECTIVE To investigate the effect of fatigue, which is induced by repeated posterior tongue lift movement (TLM), on the occurrence of GD peaks, thus, to provide possible basis as a parameter for future fatigue evaluation. METHODS Nineteen healthy adults (9 men and 10 women) participated in this study. The muscle fatigue protocol consisted of repetitive posterior TLM and maximum voluntary contractions (MVC). Bilateral N-EMG (Neck surface EMG for measuring the muscle activity of the posterior tongue) was recorded. RESULTS Subjective tongue fatigue at the end of the protocol was significantly higher than at beginning throughout the muscle fatigue protocol (p < .01). The frequency of occurrence of GD peaks was 0.9 ± 1.2 (per second) at the baseline in 33 of 38 subject sides, and significantly increased depending on fatigue progression (p < .01). CONCLUSION It was shown that fatigue due to repetitive posterior tongue lifting resulted in significant increase in the frequency of occurrence of GD peaks. Especially, the nature of GD, showing very few occurrences at non-fatigue condition, might work as an advantageous property for its use in future absolute evaluation of fatigue phenomena.
Collapse
Affiliation(s)
- Hiroshi Furutera
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Shigehisa Kawakami
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Naoki Kodama
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Yosuke Manda
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Keisuke Kitagawa
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Ryuichi Nakahara
- Department of Orthopaedic Surgery, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| |
Collapse
|
9
|
Murakami A, Hara T, Yamada-Kubota C, Kuwahara M, Ichikawa T, Minagi S. Lack of occlusal support did not impact amyloid β deposition in APP knock-in mice. J Prosthodont Res 2021; 66:161-166. [PMID: 34305086 DOI: 10.2186/jpr.jpr_d_20_00205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PURPOSE The lack of occlusal support is an epidemiological risk factor linked to Alzheimer's disease. This study sought to assess the relationship between amyloid β (Aβ) deposition and the lack of occlusal support in amyloid precursor protein (APP) knock-in mice. METHODS Sixteen experimental animals were divided into two groups. The upper molars were extracted in the extraction group (group E), and a sham operation was performed in the control group (group C). The Morris water maze test was performed 4 months after the tooth extraction. Aβ immunohistochemical staining and Nissl staining of the hippocampus were performed. Hippocampal plasma corticosterone and Aβ protein levels were measured. RESULTS In the maze task, the escape latency was significantly longer in group E than in group C. In the probe trials, the time elapsed in the target quadrant was significantly shorter in group E than in group C. The number of hippocampal neurons decreased in group E. There was no significant difference in the plasma corticosterone levels between the two groups, indicating that there was no effect of chronic stress on the behavioral results. Hippocampal Aβ40 and Aβ42 protein levels and Aβ deposition areas by immunohistochemical staining were not significantly different between the two groups. CONCLUSIONS Aβ deposition was not increased in the hippocampus of molarless APP knock-in mice. As such, it appears that cognitive impairment due to a lack of occlusal support was not related to Aβ deposition.
Collapse
Affiliation(s)
- Asuka Murakami
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University
| | - Tetsuya Hara
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University
| | - Chie Yamada-Kubota
- Department of Occlusion and Removable Prosthodontics, Okayama University Hospital
| | - Miho Kuwahara
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University
| | - Tomoka Ichikawa
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University
| |
Collapse
|
10
|
Nagatsuka H, Kawakami S, Kuwahara M, Kubota C, Kodama N, Minagi S. Newly designed flat surface artificial tongue system for speech improvement in glossectomy patients: A preliminary study. J Prosthodont Res 2021; 66:87-92. [PMID: 34261846 DOI: 10.2186/jpr.jpr_d_20_00230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PURPOSE To design an efficient tongue prosthesis with reproducibility and to objectively evaluate improvement in speech function. METHODS A silicon anatomical artificial tongue (AT) and a flat surface artificial tongue system (FTS) were used in our study. Twenty healthy participants (10 males and 10 females, 26.3 ± 1.8 years) were fitted with a tongue movement suppression appliance (TSA) that fit the dental arch to simulate the glossectomy condition. TSA, TSA + FTS, and TSA + AT simulated the state of glossectomy patients without artificial tongue, with normal artificial tongue, and newly designed artificial tongue, respectively. Three speech intelligibility tests were performed for each of the following conditions: pronouncing 100 Japanese monosyllables, 40 Japanese words, and reading a short story. One-way ANOVA, Wilcoxon signed-rank test, and Tukey-Kramer post-hoc test were used for statistical analyses. RESULTS Significant differences were observed for 100 Japanese monosylla bles and 40 Japanese words between the TSA + FTS, TSA, and TSA + AT conditions (p ‹ 0.05). Regarding the speech intelligibility test for reading a short story, the TSA + FTS condition resulted in a significantly higher speech intelligibility than the TSA and TSA + AT conditions (p ‹ 0.05). CONCLUSIONS A flat surface artificial tongue system contributed to the improvement in speech function. This structure can be easily used in cases where conventional artificial tongue are applicable, regardless of variation in the oral condition; thus, making it a widely applicable treatment option for glossectomy patients.
Collapse
Affiliation(s)
- Hiroaki Nagatsuka
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama
| | - Shigehisa Kawakami
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama
| | - Miho Kuwahara
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama
| | - Chie Kubota
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama
| | - Naoki Kodama
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama
| |
Collapse
|
11
|
Mori K, Manda Y, Kitagawa K, Nagatsuka H, Furutera H, Kodama N, Minagi S. Coordination of surface electromyography activity in the posterior tongue region during mastication of differently textured foods. J Oral Rehabil 2020; 48:403-410. [PMID: 33319400 DOI: 10.1111/joor.13135] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 12/04/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND Masticatory movement occurs complicatedly and bilaterally. Although the tongue plays an important role in mastication, bilateral tongue function during mastication has not been clarified yet. OBJECTIVE To investigate the effect of food properties on posterior tongue activity and coordination of muscles bilaterally by electromyography (EMG). METHODS Twenty healthy adults (10 males and 10 females; mean age 28 years; range: 22-33 years) participated in this study. Three test foods, gummy jelly (hard food), sponge cake (soft food requiring crushing), and mashed potatoes (soft food not requiring crushing), were used. Bilateral masseter N-EMG (surface electromyography for measuring the muscle activity of posterior tongue) and submental EMG were carried out while the participants chewed three test foods. The participants were instructed to masticate three test foods only on the right side and only on the left side unilaterally. RESULTS In the case of gummy jelly, N-EMG activity on the mastication side was significantly larger than that on the non-mastication side (P < .01). Regarding temporal relationship between the masseter and N-EMG activity, in the case of gummy jelly, the percentage of cases where the N-EMG peak was observed during masseter muscle EMG bursts was significantly higher than those for sponge cake and mashed potatoes (P < .01). CONCLUSION N-EMG activity on the mastication side was significantly larger than that on the non-mastication side in the mastication of hard foods. Tongue showed activity pattern changes and coordinated with the masseter muscle depending on food texture.
Collapse
Affiliation(s)
- Keitaro Mori
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Yousuke Manda
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Keisuke Kitagawa
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Hiroaki Nagatsuka
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Hiroshi Furutera
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Naoki Kodama
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| |
Collapse
|
12
|
Maruo Y, Yoshihara K, Irie M, Nishigawa G, Nagaoka N, Matsumoto T, Minagi S. Flexural properties, bond ability, and crystallographic phase of highly translucent multi-layered zirconia. J Appl Biomater Funct Mater 2020; 18:2280800020942717. [PMID: 33032503 DOI: 10.1177/2280800020942717] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
This study investigated the mechanical properties, bond ability, and crystallographic forms of different sites in a highly translucent, multi-layered zirconia disk. Flexural properties, bond ability to resin cement, and phase composition were investigated at three sites of a highly translucent, multi-layered zirconia disk: incisal, middle, and cervical. Flexural strength (FS) and flexural modulus (FM) were measured with static three-point flexural test. Shear bond strength (SB) to resin cement was measured after 24 h storage (37°C). Phase composition under mechanical stress was analyzed using X-ray diffraction. Without air abrasion, FS at the incisal site yielded the lowest value and was significantly lower than the middle and cervical sites. Air abrasion lowered the FS of each site. FM at the incisal site without air abrasion showed the significantly lowest value, and air abrasion increased its FM value. At the middle and cervical sites, their FM values were higher than the incisal site but were not significantly affected by air abrasion. SB value did not show significant differences among the sites. After sintering, cubic zirconia was detected at each site. Rhombohedral phase transformation occurred after mirror polishing. In highly translucent, multi-layered zirconia which was mainly composed of cubic zirconia, rhombohedral phase transformation occurred under mechanical stress and resulted in weakened mechanical properties.
Collapse
Affiliation(s)
- Yukinori Maruo
- Department of Occlusion and Removable Prosthodontics, Okayama University, Okayama, Japan
| | - Kumiko Yoshihara
- National Institute of Advanced Industrial Science and Technology, Health Research Institute, Takamatsu, Kagawa, Japan
| | - Masao Irie
- Department of Biomaterials, Okayama University, Okayama, Japan
| | - Goro Nishigawa
- Department of Occlusion and Removable Prosthodontics, Okayama University, Okayama, Japan
| | - Noriyuki Nagaoka
- Advanced Research Center for Oral and Craniofacial Sciences, Okayama University, Okayama, Japan
| | | | - Shogo Minagi
- Advanced Research Center for Oral and Craniofacial Sciences, Okayama University, Okayama, Japan
| |
Collapse
|
13
|
Tokunaga E, Nagaoka N, Maruo Y, Yoshihara K, Nishigawa G, Minagi S. Phosphate group adsorption capacity of inorganic elements affects bond strength between CAD/CAM composite block and luting agent. Dent Mater J 2020; 40:288-296. [PMID: 33028787 DOI: 10.4012/dmj.2020-029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study aimed to investigate whether inorganic elements of polymer-infiltrated ceramic (PIC) and microfilled resin (MFR) for CAD/CAM would affect initial bond strength to luting agent. Inorganic elements of PIC and MFR were different with shape and ingredient observed by SEM, STEM and EDS. Microtensile bond strengths (µTBS) value of PIC was increased by 10-methacryloyloxydecyl dihydrogen phosphate (MDP) and acetic acid (AA)- or MDP-activated silane treatment, and further increased by succeeding heat treatment (HT). The µTBS of MFR was increased by MDP and MDP-activated silane, but decreased by AA-activated silane without HT. The HT improved the µTBS of MFR with AA-activated silane, but conversely for MDP-activated silane. Only in MFR, phosphoric acid (PA) application before each surface treatment dramatically decreased the µTBS of AA-activated silane. FTIR peaks in MFR shifted according to phosphate group's peak. MFR would possess high phosphate group adsorption capacity, with MDP effectively improving its bonding capability.
Collapse
Affiliation(s)
- Eri Tokunaga
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
| | - Noriyuki Nagaoka
- Advanced Research Center for Oral and Craniofacial Science, Okayama University
| | - Yukinori Maruo
- Department of Occlusion and Removable Prosthodontics, Okayama University
| | - Kumiko Yoshihara
- Health Research Institute, National Institute of Advanced Industrial Science and Technology
| | - Goro Nishigawa
- Department of Occlusion and Removable Prosthodontics, Okayama University
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
| |
Collapse
|
14
|
Tanaka Y, Sugimoto H, Kodama N, Minagi S. Effects of stage II transport and food bolus sampling methods on the properties of food particles. J Oral Rehabil 2019; 47:196-203. [DOI: 10.1111/joor.12879] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Revised: 07/24/2019] [Accepted: 08/20/2019] [Indexed: 02/06/2023]
Affiliation(s)
- Yuki Tanaka
- Occlusion and Removable Prosthodontics Okayama University Hospital Okayama Japan
| | - Hikaru Sugimoto
- Department of Occlusal and Oral Functional Rehabilitation Graduate School of Medicine Dentistry and Pharmaceutical Sciences Okayama University Okayama Japan
| | - Naoki Kodama
- Department of Occlusal and Oral Functional Rehabilitation Graduate School of Medicine Dentistry and Pharmaceutical Sciences Okayama University Okayama Japan
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation Graduate School of Medicine Dentistry and Pharmaceutical Sciences Okayama University Okayama Japan
| |
Collapse
|
15
|
Sugimoto H, Tanaka Y, Kodama N, Minagi S. Differences in comminution progress during mastication in healthy dentate and denture-wearing elderly people. J Prosthodont Res 2019; 64:257-263. [PMID: 31455559 DOI: 10.1016/j.jpor.2019.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Revised: 07/24/2019] [Accepted: 08/06/2019] [Indexed: 10/26/2022]
Abstract
PURPOSE This study aimed to investigate the effect of removable denture prostheses on the comminution progress in elderly people. METHODS Twenty-two denture wearers of Eichner's classification B and C (75.1±5.3 years old) and 20 young fully dentate subjects (27.6±1.9 years old) participated in the masticatory examination, which used a combined test food from 5 daily food materials. Full masticatory cycles lasting until subjects needed to swallow and the half number of the cycles were adopted as masticatory conditions. Digital images of food particles under wet conditions were obtained for each bolus, and particles were analyzed by calculating the homogeneity and particle size indices. RESULTS The characteristic properties of the food particles were observed using a homogeneity index in the elderly denture group for half masticatory strokes. Their homogeneity index was significantly higher than that of the young dentate group. By contrast, no significant difference was observed in the indices for particles immediately before swallowing between two groups. CONCLUSIONS The comminuted particle size before swallowing in healthy denture wearers was not significantly different from that in the natural dentate group. The comminution of the first-half process in denture wearers was typical and could be one possible focus for meal property specifications in future studies.
Collapse
Affiliation(s)
- Hikaru Sugimoto
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8525, Japan
| | - Yuki Tanaka
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8525, Japan
| | - Naoki Kodama
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8525, Japan.
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8525, Japan
| |
Collapse
|
16
|
Maeda N, Kodama N, Manda Y, Kawakami S, Oki K, Minagi S. Characteristics of Grouped Discharge Waveforms Observed in Long-term Masseter Muscle Electromyographic Recording: A Preliminary Study. Acta Med Okayama 2019; 73:357-360. [PMID: 31439959 DOI: 10.18926/amo/56938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We investigated the characteristics of grouped discharge (GD) waveforms obtained from long-term masseter electromyogram (EMG) recording in 6 female temporomandibular disorder (TMD) patients with myofascial pain and 6 healthy females. The EMG measurement was performed from the morning of the experiment day until the subject woke up the next day. We observed a significantly larger number of GD waveforms in the TMD group compared to the control group (p=0.002). Our results indicate that the existence of GD waveforms in masseter EMGs might be a predictor of future TMD with myofascial pain.
Collapse
Affiliation(s)
- Naoto Maeda
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
| | - Naoki Kodama
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
| | - Yosuke Manda
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
| | - Shigehisa Kawakami
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
| | - Kazuhiro Oki
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
| |
Collapse
|
17
|
Manda Y, Kodama N, Maeda N, Minagi S. Effect of food properties and chewing condition on the electromyographic activity of the posterior tongue. J Oral Rehabil 2019; 46:511-517. [DOI: 10.1111/joor.12774] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 01/27/2019] [Accepted: 01/30/2019] [Indexed: 11/29/2022]
Affiliation(s)
- Yousuke Manda
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Okayama Japan
| | - Naoki Kodama
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Okayama Japan
| | - Naoto Maeda
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Okayama Japan
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Okayama Japan
| |
Collapse
|
18
|
Kurozumi A, Hara T, Sakamoto S, Araki D, Iida-Tamada S, Kuroda-Ishimine C, Minagi S. Effects of the loss and reconstruction of molar occlusal support on memory retrieval and hippocampal neuron density in rats. J Prosthodont Res 2019; 63:283-287. [PMID: 30686619 DOI: 10.1016/j.jpor.2018.12.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 12/07/2018] [Accepted: 12/19/2018] [Indexed: 11/17/2022]
Abstract
PURPOSE Animal experiments have shown that the loss of occlusal support causes impairments in spatial cognition. Many reports have focused on the memory encoding process, and only few studies have investigated the effect on memory retrieval. This study aimed to examine the effects of both the loss and reconstruction of occlusal support on the memory retrieval process and on the number of hippocampal pyramidal cells. METHODS The experimental animals were divided into a molarless group, in which molars were extracted, a denture-wearing molarless group with experimental dentures inserted after molar extraction, and a control group. Radial maze trials were performed for 20 consecutive days (acquisition phase). The rats were tested on long-term memory retention following the acquisition phase in eight trials every five days, and in an additional trial 20 days later (probe phase). RESULTS The denture-wearing molarless group showed higher levels of spatial learning and memory than the molarless group. There were no significant differences in memory retrieval during the probe phase between the denture-wearing molarless and the control group. The molarless group showed significantly worse spatial learning and memory and had fewer neurons in the hippocampus than the control group. CONCLUSIONS Our results suggest that the loss of occlusal support decreases the number of pyramidal cells in the hippocampus and impairs memory decoding and retrieval. However, this effect is suppressed by the reconstruction of occlusal support.
Collapse
Affiliation(s)
- Akimasa Kurozumi
- Occlusion and Removable Prosthodontics, Okayama University Hospital, Okayama, Japan
| | - Tetsuya Hara
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
| | - Shunichi Sakamoto
- Occlusion and Removable Prosthodontics, Okayama University Hospital, Okayama, Japan
| | - Daisuke Araki
- Occlusion and Removable Prosthodontics, Okayama University Hospital, Okayama, Japan
| | - Sachiyo Iida-Tamada
- Occlusion and Removable Prosthodontics, Okayama University Hospital, Okayama, Japan
| | | | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| |
Collapse
|
19
|
Hirata A, Kato S, Mude AH, Oki K, Matsunaga T, Minagi S. Passive Periodontal Sensation Threshold of Upper Molars in Patients with Myofascial Pain. Open Dent J 2018. [DOI: 10.2174/1874210601811131012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Background and Objective:
The relationship between periodontal sensation and Myofascial Pain (MP) is not yet fully clarified. The aim of this study was to test the null hypothesis that there is no difference in the periodontal sensation threshold between subjects with MP and subjects with no Temporomandibular Disorders (TMD).
Methods:
Participants have clinically assessed in accordance with the Research Diagnostic Criteria for Temporomandibular Disorders version 1.0 guidelines and assigned to the MP group (mean age 54.8 ± 14.8 years; 1 male and 11 females) or the control group (mean age: 63.9 ± 13.2 years; 1 male and 15 females). The Passive Periodontal Sensation Threshold (PPST) was evaluated using impulsive mechanical stimulation on the occlusal surface parallel to the tooth axis of the maxillary first molar, if present. The difference in the mean PPST between the MP group and the control group was evaluated using the Student t-test after checking for homoscedasticity.
Results:
The mean PPST value was 1050.1 ± 480.3 mN in the MP group and 712.3 ± 288.5 mN in the control group. A significant difference was observed between these mean PPST values (p = 0.045).
Conclusion:
There was a significant difference in PPST between the MP group and the control group. Although the etiology of the change of PPST is still unknown, the higher PPST value observed in MP patients suggests that future study on occlusal dysesthesia or occlusal sensation-related pathosis is warranted.
Collapse
|
20
|
Kato S, Ekuni D, Kawakami S, Mude AH, Morita M, Minagi S. Relationship between severity of periodontitis and masseter muscle activity during waking and sleeping hours. Arch Oral Biol 2018. [DOI: 10.1016/j.archoralbio.2018.02.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
21
|
Hashimoto Y, Sugimoto K, Tanaka Y, Sugimoto H, Minagi S. Short-Term Crossover Study on the Effect of Orthogonalized Deep-Grooved Posterior Artificial Teeth on the Masticatory Efficiency of Complete Denture Wearers. Open Dent J 2018; 12:255-264. [PMID: 29760818 PMCID: PMC5898015 DOI: 10.2174/1874210601812010255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 02/15/2018] [Accepted: 03/14/2018] [Indexed: 12/03/2022] Open
Abstract
Background: Mastication has been regarded to play an important role in achieving quality daily life for the elderly. On the occlusal surface of posterior artificial teeth, parallel grooves of 1 mm depth and 1 mm width with an inter-groove distance of 2 mm have been found to significantly improve masticatory efficiency on a mechanical simulator.
Materials and Methods: In the present study, the effect of the grooved design on masticatory efficiency in edentulous subjects using a short-term crossover trial was evaluated. Six edentulous participants, 1 male and 5 females, were assigned into two groups. One received duplicated complete dentures with grooved molars first, and the other received duplicated complete dentures with conventional molars first. The design of the teeth was crossover after evaluating masticatory efficiency. Raw carrot, raw lettuce and mixed foodstuffs were used to evaluate masticatory efficiency. Subjects were instructed to masticate 20 strokes and arbitrary strokes until they felt like swallowing. Results: The number of masticatory strokes taken was significantly smaller using the grooved design (p<.05). Masticatory efficiency analysis revealed that the grooved design achieved significantly higher masticatory efficiency at 20 masticatory strokes for raw carrot and mixed foodstuffs (p<.05). Conclusion: Results show that compared with conventional lingualized occlusion, the grooved design accomplishes higher masticatory efficiency in vivo. Considering the distinction of this design that it can be applied to any existing denture occlusion, the design might help improve the dietary life of the elderly.
Collapse
Affiliation(s)
- Yuki Hashimoto
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan
| | - Kyoko Sugimoto
- Dental Education Reforming Unit, Center for the Development of Medical and Health Care Education, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan
| | - Yuki Tanaka
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan
| | - Hikaru Sugimoto
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan
| |
Collapse
|
22
|
Mude AH, Kawakami S, Kato S, Minagi S. Properties of tonic episodes of masseter muscle activity during waking hours and sleep in subjects with and without history of orofacial pain. J Prosthodont Res 2018; 62:234-238. [DOI: 10.1016/j.jpor.2017.09.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 09/26/2017] [Accepted: 09/27/2017] [Indexed: 11/16/2022]
|
23
|
Matsubara R, Yanagi Y, Oki K, Hisatomi M, Santos KC, Bamgbose BO, Fujita M, Okada S, Minagi S, Asaumi J. Assessment of MRI findings and clinical symptoms in patients with temporomandibular joint disorders. Dentomaxillofac Radiol 2018; 47:20170412. [PMID: 29451403 DOI: 10.1259/dmfr.20170412] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To investigate the correlations among various temporomandibular joint (TMJ) findings on MRI and the relationships between MRI findings and symptoms. METHODS 425 patients (850 TMJs) with temporomandibular joint disorders (TMDs) who underwent MRI were enrolled. Oblique sagittal proton density-weighted and T2 weighted images in open- and closed-mouth positions were evaluated. MRI findings included disc configuration, disc position, condylar morphology, bone marrow pattern, and joint effusion. Symptoms included TMJ pain, TMJ noise, and limitation of mouth opening. For statistical analyses, Spearman's rank correlation coefficient and logistic regression analysis were applied. RESULTS Folded disc, disc displacement without reduction (DDWOR), and osteophytes had significant negative correlations with other normal MRI findings (p < 0.01). DDWOR and marrow edema were associated with TMJ pain. Conversely, osteophytes [odds ratio (OR): 0.52; 95% CI (0.30-0.90)] and combination-type condylar degeneration [OR: 0.45; 95% CI (0.24-0.83)] were associated with decreased risk of TMJ pain. Condylar flattening was positively associated with TMJ noise [OR: 5.25; 95% CI (1.44-19.07)] and negatively associated with limitation of mouth opening [OR: 0.34; 95% CI (0.11-0.99)]. High-grade joint effusion was significantly associated with TMJ pain and noise. CONCLUSIONS DDWOR and high-grade joint effusion (an indicator of inflammation in the articular cavity) were associated with TMD symptoms. This finding suggests that treatment strategy for DDWOR and decreasing inflammation might lessen clinical TMD symptoms. Condylar degeneration was not associated with indicators of inflammation or TMJ symptoms. These results suggest that patients with TMD symptoms should undergo initial MRI to allow rapid selection of appropriate therapies.
Collapse
Affiliation(s)
- Risa Matsubara
- 1 Department of Oral and Maxillofacial Radiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University , Okayama , Japan
| | - Yoshinobu Yanagi
- 2 Department of Dental Informatics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University , Okayama , Japan
| | - Kazuhiro Oki
- 3 Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University , Okayama , Japan
| | - Miki Hisatomi
- 4 Department of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University Hospital , Okayama , Japan
| | - Karina Cp Santos
- 5 Department of Stomatology, School of Dentistry, University of Sao Paulo , Sao Paulo , Brazil
| | - Babatunde O Bamgbose
- 1 Department of Oral and Maxillofacial Radiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University , Okayama , Japan.,6 Oral Diagnostic Sciences, Faculty of Dentistry, Bayero University , kano , Nigeria
| | - Mariko Fujita
- 7 Preliminary Examination Room, Okayama University Hospital , Okayama , Japan
| | - Shunsuke Okada
- 4 Department of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University Hospital , Okayama , Japan
| | - Shogo Minagi
- 3 Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University , Okayama , Japan.,8 Department of Occlusal and Oral Funtional Rehabilitation, Okayama University Hospital , Okayama , Japan
| | - Junichi Asaumi
- 1 Department of Oral and Maxillofacial Radiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University , Okayama , Japan.,4 Department of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University Hospital , Okayama , Japan.,7 Preliminary Examination Room, Okayama University Hospital , Okayama , Japan
| |
Collapse
|
24
|
Kumazaki Y, Kawakami S, Hirata A, Oki K, Minagi S. Ipsilateral Molar Clenching Induces Less Pain and Discomfort than Contralateral Molar Clenching in Patients with Unilateral Anterior Disc Displacement of the Temporomandibular Joint. J Oral Facial Pain Headache 2017; 30:241-8. [PMID: 27472527 DOI: 10.11607/ofph.1405] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
AIMS To assess the influence of clenching side and location (ie, tooth) on the bite force necessary to induce pain or discomfort in patients with unilateral anterior disc displacement (ADD) of the temporomandibular joint (TMJ). METHODS A total of 17 patients with unilateral ADD diagnosed clinically and with magnetic resonance imaging were included. A bite force meter was positioned at each of four experimental positions: the mandibular first premolars and first molars, bilaterally. Subjects were instructed to clench on the bite force meter until they felt pain or discomfort in the orofacial area and to report the location of the pain. Differences in pain location (ADD side versus contralateral side) and in the bite force thresholds for eliciting pain or discomfort were assessed by means of the paired t test and Wilcoxon signed-rank test. RESULTS Only 18% of subjects (3 out of 17) reported pain in the TMJ with ADD during clenching at the ipsilateral molar, whereas 65% (11 out of 17) reported joint pain during clenching on the contralateral molar (P = .005). At the molars, the mean ± standard deviation bite force necessary to induce pain was 241.2 ± 135.5 N on the side with ADD and 160.9 ± 78.0 N on the contralateral side. The mean molar bite force necessary to induce pain on the side with ADD was significantly higher than that on the contralateral side (P = .002). CONCLUSION Patients with unilateral ADD had fewer reports of TMJ pain and discomfort when they were molar clenching on the ipsilateral side compared to molar clenching on the contralateral side.
Collapse
|
25
|
Pan Q, Maeda N, Manda Y, Kodama N, Minagi S. Validation of the optimal site in the neck region for detecting swallowing sounds. J Oral Rehabil 2016; 43:840-846. [PMID: 27627032 DOI: 10.1111/joor.12440] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/11/2016] [Indexed: 12/14/2022]
Abstract
Recently, the swallowing sound has been used to detect swallowing events non-invasively. A previous study, using an accelerometer, showed that the site over the lateral border of the trachea immediately inferior to the cricoid cartilage was the optimal site for detecting swallowing sounds. However, the optimal site for detection of the swallowing sound using a microphone remains undetermined. To validate the optimal site in the neck region for detecting swallowing sounds. Fourteen healthy subjects (mean age, 27·6 ± 2·2 years; seven male and seven female) participated in this study. Twenty condenser microphones were attached to 20 sites on the left neck surface to detect swallowing sounds. Participants were instructed to swallow five different stimuli three times as follows: Resting saliva, 1 and 5 mL of Japanese tea, and 1 and 5 mL of yoghurt. Mean relative peak intensity was used to indicate the magnitude of the swallowing sound. Sound spectrograms were used to illustrate differences in the properties of swallowing sounds. Mean relative peak intensity number was highest in sites at the inferior border of the mandible just above the sternocleidomastoid muscle (site 11) and sites over the lateral border of the trachea immediately inferior to the cricoid cartilage (site 8). Comparison of spectrograms showed a greater density distribution of higher frequency components at site 11 compared with site 8. These results indicate that the inferior border of the mandible just above the sternocleidomastoid muscle is the optimal site for the detection of swallowing sounds.
Collapse
Affiliation(s)
- Q Pan
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - N Maeda
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
| | - Y Manda
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - N Kodama
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - S Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| |
Collapse
|
26
|
Kozaki KI, Kawakami S, Konishi T, Ohta K, Yano J, Onoda T, Matsumoto H, Mizukawa N, Kimata Y, Nishizaki K, Iida S, Gofuku A, Abe M, Minagi S. Structure of a New Palatal Plate and the Artificial Tongue for Articulation Disorder in a Patient with Subtotal Glossectomy. Acta Med Okayama 2016; 70:205-211. [PMID: 27339210 DOI: 10.18926/amo/54420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A palatal augmentation prosthesis (PAP) is used to facilitate improvement in the speech and swallowing functions of patients with tongue resection or tongue movement disorders. However, a PAP's effect is limited in cases where articulation disorder is severe due to wide glossectomy and/or segmental mandibulectomy. In this paper, we describe speech outcomes of a patient with an articulation disorder following glossectomy and segmental mandibulectomy. We used a palatal plate (PP) based on a PAP, along with an artificial tongue (KAT). Speech improvement was evaluated by a standardized speech intelligibility test consisting of 100 syllables. The speech intelligibility score was significantly higher when the patient wore both the PP and KAT than when he wore neither (p=0.013). The conversational intelligibility score was significantly improved with the PP and KAT than without PP and KAT (p=0.024). These results suggest that speech function can be improved in patients with hard tissue defects with segmental mandibulectomy using both a PP and a KAT. The nature of the design of the PP and that of the KAT will allow these prostheses to address a wide range of tissue defects.
Collapse
Affiliation(s)
- Ken-Ichi Kozaki
- Department of Dental Pharmacology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Manda Y, Maeda N, Pan Q, Sugimoto K, Hashimoto Y, Tanaka Y, Kodama N, Minagi S. New method of neck surface electromyography for the evaluation of tongue-lifting activity. J Oral Rehabil 2016; 43:417-25. [DOI: 10.1111/joor.12389] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2016] [Indexed: 11/28/2022]
Affiliation(s)
- Y. Manda
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - N. Maeda
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - Q. Pan
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - K. Sugimoto
- Dental Education Reforming Unit; Center for the Development of Medical and Health Care Education; Okayama University; Okayama Japan
| | - Y. Hashimoto
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - Y. Tanaka
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - N. Kodama
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - S. Minagi
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| |
Collapse
|
28
|
Nishigawa G, Maruo Y, Irie M, Maeda N, Yoshihara K, Nagaoka N, Matsumoto T, Minagi S. Various Effects of Sandblasting of Dental Restorative Materials. PLoS One 2016; 11:e0147077. [PMID: 26764913 PMCID: PMC4713057 DOI: 10.1371/journal.pone.0147077] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 12/27/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Sandblasting particles which remain on the surfaces of dental restorations are removed prior to cementation. It is probable that adhesive strength between luting material and sandblasting particle remnants might exceed that with restorative material. If that being the case, blasting particles adhere to sandblasted material surface could be instrumental to increasing adhesive strength like underlying bonding mechanism between luting material and silanized particles of tribochemical silica coating-treated surface. We hypothesize that ultrasonic cleaning of bonding surfaces, which were pretreated with sandblasting, may affect adhesive strength of a resin luting material to dental restorative materials. METHODS We therefore observed adhesive strength of resin luting material to aluminum oxide was greater than those to zirconia ceramic and cobalt-chromium alloy beforehand. To measure the shear bond strengths of resin luting material to zirconia ceramic and cobalt-chromium alloy, forty specimens of each restorative material were prepared. Bonding surfaces were polished with silicon abrasive paper and then treated with sandblasting. For each restorative material, 40 sandblasted specimens were equally divided into two groups: ultrasonic cleaning (USC) group and non-ultrasonic cleaning (NUSC) group. After resin luting material was polymerized on bonding surface, shear test was performed to evaluate effect of ultrasonic cleaning of bonding surfaces pretreated with sandblasting on bond strength. RESULTS For both zirconia ceramic and cobalt-chromium alloy, NUSC group showed significantly higher shear bond strength than USC group. CONCLUSIONS Ultrasonic cleaning of dental restorations after sandblasting should be avoided to retain improved bonding between these materials.
Collapse
Affiliation(s)
- Goro Nishigawa
- Occlusion and Removable Prosthodontics, Okayama University Hospital, Okayama, Japan
- * E-mail:
| | - Yukinori Maruo
- Occlusion and Removable Prosthodontics, Okayama University Hospital, Okayama, Japan
| | - Masao Irie
- Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Naoto Maeda
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Kumiko Yoshihara
- Center for Innovative Clinical Medicine, Okayama University Hospital, Okayama, Japan
| | - Noriyuki Nagaoka
- Laboratory for Electron Microscopy, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Takuya Matsumoto
- Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| |
Collapse
|
29
|
Maruo Y, Nishigawa G, Irie M, Yoshihara K, Minagi S. Flexural properties of polyethylene, glass and carbon fiber-reinforced resin composites for prosthetic frameworks. Acta Odontol Scand 2015; 73:581-7. [PMID: 25892406 DOI: 10.3109/00016357.2014.958875] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE High flexural properties are needed for fixed partial denture or implant prosthesis to resist susceptibility to failures caused by occlusal overload. The aim of this investigation was to clarify the effects of four different kinds of fibers on the flexural properties of fiber-reinforced composites. MATERIALS AND METHODS Polyethylene fiber, glass fiber and two types of carbon fibers were used for reinforcement. Seven groups of specimens, 2 × 2 × 25 mm, were prepared (n = 10 per group). Four groups of resin composite specimens were reinforced with polyethylene, glass or one type of carbon fiber. The remaining three groups served as controls, with each group comprising one brand of resin composite without any fiber. After 24-h water storage in 37°C distilled water, the flexural properties of each specimen were examined with static three-point flexural test at a crosshead speed of 0.5 mm/min. RESULTS Compared to the control without any fiber, glass and carbon fibers significantly increased the flexural strength (p < 0.05). On the contrary, the polyethylene fiber decreased the flexural strength (p < 0.05). Among the fibers, carbon fiber exhibited higher flexural strength than glass fiber (p < 0.05). Similar trends were observed for flexural modulus and fracture energy. However, there was no significant difference in fracture energy between carbon and glass fibers (p > 0.05). CONCLUSION Fibers could, therefore, improve the flexural properties of resin composite and carbon fibers in longitudinal form yielded the better effects for reinforcement.
Collapse
Affiliation(s)
- Yukinori Maruo
- Department of Occlusion and Removable Prosthodontics, Okayama University Hospital , Okayama , Japan
| | | | | | | | | |
Collapse
|
30
|
Yano J, Shirahige C, Oki K, Oisaka N, Kumakura I, Tsubahara A, Minagi S. Effect of visual biofeedback of posterior tongue movement on articulation rehabilitation in dysarthria patients. J Oral Rehabil 2015; 42:571-9. [DOI: 10.1111/joor.12293] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/28/2015] [Indexed: 11/29/2022]
Affiliation(s)
- J. Yano
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
- Department of Speech-Language-Hearing Therapy; Rehabilitation Center; Kawasaki Medical School Hospital; Kurashiki Japan
| | - C. Shirahige
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - K. Oki
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - N. Oisaka
- Oisaka Electronic Device Ltd; Fukuyama Japan
| | - I. Kumakura
- Department of Sensory Science; Faculty of Health Science and Technology; Kawasaki University of Medical Welfare; Kurashiki Japan
| | - A. Tsubahara
- Kawasaki University of Medical Welfare; Kurashiki Japan
| | - S. Minagi
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| |
Collapse
|
31
|
Fukuike C, Kodama N, Manda Y, Hashimoto Y, Sugimoto K, Hirata A, Pan Q, Maeda N, Minagi S. A novel automated detection system for swallowing sounds during eating and speech under everyday conditions. J Oral Rehabil 2014; 42:340-7. [PMID: 25545324 DOI: 10.1111/joor.12264] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2014] [Indexed: 10/24/2022]
Abstract
The wave analysis of swallowing sounds has been receiving attention because the recording process is easy and non-invasive. However, up until now, an expert has been needed to visually examine the entire recorded wave to distinguish swallowing from other sounds. The purpose of this study was to establish a methodology to automatically distinguish the sound of swallowing from sound data recorded during a meal in the presence of everyday ambient sound. Seven healthy participants (mean age: 26·7 ± 1·3 years) participated in this study. A laryngeal microphone and a condenser microphone attached to the nostril were used for simultaneous recording. Recoding took place while participants were taking a meal and talking with a conversational partner. Participants were instructed to step on a foot pedal trigger switch when they swallowed, representing self-enumeration of swallowing, and also to achieve six additional noise-making tasks during the meal in a randomised manner. The automated analysis system correctly detected 342 out of the 352 self-enumerated swallowing events (sensitivity: 97·2%) and 479 out of the 503 semblable wave periods of swallowing (specificity: 95·2%). In this study, the automated detection system for swallowing sounds using a nostril microphone was able to detect the swallowing event with high sensitivity and specificity even under the conditions of daily life, thus showing potential utility in the diagnosis or screening of dysphagic patients in future studies.
Collapse
Affiliation(s)
- C Fukuike
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Mikamo S, Kodama N, Pan Q, Maeda N, Minagi S. Effect of nasal speaking valve on speech intelligibility under velopharyngeal incompetence: a questionnaire survey. J Oral Rehabil 2014; 42:136-43. [PMID: 25251499 DOI: 10.1111/joor.12237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/30/2014] [Indexed: 11/27/2022]
Abstract
Velopharyngeal incompetence is known as a contributing factor to speech disorders. Suwaki et al. reported that nasal speaking valve (NSV) could improve dysarthria by regulating nasal emission utilising one-way valve. However, disease or condition which would be susceptible to treatment by NSV has not been clarified yet. This study aimed to evaluate the effect of NSV by questionnaire survey using ready-made NSV. Subjects were recruited through the internet bulletin, and NSV survey set was sent to the applicant. Sixty-six participants, who agreed to participate in this study, used NSV and mailed back the questionnaire which included self-evaluation and third-party evaluation of speech intelligibility. Statistical analysis revealed that the use of NSV resulted in significant speech intelligibility improvement in both self-evaluation and third-party evaluation (P < 0·01). Regarding the type of underlying disease of dysarthria, significant effect of NSV on self-evaluation of speech intelligibility could be observed in cerebrovascular disease and neurodegenerative disease (P < 0·01) and that on third-party evaluation in neurodegenerative disease (P < 0·01). Eighty-six percent of subjects showed improvement of speech intelligibility by shutting up nostrils by fingers, and the significant effect of NSV on both self-evaluation and third-party evaluation of speech intelligibility was observed (P < 0·001). From the results of this study, it was suggested that NSV would be effective in cerebrovascular disease and neurodegenerative disease, as well as in subjects whose speech intelligibility was improved by closing nostrils.
Collapse
Affiliation(s)
- S Mikamo
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | | | | | | | | |
Collapse
|
33
|
Kawakami S, Kumazaki Y, Manda Y, Oki K, Minagi S. Specific diurnal EMG activity pattern observed in occlusal collapse patients: relationship between diurnal bruxism and tooth loss progression. PLoS One 2014; 9:e101882. [PMID: 25010348 PMCID: PMC4092086 DOI: 10.1371/journal.pone.0101882] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 06/12/2014] [Indexed: 11/18/2022] Open
Abstract
Aim The role of parafunctional masticatory muscle activity in tooth loss has not been fully clarified. This study aimed to reveal the characteristic activity of masseter muscles in bite collapse patients while awake and asleep. Materials and Methods Six progressive bite collapse patients (PBC group), six age- and gender-matched control subjects (MC group), and six young control subjects (YC group) were enrolled. Electromyograms (EMG) of the masseter muscles were continuously recorded with an ambulatory EMG recorder while patients were awake and asleep. Diurnal and nocturnal parafunctional EMG activity was classified as phasic, tonic, or mixed using an EMG threshold of 20% maximal voluntary clenching. Results Highly extended diurnal phasic activity was observed only in the PBC group. The three groups had significantly different mean diurnal phasic episodes per hour, with 13.29±7.18 per hour in the PBC group, 0.95±0.97 per hour in the MC group, and 0.87±0.98 per hour in the YC group (p<0.01). ROC curve analysis suggested that the number of diurnal phasic episodes might be used to predict bite collapsing tooth loss. Conclusion Extensive bite loss might be related to diurnal masticatory muscle parafunction but not to parafunction during sleep. Clinical Relevance: Scientific rationale for study Although mandibular parafunction has been implicated in stomatognathic system breakdown, a causal relationship has not been established because scientific modalities to evaluate parafunctional activity have been lacking. Principal findings This study used a newly developed EMG recording system that evaluates masseter muscle activity throughout the day. Our results challenge the stereotypical idea of nocturnal bruxism as a strong destructive force. We found that diurnal phasic masticatory muscle activity was most characteristic in patients with progressive bite collapse. Practical implications The incidence of diurnal phasic contractions could be used for the prognostic evaluation of stomatognathic system stability.
Collapse
Affiliation(s)
- Shigehisa Kawakami
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
- * E-mail:
| | - Yohei Kumazaki
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Yosuke Manda
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Kazuhiro Oki
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| |
Collapse
|
34
|
Sakamoto S, Hara T, Kurozumi A, Oka M, Kuroda-Ishimine C, Araki D, Iida S, Minagi S. Effect of occlusal rehabilitation on spatial memory and hippocampal neurons after long-term loss of molars in rats. J Oral Rehabil 2014; 41:715-22. [PMID: 24909970 DOI: 10.1111/joor.12198] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2014] [Indexed: 11/28/2022]
Abstract
Experimental loss of occlusal support caused by the extraction or grinding of molar teeth has been reported to foment the impairment of learning and memory in laboratory animals. The purpose of this study was to examine the effect of occlusal reconstruction after long-term loss of molars on spatial memory by using 8-arm radial maze and by assessing histopathological changes of neuron density in the hippocampus. Experimental dentures were inserted into the oral cavities of molarless rats to recover the occlusal support. Age-matched groups of control, molarless and denture-wearing rats were trained to perform the maze tasks. The difference of the error incidence in the maze task was evaluated between three groups. The difference of neuron density between three groups was also evaluated at the end of the maze task. Serum corticosterone levels were also measured to estimate the chronic stress, which could be caused by extraction, insertion of the experimental denture or any experimental procedure. The error incidence in the denture-wearing group was significantly higher than that of the control group, but significantly lower than that of the molarless group. Significant differences of neuron density were observed between three groups in each of the hippocampal CA1, CA3 and DG subfields. No significant difference of the serum corticosterone levels between three groups could be observed. From the results of this study, it was suggested that the recovery of occlusal support would bring amelioration of cognitive impairment concomitant with long period loss of molars in rats.
Collapse
Affiliation(s)
- S Sakamoto
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | | | | | | | | | | | | | | |
Collapse
|
35
|
Sanagawa T, Hara T, Minagi S. A new quantitative screening method for removable prosthesis using pressure-indicating paste. J Oral Rehabil 2014; 41:737-43. [DOI: 10.1111/joor.12200] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2014] [Indexed: 12/27/2022]
Affiliation(s)
- T. Sanagawa
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - T. Hara
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - S. Minagi
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| |
Collapse
|
36
|
Iegami CM, Barbosa WF, Furuyama RJ, Lima JRB, de Campos TT, Minagi S, Tamaki R. Masticatory efficiency in complete denture wearers with reduced dental arches--a randomised cross-over study. J Oral Rehabil 2014; 41:619-23. [PMID: 24779746 DOI: 10.1111/joor.12179] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/03/2014] [Indexed: 11/28/2022]
Abstract
One obstacle to placing artificial posterior teeth in manufacturing complete dentures is a reduction of the space between the maxilla and the mandible. Occasionally, second molar placement is not performed, as it does not affect aesthetics, phonetics or comfort. The aim of this study was to compare the masticatory efficiency between patients wearing maxillary and mandibular complete dentures with reduced dental arches (without second molars) (WSM) and with full dental arches (FDA). Twenty subjects were divided into two groups and randomly received new complete dentures. Patients in Group 1 were given dentures WSM, and those in Group 2 were given dentures with FDA. After the post-placement visits, an initial masticatory efficiency test was performed with Optocal, an artificial test food. Fifteen days later, second molars were placed in Group 1 and removed from Group 2, and a new test was performed. Comminuted material was treated and sieved under vibration. The mean and standard deviation of masticatory efficiency with FDA were 10.4 and 8.1, respectively. In the tests WSM, the mean and standard deviation were 8.4 and 3.3, respectively. After removing the second molars in Group 2 and adding them in Group 1, the mean and standard deviation were 15.7 and 14.7 for Group 1 and 12.5 and 10.4 for Group 2, respectively. Within the limitations of this study, placing artificial teeth up to the first molars can be performed when needed without compromising masticatory efficiency.
Collapse
Affiliation(s)
- C M Iegami
- Department of Prosthodontics, School of Dentistry, University of São Paulo, São Paulo, Brazil
| | | | | | | | | | | | | |
Collapse
|
37
|
|
38
|
Kumazaki Y, Naito M, Kawakami S, Hirata A, Oki K, Minagi S. Development of a speech-discriminating electromyogram system for routine ambulatory recordings for the low-level masseter muscle activity. J Oral Rehabil 2014; 41:266-74. [DOI: 10.1111/joor.12138] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2013] [Indexed: 10/25/2022]
Affiliation(s)
- Y. Kumazaki
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - M. Naito
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - S. Kawakami
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - A. Hirata
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - K. Oki
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - S. Minagi
- Department of Occlusal and Oral Functional Rehabilitation; Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| |
Collapse
|
39
|
Hasegawa K, Okamoto M, Nishigawa G, Oki K, Minagi S. The Design of Non-Occlusal Intraoral Appliances on Hard Palate and Their Effect on Masseter Muscle Activity During Sleep. Cranio 2014; 25:8-15. [PMID: 17304912 DOI: 10.1179/crn.2007.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
This study aimed to reveal whether masseter muscle activity during sleep is affected by the difference in design of non-occlusal intraoral appliances on hard palate. Eight healthy Japanese participants were selected and wore each of the four types of appliances (horse shoe, thin, thick and medium thick) during sleep for one week with a one week interval without appliance during sleep. A masseter muscle electromyograph (EMG) was recorded during sleep. The EMG activities were analyzed by calculating the number of bursts per hour, episodes per hour, and bursts per episode. The EMG parameters with the thick type appliance were significantly lower than the baseline condition without appliance. In this study, it is suggested that a thick type appliance has an active effect on suppression of masseter muscle activity.
Collapse
Affiliation(s)
- Koichi Hasegawa
- Occlusion and Removable Prosthodontics, Okayama University Hospital, 2-5-1 Shikata-cho, Okayama 700-8525, Japan.
| | | | | | | | | |
Collapse
|
40
|
Sugimoto K, Hashimoto Y, Fukuike C, Kodama N, Minagi S. Image analysis of food particles can discriminate deficient mastication of mixed foodstuffs simulating daily meal. J Oral Rehabil 2014; 41:184-90. [PMID: 24447165 DOI: 10.1111/joor.12133] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2013] [Indexed: 11/29/2022]
Affiliation(s)
- K. Sugimoto
- Department of Occlusal and Oral Functional Rehabilitation; Okayama University; Okayama Japan
| | - Y. Hashimoto
- Department of Occlusal and Oral Functional Rehabilitation; Okayama University; Okayama Japan
| | - C. Fukuike
- Department of Occlusal and Oral Functional Rehabilitation; Okayama University; Okayama Japan
| | - N. Kodama
- Department of Occlusal and Oral Functional Rehabilitation; Okayama University; Okayama Japan
| | - S. Minagi
- Department of Occlusal and Oral Functional Rehabilitation; Okayama University; Okayama Japan
| |
Collapse
|
41
|
Maeda N, Kobashi M, Mitoh Y, Fujita M, Minagi S, Matsuo R. Differential involvement of two cortical masticatory areas in submandibular salivary secretion in rats. Brain Res 2013; 1543:200-8. [PMID: 24309141 DOI: 10.1016/j.brainres.2013.11.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 11/21/2013] [Accepted: 11/24/2013] [Indexed: 01/01/2023]
Abstract
To evaluate the role of the masticatory area in the cerebral cortex in the masticatory-salivary reflex, we investigated submandibular salivary secretion, jaw-movement trajectory and electromyographic activity of the jaw-opener (digastric) and jaw-closer (masseter) muscles evoked by repetitive electrical stimulation of the cortical masticatory area in anesthetized rats. Rats have two cortical masticatory areas: the anterior area (A-area) in the orofacial motor cortex, and the posterior area (P-area) in the insular cortex. Our defined P-area extended more caudally than the previous reported one. P-area stimulation induced vigorous salivary secretion (about 20 µl/min) and rhythmical jaw movements (3-4 Hz) resembling masticatory movements. Salivary flow persisted even after minimizing jaw movements by curarization. A-area stimulation induced small and fast rhythmical jaw movements (6-8 Hz) resembling licking of solutions, but not salivary secretion. These findings suggest that P-area controls salivary secretion as well as mastication, and may be involved in the masticatory-salivary reflex.
Collapse
Affiliation(s)
- Naoto Maeda
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan
| | - Motoi Kobashi
- Department of Oral Physiology, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan
| | - Yoshihiro Mitoh
- Department of Oral Physiology, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan
| | - Masako Fujita
- Department of Oral Physiology, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan
| | - Ryuji Matsuo
- Department of Oral Physiology, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan.
| |
Collapse
|
42
|
Iida S, Hara T, Araki D, Ishimine-Kuroda C, Kurozumi A, Sakamoto S, Miyazaki T, Minagi S. Memory-related gene expression profile of the male rat hippocampus induced by teeth extraction and occlusal support recovery. Arch Oral Biol 2013; 59:133-41. [PMID: 24370184 DOI: 10.1016/j.archoralbio.2013.10.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 10/04/2013] [Accepted: 10/12/2013] [Indexed: 11/30/2022]
Abstract
OBJECTIVES The present study aimed to identify the effect of memory-related genes on male rats tested for spatial memory with either molar teeth extraction or its restoration by occlusal support using experimental dentures. DESIGN Memory-related genes were detected from hippocampi of male Wistar rats (exposed to teeth extraction with or without dentures, or no extraction (control)) (7-week old) after behavioural testing (via the radial maze task) using a DNA microarray. The time course of the expression of these genes was evaluated by quantitative real-time polymerase chain reaction (PCR) (on 49-week-old rats). RESULTS In preliminary experiments, to determine which memory genes are affected by spatial memory training, DNA microarray analysis revealed that thyrotropin-releasing hormone (Trh) and tenascin XA (Tnxa) were up-regulated and neuronatin (Nnat) and S100a9 were down-regulated after the maze training. The expression of Tnxa, Nnat and S100a9 of 49-week-old rats (during the time course) via quantitative real-time PCR was consistent with the results of microarrays of the preliminary experiment. Expression of Trh that was evaluated by quantitative real-time PCR did not agree with the results for this gene from the microarray for all groups. Therefore, expression of Trh may have increased in only young, trained rats. The expression of S100a9 prior to the maze task was down-regulated in only the extraction group. CONCLUSION These results demonstrated that Trh, Tnxa and Nnat genes were affected according to the degree of memory in male rats. This study also indicated that S100a9 is a memory-related gene, which is affected by the presence of occlusal support.
Collapse
Affiliation(s)
- Sachiyo Iida
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan.
| | - Tetsuya Hara
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan
| | - Daisuke Araki
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan
| | - Chisa Ishimine-Kuroda
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan
| | - Akimasa Kurozumi
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan
| | - Shunichi Sakamoto
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan
| | - Takako Miyazaki
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan
| | - Shogo Minagi
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan
| |
Collapse
|
43
|
Yoshihara K, Yoshida Y, Nagaoka N, Hayakawa S, Okihara T, De Munck J, Maruo Y, Nishigawa G, Minagi S, Osaka A, Van Meerbeek B. Adhesive interfacial interaction affected by different carbon-chain monomers. Dent Mater 2013; 29:888-97. [PMID: 23768795 DOI: 10.1016/j.dental.2013.05.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 05/11/2013] [Accepted: 05/14/2013] [Indexed: 10/26/2022]
Abstract
OBJECTIVES The functional monomer 10-methacryloxydecyl dihydrogen phosphate (10-MDP), recently used in more self-etch adhesives, chemically bonds to hydroxyapatite (HAp) and thus tooth tissue. Although the interfacial interaction of the phosphoric-acid functional group of 10-MDP with HAp-based substrates has well been documented, the effect of the long carbon-chain spacer of 10-MDP on the bonding effectiveness is far from understood. METHODS We investigated three phosphoric-acid monomers, 2-methacryloyloxyethyl dihydrogen phosphate (2-MEP), 6-methacryloyloxyhexyl dihydrogen phosphate (6-MHP) and 10-MDP, that only differed for the length of the carbon chain, on their chemical interaction potential with HAp and dentin, this correlatively using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Commercial 6-MHP and 10-MDP containing adhesives were investigated as well. RESULTS XRD revealed that on HAp only 10-MDP produced monomer-calcium salts in the form of 'nano-layering', while on dentin all monomers produced 'nano-layering', but with a varying intensity in the order of 10-MDP>6-MHP>2-MEP. TEM confirmed that 10-MDP formed the thickest hybrid and adhesive layer. XRD and TEM revealed 'nano-layering' for all commercial adhesives on dentin, though less intensively for the 6-MHP containing adhesive than for the 10-MDP ones. SIGNIFICANCE It is concluded that not only the phosphoric-acid group but also the spacer group, and its length, affect the chemical interaction potential with HAp and dentin. In addition, the relatively strong 'etching' effect of 10-MDP forms more stable monomer-Ca salts, or 'nano-layering', than the two shorter carbon-chain monomers tested, thereby explaining, at least in part, the better bond durability documented with 10-MDP containing adhesives.
Collapse
Affiliation(s)
- Kumiko Yoshihara
- KU Leuven BIOMAT, Department of Oral Health Research, KU Leuven (University of Leuven) & Dentistry, University Hospitals Leuven, Belgium
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Oki K, Shirahige C, Maeda N, Sakamoto S, Kumazaki Y, Mikamo S, Miyazaki T, Yamamoto Y, Minagi S. Dependence of psychophysical threshold on rate of applied force to the upper first molar in humans. Arch Oral Biol 2013; 58:474-81. [DOI: 10.1016/j.archoralbio.2012.10.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2012] [Revised: 10/21/2012] [Accepted: 10/23/2012] [Indexed: 11/24/2022]
|
45
|
Yoshida Y, Yoshihara K, Hayakawa S, Nagaoka N, Okihara T, Matsumoto T, Minagi S, Osaka A, Van Landuyt K, Van Meerbeek B. HEMA inhibits interfacial nano-layering of the functional monomer MDP. J Dent Res 2012; 91:1060-5. [PMID: 22968157 DOI: 10.1177/0022034512460396] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Previous research showed that the functional monomer 10-methacryloxydecyl dihydrogen phosphate (MDP) ionically bonds to hydroxyapatite (HAp) and forms a nano-layered structure at the interface with HAp-based substrates. Such hydrophobic nano-layering is considered to contribute to the long-term durability of the bond to tooth tissue. However, dental adhesives are complex mixtures usually containing different monomers. This study investigated the effect of the monomer 2-hydroxyethylmethacrylate (HEMA) on the chemical interaction of MDP with HAp by x-ray diffraction (XRD), nuclear magnetic resonance (NMR), and quartz crystal microbalance (QCM). We examined the chemical interaction of 5 experimental MDP solutions with increasing concentrations of HEMA. XRD revealed that addition of HEMA inhibits nano-layering at the interface, while NMR confirmed that MDP remained adsorbed onto the HAp surface. QCM confirmed this adsorption of MDP to HAp, as well as revealed that the demineralization rate of HAp by MDP was reduced by HEMA. It was concluded that even though the adsorption of MDP to HAp was not hindered, addition of HEMA inhibited interfacial nano-layering. Potential consequences with regard to bond durability necessitate further research.
Collapse
Affiliation(s)
- Y Yoshida
- Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8525, Japan.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Morimoto Y, Oki K, Iida S, Shirahige C, Maeda N, Kawakami S, Matsunaga T, Minagi S. Effect of transient occlusal loading on the threshold of tooth tactile sensation perception for tapping like the impulsive stimulation. Odontology 2012; 101:199-203. [PMID: 22806609 DOI: 10.1007/s10266-012-0072-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 05/06/2012] [Indexed: 11/24/2022]
Affiliation(s)
- Yuta Morimoto
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8525, Japan
| | | | | | | | | | | | | | | |
Collapse
|
47
|
Sugimoto K, Iegami CM, Iida S, Naito M, Tamaki R, Minagi S. New image analysis of large food particles can discriminate experimentally suppressed mastication. J Oral Rehabil 2012; 39:405-10. [PMID: 22372665 DOI: 10.1111/j.1365-2842.2012.02288.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- K Sugimoto
- Department of Occlusal and Oral Functional Rehabilitation, Okayama University, Okayama, Japan
| | | | | | | | | | | |
Collapse
|
48
|
Maeda N, Sakamoto S, Kodama N, Oki K, Shibata T, Soga K, Shirahige T, Nishikawa G, Minagi S. Denture Treatment and Assessment in Relation to Cognitive Functions and Activity of Daily Living in Elderly Inpatients: A Preliminary Study. ACTA ACUST UNITED AC 2012. [DOI: 10.2186/ajps.4.419] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
49
|
Irie M, Nagaoka N, Tamada Y, Maruo Y, Nishigawa G, Minagi S, Finger WJ. Effect of spherical silica additions on marginal gaps and compressive strength of experimental glass-ionomer cements. Am J Dent 2011; 24:310-314. [PMID: 22165460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
PURPOSE To clarify the effects of the addition of silanized (S) and unsilanized (U) spherical silica filler to resin-modified glass-ionomer cement and of powder-liquid ratio on (1) the early marginal gap-width of restorations in both tooth cavities and Teflon molds, (2) the gap-formation of restorations in Class V cavities, and (3) the compressive strength of the cement. METHODS Resin-modified glass-ionomer powder (Fuji II LC EM, GC) was modified by adding 5 and 10 wt% of powder respectively, of S and U, and then the powder-liquid ratio was increased up to 4.8. Human premolars, extracted for orthodontic reasons, were used for this study. Cylindrical cavities (1.5 mm deep, 3.5 mm in diameter; one cavity was prepared in each tooth in the coronal region and medial surface) were prepared in extracted human premolar teeth and restored with resin-modified glass-ionomer cements. Each restoration margin was inspected immediately after curing and polishing (as the immediate condition was the most severe), the maximum gap-width and the opposing width (if any) were determined microscopically (n = 10). An additional test was conducted in model Class V cavities. After finishing of restorations in model Class V cavities, each tooth was sectioned in a bucco-lingual direction through the center of the restoration, and the presence or absence of gaps along the cavity interface was evaluated (n = 10). Additionally, the maximum marginal gap-width and the opposing-width along margins of restorations in cylindrical Teflon molds were measured (n= 10). The compressive strengths of the restorative materials were determined immediately after light-activation (n = 10). RESULTS Marginal gap (tooth cavity: 0.32 to 0.25-0.20%, P < 0.05; Teflon cavity: 0.94 to 0.6-0.8%, P < 0.05) and cavity adaptation (no gap in the Class V: 22 to 40-50%, P < 0.05) of the restorations improved with increasing powder-liquid ratio (3.0 to 4.4-4.8) and compressive strength increased (111 to 150-170 MPa, P < 0.05). Highly significant correlation coefficients were found for the relationships between powder-liquid ratio and (1) percentage of marginal gap width in the tooth cavity (r = -0.96, P = 0.002, n = 6), (2) gap-free tooth/cement interfaces (r = 0.90, P = 0.015, n = 6), (3) percentage of marginal gap widths in the Teflon mold (r = 0.98, P = 0.0004, n = 6) and (4) compressive strengths of the cements (r = 0.95, P = 0.004, n = 6).
Collapse
Affiliation(s)
- Masao Irie
- Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Phamaceutical Sciences, 2-5-1, Shikata-cho, Kita-ku, Okayama 700-8525, Japan.
| | | | | | | | | | | | | |
Collapse
|
50
|
Yoshihara K, Yoshida Y, Hayakawa S, Nagaoka N, Irie M, Ogawa T, Van Landuyt KL, Osaka A, Suzuki K, Minagi S, Van Meerbeek B. Nanolayering of phosphoric acid ester monomer on enamel and dentin. Acta Biomater 2011; 7:3187-95. [PMID: 21575747 DOI: 10.1016/j.actbio.2011.04.026] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 04/06/2011] [Accepted: 04/27/2011] [Indexed: 11/25/2022]
Abstract
Following the "adhesion-decalcification" concept, specific functional monomers possess the capacity to primary chemically interact with hydroxyapatite (HAp). Such ionic bonding with synthetic HAp has been demonstrated for 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP), manifest as self-assembled "nanolayering". In continuation of that basic research this study aimed to explore whether nanolayering also occurs on enamel and dentin when a 10-MDP primer is applied following a common clinical application protocol. Therefore, the interaction of an experimental 10-MDP primer and a control, commercially available, 10-MDP-based primer (Clearfil SE Bond primer (C-SE), Kuraray) with enamel and dentin was characterized by X-ray diffraction (XRD), complemented with transmission electron microscopy interfacial ultrastructural data upon their reaction with enamel and dentin. In addition, XRD was used to study the effect of the concentration of 10-MDP on nanolayering on dentin. Finally, the stability of the nanolayers was determined by measuring the bond strength to enamel and dentin when a photoinitiator was added to the experimental primer or when interfacial polymerization depended solely on the photoinitiator supplied with the subsequently applied adhesive resin. XRD confirmed nanolayering on enamel and dentin, which was significantly greater on dentin than on enamel, and also when the surface was actively rubbed with the primer. Nanolayering was also proportional to the concentration of 10-MDP in the primer. Finally, the experimental primer needed the photoinitiator to obtain a tensile bond strength to dentin comparable with that of the control C-SE primer (which also contains a photoinitiator), but not when bonded to enamel. It is concluded that self-assembled nanolayering occurs on enamel and dentin, even when following a clinically used application protocol. The lower bonding effectiveness of mild self-etch adhesives to enamel should be ascribed in part to a lower chemical reactivity (nanolayering) with enamel HAp.
Collapse
|