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Chawshli OF, Hasan HS, Yalda FA, Al-Talabani SZ. The success rate of mini-screws for incisors intrusion and patient age, gender, and insertion angle in the maxilla using CBCT and implant-guided surgery. A split-mouth, randomized control trail. Orthod Craniofac Res 2024; 27:118-125. [PMID: 37496467 DOI: 10.1111/ocr.12700] [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: 04/27/2023] [Accepted: 07/17/2023] [Indexed: 07/28/2023]
Abstract
BACKGROUND AND OBJECTIVES The intrusion of anterior teeth is a routine procedure in orthodontics, which has been performed efficiently with the help of mini-screws in the anterior region, especially the upper maxilla. This study aimed to investigate the effect of insertion angle and sociodemographic features on the success rate of mini-screws at the anterior maxillary region. MATERIALS AND METHODS Twenty-nine patients (18 Females and 11 Males) aged 18-40 years old were involved in the current study. A split-mouth design was carried out in which recruited patients needed bilateral anterior screws at the labial bone in the region of the incisor for the intrusion of upper anterior incisor teeth as part of their orthodontic treatment with a fixed appliance (upper right side received 90-degree insertion angle mini-screw and 45° for left side) using a surgical guide fabricated from patients CBCT and intraoral scans. The mini-screws were inserted at the attached gingiva bilaterally to achieve intrusion of upper anterior teeth with a power chain ligated from the main archwire to the anterior min-implants. The patient was recalled monthly for orthodontic appliance activation and screw assessment for 6 months. The intrusion force was 15 g on each side. RESULTS The results of the study showed that screw stability was higher in the male group than the female group at the 6th monthly follow-up visit with a statistically significant difference between both genders (P = .044). Concerning insertion angle, results showed a statistically significant difference between 45° and 90° as an insertion angle with a P-value <.01 in most of the follow-up months. CONCLUSION This study found that male patients with mini-screws inserted at 90° showed greater screw stability over time.
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Affiliation(s)
- Omar Fawzi Chawshli
- The Department of Pedodontics, Orthodontics and Preventive Dentistry, College of Dentistry, Hawler Medical University, Erbil, Iraq
| | - Hasan Sabah Hasan
- Orthodontic Department, Azadi Dental Center, General Directorate of Hawler, Ministry of Health, Erbil, Iraq
- Orthodontic Department, Privet Specialized Dental Clinic, Erbil, Iraq
| | - Fedil Andraws Yalda
- The Department of Oral Diagnosis, College of Dentistry, Hawler Medical University, Erbil, Iraq
| | - Shaho Z Al-Talabani
- P.O.P Department, College of Dentistry, Hawler Medical University, Erbil, Iraq
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Yuvashree CS, Jain RK, Prasad AS. Severity of mandibular arch crowding in different sagittal malocclusions. J Adv Pharm Technol Res 2022; 13:S45-S49. [PMID: 36643145 PMCID: PMC9836158 DOI: 10.4103/japtr.japtr_121_22] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 06/13/2022] [Accepted: 06/14/2022] [Indexed: 01/17/2023] Open
Abstract
Mandibular anterior crowding is caused by a variety of factors. Mandibular incisor crowding can be caused by a number of causes including incisor and molar inclination, early loss of deciduous molars, mandibular growth, and oral musculature. The study was aimed to perform an association of the lower anterior crowding severity with gender and type of malocclusion. The current study was performed in a hospital setup and data about mandibular arch crowding patients were collected from the Records management system of a Private Dental Hospital in Chennai city. All the patient data on Mandibular arch crowding were sourced and tabulated after which statistical analysis with SPSS-IBM was done. Data collection was done over a period from June 2019 to February 2021. The entire study sample size was 634 case records. The result obtained from the statistical analysis was found that nearly 46% of the patients were found to have Mandibular arch crowding with female predilection (50%). The most commonly associated age groups were children than adults (63.2%) associated with mild type of crowding (65.1%). The most commonly involved malocclusion was found to be Class 1 (88.4%) Mild imbrications of the lower arch were common and were seen mainly in subjects with Class I malocclusion. Female subjects presented with more prevalence of mandibular arch crowding when compared to male subjects. Children were more affected by crowding than adults.
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Affiliation(s)
- C. S. Yuvashree
- Department of Orthodontics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, Tamil Nadu, India
| | - Ravindra Kumar Jain
- Department of Orthodontics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, Tamil Nadu, India,Address for correspondence: Dr. Ravindra Kumar Jain, Department of Orthodontics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, Tamil Nadu, India. E-mail:
| | - Arya S. Prasad
- Department of Orthodontics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, Tamil Nadu, India
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Valizadeh S, Zafarmand AH, Hassan Yazdi S, Ghazizadeh Ahsaie M, Lo Giudice A. Quantitative Assessment of Posterior Maxillary Arch for Orthodontic Miniscrew Insertion Using Cone Beam Computed Tomography: A Cross-Sectional Analysis. Int J Dent 2022; 2022:1-9. [PMID: 35662891 PMCID: PMC9162861 DOI: 10.1155/2022/8257256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 04/19/2022] [Accepted: 05/05/2022] [Indexed: 11/17/2022] Open
Abstract
Methods and Materials Cone beam computed tomography records of 35 patients (70 quadrants) from maxilla were evaluated. The images were analyzed using the NNT viewer software (version 23). The measurements were made on axial sections at 2, 4, 6, and 8 mm from CEJ. The optimal sites were defined in terms of mesiodistal palatal or buccal interradicular distance, alveolar cortical bone thickness, and palatal or buccal safe depth of the bone for miniscrew insertion. Descriptive statistics, paired t-test, and repeated measure ANOVA were used to analyze the data. Results The mean buccal interradicular distance was the lowest between first and second molar (2.44 mm) and the highest between first and second premolar (3.28 mm). The mean palatal interradicular distance was the lowest between first and second premolar (3.64 mm) and the highest between second premolar and first molar (5.30 mm). The mean buccal safe depth was the lowest between canine and first premolar (1.96 mm) and the highest between first and second molar (2.61 mm). The mean palatal safe depth was the lowest between second premolar and first molar (3.35 mm) and the highest between first and second molar (3.56 mm). The thinnest and thickest buccal cortical thicknesses were detected on canine and first molar (1.04 mm) and on the second premolar and second molar (1.56 mm). Conclusion The quantity and quality of the maxillary alveolar process is an important factor to decide where to insert the orthodontic miniscrews, necessitating careful preoperative evaluation.
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Zhang S, Wei X, Wang L, Wu Z, Liu L, Yan X, Lai W, Long H. Evaluation of Optimal Sites for the Insertion of Orthodontic Mini Implants at Mandibular Symphysis Region through Cone-Beam Computed Tomography. Diagnostics (Basel) 2022; 12:diagnostics12020285. [PMID: 35204375 PMCID: PMC8871083 DOI: 10.3390/diagnostics12020285] [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: 12/09/2021] [Revised: 01/09/2022] [Accepted: 01/17/2022] [Indexed: 01/27/2023] Open
Abstract
This study aims to evaluate the overall bone thickness (OBT) and cortical bone thickness (CBT) of mandibular symphysis and to determine the optimal sites for the insertion of orthodontic mini implants. Cone-beam computed tomography (CBCT) images of 32 patients were included in this study. The sample was further categorized into three facial types: low-, average-, and high-angle. OBT and CBT were measured at the mandibular symphysis region. All measurements were performed at six different heights from the cementoenamel junction [CEJ] and at seven different angles to the occlusal plane. Analysis of variance (ANOVA) was used for statistical comparison and a p value less than 0.05 was considered statistically significant. Our results revealed that neither OBT nor CBT was influenced by age or sex, except for the observation that CBT was significantly greater in adults than in adolescents. OBT and CBT were significantly greater in low-angle cases than in average- and high-angle cases. Both OBT and CBT were significantly influenced by insertion locations, heights and angles, and their interactions. CBT and OBT were greatest at the location between two lower central incisors, and became greater with increases in insertion height and angle. Both recommended and optimal insertion sites were mapped. The mandibular symphysis region was suitable for the placement of orthodontic mini implants. The optimal insertion site was 6–10 mm apical to the CEJ between two lower central incisors, with an insertion angle being 0–60 degrees to the occlusal plane.
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Affiliation(s)
- Shizhen Zhang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; (S.Z.); (X.W.); (Z.W.); (L.L.); (X.Y.)
| | - Xiaoyu Wei
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; (S.Z.); (X.W.); (Z.W.); (L.L.); (X.Y.)
| | - Lufei Wang
- Department of Oral and Craniofacial Health Sciences, University of North Carolina Adams School of Dentistry, Chapel Hill, NC 27599, USA;
| | - Zhouqiang Wu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; (S.Z.); (X.W.); (Z.W.); (L.L.); (X.Y.)
| | - Lu Liu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; (S.Z.); (X.W.); (Z.W.); (L.L.); (X.Y.)
| | - Xinyu Yan
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; (S.Z.); (X.W.); (Z.W.); (L.L.); (X.Y.)
| | - Wenli Lai
- Department of Orthodontics, West China School of Stomatology, Sichuan University, Chengdu 610041, China
- Correspondence: (W.L.); (H.L.)
| | - Hu Long
- Department of Orthodontics, West China School of Stomatology, Sichuan University, Chengdu 610041, China
- Correspondence: (W.L.); (H.L.)
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Keo P, Matsumoto Y, Shimizu Y, Nagahiro S, Ikeda M, Aoki K, Ono T. A pilot study to investigate the histomorphometric changes of murine maxillary bone around the site of mini-screw insertion in regenerated bone induced by anabolic reagents. Eur J Orthod 2021; 43:86-93. [PMID: 32202621 DOI: 10.1093/ejo/cjaa018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE The objective of this study was to investigate the histomorphometric changes around the site of mini-screw insertion in the regenerated bone which was induced by an anabolic-injection method using both anabolic peptide and bone morphogenetic protein 2 (BMP-2). METHODS Twenty-seven eight-week-old C57BL/6J male mice were used. Some mice received submucosal co-injections of anabolic peptide and BMP-2 just in front of the maxillary first molar. Screw insertion was then performed 4 weeks after injection. All mice underwent a weekly in vivo micro-focal X-ray computed tomography (µCT) analysis before being sacrificed at week 8. The bone formation activity was evaluated using fluorescent labelling in the undecalcified sections. The analyses, including screw insertion, were performed in the frontal plane, in front of the site of screw insertion. RESULTS Reconstructed µCT images revealed that the co-injection of anabolic reagents could lead to a gradual increase in the bone mineral density (BMD) of the injection-induced thickened bone by week 8. Both radiological and histomorphometric analyses indicated that screw insertion did not have any deleterious effects on either the BMD or the bone formation activity of the induced bone. Furthermore, the injection of anabolic reagents also led to an increase in the BMD of the underlying maxillary bone at the injection site. CONCLUSION Our histomorphometric analyses suggest that performing such anabolic injection to thicken bone could stimulate bone formation in the basal bone as well as in the induced bone. Similar augmentation of bone formation could be obtained even after subsequent screw insertion at the site of the induced bone.
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Affiliation(s)
- Preksa Keo
- Department of Orthodontic Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.,Department of Basic Oral Health Engineering, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yoshiro Matsumoto
- Department of Orthodontic Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yasuhiro Shimizu
- Department of Orthodontic Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Shigeki Nagahiro
- Department of Pediatric Dentistry/Special Needs Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.,Department of Basic Oral Health Engineering, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Masaomi Ikeda
- Department of Oral Prosthetic Engineering, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kazuhiro Aoki
- Department of Basic Oral Health Engineering, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Takashi Ono
- Department of Orthodontic Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
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Wang Y, Shi Q, Wang F. Optimal Implantation Site of Orthodontic Micro-Screws in the Mandibular Anterior Region Based on CBCT. Front Physiol 2021; 12:630859. [PMID: 34093218 PMCID: PMC8173216 DOI: 10.3389/fphys.2021.630859] [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: 11/18/2020] [Accepted: 04/15/2021] [Indexed: 11/22/2022] Open
Abstract
Background: To determine the optimal implantation site of orthodontic micro-screws based on cone beam computed tomography (CBCT) analysis in the mandibular anterior tooth region, provide a theoretical basis for orthodontic implant placement and improve post-implantation stability. Methods: Forty patients who underwent CBCT scanning were selected for this study. CBCT scanning was applied to measure the interradicular distance, buccolingual dimension, labial cortical bone thickness and lingual cortical bone thickness between mandibular anterior teeth at planes 2, 4, 6, and 8 mm below the alveolar ridge crest. The data were measured and collected to obtain a comprehensive evaluation of the specific site conditions of the alveolar bone. Results: The interradicular distance, buccolingual dimension and labial cortical bone thickness between the mandibular anterior teeth were positively correlated with the distance below the alveolar ridge crest (below 8 mm). The interradicular distance, buccolingual dimension, labial cortical bone thickness, and lingual cortical bone thickness were all greater than those in other areas between the lateral incisor root and canine incisor root 4, 6, and 8 mm below the alveolar ridge crest. Conclusion: The area between the lateral incisor root and the canine incisor root in planes 4, 6, and 8 mm from the alveolar ridge crest can be used as safe sites for implantation, while 8 mm below the alveolar ridge crest can be the optimal implantation site. An optimal implantation site can be 8 mm below the alveolar ridge crest between the lateral incisor root and the canine incisor root.
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Affiliation(s)
- Yannan Wang
- The Sixth Medical Center of PLA General Hospital, Beijing, China.,Military Hospital, Qingdao, China
| | - Quan Shi
- The General Hospital of People's Liberation Army (301 Hospital), Beijing, China
| | - Feng Wang
- The Sixth Medical Center of PLA General Hospital, Beijing, China
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Tepedino M, Cattaneo PM, Niu X, Cornelis MA. Interradicular sites and cortical bone thickness for miniscrew insertion: A systematic review with meta-analysis. Am J Orthod Dentofacial Orthop 2020; 158:783-798.e20. [PMID: 33077369 DOI: 10.1016/j.ajodo.2020.05.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 05/01/2020] [Accepted: 05/01/2020] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Safe zone maps are useful for the clinician to plan miniscrew insertion and possibly reduce radiation exposure. This study aimed to investigate the available evidence regarding the presence of sufficient interradicular space and adequate cortical bone thickness in patients with a complete permanent dentition, in the vestibular and palatal or lingual interradicular sites, mesial to the second molar. METHODS PubMed, Scopus, Web of Science, Cochrane Library, and OpenGrey databases were searched up to January 2019 for observational studies involving patients with fully erupted second molars that investigated the amount of interradicular space and/or the cortical thickness of the alveolar processes using 3-dimensional data sets. A custom tool was prepared and used to assess the risk of bias in individual studies. A meta-analysis was performed when at least 4 different studies evaluated 1 identical parameter homogeneously. Publication bias was assessed with the Egger linear regression test. RESULTS Twenty-seven observational articles were included in the qualitative synthesis. Only 11 articles were at low risk of bias. Fifteen articles were included in the meta-analysis. The results were graphically reported in "safe-zone" maps. CONCLUSIONS In the maxilla, the most suitable insertion sites are those from mesial to the first molar to distal to the first premolar, and between the canine and the lateral incisor, all at 6 mm from the cementoenamel junction. In those areas, the cortical bone has adequate thickness, not requiring predrilling. In the mandible, the preferable vestibular interradicular spaces are those between first and second molars and between first and second premolars, both at 5 mm from the cementoenamel junction, and predrilling is suggested in these areas. TRIAL REGISTRATION NUMBER PROSPERO CRD42016042081.
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Affiliation(s)
- Michele Tepedino
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy.
| | - Paolo M Cattaneo
- Section of Orthodontics, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark; Dentistry and Health Sciences, Melbourne Dental School, University of Melbourne, Melbourne, Australia
| | - Xiaowen Niu
- Section of Orthodontics, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
| | - Marie A Cornelis
- Section of Orthodontics, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark; Dentistry and Health Sciences, Melbourne Dental School, University of Melbourne, Melbourne, Australia
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Di Carlo G, Saccucci M, Luzzi V, Ierardo G, Vozza I, Sfasciotti GL, Polimeni A. Prevalence of maxillary canine impaction in skeletal Class III malocclusions compared to Class I malocclusions. J Clin Exp Dent 2019; 11:e264-e268. [PMID: 31001397 PMCID: PMC6461734 DOI: 10.4317/jced.55478] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [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: 12/05/2018] [Accepted: 01/07/2019] [Indexed: 11/05/2022] Open
Abstract
Background The aim of the present investigation was to evaluate if an orthodontic population of Class III malocclusion patients shows a different prevalence of maxillary canine impaction than Class I subjects. Material and Methods Fifty-eight subjects were retrospectively selected and assigned to the Class I group (n= 32) or the Class III group (n= 26), depending on the ANB and WITS values. Lateral cephalograms were used to collect angular and linear measurements that described the skeletal and dental maxillary features of the subjects, while orthopantomography was used to assess the impaction or the correct eruption of the maxillary canines. An independent samples T-test or a Mann-Whitney U-test was used to compare the cephalometric values between the two groups, while a chi-squared test was used to evaluate the distribution of maxillary canine impaction between the two groups. Results No statistically significant difference was found for the cephalometric variables, and the frequency of canine impaction showed no difference between the Class III and Class I subjects. Conclusions Patients with skeletal Class III malocclusions did not show a different prevalence of canine impaction; therefore, such skeletal features cannot be used as a diagnostic aid for assessment of the risk of maxillary canine impaction. Key words:Skeletal Class III, Angle Class III, maxillary canine impaction, tooth impaction.
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Affiliation(s)
- Gabriele Di Carlo
- Department of Oral and Maxillo-Facial Sciences, Sapienza University of Rome, Viale Regina Elena 287a, 00161 Rome, Italy
| | - Matteo Saccucci
- Department of Oral and Maxillo-Facial Sciences, Sapienza University of Rome, Viale Regina Elena 287a, 00161 Rome, Italy
| | - Valeria Luzzi
- Department of Oral and Maxillo-Facial Sciences, Sapienza University of Rome, Viale Regina Elena 287a, 00161 Rome, Italy
| | - Gaetano Ierardo
- Department of Oral and Maxillo-Facial Sciences, Sapienza University of Rome, Viale Regina Elena 287a, 00161 Rome, Italy
| | - Iole Vozza
- Department of Oral and Maxillo-Facial Sciences, Sapienza University of Rome, Viale Regina Elena 287a, 00161 Rome, Italy
| | - Gian-Luca Sfasciotti
- Department of Oral and Maxillo-Facial Sciences, Sapienza University of Rome, Viale Regina Elena 287a, 00161 Rome, Italy
| | - Antonella Polimeni
- Department of Oral and Maxillo-Facial Sciences, Sapienza University of Rome, Viale Regina Elena 287a, 00161 Rome, Italy
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Ciavarella D, Cianci C, Laurenziello M, Troiano G, De Cillis F, Tepedino M, Montaruli G, Grassia V, Lo Muzio L, Pappalettere C. Comparison of the Stress Strain Capacity between Different Clear Aligners. Open Dent J 2019. [DOI: 10.2174/1874210601913010041] [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: 01/08/2023] Open
Abstract
Background:
The rife use of aesthetic appliance in orthodontic treatment requires the study of the properties of the materials they are made of.
Objective:
The aim of the present study was to evaluate the dimensional stability of clear aligners made of three different materials after the application of in-vivo dynamic stress and in-vitro static stress.
Methods:
Three different aligners made of different materials (PET-G; PET; SmartTrack®), prepared on the dental arch of the same patient, were tested. For each material, three aligner samples were manufactured: one to be used in-vivo, one to be tested in-vitro, and one to be used as a control.
To evaluate the effects of the dynamic stress produced in-vivo, each aligner was worn by a single patient 22 hours per day, followed by a wash-out period of two weeks. To evaluate the effects of static stress, each aligner was exposed to the in-vitro continuous force of 50N. The tested and control aligners were scanned, then linear measurements were taken to evaluate their dimensional stability after different types of stresses.
Results:
PET seems to have the lowest percentage of deformation; PET-G and SmartTrack® showed a reduced deformation going from the posterior to the anterior area. The contact with human saliva induces a greater deformation.
Conclusion:
Different materials show different behavior following application of static stresses and dynamic stresses in the oral cavity. PET showed the highest dimensional stability.
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Tepedino M, Iancu-Potrubacz M, Grippaudo C, Chimenti C, Laganà G. Does muscular activity related to vertical facial divergence influence the time needed for orthodontic extrusion of palatally impacted maxillary canines? A retrospective study. J Clin Exp Dent 2018; 10:e869-e875. [PMID: 30386519 PMCID: PMC6203914 DOI: 10.4317/jced.55149] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [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: 07/17/2018] [Accepted: 08/06/2018] [Indexed: 11/30/2022] Open
Abstract
Background The aim of the present study was to evaluate if the different muscular activity correlated to different degrees of facial divergence has an effect on the time needed to extrude a palatally impacted maxillary canine. Material and Methods Twenty-six patients were retrospectively selected, all treated with a specific cantilever appliance that allows extrusion of the impacted canine applying a physiologic amount of force below 0.6 N in a predictable way. For all the patients, pre-treatment cephalometric tracings were used to evaluate facial divergence through the FMA angle, the angle between the maxillary and mandibular plane, and the angles between the occlusal plane and either the maxillary and mandibular plane. Linear bivariate regression was calculated to evaluate if facial divergence can predict the time needed for canine extrusion. Results The linear regression model was not able to predict extrusion time from variables explaining the facial divergence. Conclusions Palatally impacted maxillary canines can be treated with the application of physiologic extrusion force regardless of patients’ facial divergence and muscular activity. Key words:Impacted canines, cantilever, facial divergence, muscular activity.
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Affiliation(s)
- Michele Tepedino
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy
| | - Maciej Iancu-Potrubacz
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy
| | - Cristina Grippaudo
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma-Università Cattolica del Sacro Cuore. Istituto di Clinica Odontoiatrica e Chirurgia Maxillo-facciale, Rome, Italy
| | - Claudio Chimenti
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy
| | - Giuseppina Laganà
- Department of Clinical Sciences and Translational Medicine, University of Rome Tor Vergata, Rome, Italy
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