1
|
Imai T, Kubota S, Nishimoto A, Katsura-Fuchihata S, Uzawa N. Risk factors for impacted lower third molar root perforation through the undercut-shaped lingual plate: preoperative insights from panoramic radiography. Odontology 2024; 112:562-569. [PMID: 37910252 DOI: 10.1007/s10266-023-00865-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 10/08/2023] [Indexed: 11/03/2023]
Abstract
This study aimed to identify risk factors associated with perforation of the undercut (U)-shaped lingual plate (LP) by the lower third molar (LM3) root using panoramic radiography (PAN). We retrospectively examined 468 impacted LM3s from 468 individuals, categorizing LM3-LP associations and LP morphology in the coronal section of cone-beam computed tomography as perforation or nonperforation and U-type or non-U-type, respectively. The outcome was the combination of perforation and U-type, and study variables included patient demographics (age and sex) and PAN-associated features (Winter's classification, Pell-Gregory classification, and two major Rood signs). Multivariate logistic regression methods were used for analysis. Perforated and U-type LPs were observed in 205 (43.8%) and 212 (45.3%) cases, respectively. The double-positive outcome was observed in 126 LM3s (26.9%). In the multivariate model, age ≥ 26 years [odds ratio (OR), 2.66; p = 0.002], men (OR, 2.01; p = 0.002), mesioangular (OR, 2.74; p = 0.038) and horizontal impaction (OR, 3.05; p = 0.019), and root darkening (OR, 1.73; p = 0.039) were independently associated with the risk. Class III impaction (OR, 0.35; p = 0.021) and interruption of the white line (OR, 0.55; p = 0.017) were negatively correlated with the risk. In conclusion, this study highlights the importance of identifying the higher probability of U-type LP perforation by the LM3 root in men aged over their midtwenties with Class I/II impaction and mesioangularly or horizontally impacted LM3s, along with root darkening and no interruption of the white line on PAN.
Collapse
Affiliation(s)
- Tomoaki Imai
- Department of Oral and Maxillofacial Surgery, Toyonaka Municipal Hospital, 4-14-1 Shibaharatyo, Toyonaka, Osaka, 560-8565, Japan.
- Department of Oral & Maxillofacial Oncology and Surgery, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Seiko Kubota
- Department of Oral & Maxillofacial Oncology and Surgery, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Ayano Nishimoto
- Department of Oral & Maxillofacial Oncology and Surgery, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Sho Katsura-Fuchihata
- Department of Oral & Maxillofacial Oncology and Surgery, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Narikazu Uzawa
- Department of Oral & Maxillofacial Oncology and Surgery, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
| |
Collapse
|
2
|
de Lima DM, Estrela CRDA, Bernardes CMR, Estrela LRDA, Bueno MR, Estrela C. Spatial Position and Anatomical Characteristics Associated with Impacted Third Molars Using a Map-Reading Strategy on Cone-Beam Computed Tomography Scans: A Retrospective Analysis. Diagnostics (Basel) 2024; 14:260. [PMID: 38337776 PMCID: PMC10855352 DOI: 10.3390/diagnostics14030260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 12/22/2023] [Accepted: 12/28/2023] [Indexed: 02/12/2024] Open
Abstract
(1) Background: This study assessed the spatial position and anatomical features associated with impacted third molars through a map-reading strategy employing cone-beam computed tomography (CBCT). (2) Methods: The positioning of impacted third molars on CBCT was assessed using Winter's and Pell and Gregory's classifications. External root resorption in mandibular second molars was categorized according to Herman's classification. Additionally, the relationship between the mandibular third molar root apex and the mandibular canal was examined. Comparative statistical analysis was conducted using Fisher's exact test, with a significance level considered as 5%. (3) Results: The results indicated that, based on Winter's classification, 48.06 % of impacted teeth were positioned mesioangularly. Employing Pell and Gregory's classification, 43.22% of the impacted molars fell into positions B and C, with 54.2% classified as Class II. A notable 69.7% of teeth exhibited no contact between the root apex and the mandibular canal, and external root resorption in the distal aspect of the second molar was absent in 88.7% of cases. (4) Conclusions: Utilizing the map-reading strategy with CBCT scans to assess the anatomical positions and characteristics of impacted third molars enhances professional confidence and sets a standard for quality and safety in the surgical procedure for patients.
Collapse
Affiliation(s)
- Djalma Maciel de Lima
- Department of Oral Biology, School of Dentistry, Evangelical University of Goiás, Anápolis 75083-515, Brazil; (D.M.d.L.); (C.M.R.B.); (L.R.d.A.E.)
| | - Cyntia Rodrigues de Araújo Estrela
- Department of Oral Biology, School of Dentistry, Evangelical University of Goiás, Anápolis 75083-515, Brazil; (D.M.d.L.); (C.M.R.B.); (L.R.d.A.E.)
| | | | - Lucas Rodrigues de Araújo Estrela
- Department of Oral Biology, School of Dentistry, Evangelical University of Goiás, Anápolis 75083-515, Brazil; (D.M.d.L.); (C.M.R.B.); (L.R.d.A.E.)
| | - Mike Reis Bueno
- Center for Radiology and Orofacial Images, Diagnostic Imaging Center, Cuiabá 78043-272, Brazil;
| | - Carlos Estrela
- Department of Endodontics, School of Dentistry, Federal University of Goiás, Goiânia 74605-020, Brazil;
| |
Collapse
|
3
|
Pacheco A, Soós B, Lempel E, Simon I, Maróti P, Möhlhenrich SC, Szalma J. The effect of individual drilling sleeves on the precision of coronectomy tooth sections. An in vitro 3D-printed jaw model experiment. Clin Oral Investig 2023; 27:6769-6780. [PMID: 37783802 PMCID: PMC10630220 DOI: 10.1007/s00784-023-05289-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 09/27/2023] [Indexed: 10/04/2023]
Abstract
OBJECTIVES The aim of this in vitro study was to evaluate the effect of a 3D-printed drill sleeve (DS) on the precision and duration of coronectomy sections. MATERIALS AND METHODS Thirty-six trainees and oral surgeons performed 72 coronectomy cuts in a 3D-printed, entirely symmetric mandible model. Coronectomy was performed freehand (FH) on one side and with a DS on the other side. The occurrence of "too superficial" (≥ 4 mm unprepared lingual tooth tissue) and "too deep" (drilling ≥ 1 mm deeper as tooth contour) cuts and sectioning times were registered. RESULTS In 7 cases, the sections were "too deep" with FH, while none with DS (OR: 18.56; 95%CI: 1.02-338.5; p = 0.048). The deviation between virtually planned and real cut depths was significantly greater in the FH group (1.91 ± 1.62 mm) than in DS group (1.21 ± 0.72 mm) (p < 0.001). A total of 18 "too superficial" buccolingual sections occurred with FH, while 8 cases with DS (OR: 3.50; 95%CI: 1.26-9.72; p = 0.016). Suboptimal sections did not correlate with experience (p = 0.983; p = 0.697). Shortest, suboptimal drillings were most frequently seen distolingually (OR: 6.76; 95% CI: 1.57-29.07; p = 0.01). In the inexperienced group, sectioning time was significantly longer with FH (158.95 ± 125.61 s vs. 106.92 ± 100.79 s; p = 0.038). CONCLUSIONS The DS effectively reduced tooth sectioning times by less experienced colleagues. Independently from the level of experience, the use of DS obviated the need for any preparation outside the lingual tooth contour and significantly decreased the occurrence of "too superficial" cuts, leaving thinner unprepared residual tooth tissue lingually. CLINICAL RELEVANCE Coronectomy sections may result in lingual hard and soft tissue injury with the possibility of damaging the lingual nerve. The precision of the buccolingual depth-control can be improved, while surgical time can be reduced when applying a drilling sleeve.
Collapse
Affiliation(s)
- Ana Pacheco
- Department Oral and Maxillofacial Surgery, Medical School, University of Pécs, 1. Tüzér St, 7623, Pécs, Hungary
| | - Balázs Soós
- Department Oral and Maxillofacial Surgery, Medical School, University of Pécs, 1. Tüzér St, 7623, Pécs, Hungary
| | - Edina Lempel
- Department of Conservative Dentistry and Periodontology, Medical School, University of Pécs, 1. Tüzér St, 7623, Pécs, Hungary
| | - Imre Simon
- 3D Printing and Visualization Centre, University of Pécs, 2. Boszorkany St, 7624, Pécs, Hungary
| | - Péter Maróti
- 3D Printing and Visualization Centre, University of Pécs, 2. Boszorkany St, 7624, Pécs, Hungary
- Medical Skills Education and Innovation Centre, Medical School, University of Pecs, 12. Szigeti St, 7624, Pécs, Hungary
| | | | - József Szalma
- Department Oral and Maxillofacial Surgery, Medical School, University of Pécs, 1. Tüzér St, 7623, Pécs, Hungary.
| |
Collapse
|
4
|
Ye ZX, Qian WH, Wu YB, Yang C. Buccal rotation for wholly impacted maxillary third molar extraction. Head Face Med 2023; 19:2. [PMID: 36717934 PMCID: PMC9887850 DOI: 10.1186/s13005-023-00348-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Accepted: 01/25/2023] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Extracting wholly impacted maxillary 3rd molars faces difficulty due to the narrow surgical field, adjacent teeth resistances and risk of oroantral communication. This study is designed to introduce and evaluate the applicability of a novel method-buccal rotation to extract maxillary 3rd molars. MATERIALS AND METHODS In this cohort study, from October 1st 2020 to September 30th 2021, 72 wholly impacted maxillary 3rd molars were included. Based on the crowns with coronal 1/3, middle 1/3, apical 1/3 of the adjacent teeth roots, teeth were classified into position I, II, III. Based on the angles < 30°, ≥ 30°but < 60°, ≥ 60° to the adjacent teeth, teeth were classified into angulation A, B, C. Traditional method and novel method-buccal rotation were applied based on the surgical simulations. Surgical results were recorded. To analyze the data, Chi-square test was applied. RESULTS 82.00% of teeth in position I and 50.00% in position II were designed to use traditional method, 83.33% in position III were using the novel method (p < 0.05). 81.25% of teeth in angulation A and 52.63% in angulation B were designed to use traditional method, 80.00% in angulation C were using the novel method (p < 0.05). Four cases got temporary complications. CONCLUSION Buccal rotation was applicable to extract the deep impacted maxillary third molars with large angles towards the adjacent teeth.
Collapse
Affiliation(s)
- Zhou-Xi Ye
- Shanghai Xuhui District Dental Disease Prevention and Control Institute, No. 500, Fenlin Rd, Shanghai, People’s Republic of China
| | - Wen-Hao Qian
- Shanghai Xuhui District Dental Disease Prevention and Control Institute, No. 500, Fenlin Rd, Shanghai, People’s Republic of China
| | - Yu-Bo Wu
- Shanghai Xuhui District Dental Disease Prevention and Control Institute, No. 500, Fenlin Rd, Shanghai, People’s Republic of China
| | - Chi Yang
- grid.16821.3c0000 0004 0368 8293Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| |
Collapse
|
5
|
Gumber TK, Kandiara P, Bhullar RS, Dhawan A, Kapila S, Singh B. Assessment and Correlation of Variation in Lingual Cortical Plate Thickness with Different Angulations of Impacted Mandibular Third Molar Using Cone Beam Computed Tomography in North Indian Population. J Maxillofac Oral Surg 2022. [PMID: 37534344 PMCID: PMC10390454 DOI: 10.1007/s12663-022-01835-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Purpose The extraction of impacted mandibular third molar is associated with various types of intraoperative and postoperative complications, one of them is injury to lingual nerve. The present study aims to assess and correlate the variation in lingual cortical plate thickness with different angulations and determine the topographic relationship between the root apex of impacted mandibular third molar and lingual cortical plate using Cone Beam Computed Tomography (CBCT). Methods This prospective cohort study enrolled 140 patients with impacted mandibular third molars who underwent preoperative CBCT imaging. The CBCT images were used to evaluate the outcome variables such as lingual cortical plate thickness and topographical relationship between root apex of impacted mandibular third molar and lingual cortical plate. The predictor variables included age, gender, inclination of third molar, mesiodistal angle, buccolingual angle and lingual plate morphology. Results The temporary lingual nerve paresthesia was reported by 1 patient (0.71%) out of 140 patients. The lingual bone in distoangular and vertical impacted third molar was found to be 1.20 times thicker than mesioangular and horizontal teeth. Lingual bone thinning at mid-root level was observed in maximum number of cases with mesioangular teeth (68.5%), whereas horizontal impacted teeth showed lingual bone thinning (90.9%) at root apex level. The mean buccolingual angle of impacted mandibular third molar was found to be significantly associated with lingual bone perforation (p value = 0.0258). The morphology of lingual plate was observed as undercut type (37.14%) followed by slanted (36.43%), parallel (19.29%) and round type (7.14%). Conclusion Increase in buccolingual angle of impacted mandibular third molar decreases lingual bone thickness which is the natural barrier for protecting injury to lingual nerve. Also undercut and slanted lingual plate shapes were recognised as risk factors for contact/perforation between root apex and lingual plate. Therefore, proper screening and planning of high risk patients before third molar extraction is crucial.
Collapse
|
6
|
Wihokrut S, Vorakulpipat C, Manosuthi P, Waikakul A. Proximity of mandibular third molar root(s) to surrounding cortical bone: cone beam computed tomography (CBCT) and panoramic findings. Oral Maxillofac Surg 2022; 26:311-319. [PMID: 34374876 DOI: 10.1007/s10006-021-00979-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 06/03/2021] [Indexed: 06/13/2023]
Abstract
PURPOSE We evaluated the relationship between mandibular third molar roots (M3Ms) and surrounding cortical bone using cone beam computed tomography (CBCT) and panoramic findings. We studied (a) the location of mandibular third molar roots in relation with cortical bone in terms of contact, penetration, and perforation on CBCT; (b) the relationship between characteristics of a root in panoramic findings and the CBCT image (entire and segmentally); and (c) the relationship of the root plane in panoramic findings vs. CBCT. MATERIAL AND METHODS One hundred five teeth with 224 roots of mandibular third molar from 73 patients were evaluated by using cone beam computed tomography and panoramic image. RESULT The relationships were assessed using 105 images of impacted M3Ms: 104/105 (99%) showed cortical bone involvement (30.4% penetration and 68.6% perforation). The more apical the segment, the higher the proportion of perforation. Most (79.9%) of the M3M roots involved a lingual cortex with 46.9% penetration and 49.2% perforation. The panoramic signs of segmental root images-viz. clear and blurred-were not associated with cortical penetration or perforation. Panoramic signs of individual root images-in the same and different planes-could be used to predict root plane M3M roots. The same appearance in the panoramic image was significantly related to the same plane of the root in CBCT (p-value 0.048). CONCLUSION These findings could contribute to enhanced radiological assessment and surgical planning.
Collapse
Affiliation(s)
- Saowapap Wihokrut
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Mahidol University, No. 6 Yothi Road, Ratchathewi District, Bangkok, 10400, Thailand
| | - Chakorn Vorakulpipat
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Mahidol University, No. 6 Yothi Road, Ratchathewi District, Bangkok, 10400, Thailand
| | - Pattamawan Manosuthi
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Mahidol University, No. 6 Yothi Road, Ratchathewi District, Bangkok, 10400, Thailand
| | - Aurasa Waikakul
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Mahidol University, No. 6 Yothi Road, Ratchathewi District, Bangkok, 10400, Thailand.
| |
Collapse
|
7
|
Evaluation of artificial intelligence for detecting impacted third molars on cone-beam computed tomography scans. JOURNAL OF STOMATOLOGY, ORAL AND MAXILLOFACIAL SURGERY 2020; 122:333-337. [PMID: 33346145 DOI: 10.1016/j.jormas.2020.12.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 12/11/2020] [Accepted: 12/14/2020] [Indexed: 12/24/2022]
Abstract
PURPOSE The aim of this study was to evaluate the diagnostic performance of artificial intelligence (AI) application evaluating of the impacted third molar teeth in Cone-beam Computed Tomography (CBCT) images. MATERIAL AND METHODS In total, 130 third molar teeth (65 patients) were included in this retrospective study. Impaction detection, Impacted tooth numbers, root/canal numbers of teeth, relationship with adjacent anatomical structures (inferior alveolar canal and maxillary sinus) were compared between the human observer and AI application. Recorded parameters agreement between the human observer and AI application based on the deep-CNN system was evaluated using the Kappa analysis. RESULTS In total, 112 teeth (86.2%) were detected as impacted by AI. The number of roots was correctly determined in 99 teeth (78.6%) and the number of canals in 82 teeth (68.1%). There was a good agreement in the determination of the inferior alveolar canal in relation to the mandibular impacted third molars (kappa: 0.762) as well as the number of roots detection (kappa: 0.620). Similarly, there was an excellent agreement in relation to maxillary impacted third molar and the maxillary sinus (kappa: 0.860). For the maxillary molar canal number detection, a moderate agreement was found between the human observer and AI examinations (kappa: 0.424). CONCLUSIONS Artificial Intelligence (AI) application showed high accuracy values in the detection of impacted third molar teeth and their relationship to anatomical structures.
Collapse
|
8
|
Iwanaga J, Kunisada Y, Masui M, Obata K, Takeshita Y, Sato K, Kikuta S, Abe Y, Matsushita Y, Kusukawa J, Tubbs RS, Ibaragi S. Comprehensive review of lower third molar management: A guide for improved informed consent. Clin Anat 2020; 34:224-243. [DOI: 10.1002/ca.23693] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/30/2020] [Accepted: 10/08/2020] [Indexed: 12/16/2022]
Affiliation(s)
- Joe Iwanaga
- Department of Neurosurgery, Tulane Center for Clinical Neurosciences Tulane University School of Medicine New Orleans Louisiana USA
- Department of Neurology, Tulane Center for Clinical Neurosciences Tulane University School of Medicine New Orleans Louisiana USA
- Dental and Oral Medical Center, Kurume University School of Medicine Fukuoka Japan
- Division of Gross and Clinical Anatomy, Department of Anatomy Kurume University School of Medicine Fukuoka Japan
| | - Yuki Kunisada
- Department of Oral and Maxillofacial Surgery Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama Japan
| | - Masanori Masui
- Department of Oral and Maxillofacial Surgery Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama Japan
| | - Kyoichi Obata
- Department of Oral and Maxillofacial Surgery Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama Japan
| | - Yohei Takeshita
- Department of Oral and Maxillofacial Radiology Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama Japan
| | - Kotaro Sato
- Department of Oral and Maxillofacial Surgery Nagoya University Graduate School of Medicine Nagoya Japan
| | - Shogo Kikuta
- Dental and Oral Medical Center, Kurume University School of Medicine Fukuoka Japan
| | - Yushi Abe
- Dental and Oral Medical Center, Kurume University School of Medicine Fukuoka Japan
| | - Yuki Matsushita
- University of Michigan School of Dentistry Ann Arbor Michigan USA
- Department of Clinical Oral Oncology Nagasaki University Graduate School of Biomedical Sciences Nagasaki Japan
| | - Jingo Kusukawa
- Dental and Oral Medical Center, Kurume University School of Medicine Fukuoka Japan
| | - R. Shane Tubbs
- Department of Neurosurgery, Tulane Center for Clinical Neurosciences Tulane University School of Medicine New Orleans Louisiana USA
- Department of Neurology, Tulane Center for Clinical Neurosciences Tulane University School of Medicine New Orleans Louisiana USA
- Department of Structural & Cellular Biology Tulane University School of Medicine New Orleans Louisiana USA
- Department of Neurosurgery and Ochsner Neuroscience Institute Ochsner Health System New Orleans Louisiana USA
- Department of Anatomical Sciences St. George's University St. George's Grenada
| | - Soichiro Ibaragi
- Department of Oral and Maxillofacial Surgery Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama Japan
| |
Collapse
|
9
|
Amin SA, Elsheikh AK, Meyer RA, Bagheri SC. Incidence of Pre-Existing Lingual Cortex Perforation Before Removal of Mandibular Third Molars. J Oral Maxillofac Surg 2020; 78:2129-2137. [PMID: 32916133 DOI: 10.1016/j.joms.2020.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 08/11/2020] [Accepted: 08/12/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE The objective of this study was to determine the relationship between the mandibular third molar tooth (Md3) and the adjacent lingual cortical bone and determine the incidence of lingual cortex perforation by Md3s. PATIENTS AND METHODS This retrospective study was designed and implemented from 100 cone-beam computed tomographic scans (CBCTs) of patients with age ranging from 18 to 65 years old. The primary outcome was to assess the incidence of mandibular third molars (Md3s) with existing lingual cortex perforation by their roots. Perforation was assessed at the level of root apex and the most lingual portion on the apical half of the root. Other outcome variables included average thickness of covering lingual bone in the nonperforation group, lingual cortex morphology, impaction, and demographics. Descriptive statistics were computed. RESULTS More than half the radiographs showed lingual cortex perforation at the level of root apex and most lingual portion on the apical one half of the root (51.2% and 52.8%, respectively). The average thickness of the covering lingual bone was 1.25 mm around the root apex and 0.93 mm around the most lingual portion on the apical half of the root. The most common lingual cortex morphology was the undercut shape. There was statistically significant association between the presence of Md3 impaction and perforation at both root levels [(P value < .001, Effect size = 0.378) and (P value < .001, Effect size = 0.445)]. CONCLUSIONS Perforation of the lingual cortex by Md3s, whether erupted or impacted, was found in >50% of patients as determined by a preoperative CBCT scan. Therefore, the finding of lingual cortex perforation after removal of Md3s is likely to be evidence of a pre-existing condition rather than a result of surgery.
Collapse
Affiliation(s)
- Sara A Amin
- Oral & Maxillo-Facial Radiologist, Former Internal Resident, Department of Oral & Maxillo-Facial Radiology, Faculty of Dentistry, Cairo University, Cairo, Egypt.
| | - Ahmad K Elsheikh
- General Dentist, Private Practitioner, Chief Dental Officer, 360 Imaging, Atlanta, GA
| | - Roger A Meyer
- Private practice: Georgia Oral & Facial Reconstructive Surgery, Marietta, GA; Active Staff, Department of Surgery, Northside Hospital, Atlanta, GA; and Director, Maxillofacial Consultations, Ltd, Greensboro, GA
| | - Shahrokh C Bagheri
- Georgia Oral & Facial Reconstructive Surgery, Attending Oral and Maxillofacial Surgeon, Northside Hospital, Director of Fellowship Program in Facial Cosmetic and Reconstructive Surgery, Atlanta, GA
| |
Collapse
|
10
|
Syomkin VA, Kuzin AV, Ordzhonikidze MZ, Sogacheva VV, Remizov GV. [Root dislocation into the mouth floor as a complication of lower impacted third molar extraction]. STOMATOLOGII︠A︡ 2020; 99:71-75. [PMID: 32692524 DOI: 10.17116/stomat20209904171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Root dislocation into soft tissues during lower jaw third molar extraction belongs to clinically rare complications. The thickness of the cortical plate on the third molar lingual side does not exceed 1.5 mm. Working with an elevator, or headpiece, it is possible to push the roots into the adjacent soft tissue. It is not possible to remove displaced tooth fragment through the socket, it requires additional surgical access from the lingual side. The authors described three clinical cases of root dislocation during third molar removing. Successful surgical treatment was done.
Collapse
Affiliation(s)
- V A Syomkin
- Federal State Institution Central Research Institute of Dental and Maxillofacial Surgery of Ministry of Health of the Russian Federation, Moscow, Russia
| | - A V Kuzin
- Federal State Institution Central Research Institute of Dental and Maxillofacial Surgery of Ministry of Health of the Russian Federation, Moscow, Russia
| | - M Z Ordzhonikidze
- Federal State Institution Central Research Institute of Dental and Maxillofacial Surgery of Ministry of Health of the Russian Federation, Moscow, Russia
| | - V V Sogacheva
- Federal State Institution Central Research Institute of Dental and Maxillofacial Surgery of Ministry of Health of the Russian Federation, Moscow, Russia
| | - G V Remizov
- Khimki Central Clinical Hospital, Khimki, Russia
| |
Collapse
|
11
|
Huang C, Zhou C, Xu M, Zou D. Risk factors for lingual plate fracture during mandibular third molar extraction. Clin Oral Investig 2020; 24:4133-4142. [PMID: 32356209 DOI: 10.1007/s00784-020-03286-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 04/14/2020] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The aim of this study was to predict the risk of lingual plate fracture during mandibular third molar (M3) extraction. MATERIALS AND METHODS Cone beam computed tomography (CBCT) data from 264 mandibular M3s (erupted and impacted) from 264 patients (104 males and 160 females; age range, 17-75 years) were retrospectively analyzed. Lingual plate thicknesses at the levels of the mid-root and root apex of the M3s were measured and defined as "thicker" (bone thicker than 1 mm), "thinner" (bone thinner than 1 mm), or "perforated" (bone perforated by the M3 root). These measurements were correlated with potential risk factors for thinner and perforated lingual plates: tooth position of the mandibular M3, morphology of the lingual plate, and patient characteristics (age and sex). RESULTS The mean thickness of the lingual plate was 1.49 ± 1.38 mm at the mid-root of the M3s, and 2.35 ± 2.03 mm at the root apex. Multivariate regression analyses revealed that mesioangularly and horizontally impacted M3s were significantly associated with thinner and perforated lingual plates at the mid-root (P < 0.001), whereas the M3s in infra-occlusion positions (in infra-occlusion when compared with the adjacent second molar) had thinner lingual bone at the root apex (P = 0.022 and P = 0.027, depending on the level of impaction). Female patients were less likely to have lingual plate perforation (P = 0.036). CONCLUSIONS Mesioangulation, infra-occlusion, and male sex were risk factors for lingual plate fracture. CLINICAL RELEVANCE When the risk of lingual plate fracture is high, a sufficiently large flap, osteotomy, and tooth section by bur or piezosurgery are recommended to create a good operative field and avoid excessive pressure on the lingual plate.
Collapse
Affiliation(s)
- Cheng Huang
- Department of Stomatology, Shanghai Fourth People's Hospital, Tongji University School of Medicine, 1878, North Sichuan Road, Shanghai, 200081, China
| | - Chun Zhou
- Department of Stomatology, Shanghai Fourth People's Hospital, Tongji University School of Medicine, 1878, North Sichuan Road, Shanghai, 200081, China
| | - Minhua Xu
- Department of Stomatology, Shanghai Fourth People's Hospital, Tongji University School of Medicine, 1878, North Sichuan Road, Shanghai, 200081, China
| | - Derong Zou
- Department of Stomatology, Sixth People's Hospital, Shanghai Jiao Tong University, 600, Yishan Road, Shanghai, 200233, China.
| |
Collapse
|
12
|
Parhiz SA, Bakhtiary P, Mosavat F, Kharazifard MJ. Thickness of Buccal and Lingual Alveolar Bone Plates according to the Position of Impacted Mandibular Third Molars on Cone-Beam Computed Tomography Scans. Front Dent 2020; 16:279-289. [PMID: 32342057 PMCID: PMC7181348 DOI: 10.18502/fid.v16i4.2087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 05/29/2018] [Indexed: 11/24/2022] Open
Abstract
Objectives: This study sought to assess the thickness of buccal and lingual alveolar bone plates according to the position of impacted mandibular third molars on cone-beam computed tomography (CBCT) scans. Materials and Methods: Eighty-four CBCT scans of impacted mandibular third molars were evaluated in this retrospective study. All images had been obtained by ProMax 3D CBCT system with the exposure settings of 78 kVp, 12 mA, 16 s time, 0.2 mm voxel size and 10 × 9 cm field of view. The impaction angle of teeth and the thickness of buccal and lingual cortical plates were determined on images by drawing lines in the anterior, middle, posterior, superior, central and inferior regions. Thickness of bone plates was analyzed according to the position of impacted molars relative to the buccal and lingual plates using the Student t-test and relative to the second molars using one-way ANOVA and Tukey’s test. Results: In the buccolingual direction, the buccal plate thickness was maximum in lingual position followed by central position, and minimum in buccal position of the teeth. The lingual plate thickness was minimum in horizontal and distoangular positions and maximum in the mesioangular position of impacted teeth. Conclusion: Risk of lingual plate preformation is higher in surgical removal of impacted third molars with distoangular and horizontal positions. Thus, further attention must be paid by the surgeons to such cases.
Collapse
Affiliation(s)
- Seyed Alireza Parhiz
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Pegah Bakhtiary
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Farzaneh Mosavat
- Department of Oral and Maxillofacial Radiology, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Javad Kharazifard
- Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| |
Collapse
|
13
|
Khojastepour L, Khaghaninejad MS, Hasanshahi R, Forghani M, Ahrari F. Does the Winter or Pell and Gregory Classification System Indicate the Apical Position of Impacted Mandibular Third Molars? J Oral Maxillofac Surg 2019; 77:2222.e1-2222.e9. [PMID: 31306615 DOI: 10.1016/j.joms.2019.06.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 06/09/2019] [Accepted: 06/10/2019] [Indexed: 01/24/2023]
Abstract
PURPOSE The present study investigated the relationship of impacted mandibular third molars to the cortical plates and inferior alveolar canal (IAC) using cone-beam computed tomography (CBCT). MATERIALS AND METHODS The present study included CBCT images of 386 lower third molars in 226 patients, for whom the initial panoramic radiographs had revealed a close relationship between the third molars and IAC. The coronal images were prepared to determine the position of apex about the buccal and lingual cortexes and IAC. The impacted third molars were categorized using the Winter and the Pell and Gregory classifications. The relationship between the third molars and buccal/lingual cortexes and IAC was determined in the different classes of the Winter and the Pell and Gregory systems. RESULTS The mesioangular position was more prevalent in the present sample. Most teeth were Class I concerning the ascending ramus and level C in depth. Generally, the impacted mandibular third molars showed a lingual position and were in contact or intersecting into the IAC. A significant association was found between the type of tooth impaction using the Winter and the Pell and Gregory classifications and the position of the third molar teeth concerning the cortical plates and IAC. CONCLUSIONS The possibility of the buccal position of the tooth and the chance of an intersection of the apex into the IAC was greater in teeth that were mesioangular and were Class III concerning the ascending ramus and level C in depth. These data should be considered during the preoperative assessment of third molars to reduce postoperative complications.
Collapse
Affiliation(s)
- Leila Khojastepour
- Professor, Department of Oral and Maxillofacial Radiology, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Saleh Khaghaninejad
- Assistant Professor, Department of Oral and Maxillofacial Surgery, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Razieh Hasanshahi
- Undergraduate Student, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Maryam Forghani
- Associate Professor, Dental Materials Research Center, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Farzaneh Ahrari
- Associate Professor, Dental Research Center, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran.
| |
Collapse
|
14
|
Tudtiam T, Leelarungsun R, Khoo LK, Chaiyasamut T, Arayasantiparb R, Wongsirichat N. The Study of Inferior Alveolar Canal at the Lower Third Molar Apical Region With Cone Beam Computed Tomography. J Clin Med Res 2019; 11:353-359. [PMID: 31019630 PMCID: PMC6469889 DOI: 10.14740/jocmr3794] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 03/18/2019] [Indexed: 11/13/2022] Open
Abstract
Background The aim of this study was to determine the distance between the impacted mandibular third molar (IMTM) and the inferior alveolar canal (IAC) at different reference points through panoramic radiographs and cone beam computed tomography (CBCT). Methods A total of 45 male and 45 female patients with bilateral IMTM at a mean age of 27 years were recruited for this study. With the aid of panaromic radiographs and CBCT, the mandible width, the buccal bone width, IAC width, the lingual bone width, IAC height, the alveolar bone height, and the distance from the lowest part of the IMTM to the superior border of the canal were measured. Statistical analysis was done with independent samples t-test and Mann-Whitney U test for finding the difference between genders. Paired t-test and Wilcoxon signed-rank test were used for comparing both sides at P value = 0.05. Results The mandible width, IAC width, and IAC height were different between male and female patients. The IMTM roots displayed intimate contact with the IAC in 96.67% of the cases. The location of the IAC was mostly lingual in both genders. The diameter of the IAC was significant larger in men compared to in the women in terms of width and height. Conclusions This study is useful for the dental surgeon to avoid or prevent postoperative numbness or pain, because the awareness of the common location of the IAC and its approximation with the IMTM roots could allow a more cautious and precise approach during IMTM intervention.
Collapse
Affiliation(s)
- Trustiya Tudtiam
- Department of Advanced General Dentistry, Faculty of Dentistry, Mahidol University, Bangkok 10400, Thailand
| | - Rachatawan Leelarungsun
- Department of Advanced General Dentistry, Faculty of Dentistry, Mahidol University, Bangkok 10400, Thailand
| | - Lee Kian Khoo
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Mahidol University, Bangkok 10400, Thailand
| | - Teeranut Chaiyasamut
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Mahidol University, Bangkok 10400, Thailand
| | - Raweewan Arayasantiparb
- Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Mahidol University, Bangkok 10400, Thailand
| | - Natthamet Wongsirichat
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Mahidol University, Bangkok 10400, Thailand.,Walailak University International College of Dentistry 19 floor SM Tower, 979/42-46 Phahonyothin Road, Phaya Thai District, Bangkok 10400, Thailand
| |
Collapse
|
15
|
Elkhateeb SM, Awad SS. Accuracy of panoramic radiographic predictor signs in the assessment of proximity of impacted third molars with the mandibular canal. J Taibah Univ Med Sci 2018; 13:254-261. [PMID: 31435332 PMCID: PMC6694906 DOI: 10.1016/j.jtumed.2018.02.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 02/20/2018] [Accepted: 02/25/2018] [Indexed: 01/18/2023] Open
Abstract
OBJECTIVES This study aimed to validate the accuracy of panoramic radiographic risk signs through detection of presence or absence of corticalization between an impacted mandibular third molar and the inferior alveolar canal on cone beam computed tomography (CBCT). METHODS This retrospective study analyzed 210 impacted mandibular third molars from 135 patients (aged 17-51 years) who showed one or more of the seven previously established panoramic radiographic risk signs of inferior alveolar nerve exposure. These patients were referred for CBCT examination. Three-dimensional images were used to assess the canal position relative to the third molar, the proximity between the canal and third molar, and third molar angulation. The correlation of panoramic findings and CBCT was evaluated using a Chi-square test. RESULTS Panoramic findings of interruption of inferior alveolar canal wall, isolated or combined with one of these signs (darkening of third molar roots, narrowing of canal, and diversion of canal); darkening of the roots; and narrowing of canal were significantly correlated with direct contact between the inferior alveolar canal and impacted third molars on CBCT (P < 0.001). CONCLUSION Preoperative CBCT is recommended for cases showing interruption of canal wall; darkening of the roots or narrowing of the canal; or association between interruption and narrowing, diversion, or darkening of roots in a panoramic view. This study evaluated the risk relationship between the inferior alveolar nerve and impacted mandibular third molars, with the aim of reducing the occurrence of postoperative injury to the inferior alveolar nerve.
Collapse
Affiliation(s)
- Sara M. Elkhateeb
- Department of Oral Medicine, Periodontology, Diagnosis and Oral Radiology, Faculty of Dentistry, Ain Shams University, Cairo, Egypt
| | - Sally S. Awad
- Oral & Maxillofacial Surgery Department, Taibah University, Almadinah Almunawwarah, KSA
| |
Collapse
|
16
|
Mesiolingual root rotation for horizontal mandibular third molar extraction: position classification and surgical simulation. Sci Rep 2017; 7:14405. [PMID: 29089549 PMCID: PMC5663974 DOI: 10.1038/s41598-017-14914-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 10/19/2017] [Indexed: 11/16/2022] Open
Abstract
Extracting horizontal mandibular 3rd molars face considerable difficulty due to the large bone and adjacent tooth resistances. This study aims at evaluating the effectiveness of a novel method-mesiolingual root rotation to extract wisdom teeth of this type. In this study, 73 horizontal teeth extracted using piezosurgery were reviewed and classified based on impaction depth: position I, II, III refers to the highest portion of the crown on a level with upper 1/3, middle 1/3, lower 1/3 of the 2rd molar’s root. Based on the surgical simulations on their 3D CBCT reconstructions, traditional method(crown distal rotation) and novel method(root mesiolingual rotation) are applied. 79.17% of teeth in position I and 57.89% of teeth in position II were designed using traditional method, 83.33% teeth in position III were designed using the novel method(p < 0.05). The surgeries were performed according to the designs. Two cases in position II using traditional method were found temporary inferior alveolar nerve(IAN) injury; while only one case in position III using novel method got temporary IAN and lingual nerve injury. Our study suggested that root mesiolingual rotation is an effective method to extract the horizontal mandibular 3rd molars, especially the deep impacted ones.
Collapse
|
17
|
Uchida Y, Motoyoshi M, Namura Y, Shimizu N. Three-dimensional evaluation of the location of the mandibular canal using cone-beam computed tomography for orthodontic anchorage devices. J Oral Sci 2017. [PMID: 28637985 DOI: 10.2334/josnusd.16-0513] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
This study investigated guidelines for placement of monocortical screws in the mandible, particularly the mandibular canal. In this study of 35 patients, we used cone-beam computed tomography to determine the distance from the alveolar crest to the superior border of the mandibular canal (DMC) and the shortest distance from the buccal and lingual cortex to the mandibular canal (attaining distance) in the areas between premolars (premolar area), between the second premolar and first molar (middle area), and between the first and second molars (molar area). The DMC values for these areas were 16.55, 18.94, and 16.58 mm, respectively, and were similar in adults and adolescents. When the attaining distance was 8 mm, the heights on the buccal and lingual sides of the areas were 9 and 16.6 mm, 13.7 and 14.7 mm, and 15.3 and 12 mm, respectively. Risk of proximity to the mandibular canal should be considered at above heights or greater when an orthodontic anchorage device (OAD) 8 mm in length is placed. Careful attention is needed for placements on lingual side in adolescents. By reducing the OAD length to 6 mm, placement safety increases in all areas except the premolar area, especially on the buccal side.
Collapse
Affiliation(s)
- Yasuki Uchida
- Department of Orthodontics, Nihon University School of Dentistry.,Division of Clinical Research, Dental Research Center, Nihon University School of Dentistry
| | - Mitsuru Motoyoshi
- Department of Orthodontics, Nihon University School of Dentistry.,Division of Clinical Research, Dental Research Center, Nihon University School of Dentistry
| | - Yasuhiro Namura
- Department of Orthodontics, Nihon University School of Dentistry.,Division of Clinical Research, Dental Research Center, Nihon University School of Dentistry
| | - Noriyoshi Shimizu
- Department of Orthodontics, Nihon University School of Dentistry.,Division of Clinical Research, Dental Research Center, Nihon University School of Dentistry
| |
Collapse
|
18
|
Analyses of anatomical relationship between mandibular third molar roots and variations in lingual undercut of mandible using cone-beam computed tomography. J Dent Sci 2017; 12:261-267. [PMID: 30895060 PMCID: PMC6399996 DOI: 10.1016/j.jds.2016.12.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 12/02/2016] [Indexed: 11/25/2022] Open
Abstract
Background/purpose Anatomical features of the lingual undercut region is a potential factor that might increase the risk of displacement of a tooth or fragment. The aim of this study was to report the normal anatomical relationship of impacted lower third molar roots to the lingual cortex and soft tissues of mandible and anatomical variations of lingual balcony in the impacted third molar region. Materials and methods One hundred impacted third molars (54 males, 46 females) from 65 (31 men, 34 women) patients were evaluated for this study using cone-beam computed tomography. Three measurements [bone thickness, angle (Ang) 1 and Ang 2] were recorded on the coronal section slices of cone-beam computed tomography images; in these images, the impacted third molar root was closest to the lingual soft tissues. Results The average distance between the tooth root and the lingual outer cortical bone layer (bone thickness) was 1.03 mm. The averages of Ang 1 and Ang 2 were 140.61° and 153.44°. Ang 1 and Ang 2 of female patients were larger than those of male patients. Conclusion The narrow angulation of the lingual balcony region and the relationship between roots and lingual soft tissues should be noted to avoid undesirable complication of displacement of a tooth or fragment into sublingual, submandibular, and pterygomandibular spaces. There was no relation in the floor of the mouth between the position of the impacted third molar roots and different lingual undercut angulation variations.
Collapse
|
19
|
Wang D, He X, Wang Y, Zhou G, Sun C, Yang L, Bai J, Gao J, Wu Y, Cheng J. Topographic relationship between root apex of mesially and horizontally impacted mandibular third molar and lingual plate: cross-sectional analysis using CBCT. Sci Rep 2016; 6:39268. [PMID: 27991572 PMCID: PMC5171861 DOI: 10.1038/srep39268] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 11/21/2016] [Indexed: 11/08/2022] Open
Abstract
The present study was aimed to determine the topographic relationship between root apex of the mesially and horizontally impacted mandibular third molar and lingual plate of mandible. The original cone beam computed tomography (CBCT) data of 364 teeth from 223 patients were retrospectively collected and analyzed. The topographic relationship between root apex and lingual plate on cross-sectional CBCT images was classified as non-contact (99), contact (145) and perforation (120). The cross-sectional morphology of lingual plate at the level of root apex was defined as parallel (28), undercut (38), slanted (29) and round (4). The distribution of topographic relationship between root apex and lingual plate significantly associated with gender, impaction depth, root number and lingual plate morphology. Moreover, the average bone thickness of lingual cortex and distance between root apex and the outer surface of lingual plate were 1.02 and 1.39 mm, respectively. Furthermore, multivariate regression analyses identified impaction depth and lingual plate morphology as the risk factors for the contact and perforation subtypes between root apex and lingual plate. Collectively, our findings reveal the topographic proximity of root apex of impacted mandibular third molar to the lingual plate, which might be associated with intraoperative and postoperative complications during tooth extraction.
Collapse
Affiliation(s)
- Dongmiao Wang
- Department of Oral and Maxillofacial Surgery, College of Stomatology, Nanjing Medical University, Nanjing 210029, China
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Nanjing 210029, China
| | - Xiaotong He
- Department of Oral and Maxillofacial Surgery, College of Stomatology, Nanjing Medical University, Nanjing 210029, China
| | - Yanling Wang
- Department of oral prosthodontics, College of Stomatology, Nanjing Medical University, Nanjing 210029, China
| | - Guangchao Zhou
- Department of Oral and Maxillofacial Radiology, College of Stomatology, Nanjing Medical University, Nanjing 210029, China
| | - Chao Sun
- Department of Oral and Maxillofacial Radiology, College of Stomatology, Nanjing Medical University, Nanjing 210029, China
| | - Lianfeng Yang
- Department of Oral and Maxillofacial Radiology, College of Stomatology, Nanjing Medical University, Nanjing 210029, China
| | - Jianling Bai
- Department of Biomedical Statistics, College of Public Health, Nanjing Medical University, Nanjing 210029, China
| | - Jun Gao
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Nanjing 210029, China
| | - Yunong Wu
- Department of Oral and Maxillofacial Surgery, College of Stomatology, Nanjing Medical University, Nanjing 210029, China
| | - Jie Cheng
- Department of Oral and Maxillofacial Surgery, College of Stomatology, Nanjing Medical University, Nanjing 210029, China
| |
Collapse
|
20
|
Variations in the buccal-lingual alveolar bone thickness of impacted mandibular third molar: our classification and treatment perspectives. Sci Rep 2016; 6:16375. [PMID: 26759181 PMCID: PMC4725356 DOI: 10.1038/srep16375] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 10/13/2015] [Indexed: 11/11/2022] Open
Abstract
Selecting either buccal or lingual approach for the mandibular third molar surgical extraction has been an intense debate for years. The aim of this observational retrospective study was to classify the molar based on the proximity to the external cortical bone, and analyze the position of inferior alveolar canal (IAC) of each type. Cone-beam CT (CBCT) data of 110 deeply impacted mandibular third molars from 91 consecutive patients were analyzed. A new classification based on the mean deduction value (MD) of buccal-lingual alveolar bone thickness was proposed: MD≥1 mm was classified as buccal position, 1 mm>MD>−1 mm was classified as central position, MD≤−1 mm was classified as lingual position. The study samples were distributed as: buccal position (1.8%) in 2 subjects, central position (10.9%) in 12 and lingual position (87.3%) in 96. Ninety-six molars (87.3%) contacted the IAC. The buccal and inferior IAC course were the most common types in impacted third molar, especially in lingually positioned ones. Our study suggested that amongst deeply impacted mandibular third molars, lingual position occupies the largest proportion, followed by the central, and then the buccal type.
Collapse
|
21
|
Yildiz S, Bayar GR, Guvenc I, Kocabiyik N, Cömert A, Yazar F. Tomographic evaluation on bone morphology in posterior mandibular region for safe placement of dental implant. Surg Radiol Anat 2014; 37:167-73. [PMID: 25078676 DOI: 10.1007/s00276-014-1351-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 07/19/2014] [Indexed: 11/25/2022]
Abstract
The aim of this study was to examine the morphology of submandibular fossae at edentulous posterior regions of dried mandibles and to determine a safe range for proper lingual angulation during the placement of a dental implant in the posterior mandibular region, with a computerized tomographic scan study. Spiral computed tomographic images of 77 dry adult human mandibles were evaluated to determine the deepest area in the submandibular fossa. Then, the proper lingual angulations for the placement of a dental implant at these regions were measured. Pearson's correlation coefficient was calculated to show the relation between the depths of submandibular fossa and lingual implant angulations. "Paired t test" was used for differences between the lingual implant angulations and the depths of submandibular fossa on each side of the mandibles. Depths of the submandibular fossa and lingual implant angulations were varied between 1.1 and 4.6 mm: 62°-84° on right side of the mandibles, and 1.1-4.5 mm, 65°-83° on left side of the mandibles. There were statistically medium negative correlations between the degree of lingual implant angulations and the depth of submandibular fossa on each side of the mandible (r = -0.44, p < 0.001, and r = -0.38, p = 0.001). There was a statistically significant difference between the right and left sides of the mandibles in terms of the depth of submandibular fossa (p = 0.01). Within the limits of this study, the depth of submandibular fossa was measured as ≥ 2 mm in around 71.5 % of examined regions, and lingual implant angulations were between 62° and 84°. These results may be considered by clinicians who are planning the dental implant placement in posterior mandible to avoid potential risk of lingual cortical plate perforation.
Collapse
Affiliation(s)
- Selda Yildiz
- Department of Anatomy, Faculty of Medicine, Gulhane Military Medical Academy, 06018, Etlik, Ankara, Turkey,
| | | | | | | | | | | |
Collapse
|
22
|
Peker I, Sarikir C, Alkurt MT, Zor ZF. Panoramic radiography and cone-beam computed tomography findings in preoperative examination of impacted mandibular third molars. BMC Oral Health 2014; 14:71. [PMID: 24928108 PMCID: PMC4060878 DOI: 10.1186/1472-6831-14-71] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 06/09/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Preoperative radiographic examination of impacted mandibular third molars (IMTM) is essential to prevent inferior alveolar nerve injury during extraction. The purpose of this study was to evaluate the correlation between cone-beam computed tomography (CBCT) and digital panoramic radiography (DPR) findings in preoperative examination of IMTM. METHODS This retrospective study included 298 teeth in 191 individuals. The relationship between the inferior alveolar canal (IAC) and the IMTM (buccal, lingual, interradicular or inferior), the position of the IMTM with respect to the IAC (contact, no contact), the morphologic shape of the mandible in the IMTM region (round, lingual extended, lingual concave), the type of IMTM (vertical, horizontal or angular) and the number of roots of the IMTM were evaluated on CBCT images. DPR images were evaluated for the number of roots of the IMTM and for the most common radiographic findings indicating a relationship between the IAC and the IMTM (darkening of the roots, diversion of the IAC, narrowing of the IAC and interruption of the white line). Data were statistically analyzed with Cramer V coefficient, Kappa statistic, chi-square and Fisher's exact test. RESULTS There was a significant difference in number of roots detected on DPR versus CBCT images. There was a significant association between the type of IMTM and the morphologic shape of the mandible on CBCT images. Darkening of the roots and interruption of the white line on DPR images were significantly associated with the presence of contact between the IMTM and the IAC on CBCT images. CONCLUSIONS Panoramic radiography is inadequate, whereas CBCT is useful to detect multiple roots of IMTM. When darkening of the roots and interruption of the white line are observed on panoramic images, there is increased likelihood of contact between the IMTM and the IAC. CBCT is required in these cases.
Collapse
Affiliation(s)
- Ilkay Peker
- Department of Dentomaxillofacial Radiology, Gazi University Faculty of Dentistry, 82, Sok No: 4 06510, Emek-Ankara, Turkey.
| | | | | | | |
Collapse
|
23
|
Kim DS, Rashsuren O, Kim EK. Conversion coefficients for the estimation of effective dose in cone-beam CT. Imaging Sci Dent 2014; 44:21-9. [PMID: 24701455 PMCID: PMC3972402 DOI: 10.5624/isd.2014.44.1.21] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Revised: 08/17/2013] [Accepted: 09/04/2013] [Indexed: 11/21/2022] Open
Abstract
Purpose To determine the conversion coefficients (CCs) from the dose-area product (DAP) value to effective dose in cone-beam CT. Materials and Methods A CBCT scanner with four fields of view (FOV) was used. Using two exposure settings of the adult standard and low dose exposure, DAP values were measured with a DAP meter in C mode (200mm×179 mm), P mode (154 mm×154 mm), I mode (102 mm×102 mm), and D mode (51 mm×51 mm). The effective doses were also investigated at each mode using an adult male head and neck phantom and thermoluminescent chips. Linear regressive analysis of the DAP and effective dose values was used to calculate the CCs for each CBCT examination. Results For the C mode, the P mode at the maxilla, and the P mode at the mandible, the CCs were 0.049 µSv/mGycm2, 0.067 µSv/mGycm2, and 0.064 µSv/mGycm2, respectively. For the I mode, the CCs at the maxilla and mandible were 0.076 µSv/mGycm2 and 0.095 µSv/mGycm2, respectively. For the D mode at the maxillary incisors, molars, and mandibular molars, the CCs were 0.038 µSv/mGycm2, 0.041 µSv/mGycm2, and 0.146 µSv/mGycm2, respectively. Conclusion The CCs in one CBCT device with fixed 80 kV ranged from 0.038 µSv/mGycm2 to 0.146 µSv/mGycm2 according to the imaging modes and irradiated region and were highest for the D mode at the mandibular molar.
Collapse
Affiliation(s)
- Dong-Soo Kim
- Department of Oral and Maxillofacial Radiology, Dankook University College of Dentistry, Cheonan, Korea
| | - Oyuntugs Rashsuren
- Department of Oral and Maxillofacial Radiology, Dankook University College of Dentistry, Cheonan, Korea
| | - Eun-Kyung Kim
- Department of Oral and Maxillofacial Radiology, Dankook University College of Dentistry, Cheonan, Korea
| |
Collapse
|
24
|
Szalma J, Bata Z, Lempel E, Jeges S, Olasz L. Quantitative pixel grey measurement of the "high-risk" sign, darkening of third molar roots: a pilot study. Dentomaxillofac Radiol 2013; 42:20130160. [PMID: 23775927 DOI: 10.1259/dmfr.20130160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES Our aim was to examine the panoramic darkening of the root, which is a "high-risk" sign, using quantitative measurements of pixel grey values to determine different aetiological backgrounds, namely inferior alveolar nerve (IAN) exposure with or without groove formation of the third molar roots or thinning/fenestration of the lingual cortex (LCTF). METHODS 38 impacted third molars that had been surgically removed and had darkened roots on panoramic radiographs were included in this retrospective case-control study. 15 IAN exposure cases were selected for the case group, and 23 cases with proven lingual cortical thinning or fenestration were chosen for the control group. The mean pixel grey values of selected areas in the dark band (D) and control areas within the same roots (R) were determined with the ImageTool (University of Texas Health Science Center, San Antonio, TX) software. The differences in pixel values (R-D) of the IAN and LCTF groups were analysed using the Mann-Whitney U-test and Pearson's χ(2) test. RESULTS The medians of the R-D pixel values were 45.7 in the IAN group and 34.3 in the LCTF group, whereas the interquartile ranges were 12.0 (IAN) and 18.3 (LCTF) (p < 0.001). The R-D critical value at which the outcomes differed significantly was 38. If the differences in pixel grey values (R-D) were higher than 38, the chance of IAN exposure was approximately 32 times higher than the chance of LCTF (χ(2) test, p < 0.001; odds ratio, 32.0; 95% confidence interval, 3.5-293.1). CONCLUSIONS The pre-operative prediction of IAN exposure or lingual cortical thinning in cases with "darkening" is possible based on pixel grey measurements of digital panoramic radiographs.
Collapse
Affiliation(s)
- J Szalma
- Department of Oral and Maxillofacial Surgery, University of Pécs, Pécs, Hungary.
| | | | | | | | | |
Collapse
|