scholarly journals Cone beam CT imaging of the mandibular third molar: a position paper prepared by the European Academy of DentoMaxilloFacial Radiology (EADMFR)

2019 ◽  
Vol 48 (5) ◽  
pp. 20190039 ◽  
Author(s):  
Louise Hauge Matzen ◽  
Erwin Berkhout
Keyword(s):  
European Commission ◽  
Meta Analysis ◽  
Cone Beam Ct ◽  
Inferior Alveolar Nerve ◽  
Third Molar ◽  
Third Molars ◽  
Level Of Evidence ◽  
European Academy ◽  
Mandibular Third Molar ◽  
Mandibular Third Molars

Objectives: Lack of evidence on the use of CBCT for management of mandibular third molars in Radiation Protection guideline no. 172 of the European Commission made the European Academy of DentoMaxilloFacial Radiology (EADMFR) decide to update the recommendations of the guideline. Methods and materials: A literature search was performed addressing the following questions: (1) does CBCT change the treatment of the patient?; (2) does CBCT reduce the number of post-operative sensory disturbances of the inferior alveolar nerve?; and (3) can CBCT predict the risk for a post-operative sensory disturbance of the inferior alveolar nerve? Results:  Since the European Commission published the guideline in 2012 several high-evidence studies on the use of CBCT before removal of mandibular third molars have been conducted including five randomized controlled clinical trials and one meta-analysis. Present literature allows to propose recommendations with highest level of evidence. Conclusion: New and up-to-date evidence-based recommendations advocate that CBCT imaging of the mandibular third molar should not be applied as a routine method before removal of mandibular third molars and therefore, CBCT imaging should only be applied when the surgeon has a very specific clinical question in an individual patient case that cannot be answered by conventional (panoramic and/or intraoral) imaging.

scholarly journals Automated Prediction of Extraction Difficulty and Inferior Alveolar Nerve Injury for Mandibular Third Molar Using a Deep Neural Network

2022 ◽  
Vol 12 (1) ◽  
pp. 475
Author(s):  
Junseok Lee ◽  
Jumi Park ◽  
Seong Yong Moon ◽  
Kyoobin Lee
Keyword(s):  
Maxillofacial Surgery ◽  
Inferior Alveolar Nerve ◽  
Third Molar ◽  
Oral And Maxillofacial Surgery ◽  
Third Molars ◽  
Radiographic Image ◽  
Common Procedure ◽  
Radiographic Images ◽  
Mandibular Third Molar ◽  
Mandibular Third Molars

Extraction of mandibular third molars is a common procedure in oral and maxillofacial surgery. There are studies that simultaneously predict the extraction difficulty of mandibular third molar and the complications that may occur. Thus, we propose a method of automatically detecting mandibular third molars in the panoramic radiographic images and predicting the extraction difficulty and likelihood of inferior alveolar nerve (IAN) injury. Our dataset consists of 4903 panoramic radiographic images acquired from various dental hospitals. Seven dentists annotated detection and classification labels. The detection model determines the mandibular third molar in the panoramic radiographic image. The region of interest (ROI) includes the detected mandibular third molar, adjacent teeth, and IAN, which is cropped in the panoramic radiographic image. The classification models use ROI as input to predict the extraction difficulty and likelihood of IAN injury. The achieved detection performance was 99.0% mAP over the intersection of union (IOU) 0.5. In addition, we achieved an 83.5% accuracy for the prediction of extraction difficulty and an 81.1% accuracy for the prediction of the likelihood of IAN injury. We demonstrated that a deep learning method can support the diagnosis for extracting the mandibular third molar.

scholarly journals Inferior alveolar nerve injury assessment after surgical removal of mandibular third molar.

2020 ◽  
Vol 27 (03) ◽  
pp. 530-534
Author(s):  
Abdul Wahid Bhangwar ◽  
Muhammad Irfan Khan ◽  
Hira Fatima ◽  
Salman Shams
Keyword(s):  
Nerve Injury ◽  
Local Anesthesia ◽  
Maxillofacial Surgery ◽  
Inferior Alveolar Nerve ◽  
Third Molar ◽  
Surgical Removal ◽  
Third Molars ◽  
Mandibular Third Molar ◽  
Mandibular Third Molars ◽  
Inferior Alveolar Nerve Injury

To assess the nerve injury (inferior alveolar nerve) after surgical removal of mandibular third molars under local anesthesia. Study Design: Observational study. Setting: Oral & Maxillofacial Surgery Department LUMHS Jamshoro/Hyderabad. Period: From 11th November 2015 to 10th May 2016. Material & Methods: This study consisted of one hundred patients. Inclusion criteria’s were patients with impacted mandibular third molar, patient’s age from 18 to 45years and irrespective of gender. Exclusion criteria were patients younger than 18yrs of age of above 45 years, patients having neurological disorders, medically compromised patients, patients receiving radiotherapy or chemotherapy, patients with known allergy to local anesthesia, patients having pathology due to mandibular third molars, patients radiographicaly root is very near to inferior dental canal. Results: Out of 100 patients incorporated in this research 66 were male (66%) and 34 female (34%). The mean age was 29+3.20 years. Common indication of extraction were recurrent pericoronitis  52(52%) cases followed by deep caries/ pulpitis in 28(28%)  cases, orthodontic reason in 11(11%) cases and caries to adjacent tooth in 9(9%) cases. Third molar impaction according to winter’s classification were Mesioangular in 54(54%) cases followed by Horizontal in 26(26%) cases and Vertical in 11(11%). Radiographic showed Narrowing of root in 21% cases and narrowing of inferior dental (ID) canal 20% cases, followed by diversion of ID canal in 16 % cases, deflection of root 14 % cases and darkening of root in 11% cases. After surgical removal of mandibular third molar, the inferior alveolar nerve injury was observed in 6(6%) cases. Conclusion: We conclude that inferior alveolar nerve paresthesia occurs in 6% after surgical removal of mandibular third molars.

scholarly journals Comparison of Digital OPG and CBCT in Assessment of Risk Factors Associated with Inferior Nerve Injury during Mandibular Third Molar Surgery

Diagnostics ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2282
Author(s):  
Rakhi Issrani ◽  
Namdeo Prabhu ◽  
Mohammed Sghaireen ◽  
Hasna Rasheed Alshubrmi ◽  
Amal Mohamed Alanazi ◽  
...  
Keyword(s):  
Inferior Alveolar Nerve ◽  
Third Molar ◽  
Mandibular Canal ◽  
Third Molars ◽  
Factors Associated ◽  
Impacted Third Molar ◽  
Mandibular Third Molar ◽  
Mandibular Molar ◽  
Impacted Mandibular Third Molars ◽  
Mandibular Third Molars

Background: Pre-operative radiographic assessment of the anatomical relationship between the roots of the mandibular third molar and the inferior alveolar nerve (IAN) is a must to minimize the risk of IAN injury during surgery. Objectives: To compare the radiographic signs of digital orthopantomogram (OPG) and cone-beam computed tomography (CBCT). An additional objective was to assess the cortex status between the mandibular canal and third molar on CBCT images in relation to the demographic characteristics, region (right or left side), and angulation of mandibular molar. Methodology: In this retrospective study, a total of 350 impacted mandibular third molars with a close relationship between the inferior alveolar canal (IAC) and impacted mandibular third molars on digital OPG were further referred for CBCT imaging for assessment of the position of the mandibular canal. The study was conducted between August 2018 and February 2020. Digital OPGs were evaluated for radiographic signs like interruption of the mandibular canal wall, darkening of the roots, diversion of the mandibular canal, and narrowing of the mandibular canal. The age and sex of patients, site of impacted third molar, Winter’s classification of mandibular third molar, position of IAC relative to impacted molar, and the radiographic markers of OPG were assessed for cortical integrity using CBCT. Chi square testing was applied to study the values of difference and binomial logistic regression was done to assess the factors associated with cortication. Statistical significance was set at p ≤ 0.05. Results: Among 350 patients, 207 (59.1%) were male and 143 (40.9%) were female with a mean age of 36.8 years. The most common OPG sign was interruption of white line, seen in 179 (51.1%) cases. In total, 246 cases (70.3%) showed an absence of canal cortication between the mandibular canal and the impacted third molar on CBCT images. Cortication was observed in all cases with a combination of panoramic signs which was statistically significant (p = 0.047). Cortication was observed in 85 (50.6%) cases where IAC was positioned on the buccal side, 11 (16.9%) in cases of inferiorly positioned IAC, and just 8 (7.6%) for cases of lingually positioned IAC which was statistically significant (p = 0.003). Statistically insignificant (p > 0.05) results were noted for cortex status in CBCT images with regards to the age, sex, site, and angulation of impacted third molars. Conclusion: CBCT imaging is highly recommended for those cases where diversion of the mandibular canal is observed on OPG and when the roots are present between canals.

scholarly journals Mesial Migration Effect on Root Morphology of Mandibular Third Molars

2007 ◽  
Vol 77 (1) ◽  
pp. 73-76 ◽  
Author(s):  
A. Altuğ Bıçakçı ◽  
Oral Sökücü ◽  
Hasan Babacan ◽  
H. Hüseyin Köşger
Keyword(s):  
Third Molar ◽  
Root Apex ◽  
Central Line ◽  
Occlusal Plane ◽  
Third Molars ◽  
Migration Effect ◽  
Mandibular Third Molar ◽  
Root Curvature ◽  
History Of ◽  
Mandibular Third Molars

Abstract Objective: To test the hypothesis that there is a relationship between forward mandibular third molar migration and root curvature of the mandibular third molars. Materials and Methods: The study is comprised of 64 patients who had a history of unilateral mandibular first molar extraction before 16 years of age with no other missing teeth or prosthetic restorations in the mandible. The extraction space was fully or partly closed. The mean remaining space was 1.1 ± 0.41 mm. The root angles for the mesial and distal roots of the mandibular third molars were measured on the panoramic radiographs by calculating the differences between the angle formed by the long axis drawn perpendicular to the occlusal plane of the crown of mandibular third molar and the central line of the lower one ninth of the root through the root apex. The differences between the extracted and nonextracted sides for mesial and distal roots were analyzed using a paired sample t-test. Results: Both mesial and distal roots were approximately 8° more vertical on the extraction sides than on the nonextraction sides. The differences were statistically significant. Conclusion: Mesial tooth migration of mandibular third molars reduces the amount of root curvature developing on this tooth.

scholarly journals The Frequency of Mandibular Third Molar Impaction in Different Types of Vertical Skeletal Faces

2021 ◽  
Vol 30 (02) ◽  
pp. 118-123
Author(s):  
Sana Viqar ◽  
◽  
Sadia Rizwan ◽  
Syed Shah Faisal ◽  
Syed Sheeraz Hussain
Keyword(s):  
Third Molar ◽  
Third Molars ◽  
Skeletal Malocclusion ◽  
Mandibular Third Molar ◽  
Lateral Cephalograms ◽  
Significant Difference ◽  
Pre Treatment ◽  
Mandibular Third Molars ◽  
Facial Types ◽  
Third Molar Eruption

OBJECTIVE: To determine the frequency of mandibular third molar impaction in different vertical skeletal facial types. METHODOLOGY: Data was collected using pre-treatment records including orthodontic files, pre-treatment lateral cephalograms and OPGs of 90 orthodontic patients. Patients from both genders were included. The age group of selected patients was 18-30 years. Vertical skeletal malocclusion was measured using facial angle and mandibular plane angle on cephalogram to group the subjects into Mesiofacial, Brachyfacial and Dolichofacial patients. Third molar eruption status was assessed using OPG. RESULTS: Results showed that erupted third molars were mostly found in brachyfacial patients. Among 32 erupted mandibular third molars, 16 belong to brachyfacial, 11 belonged to mesiofacial and 5 belonged to dolichofacial group. Complete impaction of mandibular third molar was most common among dolichofacial patients. Among 29 completely impacted mandibular third molars, 14 belong to dolichofacial, 9 belonged to mesiofacial and 6 belonged to brachyfacial group. No significant difference was found for partially impacted third molars among the three groups of facial types. There was higher prevalence of mandibular third molar impaction in females as compared to males. CONCLUSION: Frequency of third molar impaction was found to be highest in dolichofacial patients and lowest in brachyfacial patients due to forward direction of mandibular growth contributing to greater resorption of the anterior border of ramus and the additional space required for third molar eruption.

scholarly journals Coronectomy - A viable alternative to prevent inferior alveolar nerve injury

2015 ◽  
Vol 11 (3) ◽  
pp. 1-5
Author(s):  
Alok Sagtani ◽  
Reshu Agrawal Sagtani ◽  
Mehul Jaisani ◽  
Leeza Pradhan
Keyword(s):  
Nerve Injury ◽  
Inferior Alveolar Nerve ◽  
Third Molar ◽  
Viable Alternative ◽  
Third Molars ◽  
Dry Socket ◽  
Root Exposure ◽  
Mandibular Third Molars ◽  
Inferior Alveolar Nerve Injury

Background and Objectives: Coronectomy is a relatively new method to prevent the risk of Inferior Alveolar Nerve (IAN) injury during removal of lower third molars with limited scientific literature among Nepalese patients. Thus, a study was designed to evaluate coronectomy regarding its use, outcomes and complications.Materials and Methods: A descriptive study was conducted from December 2012 to December 2013 among patients attending Department of Oral and Maxillofacial Surgery, College of Dental Sciences, BP Koirala Institute of Health Sciences, Dharan, Nepal for removal of mandibular third molars. After reviewing the radiograph for proximity of third molar to the IAN, coronectomy was advised. A written informed consent was obtained from the patients and coronectomy was performed. Patients were recalled after one week. The outcome measures in the follow-up visit were primary healing, pain, infection, dry socket, root exposure and IAN injury. The prevalence of IAN proximity of lower third molars and incidence of complications were calculated.Results: A total 300 mandibular third molars were extracted in 278 patients during the study period. Out of 300 impacted mandibular third molar, 41 (13.7%) showed close proximity to inferior alveolar nerve . The incidence of complications and failed procedure was 7.4% among the patients who underwent coronectomy. During the follow up visit, persistent pain and root exposure was reported while other complications like inferior alveolar nerve injury, dry socket and infection was not experienced by the study patients.Conclusion: With a success rate of 92.6% among the 41 patients, coronectomy is a viable alternative to conventional total extraction for mandibular third molars who have a higher risk for damage to the inferior alveolar nerve.JCMS Nepal. 2015;11(3):1-5.

scholarly journals Calcifying cystic odontogenic tumor in radiologically normal dental follicular space of mandibular third molars: report of two cases

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Gargi S. Sarode ◽  
Sachin C. Sarode ◽  
Ghevaram Prajapati ◽  
Mahesh Maralingannavar ◽  
Shankargouda Patil
Keyword(s):  
Cell Transformation ◽  
Histopathological Examination ◽  
Third Molar ◽  
Odontogenic Tumor ◽  
Third Molars ◽  
Radiographic Evidence ◽  
Odontogenic Epithelium ◽  
Mandibular Third Molar ◽  
One Year ◽  
Mandibular Third Molars

Two cases of calcifying cystic odontogenic tumor (CCOT) of the dental follicle in an impacted third molar without clinical and radiological evidence are reported during routine histopathological examination. In both the cases left mandibular third molar was mesioangularly impacted with pericoronal radiolucency of less than 2.5 mm, which was not indicative of any pathology. As a routine protocol (which is not practiced widely) of our institution, dental follicles associated with extracted molars were sent for histopathological examination. Histopathological features were consistent with CCOT with pathognomonic ghost cell transformation of odontogenic epithelium. The patients were followed for one year with no recurrence. This paper emphasizes the importance of routine histopathological examination of dental follicles associated with asymptomatic impacted teeth without any clinical or radiographic evidence of follicular lesion.

scholarly journals Cone beam CT and treatment decision of mandibular third molars: removal vs. coronectomy—a 3-year audit

2020 ◽  
Vol 49 (3) ◽  
pp. 20190250 ◽  
Author(s):  
Louise Hauge Matzen ◽  
Julie Suhr Villefrance ◽  
Sven Erik Nørholt ◽  
Jesper Bak ◽  
Ann Wenzel
Keyword(s):  
Cone Beam Ct ◽  
Inferior Alveolar Nerve ◽  
Treatment Decision ◽  
Close Relation ◽  
Mandibular Canal ◽  
Panoramic Image ◽  
Third Molars ◽  
Sensory Disturbances ◽  
Mandibular Third Molars ◽  
The Impact

Objectives: To assess: (1) the workflow in the treatment decision process of mandibular third molars based on a panoramic image and CBCT and (2) the impact of radiographic markers in CBCT on the decision to perform coronectomy. Methods: 1437 teeth in 917 patients (mean age 27.8 years, range 18–72) underwent clinical and panoramic examination. If there was an indication for removal of the tooth, and signs of a close relation to the inferior alveolar nerve were present in the panoramic image, a CBCT was performed. Treatment decision based on panoramic image and CBCT was calculated. Statistical analyses were performed to assess whether signs in CBCT had an impact on the treatment decision “coronectomy”. Moreover, the actually operated teeth and post-operative sensory disturbances were assessed and discussed in relation to the radiographic method. Results: Based on the panoramic image, in 462 cases it was decided not to treat, 553 were scheduled for surgery, and 422 referred for a CBCT examination. “No bony separation between the tooth and mandibular canal” seen in CBCT was the main factor influencing the decision to perform a coronectomy (odds ratio = 56.8, p < 0.001). 840 mandibular third molars had undergone surgical intervention, 152 had a coronectomy and 688 were fully removed. Six patients perceived a sensory disturbance of the inferior alveolar nerve: one permanent and five temporary. Conclusion: 29% of the examined cases were referred for a CBCT and of these, the majority were scheduled for coronectomy based on the sign “no bony separation between the tooth and mandibular canal” seen in CBCT.

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