Anatomical Position of Lower Third Molar in Relation to Mandibular Canal on Cone-Beam Computed Tomography Images in A Tertiary Care Hospital: A Descriptive Cross-sectional Study

Introduction: The positional relationship between the mandibularcanal with impacted mandibular third molar is the main factor of inferior alveolar nerve injury. The purpose of this study wasto classify the anatomical three dimensional relationship between the proximity of impacted mandibular third molars to the inferior alveolar canal. Methods: The descriptive cross-sectional study was conducted inthe Department of Oral and Maxillofacial Surgery of a tertiary care hospital from July 2020 to August 2020 after obtaining ethical approval from the Institutional Review Committee (Reference number 2506202001). Cone-beam computed tomography images of 200 patients’ mandibular third molars were used. A convenient sampling method was used. Data were analyzed using Statistical package for the Social Sciences. Results: Mandibular canal relative to the roots of the mandibular third molar was observed on the apical side in 104 (52.0%) and 173 (86.5%) third molars had direct contact with the mandibular canal. About 36 (97.3%) lingually placed mandibular third molars had contact with the mandibular canal. Conclusions: The findings of the study conclude that most of the mandibular third molars situated lingually had a higher occurrence of mandibular nerve involvement. The anatomic structures of the mandibular third molar and the mandibular canal may be helpful to draw upon the adequate surgical plan to avoidor reduce nerve involvement.

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Correlation Between the Maturation Stages of Mandibular Third Molars and Chronological Age in Patients Visiting Sardar Begum Dental College, Peshawar

Journal of Gandhara Medical and Dental Science ◽

10.37762/jgmds.5-2.79 ◽

2019 ◽

Vol 5 (2) ◽

pp. 3-7

Author(s):

Muhammad Ilyas ◽

Asma Khan ◽

Syed Murad Ali Shah ◽

Salman Khan ◽

Junaid Nadeem Malik

Keyword(s):

Pearson Correlation ◽

Third Molar ◽

Cross Sectional Study ◽

Chronological Age ◽

P Value ◽

Third Molars ◽

Cross Sectional ◽

Mandibular Third Molar ◽

Maturation Stages ◽

Mandibular Third Molars

OBJECTIVES: The objective of this study was to determine the correlation of chronological age with the maturation stages of mandibular third molar. METHODOLOGY: This descriptive, cross-sectional study was conducted at Sardar Begum Dental College, Gandhara University Peshawar on 384 patients from January 2018 to June 2018 and included patients having age 11-26 years with good quality Orthopantomogram showing mandibular third molar tooth germs bilaterally. Data were analyzed using SPSS version 22. p ≤ 0.05 was considered as statistically significant. RESULTS: Females 286 (74.5%) were predominant than males 98 (25.5%) with mean age presentation of 18.12±3.03 years. The most frequent stage of Demirjian’s stages of mandibular third molar was stage F (24.7%). Pearson correlation showed that maturation stages of mandibular third molars were significantly related to the chronological age ( r=0.446, p value=0.00). CONCLUSION: A correlation between maturation stages of mandibular third molars and chronological age existed.

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Assessment of role of mandibular third molar in lower anterior crowding among orthodontic patients of Kathmandu Nepal

Orthodontic Journal of Nepal ◽

10.3126/ojn.v10i3.35486 ◽

2020 ◽

Vol 10 (3) ◽

pp. 21-26

Author(s):

Bashu Dev Pant ◽

Anjana Rajbhandari ◽

Resina Pradhan ◽

Manju Bajracharya ◽

Surendra Maharjan ◽

...

Keyword(s):

Third Molar ◽

Cross Sectional Study ◽

Third Molars ◽

Chi Square ◽

Cross Sectional ◽

Anterior Crowding ◽

Mandibular Third Molar ◽

Significant Difference ◽

Orthodontic Patients

Introduction: Crowding in mandibular arch increases with increasing age and etiology of crowding is multifactorial in nature. Role of mandibular third molar in lower anterior crowding remains a topic of controvery over a period of century. The objective of this study was to assess whether there is any correlation between presence of mandibular third molar position and lower anterior crowding. Materials and Method: On the basis of third molar position one hundred and six sample of pretreatment orthodontic patients aged between 17 to 38 years were divided into erupted, erupting and agenesis group. The study was conducted in Peoples Dental College and Hospital from January 2020 to March 2020 after obtaining ethical approval from the institutional review committee. This cross-sectional study was done on dental casts and orthopantomogram; brass wire was used for measuring arch length and digital vernier caliper for measuring tooth material with modified segmental arch analysis method. Result: Among 106 samples collected 55 (51.88%) were female and 51(48.11%) were male and the mean age was 21.53 ± 3.91 years, Chi square and ANOVA test was used for Statistical analysis. This study showed no statistically significant differences between third molar position and lower anterior crowding on right (P= 0.68) and left side (P = 0.45). The study also showed that association between the third molar position and lower anterior crowding is more on left side compared to right side. Conclusion: Mandibular third molars have not statistically significant difference in lower anterior crowding so, extraction of third molars for relieving the anterior crowding is not justifiable

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Evaluation of the Relationship between Mandibular Third Molar and Mandibular Canal by Different Algorithms of Cone-beam Computed Tomography

The Journal of Contemporary Dental Practice ◽

10.5005/jp-journals-10024-1609 ◽

2014 ◽

Vol 15 (6) ◽

pp. 740-745

Author(s):

Mojdeh Mehdizadeh ◽

Navid Ahmadi ◽

Mahsa Jamshidi

Keyword(s):

Computed Tomography ◽

Cone Beam Computed Tomography ◽

Inferior Alveolar Nerve ◽

Third Molar ◽

Mandibular Canal ◽

Cross Sectional Study ◽

Cone Beam ◽

Cross Sectional ◽

Mandibular Third Molar ◽

The Relationship

ABSTRACT Objectives Exact location of the inferior alveolar nerve (IAN) bundle is very important. The aim of this study is to evaluate the relationship between the mandibular third molar and the mandibular canal by cone-beam computed tomography. Study design This was a cross-sectional study with convenience sampling. 94 mandibular CBCTs performed with CSANEX 3D machine (Soredex, Finland) and 3D system chosen. Vertical and horizontal relationship between the mandibular canal and the third molar depicted by 3D, panoramic reformat view of CBCT and cross-sectional view. Cross-sectional view was our gold standard and other view evaluated by it. Results There were significant differences between the vertical and horizontal relation of nerve and tooth in all views (p < 0.001). Conclusion The results showed differences in the position of the inferior alveolar nerve with different views of CBCT, so CBCT images are not quite reliable and have possibility of error. How to cite this article Mehdizadeh M, Ahmadi N, Jamshidi M. Evaluation of the Relationship between Mandibular Third Molar and Mandibular Canal by Different Algorithms of Cone-beam Computed Tomography. J Contemp Dent Pract 2014;15(6):740-745.

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Pattern of Impacted Mandibular Third Molar in Patients Presenting to Tertiary Care Hospital in Chitwan, Nepal

Orthodontic Journal of Nepal ◽

10.3126/ojn.v9i2.28412 ◽

2019 ◽

Vol 9 (2) ◽

pp. 38-42

Author(s):

Ashutosh Kumar Singh ◽

Safal Dhungel

Keyword(s):

Tertiary Care ◽

Third Molar ◽

Surgical Removal ◽

Care Hospital ◽

Third Molars ◽

Depth Level ◽

Level Ii ◽

Mandibular Third Molar ◽

Level I ◽

Patient Side

Introduction: Impacted third molars are a major cause of visit to the oral surgeon and are associated with various complications like pain, inflammation of associated soft tissue and trismus leading to a need for their surgical removal. They are widely classified on the basis of angulation, depth and position as evident from orthopantomogram however they present in a diverse panorama of patterns each presenting different level of difficulty and different techniques for their removal. Our study describes different pattern of impacted lower third molars and perform brief literature review of dental and skeletal implications of impacted third molars. Materials & Method: A retrospective study was designed in which 401 orthopantomogram were examined and the sex of patient, side of impaction and winters angulation based classification, depth and position classification as given by Pell and Gregory were recorded. Descriptive data analysis was performed with SPSS version 24 software. Result: Out of total number of impactions 191(47.6%) were in females and 210(52.4%) were in males. Right sided impaction was seen in 199(49.6%) cases and 202(50.4%) were seen on left side. Mesioangular impaction was most common 203(50.6%) followed by distoangular 97(24.2%), horizontal 51(12.7%) and vertical 17(4.2%). Most common depth level of impaction was level I with 203(50.6%) followed by level II 178(44.4%) and level III 20(5%). Most common position was position B 355(88.5%) followed by position A 43(10.7%) and position C 3(0.7%). The most common pattern was IB (n=170) and IIB (n=166). Conclusion: The most common impaction is mesioangular followed by distoangular and horizontal. Most of the impacted third molars are in moderately difficult position.

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The correlation between Rood and Shehab’s radiographic features and the incidence of inferior alveolar nerve paraesthesia following odontectomy of lower third molars

Dental Journal (Majalah Kedokteran Gigi) ◽

10.20473/j.djmkg.v49.i2.p59-62 ◽

2017 ◽

Vol 49 (2) ◽

pp. 59

Author(s):

David Buntoro Kamadjaja ◽

Djodi Asmara ◽

Gita Khairana

Keyword(s):

Inferior Alveolar Nerve ◽

Third Molar ◽

Mandibular Canal ◽

Cross Sectional Study ◽

Third Molar Surgery ◽

Third Molars ◽

Chi Square ◽

Cross Sectional ◽

Radiographic Features ◽

Close Relationship

Background: Odontectomy of lower third molar has a potential risk for inferior alveolar nerve impairment. Paresthesia of inferior alveolar nerve has often been associated with close relationship between the apex of lower third molar and mandibular canal. Rood and Shehab’s category has been commonly used for radiological prediction of inferior alveolar nerve injury following third molar surgery. Purpose: This study aimed to determine whether there was correlation between Rood and Shehab’s radiographic features and the incidence of inferior alveolar nerve paraesthesia following odontectomy of lower third molar. Method: This was a retrospective cross-sectional study, using data obtained from the dental record of patients who had undergone odontectomy of lower third molars in Dental hospital of Universitas Airlangga during 2 years period. Samples were cases that, from presurgical radiograph, showed close relationship between lower third molar roots and mandibular canal. The case and non-case groups were assigned based on the presence of paraesthesia and non-paraesthesia of inferior alveolar nerves, respectively. Based on Rood and Shehab’s category, the samples collected were then classified into two groups which were those whose relationship matched and did not match with the category, respectively. Data were analyzed using Chi-square correlation test. Result: Of 975 odontectomy cases included in this study, 80 cases were taken as study samples consisting of 15 and 65 cases assigned, respectively, as case and non-case. The 32 cases matched with the criteria of Rood and Shehab's category while the remainder of 48 cases did not. Of 32 cases which met the criteria of Rood and Shehab’s relationship, only 5 cases showed paraesthesia, whereas out of 48 cases which did not met the criteria 10 cases showed paraesthesia. Statistical analysis showed significance value of 0.770 (p>0.05) indicating that there was no significant correlation between relations of third molar root and mandibular canal, based on Rood and Shehab’s category, and the incidence of inferior alveolar nerve paraesthesia. Conclusion: There was no correlation between Rood and Shehab’s radiographic features and the incidence of paraesthesia of inferior alveolar nerve following odontectomy of lower third molars.

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

Diagnostics ◽

10.3390/diagnostics11122282 ◽

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.

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Panoramic Radiographic Analysis of Signs of Proximity to the Third Molar Roots of the Mandibular Canal in Yemen

Journal of Medical Clinical Case Reports ◽

10.47485/2767-5416.1017 ◽

2020 ◽

Keyword(s):

Third Molar ◽

Mandibular Canal ◽

Cross Sectional Study ◽

Third Molars ◽

Cross Sectional ◽

Panoramic Radiographs ◽

Second Molar ◽

Female Patients ◽

The Third ◽

Dental Clinics

Objectives: The objectives of this study were to assess the relationship between the third molar and the mandibular canal, to identify the radiographic markers most prevalent in predicting connectivity between these structures, and to associate these signs and proximity with the position of the third molar according to Bell, Gregory’s and Winter’s classifications. Subjects and methods: A retrospective cross-sectional study was conducted in the city of Sana’a on a sample of Yemeni patients in Ammar Dental Clinics who underwent panoramic radiography in the year 2019 until September 2020. The study consisted of panoramic radiographs of 597 patients with third molars with a total of 1017 third molars; the number of males was 216 (36.2%) and 381 females (63.8%). The panoramic radiographs were evaluated for proximity signs. Inclusion criteria were patients of both sexes who had at least a fully formed third molar of the mandible that was adjacent to the second molar. The radiographs were excluded if evidence of cystic, neoplastic, or extensive caries processes was detected. Seven radiological signs were used to determine if there was contact between the third molar and the mandibular canal. Results: A proximity to the mandibular canal was verified for 620 (61%) of 1017 third molars. The most frequent radiographic signs of proximity were darkened roots (315 teeth [31%]) and discontinuity of the mandibular canal (267 teeth [26.3%]). Third molar/mandibular canal proximity was found significantly more frequently in female patients and in patients aged 24 years and younger (P < 0.001). The tooth positions most frequently associated with proximity between the third molar and the mandibular canal were position C (highest point of the third molar located at or below the cervical margin of the second molar) and the mesioangular position (long axis of the third molar angled mesially toward the second molar). Conclusions: The frequency of third molar/ mandibular canal proximity was greater in female patients and patients aged 24 years or younger. The most frequently observed signs of proximity were darkening of the roots and discontinuity of the mandibular canal. The tooth positions most frequently associated with proximity of the third molar to the mandibular canal were position C and the mesioangular position.

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