Evaluation of Patterns of Impacted Third Molars and Their Association With Vital Structures by Radiographic Examination

Abstract

Objective: To assess the patterns of impacted 3rd molars and their proximity with adjacent vital structures.
 Study Design: Comparative cross-sectional study.
 Place and Duration of Study: Oral & maxillofacial department of Rawalpindi Dental Hospital, from Oct 2016 toFeb 2018.
 Methodology: Patient sample size was 956. Orthopantomograms (OPGs) were assessed to determine the presence, patterns of impacted third molars and their relation to maxillary sinus and inferior alveolar canal (IAC) in maxilla and mandible respectively.
 Results: Out of 956 Orthopantomograms with 3499 3rd molars examined, 808 (23.09%) were impacted. Frequency of impaction was much higher in mandible than maxilla. Out of 527 impacted mandibular 3rd molars 238 (45.16%) were mesio-angular, 370 (70.21%) had class 1 relation to mandibular ramus & 266 (50.47%) had level B depth, while among 281 impacted maxillary third molars 134 (47.69%) had vertical angulation and 162 (57.65%) had level B depth. Two hundred and eighty four (53.89%) impacted mandibular 3rd molars showed relationship with the inferior alveolar canal, out of which 187 (35.48%) impacted mandibular 3rd molars showed interruption of white line as the most common radiographic finding.
 Conclusion: Frequency of impacted third molars was more common in mandible and among females whereasthere is significant difference in patterns of impaction among mandible and maxilla. While most impacted teethhave approximation with IAC and maxillary sinus.

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

“…In this study, based on Winter’s classification [ 20 ], mesio-angular was the most common type (54.9%) followed by vertical (23.4%), horizontal (16.8%), and disto-angular (4.9%). This was in agreement with Sedaghatfar et al [ 22 ], Gomes et al [ 23 ], Wassem et al [ 41 ], Quek et al [ 53 ], Deshpande et al [ 56 ], and Nyugen et al [ 57 ] In contrast, Kim et al [ 7 ] and Tantanapornkul et al [ 19 ] revealed that the horizontal angulation was the most common, followed by angular and vertical, whereas according to Chen et al [ 13 ], Bataineh et al [ 58 ], and Almendros-Marques et al [ 59 ], vertical impaction was the most common type. In this study, canal defects were most frequently seen with disto-angular impaction (82.4%).…”

“…In this study, 104 (29.7%) of the mandibular third molars showed cortication whereas 246 cases (70.3%) showed an absence of cortication. The percentage of absence of cortication in the present study was far greater than that noted by Kim et al [ 7 ] Pandey et al [ 30 ], and Waseem et al [ 41 ], where in 61%, 63.8%, and 53.9% of CBCT images respectively, the IAN was actually in contact with the root of third molar. With respect to the OPG signs, diversion of canal showed the highest number of cases with absence of cortication between the third molar and IAC in CBCT images.…”

“…In this study, the other OPG signs associated with absence of cortication in CBCT images in sequence following the diversion of the canal were narrowing of the canal (70.2%) followed by darkening of the root (69.6%) and interruption of white line (64.8%). Fauzi et al [ 35 ], Nakagawa et al [ 40 ], Waseem et al [ 41 ], and Kursun et al [ 42 ] noted in their respective studies that interruption of the white line of the canal on OPG was significantly associated with a greater chance of having an IAC wall defect. Monaco et al [ 26 ] and Dalili et al [ 43 ] in their respective studies reported that they were more likely to find a defective IAC wall when there was narrowing of the root on OPG images.…”

Unraveling the Outcomes: A Retrospective Analysis of Aberrantly Positioned Impacted Third Molar Extractions

“…The distribution of IMTM in our study indicated a higher prevalence among younger age groups, with the majority (30.33%) observed in subjects aged 18-30 years. These findings align with previous studies conducted by various authors [28,29]. Furthermore, authors observed a higher proportion of SRIMTM cases among females, which can be explained by Hellman's theory [29].…”

“…These findings align with previous studies conducted by various authors [28,29]. Furthermore, authors observed a higher proportion of SRIMTM cases among females, which can be explained by Hellman's theory [29]. According to this theory, female jaw growth ceases when the third molars begin to erupt, whereas in males, jaw growth continues beyond the eruption time, resulting in a lower incidence of IMTM in males compared to females.…”