Pre-eruptive intracoronal resorption in "high-risk" impacted third molars: A report of four cases.

Pre-eruptive intracoronal resorption (PEIR) is usually an incidental finding as a radiolucent lesion within the coronal dentin of unerupted teeth. Through the four cases reported here, authors would demonstrate deeply impacted "high-risk" third molars with PEIR defects, showing an increased risk of inferior alveolar nerve (IAN) injury. However, follow-up or coronectomy may eliminate or reduce the risk of neurosensory disturbances, in case of PEIR lesions this can be contradictory due to the unpredictable reactions of the third molar's pulp. Cases show the important role of preoperative imaging in the diagnostics and management of deeply impacted PEIR third molars and highlight the need for investigations regarding coronectomy in such cases.

Is it possible to filter third molar cases with panoramic radiography in which roots surround the inferior alveolar canal? A comparison using cone-beam computed tomography.

Inferior alveolar nerve (IAN) entrapment in third molar (M3) roots bears a significant risk for nerve injury. The aim of this study was to identify specific panoramic radiographic (PR) signs that can reliably identify IAN entrapment (IANE) root conformations. In a retrospective case-control study, 10 IANE and 218 non-IANE third molar risk cases were examined by PR and CBCT. The collected data included "classic" specific high-risk panoramic signs, number of M3 roots, extent of inferior alveolar canal (IAC)-root tip overlap, rotated position of M3 and impaction pattern. After bivariate analysis, sensitivity, specificity, positive and negative predictive values, positive likelihood ratios (LR+) and accuracy (AC) were calculated for the most significant predictive variables. Interruption of both cortical lines (LR+: 43.6; AC: 96.0%) and upward diversion of the IAC (LR+: 36.3; AC: 96.5%) were the most accurate single signs indicating IANE. Upward diversion combined with root darkening and interruption of the IAC (AC: 97.4%) and the combination of darkening with interruption and with a rotated M3 (LR+:130.8; AC: 97.8%) were the most accurate combinations predicting IANE. IANE may be correctly filtered with PR when focusing on the signs of upward diversion, darkening, interruption and rotated M3 position, especially in cases involving their multiple (≥3) presence. CBCT evaluation is highly recommended in these cases before partial and total tooth removals.

The role of occlusal support and lower third molars in mandibular angle and condylar fractures / A bölcsességfog és az occlusio szerepének vizsgálata a mandibulaangulus és -condylus töréseiben

INTRODUCTION AND AIM: The aim of our study was to investigate the influence of the occlusal support, and mandibular third molars on mandibular angle and condylar fractures. METHOD AND RESULTS: Patients with unilateral and isolated angle or condylar fractures were included in this retrospective, cross-sectional study. Data was collected from patient records and panoramic x-rays. The predictor variables included the type of occlusal support and the presence or absence of third molars. The outcome variable was angle or condylar fracture, while other predictor variables included demographic factors. Bivariate (χ2 test) and logistic regression analyses were conducted to investigate the associations between variables and the outcome. 43 angle (mean age: 29.9 ± 12.8 years; 98.4% male) and 37 condylar (mean age: 46.8 ± 20.2 years; 62.2% male) fracture cases were included in this study. Bilateral occlusal support was present in 81.4% of angle fracture group and in 51.3% of condylar fracture group (p<0.001). In the case of bilateral occlusal support, an odds ratio (OR) of 4.2 was found for angle fractures (p<0.006). A third molar was present in 86% of the angle fracture group and in 43.2% of the condylar fracture group (p<0.001). The presence of a third molar exhibited an odds ratio of 8.1 for the angle fractures (p<0.001). When bilateral occlusal support and third molar were present simultaneously, the risk was 15.9 times higher for an angle fracture (p<0.001). CONCLUSION: The presence of occlusal support and/or third molars was significantly associated with angle fractures, however, the absence of occlusal support and/or third molars significantly correlated with condylar fractures. Orv Hetil. 2020; 161(28): 1166-1174.

Association Between Third Molar Impaction Status and Angle or Condylar Fractures of the Mandible: A Retrospective Analysis.

PURPOSE: The aim of our study was to evaluate the correlations between mandibular third molar impaction status and mandibular angle and condylar fractures. MATERIALS AND METHODS: This retrospective cross-sectional study included patients with unilateral and isolated angle or condylar fractures. Patient records and panoramic radiographs were evaluated. The predictor variables included the presence, impaction status (Pell and Gregory [P&G] classification), and angulation (Winter classification) of the third molar. The outcome variable was the type of fracture, whereas other predictor variables included demographic factors such as age, gender, and fracture etiology. Bivariate (χ2 test) and logistic regression analyses were conducted to estimate the associations between variables and the outcome. RESULTS: The sample was composed of 164 angle fracture (mean age, 31.6 ± 12.3 years; 83.5% male) and 115 condylar fracture (mean age, 41.9 ± 16.8 years; 76.5% male) patients. A third molar was present in 72.6% of the angle fracture group and 54.8% of the condylar fracture group (P = .002). Deep impactions (classes IC, IIC, IIIB, and IIIC) exhibited an odds ratio (OR) of 3.60 for angle fractures (P < .001). No association was found between tooth angulations and the type of fracture. According to logistic regression analysis, older age (adjusted OR, 1.05; 95% confidence interval [CI], 1.03 to 1.07), P&G class I impaction (OR, 1.86; 95% CI, 1.09 to 3.20), and P&G class A impaction (OR, 1.91; 95% CI, 1.12 to 3.24) were significantly associated with condylar fractures whereas the presence of a third molar (OR, 0.46; 95% CI, 0.28 to 0.76) or P&G class B impaction (OR, 0.287; 95% CI, 0.12 to 0.69) was associated with angular fractures. CONCLUSIONS: P&G class II or III and class B impaction status was significantly associated with angle fractures, whereas missing or fully erupted (class IA) third molars significantly correlated with condylar fractures.