Journal Article

Investigation Of the Relationship Between Impacted Mandibular Third Molars and Mandibular Dental Arch Parameters in Three-Dimensional Images

Erdoğdu, Çağrı, Akay, Gülsün

2025

Overview

Objective: The aim of this study was to evaluate the relationship between the dimensional measurements of the mandible, mandibular dental arch parameters, and the impaction of mandibular third molars (M3M) using three-dimensional images. Methods: This cross-sectional retrospective study analyzed cone beam computed tomography images (CBCT) of 90 M3M of 63 patients (29 males and 34 females aged 18-46 years). Impacted teeth were classified according to Pell-Gregory and Winter's classifications. The relationship between gonial angle, retromolar distance, dental arch parameters, and the position of the mandibular third molar was analyzed. The data were analyzed using one-way ANOVA, Kolmogorov-Smirnov, chi-square test, and Pearson correlation coefficient. Results: Inter-canine width, inter-premolar width, and arch length were significantly associated with the depth positions of M3M impaction (Pell-Gregory classification) (p< .05). Similarly, arch length was significantly greater in more superficial impaction groups. The retromolar space showed significant differences among ramus classification groups (p< .05). No significant association was found between gonial angle and M3M impaction across depth positions or ramus classifications. Additionally, while mesioangular impaction was the most common angulation type (57.7%), no significant differences in mandibular morphometric parameters were identified based on angulation categories. Conclusion: This study demonstrates that M3M impaction significantly influences mandibular dental arch parameters such as inter-canine width, inter-premolar width, and arch length. Three-dimensional examination with CBCT in the evaluation of M3M teeth provides valuable information for surgical planning and orthodontic treatment.