Investigation of the Relationship Between Mandibular Gonial Angle and Impacted Mandibular Third Molar

Aim: The aim of this study is to investigate changes in the gonial angles of impacted lower third molars and associated parameters in individuals with impacted lower third molars aged twenty years and below. Material and Methods: A retrospective study included 963 patients with impacted third molars. Impaction classification was done according to Pell-Gregory criteria. The teeth were divided into eight main groups based on their relationship with the ramus and second molar (1, 2, 3) and the depth within the bone (A, B, C). Teeth classified as erupted in 1A were excluded from the study. Gonial angle, mesiodistal distance (MDM), retromolar eruption distance (RED), retromolar eruption ratio (RER), A° (angle between the Gonion-symphysis plane and the long axis of the third molar), and B° (angle between the Gonion-symphysis plane and the long axis of the second molar) were evaluated. Panoramic radiographs were analyzed using specialized software to measure angles and distances. The angles and measurements were compared among impacted groups and genders. Statistical analyses including Pearson correlation and ANOVA tests were used to assess relationships between measurements and impact parameters. A significance level of p<0.05 was considered statistically significant. Results: In females, the A was found to be significantly larger than in males (p<0.05). In males, however, RSM and RSO were found to be significantly larger than in females (p<0.05). There was no significant variation in gonial angle among the impaction groups. A angle was the narrowest in group 3/B and the largest in group 2/A. Conclusion: While gonial angle are not a definitive indicator of impacted third molars, the study emphasizes the importance of A° and RED in predicting impaction.