No Evidence of Sexual Dimorphism in Third Molar Agenesis Patterns: A Cross-Sectional Study of Orthodontic Patients

Background/Objectives: Sexual dimorphism has been reported in several dental traits; however, its relevance in third molar agenesis (TMA) remains unclear. Methods: A cross-sectional retrospective study evaluated panoramic radiographs of German orthodontic patients. TMA was diagnosed using panoramic radiographs by evaluating the presence or absence of the third molars in all four quadrants of the jaws. Absence of third molar development was classified as agenesis. To ensure accuracy, diagnosis was established only in patients older than 12 years. The control group included only individuals with 32 teeth. Chi-square test was used to compare prevalence among groups. The number of TMA did not meet the assumption of normality according to the Shapiro-Wilk test, so group comparisons were performed using the Mann-Whitney U test (alpha  =  5%). Results: A total of 484 individuals were included (244 females, 240 males). TMA was present in 117 patients (59 females, 58 males). No sexual dimorphism or sex-specific differences in laterality were observed (p > 0.05). In total, 50 patients had one missing third molar, 35 patients had two missing third molars, 12 patients had three missing third molars, and 20 patients had four missing third molars. The mean number of missing third molars was 1.97 (standard error 0.16) in females and 1.88 (standard error 0.13) in males, with no significant difference between sexes (p = 0.69). Conclusions: TMA presents no sexual dimorphism as observed in other types of dental agenesis. These findings suggest that sex is unlikely to be a major factor in TMA.