Third molar agenesis: Prevalence and Association with agenesis of other teeth in a Turkish population

Background: Tooth agenesis is the congenital lack of one or more primary or permanent teeth and it is the most frequently seen dental anomaly. The prevalence of third molar agenesis is significantly higher than the agenesis of other teeth varying from 10% to 40% and shows geographical variance. Aims: The aim of this study was to investigate the prevalence of third molar agenesis and its association with other tooth agenesis of jaws. Subjects and Methods: A total of 594 Turkish subjects with or without agenesis of third molars (M3) were included in the study. Dental records and panoramic radiographs were evaluated for M3 agenesis, hypodontia and hyperdontia. Significant differences in the prevalence rate of M3 agenesis between genders among with evaluation of coexistence of M3 and other tooth agenesis were determined by Fisher's exact test. Results: The prevalence of M3 agenesis was determined as 28.7% with no statistically significant gender or location difference. Most common form of M3 agenesis involved one molar followed by two, four and three molars. Agenesis of other teeth was seen among both patient groups with and without M3 agenesis, without significant difference. Conclusions: Turkish population with M3 agenesis did not show increased prevalence of other tooth agenesis, indicating no association between occurrence of agenesis of other teeth and M3.