Relationship between Third Molar Agenesis and Other Dental Anomalies

Objective The purpose of this study was to find the prevalence of dental abnormalities in patients with third molar agenesis, and a comparison was made for the prevalence of those anomalies within the north Indian natives. Materials and Methods Pretreatment records of 518 patients were collected. Out of 518 patients whose records were analyzed, 472 patient records were selected on the basis of inclusion and exclusion standards. Panoramic radiographs and dental casts were analyzed in patients who had an absence of at least one third molar in which absence of any other tooth, presence of supernumerary teeth, presence of impacted canines, and peg-shaped lateral incisors were further assessed. The prevalence of these anomalies was compared with a randomly selected group of patients with presence of third molars that served as controls. Statistical analysis was done using the chi-square test (p < 0.05) and odds ratio. Results The incidence of third molar nondevelopment was found to be 19.2%. The presence of other anomalies was 39.5% in patients with third molar nondevelopment, and difference was statistically significant. The occurrence of impacted canines in patients with absence of third molars was 22%, and presence of third molars was 6.6%. The presence of other dental anomalies, that is, supernumerary teeth and tooth agenesis, was 7.7% in the agenesis group, which was also higher than that in the control group (3.3%) but was not statistically significant. The incidence of peg-shaped lateral incisors was similar in both the groups. Conclusion Impacted canines and total dental anomalies are more often related with absence of third molars than with the presence of third molars.