Frequency of Agenesis, Impaction, Angulation, and Related Pathologic Changes of Third Molar Teeth in Orthodontic Patients

Abstract

The objectives of the present study were to investigate the frequency of impaction, agenesis, angular position, and related pathologic changes of third molar teeth in a group of orthodontic patients. Our sample included the panoramic radiographs of 351 orthodontic patients aged 20 to 26 years (mean 22.8). The descriptive characteristics of agenesis, impaction, angular position, and pathologic changes of third molars were recorded. The chi(2) test was used for analysis. The proportion of third molar agenesis was 17.3% with no statistically significant gender differences (18.4% for women and 15.8% for men). The frequency of impacted third molars (ITMs) was 35.9% (24.2% in men and 45.0% in women; P < .05). The frequency of maxillary ITMs was 43.2% (192 of 444 teeth), and the frequency of mandibular ITMs was 56.8% (252 of 444 teeth). The position observed most often was mesioangular inclination, with a frequency of 50.0%. Only 10.4% of the ITM teeth were affected by any pathologic changes, and most of these changes were associated with the horizontal position. The present results showed that agenesis accounted for 17.3% and impaction for 35.9% of the pathologic features in this group of Turkish orthodontic patients aged 20 to 26 years of age. Mesioangular inclination was seen in 50.0%, and a small proportion (10.4%) had pathologic changes of the ITMs. Copyright 2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.