EFFECT OF NON ERUPTED 3RD MOLARS ON DISTAL ROOTS AND SUPPORTING STRUCTURES OF APPROXIMAL TEETH - A RADIOGRAPHIC SURVEY OF 202 CASES

Root resorption of 2nd molars in proximity to non-erupted 3rd molars h as been widely reported. The purpose of this study was to determine th e prevalence of root resorption in second molars adjacent to non-erupt ed third molars. Its association to age and gender of the patient, loc ation and inclination of the non-erupted third molar and to distal bon e support of the 2nd molars was analyzed. A radiographic survey of 202 periapical radiographs taken in patients with clinically missing thir d molars was conducted. 3 examiners independently evaluated the radiog raphs and only those cases where at least 2 observers agreed were incl uded in this report. Statistical analysis was performed on 186 radiogr aphs. Associations were analyzed with the Pearson chi(2) test. Radiogr aphic evidence of root resorption was found in 45 2nd molars (24.2%) o f which 12 (6.5%) showed moderate to complete root resorption. Non-eru pted tooth apical position and mesio-inclination of 60 degrees or more relative to the distal root of the second molar were significantly as sociated with root resorption (p=0.01368 and p=0.0194, respectively). Resorption was positively associated with age of patient (p=0.00606). These results may support early extraction of impacted 3rd molars espe cially in cases with a mesio-angulation of 60 degrees or more and an a pical location in proximity to the distal root of the 2nd molar.