Abstract:
Background: Mandibular third molars are the most frequently encountered impacted teeth in dental surgery cases. Impactions could be caused by differences in crown size, later development of roots, reduced skeletal growth and lack of space. If untreated, an impacted tooth can lead to a number of problems, including external root resorption, which is frequently observed in mandibular second molars. The current study was designed to investigate the prevalence of root resorption of mandibular second molar caused by impacted mandibular third molar. METHODS: A cross-sectional, observational study using panoramic radiographs obtained from December 2019 to February 2022 from of patients who visited the Dental Clinic of the University of Benghazi. All radiographs were assessed about presence, location and severity of external root resorption of second molar. Positions of the impacted third molars were classified using two classification systems Pell, Gregory's and Winter classification. Data were tabulated and analyzed using Chi Square test; P value was set at 0.05. RESULTS: Panoramic radiographs of 434 patients were examined that consisted of 244 (56.2%) female and 190 (43.7%) male. The prevalence of external root resorption of second molar was 213(49%). The severity of resorption was categorized as slight (70.4%), moderate (17.8%), and severe (11.7%), most of them was located at cervical third. External root resorption was proportionally higher in the impacted teeth with class B (50.2%) and mesio-angular positions (62.9%). CONCLUSIONS: Prevalence of external root resorption of mandibular second molars caused by Impacted third molars was high in this study especially in males. Mandibular third molars with a greater potential to cause the adjacent second molar's external root resorption were those in class B position according to Pell and Gregory classification and in mesioangular position regarding Winter classification.
