The Association of Distal Caries in Mandibular Second Molars with the Position of Mandibular Third Molars: A Cone Beam Computed Tomography Study
Author(s): Danya Hashem* and Ebtihal Zainalabdeen
Introduction: There is a high prevalence of impacted mandibular third molars (M3Ms) worldwide and surgical removal of M3Ms is a common procedure in oral and maxillofacial surgery. Few studies have explored the effect of eruption status of M3Ms on the presence of distal caries lesions of mandibular second molar (M2M) by using cone beam computed tomography (CBCT). Aim: Analyze the prevalence of caries and the degree of its severity on the distal surface of M2Ms in a Saudi population and correlate this with the eruption and position of the M3Ms in three dimensions using CBCT. Materials and Methods: CBCT scans of 160 patients were included and the patient age and gender, impaction depth and angulation of the M3M, contact point localization and horizontal position of the M3M, the presence of distal caries and its severity on the M2M were assessed. Association between distal caries and demographic/radiographic variables were analyzed using Pearson’s chi-square and Fisher exact test and multivariate regression was used to identify risk factors. Results: The prevalence of distal caries in M2Ms adjacent to the M3Ms was 15%. Contact point localization was the only variable associated with the presence of distal caries in M2Ms where impacted M3Ms with a contact point at or above the CEJ of the M2M are associated with distal caries. Conclusions: Clinical risk should influence the decision for prophylactic removal of the M3M. Careful evaluation of the distal caries on the M2M and cautious consideration of the extraction of the M3Ms should be undertaken.