OR30 - Targeted Endodontic Microsurgery: A Dimensional Analysis of Projected Osteotomy and Resection Pathways in Mandibular Molars

Targeted endodontic microsurgery (TEMS) utilizes trephine burs and 3D-printed guides to produce osteotomies with greater accuracy than by freehand surgery alone. This cone beam computer tomography (CBCT)-based dimensional analysis study sought to determine the feasibility of performing TEMS on mandibular first and second molar roots. Two board-certified endodontists analyzed 398 CBCT coronal slices of mandibular first and second molar roots for TEMS feasibility based on: depth of osteotomy, anticipated trephine violation of lingual cortical plate, proximity to inferior alveolar canal, excessive bone loss from surgery, and unfavorable resection angle/length. Age and gender were analyzed for impact on TEMS feasibility. Chi-Square tests for categorical variables were conducted and t-test and analysis of variance (ANOVA) for continuous variables were conducted. TEMS-feasibility rates of mandibular first molar mesial and distal roots was found to be 85.71% and 75.24%, respectively, whereas that of mandibular second molar mesial and distal roots could be treated using TEMS at rates of 20.24% and 12.05%, respectively. Average osteotomy depth was significantly greater for TEMS non-feasible teeth (10.45mm) than for TEMS feasible teeth (7.64mm). Age and gender were not found to have significant impacts on TEMS feasibility. Mandibular first molars are six times more likely to be treatable by TEMS than mandibular second molars. Although mandibular second molars pose more surgical and anatomical challenges, TEMS should be considered as a treatment option for favorably positioned second molars.