Relative impact of patient characteristics and radiographic variables on the difficulty of removing impacted mandibular third molars.

Aim: The aim of this study was to assess the relative contributions of patient characteristics and radiographic variables to the difficulty of extraction of impacted mandibular third molars in a Nigerian population.

Methods And Materials: Seventy-nine consecutive patients undergoing mandibular third molar extractions were recruited for this prospective cohort study. Specific patient characteristics and radiographic variables were recorded. All extractions were performed under local anesthesia by the same oral surgeon, and the surgical difficulty was assessed based on the duration of surgery.

Results: Body weight (BW) (P=0.009) and body surface area (BSA) (P=0.004) were the significant patient characteristics while tooth impaction depth (P=0.002), number of roots (P=0.035), and tooth angulation (P=0.003) were the significant radiographic variables associated with surgical difficulty using a univariate analysis. A multiple linear regression model was constructed with these variables using surgical difficulty as the dependent variable. Radiographic factors were found to be the more important determinants of surgical difficulty with the depth of impaction (P=0.038) being the singular most important factor.

Conclusion: Although the difficulty of surgical removal of impacted lower third molars is dependent on BW, BSA, impaction depth, tooth angulation, and the number of roots, radiographic variables were of greater importance with impaction depth being the most important single factor.