Multivariate relationships among risk factors and hypoesthesia of the lower lip after extraction of the mandibular third molar

Objective. In this study, we investigated the multivariate relationships among risk factors and hypoesthesia of the lower lip. Study design. Various risk factors of hypoesthesia of the lower lip after mandibular third molar extraction were investigated by univariate and multivariate analyses. Results. Applying the logistic regression model and forward stepwise algorithms, canal observed, remarkable hemorrhage, loss of the white line of the root, diversion of the canal, and close relationship of the roots to the inferior alveolar nerve were identified as significant variables. Conclusions. Procedure-related factors during surgery, such as canal observed and remarkable hemorrhage, and radiographic signs, such as loss of the white line of the root, diversion of the canal, and close relationship of the roots to the inferior alveolar nerve, were high risk factors of hypoesthesia of lower lip after extraction. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;111:e1-e7)