The prognostic value of panoramic radiography of inferior alveolar nerve damage after mandibular third molar removal: retrospective study of 400 cases

Abstract

Objective: The aim of the study was to estimate the accuracy of panoramic radiographic signs predicting inferior alveolar nerve (IAN) paresthesia after lower third molar removal.

Study design: In a case-control study the sample was composed of 41 cases with postoperative IAN paresthesia and 359 control cases without it. The collected data included "classic" specific signs indicating a close spatial relationship between third molar root and inferior alveolar canal (IAC), root curvatures, and the extent of IAC-root tip overlap. Bivariate and multivariate logistic regression analyses were completed to estimate the association between radiographic findings and IAN paresthesia.

Results: The multivariate logistic analysis identified 3 signs significantly associated with IAN paresthesia (P < .001): interruption of the superior cortex of the canal wall, diversion of the canal, and darkening of the root. The sensitivities and specificities ranged from 14.6% to 68.3% and from 85.5% to 96.9%, respectively. The positive predictive values, calculated to factor a 1.1% prevalence of paresthesia, ranged from 3.6% to 10.9%, whereas the negative predictive values >99%.

Conclusion: Panoramic radiography is an inadequate screening method for predicting IAN paresthesia after mandibular third molar removal.