Sensitivity and Specificity of Pantomography to Predict Inferior Alveolar Nerve Damage During Extraction of Impacted Lower Third Molars

Purpose

The purpose of the study was to assess the sensitivity and specificity of maxillary radiographic image findings in predicting nerve lesions in third molar surgery.

Patients and Methods

A total of 260 third molars were assessed prior to surgical removal by means of panoramic radiography in the sample of 153 patients (73.8% female). The tooth root was classified according to the presence or absence of a radiological sign of a close relationship with the mandibular canal. Of the 260 cases assessed, the presence of a radiological sign of a close relationship with the mandibular canal was recorded in 159 cases.

Results

Of the 260 cases, 9 (3.5%) presented postsurgical sensory complications. Though this percentage was higher among those in which there was judged to be a radiological sign of a close relationship with the mandibular canal than in those without such a sign, no significant association was shown to exist between the presence of the radiological sign and postsurgical changes in the inferior alveolar nerve (P = .94). The positive and negative predictive values were 0.03 and 0.97, respectively. Calculations on the results of the radiological examination in relation to the frequency of nerve lesions yielded values of 66% for sensitivity and 39% for specificity.

Conclusions

Panoramic radiography does not provide the reliable images required for predicting nerve lesions in third molar surgery.