Lingual nerve damage after third lower molar surgical extraction.

OBJECTIVES

Our objectives were to establish the incidence of lingual nerve damage after surgical removal of lower third molars, to identify the causes of the damage, and to construct a predictive model to assess the risk of lingual nerve injury.

STUDY DESIGN

We conducted a nonrandomized prospective study of 946 consecutive outpatients subjected to surgical extraction of 1117 lower molars in a university department of oral surgery. Preoperative, intraoperative, and postoperative data were gathered, and causal factors of lingual nerve damage were identified by using nonparametric tests and Pearson chi-square and Fisher exact tests. A prediction of lingual nerve injury risk was obtained by using logistic regression.

RESULTS

Of the extractions, 2.0% caused temporary nerve damage, though no lesion lasted more than 13 weeks. Lingual flap retraction, vertical sectioning of the tooth, surgeon inexperience, lingual angulation of the tooth, and prolonged operating time significantly increased the risk of nerve damage (P <. 05). The first 3 factors were included in a predictive logistic regression model.

CONCLUSIONS

Anatomical factors such as lingual angulation of the third molar, surgical maneuvers such as retraction of the lingual flap or vertical tooth sectioning, and surgeon inexperience all increase the risk of lingual nerve damage, although permanent lesions seem to be very rare.