Interval between injury and lingual nerve repair as a prognostic factor for success using type I collagen conduit

The purpose of the present study was to investigate the role of a type I collagen nerve conduit in the repair of lingual nerve injuries compared with those lingual nerve repairs performed without a collagen membrane and to identify the prognostic factors for functional sensory recovery (FSR).

This was a retrospective cohort study evaluating a sample derived from the population of patients who had undergone lingual nerve microsurgery from March 17, 2000, to February 23, 2010 by the same surgeon (V.B.Z.) with complete records available, including follow-up assessments. The primary outcome variable was the interval to successful FSR according to the British Medical Research Council criteria for FSR. The predictor variables were categorized into demographic, surgical, and clinical sensory testing. Appropriate descriptive statistics and univariate and multivariate Cox proportional hazards survival statistics were computed in analyzing the patient age at lingual nerve injury repair (in years), gender, timing of surgical intervention, mechanism of injury, specific surgical procedures, and application of a type I collagen conduit.

The study cohort included 41 patients with 42 lingual nerve injuries who underwent surgical repair. Their mean age was 28.3 ± 8.3 years (range 13 to 44), with 88% females (n = 32). In the multivariate model, the injury to surgery interval per 1-month increase (hazard ratio 1.23, 95% confidence interval 1.02 to 1.48, P = .029) and injury to surgery interval of 9 months or longer (hazard ratio 4.67, 95% confidence interval 1.04 to 20.87, P = .04) remained significantly associated statistically with successful FSR.

The results of the present study have demonstrated that the injury to surgery interval is the most significant prognostic factor in the repair of lingual nerve injuries. The use of the collagen membrane demonstrated a greater level of FSR compared with those treated without the use of the membrane. However, the results from the collagen conduit were not statistically significant.