Does early repair of trigeminal nerve injuries influence neurosensory recovery? A systematic review and meta-analysis.

This systematic review and exploratory meta-analysis of the available evidence was performed to examine whether early nerve repair of lingual nerve (LN) and inferior alveolar nerve (IAN) injuries has an effect on neurosensory recovery. A literature search was conducted to identify relevant studies meeting the inclusion criteria. Two reviewers independently evaluated the methodological quality of the included studies and the risk of bias using the ROBINS-I quality assessment tool. For the quantitative analysis, data were pooled using the Mantel-Haenszel random-effects method due to the clinical heterogeneity across the studies. Sensitivity and subgroup analyses were performed based upon the group definition of timing from injury to nerve repair, with breakpoints of 2, 3, and 6 months. A total 1236 citations were identified, with a final 13 studies included in the systematic review. A clear definition of 'early' versus 'late' repair was not reported in six studies, allowing only seven to be included in the meta-analysis. The effect of early repair on functional sensory recovery was found not to be significant in nine studies, while four studies found a significant effect of early intervention. The meta-analysis showed a combined success rate of 93.0% for the early group and 78.5% for the late group. The odds of improvement were 5.49 (95% confidence interval 1.40-21.45) in the 3-month breakpoint studies and 2.28 (95% confidence interval 1.05-4.98) in the 6-month studies. A trend towards early repair achieving better functional sensory recovery outcomes was observed, but the specific time period is unknown.