A comparative study of normal sensibility of the inferior alveolar nerve and the infraorbital nerve.

In order to assess the degree of similarity of the infraorbital nerve and inferior alveolar nerve, thirty subjects with no history of sensory injury were examined by a battery of neurosensory tests including: light touch, brush stroke direction, two-point discrimination, and thermal disk temperature assessment. In a matched sample experimental design, the sensibility of the inferior alveolar nerve (lower lip) was compared to the inferior orbital nerve (upper lip). The product moment correlations revealed a significant relationship (degree of sameness) between the upper and lower lip. The comparison of the upper and lower lip appear to be acceptable for retrospective tests for detection of neurosensory injury of the inferior alveolar nerve. Of these tests, light touch appears to be the most consistent while remaining sensitive to individual variation. The thermal disk assessment was least sensitive in that no individual variation could be demonstrated. In addition, there appear to be greater variations in men than in women.