Objective: This study was designed to observe how the mento-blink reflex (MBR) study is valuable in evaluating the inferior alveolar nerve injury.

Method: Eleven patients, suffering from the sensory discomfort after extraction of the third molar, and a control group consisting of 20 healthy individuals participated in the clinical neurosensory test (CNST) and the MBR study. The score of CNST was from 0 (normal) to 5 (worst) according to sensory deficit, and the results of MBR were divided into 3 groups: normal; prolongation of R₂ latency; no response.

Results: In the control group, R₂ latencies of right and left were 31.9⁑6.1 msec and 31.5⁑5.9 msec, respectively with the difference of 1.3⁑0.9 msec. The abnormality in the MBR study in patients was correlated with the subjective sensory symptoms (p=0.017) and the abnormality of MBR response was proportional to the score of the CNST.

Conclusion: We concluded that the MBR study is a useful diagnostic tool in reflecting the inferior alveolar nerve lesion.

Keywords :Inferior alveolar nerve, Mental nerve, Blink reflex, Mento-blink reflex