TRIGEMINAL SOMATOSENSORY-EVOKED POTENTIALS BEFORE, DURING AND AFTER AN INFERIOR ALVEOLAR NERVE BLOCK IN NORMAL SUBJECTS

The changes of the trigeminal somatosensory evoked potential (TSEP) be fore, during and after inferior alveolar nerve block were serially rec orded in six healthy subjects (33-43 years of age; mean age 38.0 years ). In four subjects in whom successful nerve block was achieved, TSEP showed linear flattening of the wave form. The recovery of TSEP slight ly preceded the recovery of threshold of the sensation to electrical s timulation and that of two-point discrimination on tile skin. In the r emaining two subjects, in whom effective nerve block failed, TSEP show ed no change in the wave form but did show slight prolongation of the latencies. We conclude that TSEP can be used as a method to confirm wh ether conduction anesthesia has been successful or unsuccessful.