Deglutitive movement of the tongue under local anesthesia

The purpose of the present study was to investigate whether or not sensory input from the tongue affects deglutitive tongue movement. Subjects were seven healthy volunteers with anesthetic applied to the surface of the tongue (surface group) and seven healthy volunteers with the lingual nerve blocked by anesthetic (blocked group). We established six stages in deglutition and analyzed deglutitive tongue movement and the time between the respective stages by cineradiography before and after anesthesia. After anesthesia in both surface and blocked groups, deglutitive tongue movement slowed and bolus movement was delayed. The deglutitive tongue tip retreated in the blocked group. These results suggest that delay of tongue movement by anesthesia causes weak bolus propulsion and that deglutitive tongue tip position is affected by sensory deprivation of the tongue or the region innervated by the inferior alveolar nerve.