We report a case where nitrous oxide-oxygen anesthesia(GO)was used to determine interocclusal relation for a patient with oral dyskinesia(OD)who required full dentures.
The goal was to improve the OD through adjustment of the existing denture and to fabricate a new denture in centric occlusion. However, it was difficult to determine the interocculusal relation for the new denture owing to instability of jaw position caused by OD. The registration was not reproducible. We attempted to use nitrous oxide-oxygen anesthesia(GO)to relax muscle tension and control jaw motion to register interocclusal relation. Registration of occlusal relation was taken when the sedative effect was achieved ten minutes after the patient began inhaling 30% nitrous oxide gas. Registration was unaffected by OD.
The new denture caused a decrease in OD. The OD of the mandible was observed using a Gnatho-Hexagraph which represents jaw movements in six degrees of freedom(GC Corp., Tokyo). Although mild OD was observed even after tne new denture was used, the severity was significantly decreased. In this case, GO produced a sedative effect that resulted in a relaxation of muscle tension that allowed control of jaw motion. This allowed fabrication of a better denture as a result of the reproducible interocclusal relationship.