To explore the influence of the type of occlusal splint on the masticatory muscles (TA,MM).TA and MM EMG during ICP maximal clenching were recorded in 20 dentate normal subjects, when they weared no occlusal splint, relaxation splint and mandibular stabilization splint.With the insertion of relaxation splint and mandibular stabilization splint, the EMG parameters of TA and MM during ICP maximal clenching was dramatically reduced (P<0.05).The relaxation splint and mandibular stabilization splint can relax the masticatory muscles.