The effects of head rotation and tilt on oral pressure and muscle activity.

We present basic data on head positions that can serve as compensatory interventions for patients with weak tongue and buccinator muscles. We studied 30 Korean adults (15 males, 15 females; mean age, 23 years; range, 20-30 years). A TPS-100 instrument was used to measure tongue and cheek pressures and suprahyoid and buccinator muscle activities at various head rotations and tilts, as independent variables. The data were subjected to one-way analysis of variance and post-hoc (linear contrast) testing. Tongue elevation pressures differed significantly when the head was flexed or extended compared to the neutral position (P<0.01). Suprahyoid muscle activity varied significantly when the head was rotated left or right compared to neutral, or tilted with the tongue elevated (P<0.01). Cheek pressure varied significantly when the head was rotated left or right compared to neutral, or tilted (P<0.01). Both tongue and cheek pressures increased significantly when the head was extended or rotated contralaterally compared to the neutral position. Suprahyoid muscle activity increased when the head was flexed or extended, or contralaterally or ipsilaterally rotated compared to the neutral position. Therefore, we suggest that head rotation or tilting could be used to vary oral pressure and muscle activity.