A simple method for evaluation of tongue position

Neck extension because of contraction of cervical extensor muscles often brings about a lower-positioned tongue secondary to jaw opening in patients with congenital myopathy (CM). We hypothesized that neck extension in control subjects would reproduce the lower position of the tongue similar to that found in a CM patient. A simple method was formulated to evaluate the tongue position in terms of tongue pressure on the maxillary molar. A pair of pressure sensors was attached to the buccal and lingual surfaces of the upper molar for both the CM patient and four control subjects. Changes in the buccal and tongue pressures were recorded at the neck extension position for the CM patient and during both the natural head position and neck extension for the control subjects. There was a remarkable difference between buccal and tongue pressures in the neck extension position in the CM patient: tongue pressure was not detected at all, indicating there was no contact between tongue and upper molar. The buccal and tongue pressures were approximately equal in the natural head position in the control subjects. However, both buccal and tongue pressures were reduced during neck extension in the control subjects, with a greater decrease in the tongue pressure than the buccal pressure. These findings suggest that neck extension in a control subject reproduces the lower position of the tongue observed in CM patients. We propose that the pressure sensor enables evaluation of the tongue position, but further investigation is required.