[Muscular compliance of the auditory tube]

The simultaneous electromyographical assessment of innervation patterns of the mylohyoid and the tensor veli palatini muscle is introduced as a new technique for the examination of the auditory tube function.

Clinical studies were performed on 30 healthy volunteers and 50 patients suffering from chronic tubotympanic mucositis and cholesteatoma. Concentric needle electrodes were advanced into the tensor veli palatini muscle through the palate. The mylohyoid muscle was examined using surface electrodes.

Innervation patterns of the tensor veli palatini muscle in volunteers were limited to the time interval of the mylohyoid innervation pattern only, i.e., the oral and pharyngeal phases of swallowing. In 14 of the chronic otitis patients these tensor muscle innervation patterns were found outside this interval.

This observation provides a new pathophysiological explanation for the clinical concept of a relative closing failure of the auditory tube. These results emphasize the significance of coordination in muscular compliance of the tube.