Electromyography after lateral pterygoid myotomy in monkeys.

Neuromuscular patterns of five female rhesus monkeys (Macaca mulatta) were studied to determine the effect of laternal pterygoid myotomy on the function of selected groups of masticatory muscles. Activity characteristics of the lateral pterygoid muscle were recorded as early as four days postoperatively. By the end of the second postoperative month, bilateral lateral pterygoid muscle activity was demonstrated in all animals. In all cases, it closely resembled preoperative patterns of lateral pterygoid muscle function. The activity was observed regardless of whether an inert barrier was used to prevent reattachment of the muscle. The results of this study indicate that the lateral pterygoid myotomy does not have a long-term effect of inhibiting the function of the lateral pterygoid muscle.