Electromyographic Evaluation of Temporalis Muscle Following Temporalis Tendon Transfer (Facial Reanimation) Surgery.

Abstract

Facial paralysis is a significant functional and aesthetic handicap. Many techniques have been defined for facial reanimation. The aim of the study was to evaluate postoperative electromyographical (EMG) activity of temporalis muscle to assess the potential neural impairments related to the surgical procedure. Four patients with facial paralysis were operated with the temporalis muscle tendon transfer technique. Simultaneous surface electromyographic (sEMG) activity at first postoperative year from the bilateral temporalis and masseter muscles was obtained at mandibular rest position and then during maximal clenching. Patients were followed for a minimum period of 18 months. Surface electromyographic evaluations during passive state revealed similar values for the operated and contralateral side. Measurements during active "clench-smiling" of the jaw revealed similar amplitudes for both muscles of the operated side in all cases except case #2. Case #2 revealed lower values for both measurements of temporalis and masseter muscles of the operated side compared with the contralateral side. Dissonant results of case #2 can be the consequence of impaired temporalis muscle activity because of the tension on the muscle as a consequence of overcorrection. Temporalis muscle transfer to the perioral region does not hinder contractility of the muscle as long as the facial deformity is not overcorrected.