Assessment of changes in muscle activity using electromyography in patients undergoing orthognathic surgery

Abstract

The aim of the present clinical trial study is to evaluate the effect of double jaw orthognathic surgery (OGS) on electromyographic activity of the masseter, anterior temporal, digastric, and sternocleidomastoid muscles in skeletal Class III patients. This prospective study included 10 patients who underwent Lefort 1 osteotomy of the maxilla and genioplasty of the mandible to correct skeletal dental class III malocclusion and presurgical and postsurgical EMG data were analyzed and compared. The participants underwent bilateral surface electromyography activity evaluation with a focus on the masseter, anterior temporalis, digastric and sternocleidomastoid muscles. Recordings were made each during 3 jaw positions: clench, resting and swallowing positions. The pre-surgical EMG data were compared with the post-surgical EMG data taken after 1 month to evaluate any changes in muscle activity. A significant increase in the average EMG activity after an orthognathic corrective surgery was observed. There were no significant postoperative changes in the EMG potentials of the anterior temporalis and masseter bilateral balance in the pre-op and post-op clench positions. Significant muscle posturing was observed in the post-op resting position with bilateral masseter, sternocleidomastoid, and right temporalis values>2mcv with mandible and rest.