The anatomical basis for surgical preservation of temporal muscle

Mobilizing the temporal muscle is a common neurosurgical maneuver. Unfortunately, the cosmetic and functional complications that arise from postoperative muscular atrophy can be severe. Proper function of the muscle depends on proper innervation, vascularization, muscle tension, and the integrity of muscle fibers. In this study the authors describe the anatomy of the temporal muscle and report technical nuances that can be used to prevent its postoperative atrophy.

This study was designed to determine the susceptibility of the temporal muscle to injury during common surgical dissection. The authors studied the anatomy of the muscle and its vascularization and innervation in seven cadavers. A zygomatic osteotomy was performed followed by downward mobilization of the temporal muscle by using subperiosteal dissection, which preserved the muscle and allowed a study of its arterial and neural components. The temporal muscle is composed of a main portion and three muscle bundles. The muscle is innervated by the deep temporal nerves, which branch from the anterior division of the mandibular nerve. Blood is supplied through a rich anastomotic connection between the deep temporal arteries (anterior and posterior) on the medial side and the middle temporal artery (a branch of the superficial temporal artery [STA]) on the lateral side.

Based on these anatomical findings, the authors recommend the following steps to preserve the temporal muscle: 1) preserve the STA; 2) prevent injury to the facial branches by using subfascial dissection; 3) use a zygomatic osteotomy to avoid compressing the muscle, arteries, and nerves, and for greater exposure when retracting the muscle; 4) dissect the muscle in subperiosteal retrograde fashion to preserve the deep vessels and nerves; 5) deinsert the muscle to the superior temporal line without cutting the fascia; and 6) reattach the muscle directly to the bone.