Subfascial and submuscular methods of temporal muscle dissection and theirrelationship to the frontal branch of the facial nerve - Technical note

The microsurgical anatomy of the temporal and zygomatic branches of the fac ial nerve are presented along with related local vasculature (frontal and p arietal branches of the superficial temporal artery [STA]) as encountered w hen using subfascial and submuscular temporal muscle dissection techniques for anterolateral craniotomies. Twenty sides were studied in 10 cadaveric specimens that had been previousl y injected with latex. The rami of the temporal and zygomatic branches of t he facial nerve and branches of the STA were dissected out through pteriona l and orbitozygomatic approaches by using a submuscular or subfascial tempo ral muscle dissection technique. The three rami of the temporal branch of t he facial nerve (the auricularis, frontalis, and orbicularis) were found to run within the galeal plane of the scalp. The zygomatic branch of the faci al nerve was found to course deeper than the most caudal extension of the g alea, known as the superficial musculoaponeurotic layer. The frontal branch of the STA served as an important landmark for the subfascial or submuscul ar dissections because excessive reflection of the scalp flap inferior to t he level of this vessel would inadvertently injure the frontalis branch of the facial nerve. Subfascial and submuscular dissections of the temporal muscle offer an alte rnative to the interfascial technique during anterolateral craniotomies. Sc alp and temporal dissection performed with careful attention to anatomical landmarks (frontal branch of the STA and the suprafascial fat pad) provides a safe and expeditious alternative to the traditional interfascial techniq ue.