The coronal or bi-temporal approach is used to expose the anterior cranial vault, the forehead, and the upper and middle regions of the facial skeleton. The extent and position of the incision, as well as the layer of dissection, depends on the particular surgical procedure and the anatomic area of interest. The coronal approach is placed remotely in order to avoid visible facial scars.
The subperiosteal or subgaleal planes are commonly used for coronal flap dissection. The scalp incision is extended lateroinferiorly into the preauricular region to gain access to the zygomatic arch and/or temporomandibular joint (TMJ). To protect the temporal branch of the facial nerve when the zygoma and the zygomatic arch are accessed, the superficial layer of the temporalis fascia is divided along an oblique line from the level of the tragus to the supraorbital ridge to enter the temporal fat pad. The dissection
below this fascial splitting line is carried out just inside the fat pad deep to the superficial layer of temporalis fascia until the zygomatic arch and zygoma are subperiosteally exposed.