Surgical anatomy and blood supply of the fascial layers of the temporal region.

In 15 fresh cadavers (30 sides), we studied the two layers of fascia in the temporal region, with particular regard to their blood supply and to their usefulness--together or separately--as microvascular free-tissue autografts. The superficial temporal fascia (temporoparietal fascia, epicranial aponeurosis) lies immediately deep to the hair follicles. It is part of the subcutaneous musculoaponeurotic system and is continuous in all directions with other structures belonging to that layer--including the galea above and the SMAS layer of the face below. The deep temporal fascia (temporalis fascia, investing fascia of temporalis) is separated from the superficial fascia by an avascular plane of loose areolar tissue. It completely invests the superficial aspect of the temporalis muscle down to (but not beyond) the zygomatic arch. It is firmly attached to periosteum all around the margin of the muscles. Below it is attached to the upper border of the zygomatic arch. We found the deep temporal fascia to be supplied solely by the middle temporal artery, a constant branch of the superficial temporal. The middle temporal artery arises 1 to 3 cm below the upper border of the zygomatic arch, runs always superficial to the arch, and enters the deep temporal fascia immediately above that layer's attachment to the zygomatic arch. If the middle temporal vessels are protected, the two layers of temporal fascia can be raised together as a fully vascularized tissue island. This island can be fashioned as a bilobed or a double-layered flap, depending on the manner of dissection. The potential surgical usefulness of these findings is discussed.