Zygomaticotemporal nerve passage in the orbit and temporal area.

Injury of the zygomaticotemporal nerve causes paresthesia in its distributed area, and its entrapment induces protractive pain in case of manipulation of the orbital lateral wall, a Gillies or Dingman reduction procedure for a zygomatic fracture, or an endoscopic subperiosteal facelift. The aim of this study was to elucidate the surgical anatomy of the zygomaticotemporal nerve in the orbit and temporal area. Twenty hemifaces from 10 adult Korean cadavers (10 male and 10 female) were used in the study. The zygomaticotemporal nerve ran along the lateral wall of the orbit, passed through the zygomaticotemporal foramen, and reached to the temporal fossa. The point where the zygomaticotemporal nerve appears at the margin of zygomatic bone is defined as the vulnerable point (Vp); hence, the nerve might be injured during surgical procedures. The Vp was 11.29 +/- 2.65 mm below the zygomaticofrontal suture and 21.76 +/- 2.76 mm from the superior border of zygomatic arch. The most vulnerable points were within a 10-mm diameter circle (vulnerable zone). Its center was 11 mm from the zygomaticofrontal suture at an angle of 45 degrees inferolaterally. The zygomaticotemporal nerve ran between the deep layer and the superficial layer of the deep temporal fascia. It ran just superficial to the deep layer of the deep temporal fascia toward the temporal area and innervated the temporal skin. The area innervated by terminal branches of the zygomaticotemporal nerve included a circle with 30-mm diameter, with the center located 10 mm superior to the top of the auriculocephalic sulcus and 30 mm lateral to the lateral canthus. Precautions should be taken when working in the area of the vulnerable zone during the Dingman procedure involving periorbital incision in case of zygomatic fracture.