The course of the temporal branch of the facial nerve in the periorbital region.

PURPOSE: This study identified the terminal temporal and zygomatic branches of the facial nerve as they enter the orbicularis oculi muscle and related these branches to identifiable surface markings.

MATERIALS AND METHODS: The temporal and zygomatic branches of the facial nerve were dissected from 5 preserved cadavers (10 sides). The most superior temporal branch entering the orbicularis oculi muscle was identified and related to the lateral canthus of the eye. A vertical line was passed through this point so that the line was equidistant from the nasal tip and chin point. A line perpendicular to the vertical line through the lateral canthus served as the horizontal scale. Vertical and horizontal lines through the lateral canthus were used to establish the anatomic relationship between the lateral canthus and the branch of the temporal nerve entering the orbicularis oculi muscle.

RESULTS: The temporal branch was an average of 2.85 +/- 0.69 cm superior to the lateral canthus and an average of 2.54 +/- 0.43 cm lateral to the lateral canthus as it courses into the orbicularis oculi muscle. At the lateral border of the orbicularis oculi muscle, where the temporal and zygomatic nerves insert into the muscle, the mean vertical distance between the temporal and zygomatic nerves was 1.72 +/- 0.62 cm.

CONCLUSION: Incisions superior or inferior and parallel to the course of the facial nerve, can provide access to the fronto zygomatic suture and the superior and lateral orbit without damaging its branches.