LAUSR

BACKGROUND The facial nerve (CN VII) is an anatomically intricate structure with its branches serving several physiological functions. CN VII innervates the muscles of facial expression which are crucial for eye protection, oral competence, and social interaction. The temporal branch, clinically referred to as the frontotemporal branch (FTB), is the most superior of the five branches and is at risk during cutaneous surgery in the temporal region and of the parotid gland. Several methods for delineating the FTB trajectory exist, the most widely known being Pitanguy's Line; defined as running from 0.5 cm below the tragus to 1.5 cm above the lateral eyebrow. However, variations in eyebrow location, often affected by modern day cosmetic trends, complicate the accuracy of Pitanguy's Line. OBJECTIVE We aim to develop a surgical landmark that can be used to identify the FTB location without the use of soft tissue structures. METHODS To minimize variation, we chose landmarks that were both consistent and easy to locate on patients using simple surface anatomy. Twenty-one cadaver hemifaces were dissected in order to locate the FTB in relation to the inferior border of the zygomatic arch and the apex of the tragus. RESULTS We found that the average distance from the apex of the tragus to the point where the FTB crossed the inferior border of the zygomatic arch was 3.21 cm ± 0.05 cm. CONCLUSION With this measurement, we aim to avoid the pitfalls of previous techniques, and maintain a widely applicable clinical tool using landmarks easily found on any patient.