Document Type
Article
Publication Title
JPRAS Open
Abstract
Background
Anatomy of the frontal branch of the facial nerve relative to the zygomatic arch and the superficial musculoaponeurotic system (SMAS) has been well described. The variability centers on the location where the frontal branch traverses from a deeper to more superficial plane in the SMAS. The goal of this study is to examine the depth transition of the frontal branch of the facial nerve relative to the zygomatic arch with hopes of pinpointing a caution zone for dissection to avoid nerve injury.
Methods
The frontal branch of the facial nerve was dissected in 36 hemifacial fresh cadaver specimens. Pitanguy's line, the zygomatic arch, and temporal crest were marked. Measurements were taken from the zygomatic arch to the location where the frontal branch pierced the temporoparietal fascia. Locations of the superficial temporal artery (STA), the frontal branch cross relative to the lateral orbital rim and frontalis muscle were also measured.
Results
In 94.4% (n = 36) of the specimens, the frontal branch was found to transition to an intra-SMAS plane approximately 9.6 mm above the zygomatic arch. In all specimens, the frontal branch transitioned to an intra-SMAS plane approximately 12.2 mm posterior to Pitanguy's line.
Conclusions
This study describes a surgical “caution zone” centered on a point 9.6 mm above the arch and 12.2 mm posterior to Pitanguy's line, and related to the anterior branch of the STA. We hope this anatomical detail will help to decrease the likelihood of intraoperative injury to the frontal branch of the facial nerve.
DOI
10.1016/j.jpra.2019.11.009
Publication Date
12-2020
Keywords
rhytidectomy, frontal branch of the facial nerve, Pitanguy's line, temporoparietal fascia, SMAS
ISSN
2352-5878
Recommended Citation
Pankratz J, Baer J, Mayer C, Rana V, Stephens R, Segars L, Surek CC. Depth Transitions of the Frontal Branch of the Facial Nerve: Implications in SMAS Rhytidectomy. JPRAS Open. 2020; 26. doi: 10.1016/j.jpra.2019.11.009.
