The surgical anatomy of the deep temporal nerve: A cadaveric study.

BACKGROUND: The aims of this study were to investigate the surgical anatomy of the deep temporal nerve (DTN) and find (fixed/static) anatomical landmarks that could be used during surgery to localise the DTN branches. METHODS: Ten hemifaces of Dutch cadavers were dissected at the Department of Anatomy of the Radboudumc. Landmarks and measurements of interest were number of branches of the DTN, distance from the tragus to the DTN, and distance from the cranial and caudal parts of the posterior root of the zygomatic bone until the DTN. RESULTS: In this cadaveric study, 10 hemifaces were dissected (male, n = 6 [60%]; female, n = 4 [40%]) with an equal left/right side division. The number of deep temporal branches varied from 2 (30%) to 3 (70%) per side. The mean distance to the tragus varied from 40 to 53 mm, with a mean distance of 44.3 ± 4.4 mm. The mean distance from the cranial part of the posterior root of the zygomatic bone to the DTN varied from 29 to 35 mm, with a mean distance of 31.3 ± 2.1 mm. The distance from the caudal part of the posterior root of the zygomatic bone to the DTN varied from 8 to 17 mm, with a mean distance of 13.4 ± 3.4 mm. CONCLUSION: This study investigated the surgical anatomy and landmarks used for identification of the DTN and its branches. It suggested using firm landmarks for nerve identification, such as the posterior root of the cranial and/or the caudal zygomatic bone.

Deep temporal nerve transfer: A systematic review of anatomy, anatomical landmarks and clinical applications.

Background: Facial paralysis has a debilitating impact on facial function, especially the eyebrow. Static procedures have long been the standard treatment strategy, but in more recent years, dynamic procedures are being developed. To reconstruct the upper branches of the facial nerve (temporal and zygomatic branches), the deep temporal nerve (DTN) and its branches, with its close proximity to the eyebrow, can be used as a possible donor nerve for reinnervation. This systematic review provides an overview of the DTN anatomy and possible surgical treatment strategies. Materials and methods: A PubMed systematic literature search was performed in October 2021. Studies on cadavers and clinical studies providing anatomical or surgical information on the dissection of the DTN as well as surgical treatment strategies using the DTN were included. Results: The literature search produced 311 results, including 36 duplicates. After screening on title and abstract, 11 studies were found possibly relevant and underwent a full-text critical appraisal, resulting in 4 exclusions. In total seven studies were included. The data gathered were used to adequately describe the DTN anatomy, surgical approaches and landmarks used during surgery. Conclusion: The DTN and its branches prove to be a viable donor for the reconstruction of facial nerve branches, since the location and anatomical consistency can be relied upon through a multitude of studies, especially of the middle branch. Our study describes anatomy and nerve characteristics for its use in facial reanimation.