Reevaluation of the Layered Anatomy of the Forehead: Introducing the Subfrontalis Fascia and the Retrofrontalis Fat Compartments

Abstract

Background: Novel imaging methods have provided new insights into the layered anatomy of the forehead. This study seeks to critically reevaluate the layered anatomy of the forehead by using ultrasound imaging and cadaveric dissection to provide an accurate anatomical description that can be used to guide safer surgical and minimally invasive frontal procedures. Methods: This study used ultrasound imaging in a sample of 20 volunteers (12 female and eight male volunteers; aged 35.25 ± 4.2 years; body mass index, 24.28 ± 3.5 kg/m2) and cadaveric dissections of 16 body donors (12 female and four male body donors; aged 72.76 ± 9.5 years) to reevaluate the layered anatomy of the forehead. Layer-by-layer dissections and ultrasound-based measurements of the frontal structures guided conclusions. Results: The following layered arrangement was identified: layer 1, skin; layer 2, superficial fatty layer; layer 3, suprafrontalis fascia; layer 4, orbicularis oculi and frontalis muscle (same plane); layer 5, a homogenous layer of fat [preseptal fat (in the upper eyelid), retro-orbicularis fat (deep to the orbicularis oculi muscle), and retro-frontalis fat (deep to the frontalis muscle); layer 6, subfrontalis fascia; layer 7, preperiosteal fat within the prefrontal space in the lower forehead and deep compartments in the upper forehead; and layer 8, periosteum. Conclusions: The results of this study add to the current understanding of the layered arrangement of the forehead. The combination of ultrasound imaging and cadaveric dissections provided evidence for a continuous fatty layer deep to the frontalis muscle.

Tips and Tricks for Facial Toxin Injections with Illustrated Anatomy

“…Here, the frontalis muscle is located within a fascial envelope that is termed suprafrontalis and subfrontalis fascia. 11 The suprafrontalis fascia was previously described 12 and recently confirmed in histologic studies 13 and functions as a force-transmitting unit between the contracting muscles and the overlying skin of the forehead. The suprafrontalis fascia acts in close interaction with the subdermal fatty layer of the forehead, 11 and it is plausible that the increase in fatty layer thickness results in a reduced muscle contraction visibility on the overlying skin.…”

“…11 The suprafrontalis fascia was previously described 12 and recently confirmed in histologic studies 13 and functions as a force-transmitting unit between the contracting muscles and the overlying skin of the forehead. The suprafrontalis fascia acts in close interaction with the subdermal fatty layer of the forehead, 11 and it is plausible that the increase in fatty layer thickness results in a reduced muscle contraction visibility on the overlying skin. The same arrangement can be found in the lateral periorbital region, in the upper and lower eyelids, and in the tear trough; however, in the majority of patients, the layer of fat in the periorbital region is substantially reduced or even absent.…”

Aesthetic considerations for treating the Asian patient: Thriving in diversity international roundtable series

“…Injection in the forehead is an important approach for managing facial shape and projection. Prior to injecting the forehead, the injector should have a firm understanding of anatomy, including the organization of tissue layers and the paths and depths of resident nerves and vessels 34–36 . In addition, awareness of how these structures change depending on location relative to the medial and inferior frontal septum is critical.…”

Detection of Lymphatic Vessels in the Superficial Fascia of the Abdomen

“…In the past, the hypodermis was considered to be a homogeneous structure filling the space between the skin and the muscles, but recently many studies have highlighted that it is divided into two layers—the superficial adipose tissue (SAT) and deep adipose tissue (DAT) [ 5 , 6 , 7 ]—by the superficial fascia (SF). The superficial fascia, recognized as a specific anatomical structure with a distinct anatomical identity, presents specific characteristics of cells and innervation; it is a continuous thin fibrous membrane that is rich in elastic fibers, with a mean thickness of 847.4 ± 295 μm [ 8 , 9 ].…”