Skin Anatomy and Analysis.

This article provides a comprehensive review and strong reference for facial and neck anatomy. An anatomic foundation is built for the dermatologic concepts, techniques, procedures, and surgeries detailed in noninvasive skin treatments. Superficial anatomic landmarks have been established that allow for more nuanced navigation and measurement of facial features. Throughout this article, we discuss key anatomic features of the face and neck, compare dermal thickness in various regions and ethnic anatomic differences, review insertion points of retaining ligaments of the superficial musculoaponeurotic system, and detail diagnostic tools including ultrasound and optical coherence tomography analysis of the skin.

Anatomy behind the Paramedian Platysmal Band: A Combined Cadaveric and Computed Tomographic Study.

BACKGROUND: The muscular hypothesis explanation of the pathophysiology behind paramedian platysmal bands does not seem to provide a sufficient explanation for the clinical presentation of these platysmal bands in aged individuals with cervical soft-tissue laxity. The purpose of this study was to investigate the fascial relationships of the anterior neck to enhance appropriate surgical treatment. METHODS: Retrospective analysis of computed tomographic scans of 50 Caucasian individuals (mean age, 55.84 ± 17.5 years) and anatomical dissections of 20 Caucasian and 10 Asian body donors (mean age, 75.88 ± 10.6 years) were conducted. Fascial adhesions were classified according to platysma fusion types, and platysma mobility was tested during dissection procedures. RESULTS: Fusion between the left and right platysma muscles occurred in 64 percent in the suprahyoid region and in 20 percent at the thyroid cartilage, and in 16 percent, the platysma attached to the mandible without fusion. In the absence of muscular fibers, a fascial adhesion zone with limited mobility was observed where the superficial cervical fascia fused with the investing layer of the deep cervical fascia. CONCLUSIONS: Muscular contraction of the platysma results in elevation of the most medial platysma muscle fibers, which are not attached in the fascial adhesion zone. The presence of a fatty layer deep to the platysma enables platysmal movement and anterior and inferior gliding of the skin and platysma when cervical soft-tissue laxity exists. Surgical treatments should include transection of the fascial adhesion; this could potentially prevent the recurrence of paramedian platysmal bands.

Anatomical Continuation Between the Sub-Superficial Musculoaponeurotic System Fat and Retro-Orbicularis Oculi Fat: The True Nature of the Retro-Orbicularis Oculi Fat.

Objective: This study aims to analyze the anatomical location and continuation between the retro-orbicularis oculi fat (ROOF) and sub-superficial musculoaponeurotic system fat (subSMAS fat; named "innominate fascia") by comparing their layered structures, thereby letting us suggest a safe minimally invasive procedure guideline for the forehead and temple. Methods: Ultrasonographic scanning was performed from the upper medial eyebrow to the lateral side of the superior temporal line in 109 volunteers. Hematoxylin and eosin staining was performed on five specimens at the same area as ultrasonographic scanning. Then, four embalmed cadavers were dissected from the orbicularis oculi, frontalis muscle, superficial temporal fascia, and SMAS to confirm the location and continuation pattern of the ROOF and subSMAS fat. Results: On ultrasonography and histological images, there was a continuous fatty layer from the ROOF to the subSMAS fat. When dissecting, the ROOF, which was located deep below the frontalis muscle, also continued to the subSMAS fat, passing through the superior temporal line in the upper temporal region. Conclusions: This study confirmed that the subSMAS fat is an anatomical fat structure that is continuous with the ROOF. Since the subSMAS fat layer is known as a less vascular area, it is considered a safer layer to avoid serious complications, and injecting accurately into the subSMAS fat layer has been a goal of clinicians. Based on this study, a cannula will safely approach the subSMAS fat through the ROOF injection that named "forehead-downward approach."

Basic Consideration for Facial Aging: Analyses of the Superficial Musculoaponeurotic System Based on Anatomy.

BACKGROUND: The superficial musculoaponeurotic system (SMAS) is an important structure to understand for face-lift surgeries. However, the detailed distribution and imaging findings of the SMAS have not been established yet. OBJECTIVES: The aim of this study was to establish the accurate distribution and computed tomography (CT) imaging findings of the SMAS based on cadaveric studies. METHODS: This study was designed in a 3-step procedure. First, 7 cadaver faces were utilized to understand the distribution and histology of the SMAS. Second, the SMAS findings from the cadaveric studies were compared with the CT images. Third, CT images were enrolled for the SMAS interpretation. RESULTS: In 7 cadaveric studies, the SMAS was observed as a subcutaneous fibro-membranous structure extending from the galea aponeurotica to the platysma muscle and laterally connected to the parotid fascia. On the medial side, it also connects with major and minor zygomatic muscles. The SMAS consisted of muscular fibers, collagen fibers, and elastic fibers histologically. Eighteen CT images (all females; age range, 21-82 years) showed the thin linear structures corresponding to the fibro-membranous structures in the cadaveric studies. CT density of the SMAS was similar with that of the muscle, and the SMAS was recognizable in all 18 subjects. CONCLUSIONS: The SMAS is a definite anatomical structure that can be demonstrated as a thin membranous structure on CT. This clinical application could be applicable to the development the cosmetic surgical procedures.

Influence of Age, Sex, and Body Mass Index on the Depth of the Superficial Fascia in the Face and Neck.

BACKGROUND: Nonsurgical skin-tightening procedures are increasing in popularity, as patients seek aesthetic interventions that are safe with minimal downtime. OBJECTIVE: This study was designed to provide precise data on the depth of the superficial fascia-the structure of action-of the face and neck. METHODS: One hundred fifty Caucasian individuals (75 men and 75 women) were investigated with a balanced distribution of age (n = 30 per decade: 20-29, 30-39, 40-49, 50-59, and 60-69 years) and body mass index (BMI) (n = 50 per group: BMI ≤ 24.9 kg/m, BMI between 25.0 and 29.9 kg/m, and BMI ≥ 30 kg/m). The distance between skin surface and the superficial fascia was measured through ultrasound in the buccal region, premasseteric region, and lateral neck. RESULTS: The mean distance between skin surface and superficial fascia was for the buccal region 4.82 ± 0.9 mm, range (2.60-6.90); for the premasseteric region 4.25 ± 0.6 mm, range (2.60-5.80); and for the lateral neck 3.71 ± 0.5 mm, range (2.0-5.0). The depth of the superficial fascia increased with increasing BMI, whereas it decreased with advanced age. CONCLUSION: Knowing the precise depth of the superficial fascia for nonsurgical skin-tightening procedures will guide practitioners toward safer and more effective outcomes.