Superficial Fascia of the Cheek and Nasolabial Area Shown in P45 Sheet Plastination

초록

Purpose: The aim of this study was to determine the extent of the superficial fascia of the cheek, and elucidate the relationships between the nasolabial fold and superficial fascia on histology and P45 sheet plastination. Methods: Two centimeter width specimen of the nasolabial area were harvested from the skin to periosteum. Then, 10-μm sections were made, stained with Masson trichrome, and observed under light microscope. Three head and neck specimens were sliced in horizontal (46 slices), coronal (30 slices), and sagittal (29 slices) sections using P45 sheet plastination (special polyester resin corrosion-resistant method designed to preserve biological sectional specimens in situ). Through slicing, bleaching, dehydration, casting, forced impregnation, curing, cutting, and sanding the molds, P45 plastination sheets provided good light transmission, allowing the internal structures within the sheet to reveal clearly in their intact form. Results: P45 sheet plastination revealed that the superficial fascia in the cheek area is generally composed of 3 layers: a superficial fatty layer, a membranous layer, and a deep fatty layer. Anteriorly, the MSF extended to the posterior border of the zygomaticus major muscle, enveloping this muscle, and then to the lateral border of the orbicularis oculi muscle. Posteriorly, the MSF extended to the anterior border of the parotid gland, and then was continuous with the parotid fascia. Superiorly, the MSF extended to the line from the tragus to the alar base. Inferiorly, the MSF extended to the line from the mandibular angle to the mouth corner. Below this line, SMAS continued to the upper border of the platysma muscle. The observations on histology and P45 sheet plastination correlated well. The nasolabial fold consisted of the superficial fatty layer of superficial fascia (SFS).