Introduction

The superficial musculoaponeurotic system (SMAS) is a controversial functional fibro-adipose layer that connects the mimic muscles to the skin and is involved in a variety of facial mimic expressions. The presence of muscle fibers within SMAS fibrous septa is hypothetical. The present study analyzed SMAS fibrous septa composition for the existence of striated muscle cells.

Methods

Histological serial sections of the sample borders (n = 107) of 19 in sano-resected and diagnosed cutaneous tumors of the midfacial region were investigated. Immunohistochemical (actin and myosin) and hematoxylin and eosin staining were performed to detect striated muscle cells in SMAS fibrous septa.

Results

A fibro-neuro-musculo-vascular functional unit within SMAS fibrous septa was demonstrated. SMAS striated muscle cells were morphologically independent from preparotideal and periorbital mimic muscles. Intraseptal blood vessels draining the superficial and deep SMAS vascular system were described.

Conclusions

Striated muscle cells were demonstrated within SMAS fibrous septa. Nerve cells and vascular tissue together with the SMAS fibro-muscular meshwork demonstrated an autonomous operating functional unit that hypothetical modulated individual mimic expression contributing to the diversity of mimic expression. The SMAS develops with mimic muscle contractions as a synergetic effect during facial crease and fold formation processes.

中文翻译：

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中面部浅表肌肉腱膜系统内横纹肌细胞的免疫组织化学证据

介绍

浅表肌肉腱膜系统 (SMAS) 是一个有争议的功能性纤维脂肪层，它将模拟肌肉连接到皮肤，并参与各种面部模拟表情。SMAS 纤维间隔内存在肌纤维是假设性的。本研究分析了 SMAS 纤维隔膜成分是否存在横纹肌细胞。

方法

研究了 19 个样本边界 ( n  = 107) 的组织学连续切片，这些切片是在面部中部区域的 sano 切除和诊断的皮肤肿瘤中进行的。进行免疫组织化学（肌动蛋白和肌球蛋白）和苏木精和伊红染色以检测 SMAS 纤维间隔中的横纹肌细胞。

结果

展示了 SMAS 纤维间隔内的纤维神经肌肉血管功能单元。SMAS 横纹肌细胞在形态上独立于腮腺前和眶周模拟肌。描述了引流浅表和深部 SMAS 血管系统的间隔内血管。

结论

SMAS 纤维隔膜内显示横纹肌细胞。神经细胞和血管组织与 SMAS 纤维肌肉网一起展示了一个自主操作的功能单元，假设调节个体模拟表达有助于模拟表达的多样性。SMAS 以模拟肌肉收缩作为面部皱纹和褶皱形成过程中的协同效应而发展。