Abstract
BACKGROUND/PURPOSE: The superficial musculoaponeurotic system (SMAS) represents a pivotal component of midfacial soft tissue architecture, with significant implications for both aesthetic and reconstructive interventions. However, the histological characteristics of the nasal SMAS remain inadequately elucidated, particularly within Asian populations. This study aimed to characterize the histological features of the nasal SMAS in adult Vietnamese cadavers and to assess its potential relevance to oral and maxillofacial surgical procedures involving the midface. MATERIALS AND METHODS: Histological analyses were performed on eight formalin-fixed nasal tissue specimens obtained from adult Vietnamese cadavers. Sections encompassing the skin to the periosteum overlying the nasal bone were subjected to hematoxylin-eosin and Trichrome staining. Microscopic evaluation focused on the SMAS architecture, as well as associated vascular, neural, and adipose structures, assessed across five anatomical landmarks: glabella (G), nasion (N), sellion (S), kyphion (K), and rhinion (R). RESULTS: A distinct SMAS layer was identified in all specimens, exhibiting two primary fibrous configurations: vertically oriented septa at G, N, and S, and parallel-running fibers at K and R. Vascular and neural elements were consistently observed superficial to the SMAS, with variable intralayer presence. The superficial fat layer demonstrated greater thickness at G and N, whereas the deep fat layer was predominantly noted at G. CONCLUSION: This study provides novel histological insights into the nasal SMAS, contributing to a more precise anatomical framework pertinent to oral and maxillofacial surgical planning. Understanding these structural nuances may enhance surgical safety and optimize aesthetic and functional outcomes in midfacial procedures.