Morphological analysis and three-dimensional reconstruction of the SMAS surrounding the nasolabial fold

Abstract

The NLF has a recognizable condensed cheek SMAS structure and represents the transition zone between the two SMAS types. Specimen-specific morphological differences necessitate individual planning and area-specific surgical procedures.

Facial fold and crease development: A new morphological approach and classification

“…Previous studies investigated the phenotype of the NLF, describing its shape and angle, which could be concave, straight, or convex (Rubin et al ; Zufferey ; Pessa et al ). Our most recent published study analyzed the three‐dimensional aspect of the SMAS bordering the NLF and concluded, similar to the results of the present study, that the NLF defined the transition area between two SMAS morphologies: Type I in the cheek area and Type II in the perioral area (Sandulescu et al , , ). Furthermore, in the present study, there were no morphological differences in SMAS architecture between the straight and convex NLF phenotypes as described by Pessa and colleagues (Pessa et al ).…”

“…Analysis of the subcutaneous tissue demonstrated three different SMAS morphological types: Type I in the cheek and forehead region, Type II in the perioral region medial to the NLF and MF, and Type III covering the upper and lower eyelid regions caudal to the UEF and cranial to the IOF. The existence of Type I SMAS covering the perioral region and Type II SMAS covering the midfacial and the forehead areas was demonstrated in early studies by Ghassemi et al () and corroborated by our latest studies (Ghassemi et al ; Sandulescu et al , , ). A previous study described Type III SMAS in the lower eyelid area cranial to the IOF (Sandulescu et al ).…”

“…The NLF is macroscopically situated on the cheek region starting from the tip of the ala of the nose and ending at the corner of the mouth, marking the transition to the perioral area (Lemperle et al ;Sandulescu et al , , ). As one of the most investigated facial folds, the NLF was mentioned in earlier studies under various labels such as “melolabial fold” (Bagal et al ; Gassner et al ) or “nasomandibular fold” (Robbins et al ).…”

“…Unfortunately, there are various interchangeable terms for wrin, including “wrinkle,” “crease,” “furrow,” “line,” and “fold,” describing the same cutaneous formations (Mallouris et al ; Hadi and Wilkinson ). Recent studies have demonstrated that the superficial musculoaponeurotic system (SMAS) defined a subcutaneous spreading musculoaponeurotic‐adipose layer covering the face with regional morphological differences probably related to nasolabial fold (NLF) development (Sandulescu et al , , ). Despite these histomorphological findings, the lack of uniform terminology has caused three different nomenclatures, “naso‐labial crease,” “naso‐labial groove,” and “naso‐labial fold,” to be used for the area marking the border between the cheek and the perioral area (Dunn and Harrison ; Hadi and Wilkinson ; Sandulescu et al , , ).…”

“…Nevertheless, the lack of set nomenclature and the inconsistent application of the various terms leads to misinterpretation (Dunn and Harrison ). Therefore, as with SMAS description, a standardized facial crease nomenclature is necessary for effective scientific communications among clinicians, the scholarly community and researchers (Ghassemi et al ; Hadi and Wilkinson ; Sandulescu et al , , ).…”