Nuances in Superficial Musculoaponeurotic System Rhytidectomy

Histomorphological analysis of the superficial musculoaponeurotic system in Macaca mulatta species

INTRODUCTION

The superficial musculoaponeurotic system (SMAS) is a well described facial functional unit in humans. SMAS connects mimic musculature to the skin having many implication in facial mimic expression. One of the various morphological and physiological analogies in human and Macaca mulatta species is the facial mimic. The present study analyzed Macaca mulatta species SMAS morphology and its facial topographical differences and compared this with human SMAS tissue morphology.

MATERIAL AND METHODS

Macaca mulatta full-graft tissue blocks of skin, subcutaneous tissue and mimic muscles from five topographical different facial regions (Regio Temporalis, Regio Buccalis, Regio Infraorbitalis, Regio Angulus Oris and Regio Mandibularis) were collected postmortem from eight individuals (n = 8) at the German Primate Center, Leibniz Institute for Primate Research in Göttingen (DPZ) and studied histologically. Haematoxylin-eosin and azan stained histological serial sections of full-graft tissue blocks were analyzed and SMAS topographical differences evaluated.

RESULTS

SMAS typical tissue morphology was recognized in all Macaca mulatta histological serial sections (n = 780). Regio Infraorbitalis Macaca mulatta SMAS (MmSMAS) morphology was similar to human infraorbital SMAS morphology (type I SMAS). Suborbicularis oculi fat pad was recognized in Macaca mulatta samples. Human type I similar SMAS morphology was demonstrated over Macaca mulatta Regio Temporalis and Regio Buccalis. Regio Angulus Oris and the cranial area of the Regio Mandibularis presented human type II similar SMAS morphology. Type IV MmSMAS was closely related to the parotid gland tissue presence. The cervical area of the Regio Mandibularis presented human type V similar SMAS morphology.

CONCLUSIONS

SMAS is a complex fibro-musculo-adipose tissue network and probably an important pivot in Macaca mulatta facial system supporting mimic expression. This study provided insights into MmSMAS typology and similarity with human SMAS tissue morphology.

Facelift Surgery after Permanent Filler: Outcomes after Removal of Permanent Filler under Local Anesthesia

Permanent fillers were previously used to fix wrinkles associated with aging as they were considered a reasonable choice for facial rejuvenation. However, the subsequent removal of permanent fillers is of great concern to surgeons before performing a facelift surgery. Many studies have evaluated the outcomes of facelift surgery; however, we sought to evaluate the outcomes of facelift surgery which required removal of fillers beforehand.

Methods

This retrospective cohort study evaluated the outcomes of 50 patients with regard to patient satisfaction and postoperative complications of facelift surgery with removal of permanent filler under local anesthesia. A short scar rhytidectomy with superficial muscular aponeurotic system plication was performed. Preoperative and postoperative photographs were analyzed by two independent surgeons to report asymmetry scores ranging from one to three (one none, two slight, and three obvious asymmetries). Patient satisfaction scores were also recorded.

Results

The preoperative presentations of the permanent filler were asymmetry (82%) and disfiguring facial edema (26%). Removing fillers under local anesthesia is generally tolerable, with 56% of patients tolerating rhytidectomy. The degree of the participants' satisfaction after follow-up was satisfactory; two-thirds of patients (62%) were satisfied. There was a significant difference between surgeons' preoperative and postoperative assessment of asymmetry scores (P < 0.05).

Conclusions

Permanent filler removal with concomitant face-neck lift surgery has satisfactory outcomes. The procedure length was primarily determined by the patient's skin characteristics and the severity of the local condition.