The Medial Canthus Fibrous Band's Impact on Epicanthal Fold Severity and Classification in Asians: Implications for Epicanthoplasty

Abstract

Abstract Background The epicanthal fold (EF) is a semilunar skin fold located in the medial canthus in most Asians. The medial canthus fibrous band (MCFB) reportedly plays a critical role in EF formation. Variations in MCFB shape and size affect the severity and type of EF. Objectives We aimed to analyze MCFB variations in different types and severities of EF and explore the effect of the MCFB resection epicanthoplasty technique (MCFB epicanthoplasty). Methods Surgical videos of 40 patients undergoing MCFB epicanthoplasty in our department were reviewed. The MCFB (area), transverse dimension, vertical dimension, upper eyelid direction length (UEDL), and lower eyelid direction length (LEDL) were measured. For aesthetic assessment, 37 patients were followed up for 6 months; intercanthal distance (ICD) and horizontal lid fissure length (HLFL) were measured. Preoperative and postoperative ICD/HLFL ratios were compared. Postoperative scar recovery was evaluated with the Patient and Observer Scar Assessment Scale. Statistical significance was set at P < .05. Results The MCFB diameter and area were larger for severe EF than for moderate EF (P < .01). Patients with severe EF had larger LEDL than UEDL (P < .01). The tarsalis type had a larger LEDL than the palpebralis type with the same severity (P < .01). MCFB epicanthoplasty yielded favorable postoperative cosmetic effects and scar recovery. Postoperative ICD decreased, while HLFL increased compared to preoperative values (P < .001). The ICD/HLFL ratio was significantly lower postoperatively than preoperatively (P < .001). Postoperative ICD/HLFL ratio was 1.2:1. Conclusions The MCFB affects the severity and type of EF. MCFB epicanthoplasty effectively corrected moderate to severe EF. Level of Evidence: 3