Understanding Perceived Forehead Changes Post-Endoscopic Brow Lift: The Impact of Frontalis Muscle Contraction

BACKGROUND: Endoscopic brow lift surgery is increasingly performed, yet there are concerns about potential increase in forehead height and hairline position postoperatively. We believe one of the main factors in determining forehead height is the effect of frontalis muscle contraction. This study aims to investigate perceived changes in forehead dimensions following endoscopic brow lift surgery by using a closed-eye model that effectively eliminates frontalis muscle contraction and utilizing an artificial intelligence technique for precise measurement to assess whether forehead is indeed enlarged after this procedure. METHODS: A total of 35 patients who underwent endoscopic brow lift surgery were analyzed using the SPIGA model for facial landmark detection. Preoperative and postoperative measurements of forehead height and brow position were taken in both open and closed-eye states. Statistical analyses were conducted to compare these measurements. RESULTS: Significant increases in forehead height were observed postoperatively in the open-eye state (P＜0.001). However, no significant changes in forehead height were noted in the closed-eye state (P>0.05), indicating that the forehead itself does not elongate postoperatively. The perceived increase in forehead size is attributed to the comparison of contracted preoperative states with relaxed postoperative states. CONCLUSIONS: Endoscopic brow lift surgery does not inherently cause an increase in forehead size. The perception of elongation is likely due to the relaxation of the frontalis muscle post-surgery. The integration of AI in measuring facial changes offers a promising avenue for future research.CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.