Treatment of Chin Retrusion With Botulinum Toxin Plus Hyaluronic Acid Filler in Comparison With Hyaluronic Acid Filler Alone: A Randomized, Evaluator-Blinded, Controlled Study

Hyaluronic acid (HA) has already been widely used for chin augmentation. Patients with chin retrusion frequently present with increased chin hypertonia. Monotherapy with HA falls short in addressing the multifaceted cosmetic concerns associated with chin retrusion.This study aimed to investigate the clinical efficacy and safety of the combination therapy involving Botulinum Toxin (BTX) and HA in the treatment of chin retrusion.We enrolled subjects with moderate to severe chin retrusion for a 9-month follow-up, where they received either combined treatment with BTX plus HA or monotreatment with HA. We also calculated surface-volume coefficient using 3D digital scanning technique, and evaluated outcomes based on Allergan Chin Retrusion Scale (ACRS), Global Aesthetic Improvement Scale (GAIS) and Treatment-Related Adverse Events (TRAEs).A total of 50 subjects were recruited and randomized in treatment group (BTX plus HA) or control group (HA alone) in a 1:1 ratio. Subjects in treatment group exhibited significantly higher surface-volume coefficients during the first 6 months (p < 0.05). ACRS scores and responder rates in two groups remained similar throughout the follow-up (p > 0.05). Within the initial 3 months, the GAIS responder rate in treatment group was significantly higher than that in control group (p < 0.05). Mild TRAEs were observed in both groups, and subsided within 7 days. There was no increase in adverse effects with the combined treatment.In comparison to monotherapy, the combined treatment not only improved the surface-volume coefficient of Hyaluronic acid but also achieved similar ACRS scores using less HA volume. Furthermore, it yielded superior treatment outcomes for individuals with chin retrusion.