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

[BACKGROUND] Hyaluronic acid (HA) has already been widely administered 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.

[OBJECTIVES] 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.

[METHODS] We enrolled patients with moderate to severe chin retrusion for 9 months of follow-up after they received either combined treatment with BTX plus HA or monotreatment with HA. We also calculated the surface-volume coefficient with 3-dimensional digital scanning technique, and evaluated outcomes based on the Allergan Chin Retrusion Scale (ACRS), the Global Aesthetic Improvement Scale (GAIS), and treatment-related adverse events (TRAEs).

[RESULTS] A total of 50 patients were recruited and randomized to the treatment group (BTX plus HA) or control group (HA alone) in a 1:1 ratio. Patients in the treatment group exhibited significantly higher surface-volume coefficients during the first 6 months (P < .05). ACRS scores and responder rates in the 2 groups remained similar throughout the follow-up (P > .05). Within the initial 3 months, the GAIS responder rate in the treatment group was significantly higher than that in the control group (P < .05). Mild TRAEs were observed in both groups, and subsided within 7 days. There was no increase in adverse effects with the combined treatment.

[CONCLUSIONS] In comparison to monotherapy, the combined treatment not only improved the surface-volume coefficient of hyaluronic acid but also achieved similar ACRS scores with less HA volume. Furthermore, the combination treatment yielded superior treatment outcomes for individuals with chin retrusion.