Efficacy, Influencing Factors and Prediction Models of Type A Botulinum Toxin in Treating Glabellar Lines.

[BACKGROUND] Botulinum Toxin Type A (BoNT/A) injection for glabellar lines is popular due to its minimally invasive nature, safety, and efficacy. However, injection techniques and factors influencing outcomes need further study. This study compares three-point and five-point injection techniques and constructs a predictive model based on five-point injection results.

[METHODS] 444 patients were divided into three-point (219) and five-point (225) injection groups. Wrinkle improvement was assessed using the Facial Wrinkle Scale (FWS) and Patient-Rated Facial Wrinkle Severity Scale (PFWS), and complications were recorded. A retrospective analysis of 259 patients (including new patients) receiving five-point injections was conducted. A nomogram prediction model was built using multivariable logistic regression and evaluated using ROC curves, calibration curves, and the Hosmer-Lemeshow test. Decision curve analysis validated its clinical applicability.

[RESULTS] The five-point technique had significantly higher long-term efficacy (P=0.041) and similar complication rates to the three-point technique. Age, pretreatment patient self-assessment, physician scores, and procedure time influenced outcomes. Age and moderate-to-severe pretreatment resting physician scores were risk factors for inefficacy, while severe pretreatment patient and physician scores were protective. The nomogram model showed excellent discriminative ability (AUC=0.836) and good consistency.

[CONCLUSION] The five-point BoNT/A injection technique offers superior long-term efficacy and safety. Age and pretreatment scores affect outcomes. The nomogram model effectively evaluates postoperative outcomes, providing a scientific basis for personalized treatment plans and improving patient satisfaction.