Efficacy and Safety of Botulinum Toxin Type A in the Treatment of Benign Parotid Hypertrophy: a Prospective, Single-arm Clinical Trial

Benign parotid hypertrophy makes the earlobe area appear swollen and weakens the lateral facial contour and aesthetics. Efficacious treatment for benign parotid hypertrophy is not available. The authors evaluated the efficacy and safety of botulinum toxin type A for benign parotid hypertrophy treatment.Thirty-six participants with benign parotid hypertrophy were enrolled and treated with botulinum toxin type A injection. After 6 months of follow-up, changes in the thickness and length of the superficial lobe of the parotid gland were assessed. Analyses of patient subgroups and image analyses were also undertaken to assess improvement.Thirty-three participants completed this study. Superficial lobe of the parotid gland thickness was reduced significantly after botulinum toxin type A injection, but the longitudinal diameter of the parotid gland was not changed significantly ( p < 0.001 and p = 0.146, respectively). Subgroup analyses showed that the degree of parotid gland hypertrophy affected treatment efficacy and degree of improvement, but age and sex did not ( p < 0.001, p = 0.137, and p = 0.138, respectively). Image analyses showed improvement in the facial contour ( p < 0.05). Serious adverse reactions or complications were not observed.Botulinum toxin type A can be used to treat benign parotid hypertrophy, reduce parotid gland volume, and improve the facial contour.Therapeutic, IV.