The goal of this study was to evaluate the efficacy and safety of two injection techniques in the management of masseteric hypertrophy using Xeomin Cosmetic.

Background: Xeomin Cosmetic has been used previously in the management of masseteric hypertrophy. However, a standardized injection technique has not been established. The goal of the present study was to evaluate the efficacy and safety of two injection techniques in the management of masseteric hypertrophy using Xeomin Cosmetic.

Methods: Thirty female patients with masseteric hypertrophy were recruited and evenly randomized to receive bilateral treatments of either 1) a single injection technique (SIT), or 2) a multi-injection technique (MIT). Improvement of masseteric hypertrophy was assessed at Week 16 using standardized measurements and photographs. Patients completed a 5-point satisfaction questionnaire while physicians the global aesthetic improvement scale (GAIS) and 10-point photonumeric masseter prominence rating scale.

Inclusion Criteria:

1. At the time of consent, women over the age of 18 years old.
2. Patients with established hypertrophy of the masseters, palpable and visible.
3. Accepted the obligation not to receive any other facial procedures through the 6-month follow-up.
4. Understood and accepted the obligation and would be logistically able to appear for all scheduled follow-up visits.
5. No previous facial fillers for a period of 6 months prior to this study.
6. No previous facial fillers along the jawline for 18 months
7. Capable of providing informed consent.
8. No previous botulinum toxin type A treatment for masseteric hypertrophy in the last 12 months.

Exclusion Criteria:

1. Current Pregnancy or lactation
2. Hypersensitivity to Xeomin
3. Generalized disorders of muscle activity (e.g. myasthenia gravis, Lambert Eaton syndrome)
4. Presence of infection at the site of injection
5. Inability to comply with follow-up and abstain from facial injections during the study period
6. Patients with a score of 2 or greater on the Merz Aesthetics Scale for the Jawline