BOTOX® Treatment of Masseter Muscle Hypertrophy

This study will evaluate the safety and efficacy of a range of doses of botulinum toxin Type A (BOTOX®) for the treatment of patients with bilateral Masseter Muscle Hypertrophy (MMH).

BOTOX

Botulinum Toxin Type A

Injection

100

Primary Outcome Measures :
Change From Baseline in Lower Facial Volume Using VECTRA 3D Images [ Time Frame: Baseline (Day 1) to Day 90 of Treatment Cycle 1 ]
Lower facial volume was calculated from 3-dimensional (3D) images captured with the VECTRA M3 3D Stereophotogrammetry imaging system and was analyzed using computer assisted systems and predetermined facial landmarks. The difference in volume was measured between the select region of the baseline surface 3D model and the select region of the posttreatment surface 3D model. A negative change from Baseline (decrease in volume) indicates improvement.

Secondary Outcome Measures :
Percentage of Participants Who Achieved a Masseter Muscle Prominence Scale (MMPS) Grade ≤ 3 as Assessed by the Investigator [ Time Frame: Day 90 of Treatment Cycle 1 ]
The investigator used visual inspection and palpation to grade the prominence of the participant's masseter muscle on the left and right sides of the face using the MMPS where: 1=minimal prominence (best), 2=mild prominence, 3=moderate prominence, 4=marked prominence, 5=very marked prominence (worst). The percentage of participants with grade 3 or less is reported.

Inclusion Criteria:

-Participants with Masseter Muscle Hypertrophy

Exclusion Criteria:

Diagnosis of Myasthenia gravis, Eaton-Lambert syndrome, amyotrophic lateral sclerosis, or any other condition that might interfere with neuromuscular function
Prior botulinum toxin treatment of any serotype to the masseter muscle or lower face
History of dental or surgical procedure for lower facial shaping or masseter muscle reduction
History of or current temporomandibular joint disorder (TMJD)