Conservative treatment of the masseter muscle hypertrophy associated with temporomandibular joint disorder

Masseter muscle hypertrophy occurs bilaterally with the squared lower third of the face. Etiology is unknown, related to gum chewing, bruxism, malocclusion, psychological disorders, and temporomandibular joint disorders. Patients complain of facial asymmetry; symptoms are pain, trismus, or
bruxism. Several treatment options are presented: pharmacotherapy, occlusal splints, neuromodulator botulinum toxin, and surgical reduction. Patients were treated with a conservative approach the occlusal equilibration by splints and injecting botulinum toxin locally into the hypertrophied muscle. A significant reduction in muscle thickness and facial reduction was observed on a 6-month follow-up. Botulinum toxin injection is a safe, effective treatment for masseter hypertrophy.