Botulinum toxin used to treat patients with masseteric muscle hypertrophy

For patients with an uncommon condition causing a swollen appearance of the lower face, treatment with botulinum toxin type A (Botox) provides an effective alternative to plastic surgery, according to a study in the November Journal of Craniofacial Surgery.

Dr. Gianpaolo Tartaro and colleagues of Seconda Università degli Studi di Napoli, Italy, report on the use of botulinum toxin type A to treat patients with masseteric muscle hypertrophy (MMH). Patients with MMH have painless enlargement of the masseter (cheek) muscles, causing a swollen or "square-faced" appearance. The cause of MMH is unknown. In the past, the only treatment option was plastic surgery to remove part of the masseter muscle and/or jawbone.

Dr. Tartaro and colleagues used botulinum toxin type A to treat MMH in five patients—three women and two men, aged 46 to 56 years. Known by the brand name Botox, botulinum toxin is commonly used for cosmetic plastic surgery, including treatment of forehead wrinkles. Injected into muscles, the toxin blocks nerve transmission, causing those muscles to relax.

In the MMH patients, botulinum toxin was injected directly into the swollen masseter muscle. An average of 20 days later, the patients had reduced swelling and improvement in the contour of the lower face. In one patient, treatment had to be repeated on one side of the face. None of the patients had any complications, and all were highly satisfied with their results.

Botulinum toxin has become a useful treatment for a wide range of problems affecting the facial muscles—not just for "cosmetic" issues like frown lines and wrinkles, but also for problems of eye alignment (strabismus), facial muscle spasms, and others.

The new study adds to previous reports showing that botulinum toxin injection is a safe and effective alternative to plastic surgery for patients with lower facial deformity caused by MMH. Dr. Tartaro and his coauthors conclude, "[T]his study suggests that the use of botulinum toxin type A…can be established as a simple, predictable, alternative facial contouring procedure."