Neuromudulators for Masseter muscles.

Teaching Tip—-

The role of Neuromodulator type A in the treatment of masseter muscle hypertrophy is to create a more slimmer and more oval or heart-shaped face. Appropriate patient selection is critical, since patients who have large facial bones and/or high cheek bones may have those features amplified by masseter muscle injection, causing an undesirable appearance outcome.

The masseter muscle anatomy presents as a quadrangular shape muscle and originates from the zygomatic arch and inserts along the angle and lateral surface of the mandibular ramus. The masseter is primarily responsible for the elevation of the mandible and some protraction of the mandible. 

After the neuromodulator injection into the masseter muscle, not only the muscles around the chin but also the muscles below the zygomatic bone get atrophied, therefore they may look more prominent or protrusive (Nam-Ho Kim, et al, 2001).

Lesson learned:  Make sure your patient understands what to expect from a masseter injection; set expectations with those features BEFORE you inject!

Nam-Ho Kim, M.D., Jee-Hyeok Chung, M.D., Rho-Hyuk Park, M.D., and Jong-Beum Park, M.D. revised April 5, 2004. DOI: 10.1097/01.PRS.0000153236.79775.A0