Masseter hypertrophy is commonly treated with neurotoxin to reduce the size and shape of the jaw, especially in Asia where one dermatologist uses a technique she says she’s refined over time that uses lower doses and also includes addressing the parotid gland.
Compared with older data at higher doses, “…today what we do is we do more medium to a lower dose injection which is personalized to that patient and their skin type,” says Chytra Anand, M.D., Bangalore city, India, who spoke at the 2019 Cosmetic Surgery Forum in Nashville, Tenn.
The typical patient is one who may complain about a “fat” face and who would look more attractive with an oval face shape, according to Dr. Anand.
“We inject into the masseter muscle and the parotid gland,” she says. “This is very common procedure that happens in Asia.”
First, it’s important to map out the area of injection, according to Chapter 51 of Kelley and Firestein's Textbook of Rheumatology.
“Treatment is begun by asking the patient to clench their teeth and the injector identifies the most prominent areas of muscular contraction with a surgical marker,” the authors write. “The maneuver is repeated, and the next most prominent region is marked. A horizontal line is made across the zygomatic arch and a vertical line is made at the interior border of the masseter that intersects the first line.”
Dr. Anand says that it’s important to stay within the recommended safety zone of the face.
“You do not want to cross a line between the corner of the lip to the lower ear lobe because if you go higher, there's a chance that you can affect the risorius muscle or the zygomaticus major muscle,” she says.
When performing the procedure, she says, due to the substantial size of the muscle, remember to inject deeply into the masseter to be sure to completely debulk the area.
“It has a superficial and a deep head,” she says. “You want to get both the fibers, otherwise you could get an almost gill-like appearance. When they chew, you'll actually see a projection of the superficial head.”
Firestein GS, Budd R, Gabriel SE et al. Kelley and Firestein's Textbook of Rheumatology (Tenth Edition) E-Book. Elsevier Health Sciences; 2017. Pages 756-767.