Temporal volume increase after reduction of masseteric hypertrophy utilizing incobotulinumtoxin type A

Background: Treating the lower face with neuromodulators and targeting the masseter muscle can reduce masseteric hypertrophy but can also change the facial shape. A novel observation after the treatment of the masseter muscle with incobotulinumtoxin Type A was the increase in temporal volume.

Aim: Objectively assess temporal volume increase following treatment of masseteric hypertrophy using incobotulinumtoxin Type A.

Methods: Nine female patients with a mean age of 35.11 years ± 9.1 [Asian (11.1%) and Caucasian (88.9%)] were treated with incobotulinumtoxin Type A for masseteric hypertrophy. Masseteric prominence and temporal volume were assessed by two independent raters, and temporal fossa volume was measured via 3-dimensional volumetric imaging.

Results: Independent of the neuromodulator injection technique (ie, single-injection versus multi-injection), a reduction in masseteric hypertrophy occurred represented by a decrease in the masseter prominence scale. In addition, the treatment resulted in a significant improvement of the temporal volume scale and an increase in the measured volume of the temporal fossa. None of the presented measurements were statistically significantly different between the two utilized injection techniques.

Conclusions: This study supports using a full-face approach when performing aesthetic treatments. Anatomical concepts can help to guide treatments: the compensatory increase in temporalis function after masseter muscle treatment resulted in an increased in temporal fossa volume. The findings presented herein should not be considered as a new concept for treating the temporal fossa but rather as an additional possibility for increasing the temporal volume.