Augmentation of the jaw angles can be done by both injections and implants, each with their distinct advantages and disadvantages. Unlike implants injections can be done by materials with different biologic properties. Synthetic fillers provide facial volume effects but usually are not permanent. Fat has the potential to be permanent by tissue integration but that effect is unpredictable. In theory fat survives better in well vascularized tissue like muscle which suggests that the masseter muscle may be a good fat injection site with a sustained effect.
In the March 2024 issue of the journal Plastic & Reconstructive Surgery Global Open an article on this topic was published entitled ‘Jawline Aesthetic Definition: Enhancement with Masseteric Augmentation Using Ultrasound-Guided Fat Transfer’. In this clinical study the authors studied the effects of fat injections to the masseter muscle for jaw angle enhancement. Using ultrasound-guided fat transfer on 10 men and 10 women over a one year period, an average of 5+ccs was injected into each side. Muscle thickness increased immediately after injection as expected but decreased one month later. But despite the loss of visible volume the muscle remained significantly thicker on each side compared to presurgical size.
This study demonstrates that fat injections to the masseter muscle is safe and does provide some visible contour enhancement at the jaw angles. In the face the masseter muscle is the most well vascularized thick depository for fat injections so theoretically it should initially survive well. How the fat transfer holds up over the long term, however, remains to be further evaluated and this study does not yet provide that important information.
Dr. Barry Eppley
World-Renowned Plastic Surgeon