ABSTRACT
Background: The rejuvenation and restoration of a well-defined jawline contour are crucial for enhancing facial aesthetics in both men and women. Within the jawline aesthetic unit (mandibular angle), the masseter muscle plays a significant role, as it is responsible for mandibular masticatory movements. We propose a new approach using ultrasound-guided intramuscular fat transfer to enhance the mandibular angle and jawline. Methods: The multicenter study included 20 patients from three countries (Peru, Brazil, and Mexico). After fat harvesting, the ultrasound-guided masseteric fat transfer was performed with a 1.5-mm Viaro cannula from an incision beneath the ear lobule. The fat was then injected intramuscularly into the masseter at each side of the mandibular angle. Results: Masseter ultrasound-guided fat transfer was performed on 10 men and 10 women between 2021 and 2022. The patients had a mean age of 34.4â ±â 6.39 years and a mean body mass index of 22.39â ±â 2.59 kg per m2. The mean injected volume was 5.83 mL and 5.58 mL on the right and left sides, respectively. Muscle thickness increased in patients immediately postsurgery, but decreased after 1 month. The muscle remained significantly thicker on each side than the presurgery measurements in patients regardless of gender (both P < 0.0001). Conclusions: Ultrasound-guided intramuscular fat transfer is a safe and reproducible technique for enhancing the jawline contour at the mandibular angle. We believe that it could be a more durable solution than other procedures, although further evaluation of long-term results is necessary.