Background: The lower third of the face plays a crucial role in overall facial harmony, and age-related volume loss in areas such as the pre-jowl region, labiomental folds, and lips can significantly impact esthetic appearance. High-resolution ultrasound is helpful for identifying key structures, such as the facial artery, parotid gland, and masseter muscle, which are critical to avoid during filler injections. Objectives: This article, the final installment in a three-part series on ultrasound-guided facial injections, provides an in-depth analysis of the sonographic anatomy of the lower face, including the mandibular, marionette, and chin regions. Methods: This article outlines step-by-step techniques for ultrasound-guided filler procedures, with a focus on the importance of pre- and intra-procedural scanning to ensure safe and accurate filler placement. Results: By employing techniques like "scan before injecting" and "scan while injecting", injectors aim to reduce risks such as vascular occlusion, muscle injection, and skin necrosis. Discussion: The use of ultrasound guidance in these regions enhances both esthetic outcomes and patient safety, providing optimal results while minimizing complications. With continued advancements, ultrasound-guided injections will become increasingly precise, enabling more targeted and safer treatments in the lower face.
Keywords: chin; filler; guided injections; hyaluronic acid; jawline; lips; marionette line; perioral; pre-jowl.