Abstract
BACKGROUND: As lip enhancement with fillers has grown in popularity, practitioners have sought to identify injection methods that achieve aesthetically pleasing results while avoiding adverse events such as arterial injury due to intravascular injection. OBJECTIVES: The primary objective of this study was to establish a safe injection technique for creating appealing, proportionate, and aesthetically pleasing lips while elevating the lip corners with filler. METHODS: Before injection, the locations of the superior and inferior labial arteries were established by sonography and a 9-point injection technique (9-PIT) was devised to reliably achieve fashionable lips. Particle hyaluronic acid filler was administered to 50 patients by the 9-PIT and these patients were monitored for 3 months. The extent of lip corner elevation and the angle of lip corners were quantified by 3-dimensional analysis, while changes in the length and curvature along the upper peristomal lines were evaluated after 1 week. RESULTS: The superior and inferior labial arteries originated from the deep lateral aspect of the lip and gradually traversed toward the midline in the superficial layer. Superficial arterial branches were identified in the submucosal layer near the midline. All patients expressed satisfaction with the lip shaping and corner elevation, without any adverse effects or vascular complications. The angle of lip corners decreased by 8.80%, and lip corners were lifted by 1.02 mm. The upper lip exhibited a more pronounced S-shape, with the upper lip line being elongated by 6.5%. This accentuated S-shape contributed to the appearance of lifted lip corners. CONCLUSIONS: The 9-PIT facilitated safe and aesthetically pleasing lip volumization with corner elevation in a consistent manner, while elucidating vascular pathways. Lip corner elevation was achieved solely using HA filler.