LAUSR

BACKGROUND The facial artery (FA) is a high-risk structure when performing filler injections at the nasolabial fold, buccal, and mandibular regions. OBJECTIVES This study aimed to establish reference landmarks locating the course of the FA and its essential branches. METHODS Thirty-one embalmed cadavers were enrolled in this study. The course of the FA was observed in regard to the following reference points: masseter insertion, oral commissure, and common bony landmarks. The corner of the mouth was used as the landmark to measure the turning point of the FA. RESULTS Seven points were established to identify the course and turning point of the FA. These included the anterior masseteric (AMP), lateral mental (LMP), post-modiolar (PMP), supra-commissural (SCP), basal alar (BAP), the infraorbital points (IOP), and medial canthal point (MCP). The course of the FA deviates at least twice at the LMP and at the SCP or PMP. The facial artery appeared more medially when the artery turned at the PMP and SCP. It presented through the lateral channel if the turning point was solely at the PMP. Wherever the FA was found to deviate, it can be divided into three segments: the mandibular, buccal, and nasolabial segments. The arterial course may deviate laterally from the mouth corner towards PMP. The nasolabial segment may also deviate laterally to the BAP at the alar grove for 0.5-1 cm. CONCLUSIONS The deviation of FA closely relates with mandibular, buccal, and nasolabial segments. It is essential for physicians and surgeons who perform procedures in these areas.