Anatomic study of the blood supply of perioral region

Abstract

The use of flaps to reconstruct lip defects requires detailed knowledge of the local vasculature. New flaps for surgery around the mouth can be devised if the surgeon knows the distribution of the perioral arterial branches. Examination of the anatomy of perioral branches of the facial artery (FA) confirmed the consistent presence of septal and alar branches in the upper lip and a labiomental branch in the lower lip. Mucosal flaps from the upper lip based on the deep septal branch or the alar branch of the FA can be used to restore lower lip defects. A composite flap from the lower lip supplied by the labiomental branch of the FA can be used to restore combined defects of the upper lip and nose or partial defects of the lower lip. We studied the vascular anatomy of the perioral region in 25 cadaver dissections. Fixation was by 10% formaldehyde solution. Red latex was injected into the common carotid arteries before dissection. In the 50 specimens, the primary supplying vessels were identified and the size and distribution of the vessels were investigated. The FA was symmetrical in 17 (68%) of 25 heads. It terminated as an angular facial vessel in 11 (22%), as a nasal facial vessel in 30 (60%), as an alar vessel in six (12%), and as a superior labial vessel in two (4%) facial halves. It terminated as a hypoplastic type of FA in one (2%) facial half. The average external diameter of the superior labial artery (SLA) was 1.6 mm (min-max: 0.6-2.8 mm) at its origin. The origin of the SLA was superior to the angle of the mouth in 34 of 47 specimens (72.3%), and at the angle of the mouth in 13 of 47 specimens (27.7%). In two of the remaining three specimens, the SLA was the continuation of the FA and the other was of the hypoplastic type. The SLA supplied the columellar branches in all specimens except for the hypoplastic type (49 specimens). Columellar branches were classified according to their number and their type. In five specimens (10%) the inferior labial artery (ILA) was not found. In the other specimens, the site of origin of the ILA varied between the lower margin of the mandible and the corner of the mouth. Its external diameter measured min-max: 0.5-1.5 mm. The ILA arose from the FA above the angle of mouth in 4 specimens (8%), inferior to the angle of mouth in 11 specimens (22%), and at angle of mouth in 30 specimens (60%). We observed that the labiomental arteries, which formed anastomoses between the FA, ILA, and submental artery, showed variations in their course in the labiomental region. We suggest that knowledge of the location of arteries with respect to easily identifiable landmarks will help to avoid complications at surgery.