Arterial anatomy of the lower lip.

The arterial anatomy of the lower lip was investigated in 12 sides of six fresh cadavers that had been injected systemically with a lead oxide and gelatin mixture. We found that the blood supply of the lower lip was derived from the facial artery and three dominant labial arteries: the inferior labial artery, the horizontal labiomental artery, and the vertical labiomental artery. The inferior labial artery was derived from the facial artery or superior labial artery, and ran through the submucous tissue horizontally. The horizontal labiomental artery arising from the facial artery was located between the depressor labii inferioris muscle and orbicularis oris muscle. The vertical labiomental artery arose from the submental artery. These three arteries provided small vessels that traversed vertically. These small vessels and the small branches of the facial artery, that run superficial and deep to the orbicularis oris muscle, formed a vascular network in subcutaneous and submucous tissues and minute vessels branched off to the skin, mucosa, and muscles.