Variation in arterial supply to the floor of the mouth and assessment of relative hemorrhage risk in implant surgery

Abstract

Bleeding in the floor of the mouth during implant surgery is attributed to arterial injuries in the sublingual space: clinicians may injure the submental and sublingual arteries, which originate from the facial and lingual arteries, respectively. This study aimed to clarify the three-dimensional courses of submental and sublingual arteries and their topographic relation to the mandible. During the gross anatomy course at the Faculty of Dentistry and Graduate School, Niigata University (2009-2011), we investigated the relationship between the courses of submental and sublingual arteries and their dividing patterns of the mylohyoid muscle, sublingual gland, and mandible using 27 human cadavers. The courses of submental and sublingual arteries were divided into four patterns: (1) the sublingual space was supplied by the sublingual artery (type I: 63%), (2) it was supplied by both the sublingual and submental arteries (type II: 5.6%), (3) it was supplied by the submental artery without the sublingual artery (type III: 29.6%), and (4) type III without the deep lingual artery originated from the lingual artery (type IV: 1.8%). In type II, III, and IV, the submental artery perforates the mylohyoid muscle or takes a roundabout route to travel near the surface of the mandible. The percentage occurrence of arteries traveling between the sublingual gland and mandible in type II, III, and IV (55%) is higher than that in type I (8.8%). Susceptibility of the submental artery in type II, III, and IV to injury during implant surgery is suggested.