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

Objectives: 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.

Materials And Methods: 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.

Results: 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%).

Conclusion: Susceptibility of the submental artery in type II, III, and IV to injury during implant surgery is suggested.