The floor of the mouth is richly vascularized by a number of branches of the submental and sublingual arteries. During a dental implant procedure in the anterior zone of the mandible, perforation of the lingual cortex may invade the floor of the mouth and therefore damage structures within the sublingual space. The anatomy of the lower portion of the anterior mandibular zone, with the mylohyoid ridge, makes it particularly vulnerable to this kind of injury, particularly in patients with atrophic mandibles. Only a few cases have been reported in the literature to date.