When placing an implant in the mandible, which structure is LIFE-THREATENING if damaged?

Correct answer: C. Sublingual artery

• A. The geniohyoid muscle is a suprahyoid muscle — damaging it causes functional impairment but is not life-threatening.
• B. The mental artery exits the mental foramen with the mental nerve — its injury causes local bleeding but is not life-threatening in the same way as sublingual artery hemorrhage.
• C. The SUBLINGUAL ARTERY (branch of the lingual artery) runs in the floor of the mouth above the mylohyoid muscle. If perforated during anterior mandibular implant placement (especially through lingual perforation), it can cause LIFE-THREATENING hemorrhage in the floor of the mouth. The resulting hematoma can rapidly expand, elevating the tongue and floor of mouth, obstructing the airway and causing asphyxiation. This is a known and potentially fatal complication of anterior mandibular implant placement.
• D. The mylohyoid muscle forms the floor of the mouth — perforation through it exposes the sublingual space and increases the risk of hemorrhage, but the SPECIFIC life-threatening structure is the sublingual artery.