After a radiograph revealed a sialolith (stone) in a patient's right submandibular duct, the surgeon exposed the duct an intraoral approach. In this approach, what tissues or structures must be cut through?: (A) Mucous membrane only, (B) Mucous membrane and genioglossus muscle, (C) Mucous membrane and mylohyoid muscle, (D) Mucous membrane and hyoglossus muscle
Answer is A. The submandibular duct is found deep to the mucous membrane of the mouth, but superficial to the muscles of the tongue and the muscles on the floor of the mouth. So, genioglossus, mylohyoid, and hyoglossus are deep to the submandibular duct.