<prompt> Parotid duct opens at the level of?First mandibular molarSecond mandibular molarFirst maxillary pre molarSecond maxillary molar  <response>: Parotid ductStensons duct passes through the buccinator muscle and pierces buccal fat, opening into the vestibule of the mouth at the parotid papilla, which lies opposite to the 2nd maxillary upper molar tooth. 