Parotid papilla: It houses the opening of Stenson duct of the parotid gland, is located in the buccal vestibule opposite the maxillary second molar.
Left maxillary buccal vestibule. Note parotid papilla with drop of saliva at opening of Stenson duct (arrow). Amalgam restorations are present in the maxillary posterior teeth
Labial frenula: Folds of mucosa in the midline maxillary and mandibular labial vestibules can be seen anchoring the lips to the alveolar mucosa or gingiva, and are known as the labial frenula, These can be quite prominent in some cases and even affect tooth eruption.
Maxillary labial vestibule showing frenulum (broken arrow). Note bulge over root of canine tooth (canine eminence; long solid arrow) and adjacent depression (canine fossa; short solid arrow). A portion of the mucogingival junction is marked with a broken line on the right. Sebaceous glands are visible on the inner aspect of the upper lip.