ABSTRACT
The oral cavity comprises the area within the confines of the vermilion border of the lips, the floor-of-mouth mucosa, the buccal mucosa of the cheeks, and a plane passing through the junction of the hard and soft palates to the circumvallate papillae of the tongue. The space is divided into several distinct areas including the lip, buccal mucosa, alveolar ridges (maxillary and mandibular), floor of mouth, retromolar trigone, hard palate, and oral tongue. Many structures are intimately related to the oral cavity, including the immediately related teeth, mandible, palatine tonsils, and soft palate, and the more distantly related (but equally important) muscles of mastication, oral pharynx, and neck. The oral cavity is not synonymous with the mouth. Anteriorly, the vestibule represents the space between the lips and the gingiva and teeth. The mouth is that space bounded by the lingual surface of the teeth and alveolar ridges, the hard and soft palates, the entire tongue and floor of mouth, and extends back to enter the oropharynx at the tonsillar pillars.
