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ANATOMY
     The oral mucosa may be divided into areas corresponding to the anatomic configuration of the jaws and associated musculature. These areas are the gingiva, buccal mucosa, labial mucosa, tongue, hard palate, and soft palate.
Gingiva
     The gingiva or "gums" refers to the tissue surrounding the teeth and covering the alveolar bone. The gingival tissue is tightly matted to the periosteum of the alveolar bone, and it covers that portion of the roots of the teeth that extends beyond the crest of alveolar tooth socket.     The gingival tissue fills the interproximal spaces between the teeth so that usually spaces are not seen between teeth that are normally aligned in the dental arch.
     The portion of the gingiva that extends beyond the alveolar bone and attaches to the teeth is referred to as the marginal gingiva or free gingival margin, because it is relatively unsupported by hard tissue and forms a continuous band along the root-crown junction of the teeth. The gingival tissue attaches to the tooth surface just below the gingival margin, so that a sulcus or gingival crevice about l to 2 mm in depth is normally found beneath the gingival margin. The exact nature of the gingival attachment to tooth has not been established, but the attachment is firm, so that gingiva cannot be detached from a tooth unless considerable force is used to tear the tissue or a surgical knife is used to sever the tissue.
     The surface of the marginal gingiva is smooth; that of the attached gingiva is stippled. The gingival tissue appears a light pink color normally.
     Beyond the gingiva and separated from it by a clear demarcation is the alveolar mucosa. The line of demarcation of referred to as the mucogingival junction, and the alveolar mucosa beyond this junction is loose, delicate tissue not matted down to underlying bone. Numerous small blood vessels can be seen through this delicate mucosa. The alveolar mucosa on the outer or buccal aspect is continuous with the mucous membrane of the lip and cheek, and a vestibule or trough is formed where they blend into one another. This trough is referred to as the mucobuccal fold or vestibule of the mouth.
Buccal and Labial Mucosa
     The buccal mucosa is the oral mucosa of the cheek; it covers the buccinator muscle. The buccal mucous membrane is freely movable and overlies loose connective tissue and adipose tissue as the musculature. The buccal mucosa is light pink in color and smooth in texture. Usually, a ridge or fold of tissue appears along the occlusal line of the teeth; this represents a tissue response to constant stimulation by the teeth during mastication. This fold may be white-gray in color and occasionally may be confused with white lesions of the buccal mucous membrane. Above the occlusal line and in the posterior part of the buccal mucosa opposite the maxillary molar teeth is the papilla of the parotid (Stensen' s) duct. This bilateral structure may normally appear quite large, and if inflamed it may simulate a tumor.
      Anteriorly, the buccal mucosa blends into the labial mucosa, which covers the masculature of the lip. The lip is a mucocutaneous junction, and the mucosal and skin surfaces are separated at the vermilion border of the lip. With the lips closed, the visible area is skin. Po