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The mouth is the beginning of the aerodigestive tract and an extension of the skin barrier. It plays an important role in mastication, deglutition and digestion, speech, and immunologic defense. The oral mucosa, salivary glands (both major and minor), jawbones, and teeth are frequently the site of primary inflammatory or neoplastic disease. However, the oral cavity may present with manifestations of systemic disease and in some cases, oral findings may precede systemic signs and symptoms by months or years. Lesions in the maxillary sinus and nasal cavity may lead to pain in the upper teeth or may extend inferiorly and present in the maxilla or palate. Metastatic lesions may present as nodules on the gingiva or masses in the jawbones.
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This chapter focuses only on the more common mucosal and salivary gland diseases encountered in dermatology practice.
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The mouth is divided into the mucosa that may be keratinized or nonkeratinized, the appendages (namely, the teeth and salivary glands), the jawbones, and the musculature. It is important to understand the histology of the oral mucosa because some lesions (e.g., minor aphthous ulcers) tend to involve primarily the nonkeratinized tissues: buccal mucosa, labial mucosa (wet surface of the lip), maxillary and mandibular sulcus or vestibule (the “gully” between the jawbones and the buccal or labial mucosa), nonattached gingiva, ventral tongue, floor of mouth, and soft palate. These tissues are movable and abut the underlying fat and muscle. Biopsies at these sites are readily performed with a standard skin punch (eFig. 76-0.1).
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Keratinized mucosae comprise the dorsum of the tongue (which is specialized for mastication and taste) with ita filiform, fungiform, and circumvallate papillae; hard palatal mucosa; and attached gingiva (stretching from the gingival margin to the mucogingival junction where the nonattached gingiva begins) (eFig. 76-0.2). The mucosa of ...