Form and Function of the Oral Mucosa

The oral cavity is lined by a stratified squamous epithelium which, together with its underlying lamina propria of fibrovascular connective tissue, has a structure and function that varies from site to site in the oral cavity. It is hardly surprising, therefore, that the incidence of oral mucous membrane disease is influenced by both anatomical structure and physiological function. In Northern European patients, intraoral squamous cell carcinoma predominates in the ventrolateral tongue, floor of mouth and mandibular alveolus regions. These areas have been postulated to form a ‘gutter zone’ into which solublecarcinogens may pool and exert their neoplastic influence. Figure 2.1 illustrates an invasive squamous cell carcinoma arising from the floor of mouth tissue. In contrast, squamous cancers are rare on the tongue dorsum and hard palate. There are probably underlying structural and functional distinctions that contribute to the increased risk of oral carcinogenesis at certain oral sites. It is thus important to have a clear understanding of both the applied anatomy of the oral cavity and the cellular biology of its lining oral mucous membrane.