Glossitis

Excerpt

The tongue is readily visible to patients who may present for assessment of a variety of incidentally noted disorders or may present as a referral from the dentist. The examination of the tongue and oral mucosa is a crucial part of the complete physical exam, and numerous systemic medical conditions can have oral manifestations or symptoms. Glossitis is an overarching term denoting inflammation of the tongue. The condition may present clinically as a painful tongue, as a change in the surface appearance of the tongue (changes in texture and or color), or both.

Anatomy

The tongue is a muscular organ in the oral cavity, which is essential for normal swallowing and speech. Embryologically, the tongue derives from a medial triangular elevation on top of the mandibular arch called the median lingual swelling. It is comprised of skeletal muscle. Motor innervation is via the hypoglossal nerve (except for the palatoglossus muscle, which is supplied by the vagus nerve), while sensory innervation of the anterior two-thirds of the tongue receives innervation from two nerves: the lingual nerve supplying general sensation and the chorda tympani, which provides taste sensation—the posterior one-third of the tongue receives innervation via the accessory nerve.

The median sulcus divides the tongue centrally, beginning at the apex of the tongue tip and extending to the foramen cecum, which creates the apex of a V-shaped groove, which is called the sulcus terminalis. The papillae are tiny protuberances on the dorsal tongue, especially on the anterior two-thirds, classified into three types. The first group called filiform papillae, which are the most common papillae uniformly distributed on the dorsum. They are thin papillae 1- to 2-mm without taste buds. The second type of papillae is called pointed filiform papillae, which morphologically give a rugged texture and promote the mechanical function of licking and chewing.

The fungiform papillae are the third type distributed mostly on the dorsum of the anterior tongue. They are recognized clinically by their dome shape and red color. The posterior tongue contains lymphoid tissue (the lingual tonsils). The ventral tongue contains the lingual veins and the lingual frenulum, attaching the ventral tongue to the anterior floor of the mouth. The submandibular (Wharton's) ducts course parallels to the lingual frenulum along the anterior floor of the mouth.