Ankyloglossia is a congenital oral anomaly which may decrease mobility of the tongue tip and is caused by an unusually short, thick lingual frenum, a membrane connecting the underside of the tongue to the floor of the mouth. Ankyloglossia varies in degree of severity from mild cases characterized by mucous membrane bands to complete ankyloglossia whereby the tongue is tethered to the floor of the mouth.
Ankyloglossia can affect feeding, speech, swallowing, and oral hygiene as well as have mechanical/social effects. Ankyloglossia can also prevent the tongue from contacting the anterior palate. This can then promote an infantile swallow and hamper the progression to an adult-like swallow which can result in an open bite deformity. It can also result in mandibular prognathism; this happens when the tongue contacts the anterior portion of the mandible with exaggerated anterior thrusts. Proper tongue function and position in the oral cavity is essential for the development of the cranium (skull and jaws) and development of a normal nasal airway.