Frenulum of tongue

The frenulum of tongue or tongue web (also lingual frenulum or frenulum linguæ) is a small fold of mucous membrane extending from the floor of the mouth to the midline of the underside of the tongue.

Development

The tongue starts to develop at about 4 weeks. The tongue originates from the first, second, and third pharyngeal arches which induces the migration of muscles from the occipital myotomes. A U-shaped sulcus develops in front of and on both sides of the oral part of the tongue. This allows the tongue to be free and highly mobile, except at the region of the lingual frenulum, where it remains attached. Disturbances during this stage cause tongue tie or ankyloglossia. During the sixth week of gestation, the medial nasal processes approach each other to form a single globular process that in time gives rise to the nasal tip, columella, prolabium, frenulum of the upper lip, and the primary palate. As the tongue continues to develop, frenulum cells undergo apoptosis, retracting away from the tip of the tongue, and increasing the tongue's mobility.