What is mandibular lingual frenum?

The mandibular lingual frenum is a small fold of tissue that connects the underside of the tongue to the floor of the mouth. It is located in the midline of the mouth, just behind the lower front teeth. The mandibular lingual frenum normally allows for full and unrestricted movement of the tongue. Ankyloglossia, commonly known as "tongue-tie", refers to restricted movement of the tongue due to an unusually short or tight lingual frenum.