Tongue thrusting has lately come under suspicion as a causative factor in orthodontic and articulation problems. A majority of investigators have agreed that the following symptoms indicate the presence of tongue thrusting: during the initiation of the swallowing act, there is contraction of the circumoral muscles, no contact of the molars, and protrusion of the tongue between the incisors. Although the etiology of tongue-thrusting behavior is uncertain, claims have been made that the way in which an infant was fed may have modified patterns of tongue activity to produce tongue thrusting
