An open bite is a dental condition where there is a gap between the upper and lower teeth when the mouth is closed. This gap can cause difficulty in biting and chewing food and may also affect speech. Open bite can be caused by a variety of factors, including thumb-sucking, tongue-thrusting, or genetics. Treatment for open bite may involve the use of orthodontic appliances, such as braces or aligners, or in more severe cases, surgery.