Mewing is the placing of the tongue on the roof of the mouth, which proponents claim may alter the face and aid in the correction of orthodontic, respiratory, and facial structural abnormalities. Proponents also claim that mewing can: reduce the risk of developing diseases such as cancer; remove toxins from the body; improve the taste sensation; and provide relief for headache, stress, and pain. However, these claims have not been verified by scientific research.