Sometimes teeth do not erupt in proper order. Normally, incisors are placed in front of canines, premolars and molars. On rare occasions, the canine appears in front of the lateral incisor. This occurs when there is crowding in the developing upper jaw, and when the developing canine starts developing in a displaced position.
On rarer occasions, the canine appears behind the first premolar. Transposition involving teeth other the canine is much less common.