Most malocclusions are inherited, but some are acquired. Inherited problems include crowding of teeth, too much space between teeth, extra or missing teeth, and a wide variety of other irregularities of the jaws, teeth and face.

Acquired malocclusions can be caused by trauma (accidents), thumb, finger or dummy (pacifier) sucking, airway obstruction by tonsils and adenoids, dental disease or premature loss of primary (baby) or permanent teeth. Whether inherited or acquired, many of these problems affect not only alignment of the teeth but also facial development and appearance as well.