Orthodontics is a branch of dentistry that specializes in the prevention, diagnosis, and treatment of irregularities in the mouth, teeth, and jaw. Spacing and crowding are the two most common reasons for seeking out treatment by an orthodontist, but there are other reasons too. An orthodontist is a dental specialist who has usually completed two or three years of further training beyond dental school. The current recommendation is to have an orthodontic exam by the age of 7 to ensure monitoring for the healthy development of the teeth and jaws.