The diagnosis, prevention, and treatment of dental and facial irregularities caused by misalignment of the teeth and jaw.

About 70% of people experience some form of malocclusion (literally "bad bite"), or poor positioning of the teeth. In Class I malocclusion the bite is even; that is, the top teeth line up with the bottom ones, but the teeth are crooked, crowded, or turned. In Class II malocclusion, also called "buck teeth," there is an overbite, in which the upper teeth extend past the top of the lower teeth, and in Class III malocclusion there is an underbite, in which the lower teeth extend past the bottom of the upper teeth. Untreated malocclusion can cause periodontal disease, digestive problems (due to the inability to chew food properly), and facial distortion. An orthodontist, who has at least two years training after dental school, performs dental manipulations to straighten the teeth and...