Malocclusion is any condition in which a person’s upper and lower teeth and jaw do not fit together properly. People with malocclusion may have trouble biting, struggle to keep teeth clean and experience health problems related to gum tissue. Malocclusion also can affect jaw growth, speech development and a person’s appearance.

Although malocclusion can cause various types of tooth and jaw abnormalities, most conditions can be grouped according to one of three categories. They are:

• Class I. Bite is normal but teeth may still be crowded or otherwise malpositioned.
  
  
• Class II. Upper jaw and teeth overlap the bottom jaw and teeth.
  
  
• Class III. Lower jaw protrudes forward. Lower teeth extend over upper teeth.

In most cases, malocclusions are developmental. A person may have malocclusion if the upper and lower jaws are not the same size. Or, malocclusion may result if a person’s mouth is especially small, causing teeth to become crowded and shift out of position.

However, other malocclusions can be acquired through certain situations, including accidents, illnesses and other problems associated with dental restorations, prolonged thumb sucking or use of a pacifier, premature loss of primary teeth, or tongue-thrusting.

Malocclusion usually causes symptoms that do not appear right away, but instead gradually develop over time. These may include chewing difficulties, tooth decay, gum disease, fractures of crowns or loosening of the teeth. It may also result in low self-esteem due to a facial appearance that is considered unusual or unattractive by conventional standards.

Typically, a dentist uncovers the nature of a patient’s malocclusion through a dental examination during childhood. If the dentist suspects malocclusion, the patient will be referred to an orthodontist. The orthodontist also will take dental x-rays and take impressions of the teeth using rubbery material. Photographs of the patient’s face and teeth also may be taken to trace how treatment changes the child’s facial appearance.

After these steps have been taken and all relevant information has been gathered, a treatment plan will be formulated. Malocclusion typically is treated using fixed or removable appliances, or a combination of both. Fixed appliances are known as braces and are the most common form of treatment for malocclusion. Removable appliances, which are composed of wires attached to a plastic base (e.g., retainer), can be removed by the patient.

Other treatments for malocclusion include adjusting, reshaping, bonding or capping rough or irregular teeth. If restoration work is the source of the malocclusion, the restoration may have to be fixed or replaced. In some cases, surgery may be necessary to correct malocclusion.