Formula Medical Group
Apple Valley, CA

James Krider, MD

   any search words
   all search words

Crooked teeth - malocclusion

What are crooked teeth?

Occlusion is the fit between the upper and lower teeth when the jaw is closed. If the teeth do not meet, or occlude, in the proper way, the result is an improper bite or malocclusion. The common name for this condition is crooked teeth, even though the teeth may appear to be straight. Common types of malocclusion include:

  • Crowded, twisted, or over­lapping teeth.
  • An overbite, in which the upper teeth protrude.
  • A bite in which the front, upper teeth come down slightly behind the lower teeth.
  • An open bite, in which there is a space between the upper and lower teeth where the cusps of the molars rest on each other.

What causes crooked teeth?

The most common cause is inheritance of oral and dental structures that do not permit perfect occlusion. For example, someone who inherits a small jaw from his or her mother and large teeth from his or her father, is likely to


  • Uneven tooth appearance.
  • Misaligned teeth or bite.

have crowded, overlapping teeth. If the jaw is too small to accommodate all of the teeth, some may develop in a twisted or slanted manner.

Premature loss of some primary (baby) teeth due to improper care and decay can also lead to crooked permanent teeth. For example, the teeth may become crooked when initial permanent teeth spread out to fill gaps, leaving inadequate space for subsequent permanent teeth.

How are crooked teeth diagnosed and treated?

Although most cases of malocclusion can be easily diagnosed by parents and the family dentist simply by looking at a child's teeth, x-rays may be required to make sure that all of the adult teeth are in place. Plaster casts of the teeth and jaws are needed to assess the bite fully and to plan any orthodontic treatment.

What can I do myself?
No self-care can correct improperly positioned teeth. If a child is fitted with braces, make sure he or she takes extra care with brushing and flossing to help assure that tooth decay does not develop adjacent to the appliance.

Orthodontic treatments are best begun at about age 12, when most of the permanent teeth have come in.

Orthodontic treatments are best begun at about age 12, when most of the permanent teeth have come in.

When should I see my dentist?
A child's first visit to the dentist should occur early in life, preferably before starting school. The dentist can then monitor tooth development and recommend orthodontia, if necessary, at the appropriate time. Orthodontia is best begun late in childhood or early in adolescence, when most of the permanent teeth are in place and the jaws are still growing.

What will the dentist do?
If the dentist identifies a possible malocclusion problem, he or she is likely to refer the child to a dental specialist known as an orthodontist.

The best time to begin the orthodontic process is usually around the age of 12. The procedure involves fitting braces — a special appliance — in the youngster's mouth to slowly pull the teeth into proper alignment. Depending on the degree of crowding, the orthodontist may recommend that some teeth be extracted. Occasionally, jaw surgery is required.

Increasingly, adults are also having crooked teeth straightened. Dental researchers have developed several new types of appliances that are less noticeable than the traditional metal braces. These are more appealing to older people who may be self-conscious about wearing braces.

Teeth before and after braces.

The course of crooked teeth

A fixed orthodontic appliance is anchored in the mouth by fitting it around or attaching it to selected teeth with metal or plastic bands and/or special glues. Sometimes tension is applied to the teeth by attaching tiny rubber bands to the braces. Children usually visit the orthodontist every 4 to 6 weeks to have the bands adjusted and tightened in order to move the teeth into new positions gradually. It usually requires 2 to 3 years for teeth to reach proper dental occlusion.

Once the proper alignment has been obtained, the child is usually fitted with a removable retainer to be worn, sometimes at night only, to help the teeth, bone, and gums stabilize in their new position. It may be necessary to wear a retainer for a year or more.

Are crooked teeth dangerous?
No, but they can cause a wide variety of dental problems, including increased tooth decay, gum disease, jaw pain, and damage to permanent teeth.

What can I do to avoid crooked teeth?

Although most malocclusion cannot be prevented, it can be treated early to prevent permanently crooked teeth. In addition, the following practices can help prevent premature tooth loss and other problems related to crooked teeth:

  • Discourage a child from thumb-sucking once his or her permanent incisors have emerged.
  • Teach children proper dental hygiene early in life.
  • Have dental checkups on a regular basis.
This article was last reviewed November 22, 2005 by Dr. James Krider.
Reproduced in part with permission of Home Health Handbook.
Premature loss of baby teeth

Return to Head & Neck