WellSpan Home

Types of Malocclusion

Topic Overview

The term "malocclusion" (poor bite) refers to a number of possible conditions. The most common are:

  • Upper protrusion (overjet). In an upper protrusion, the upper front teeth are pushed outward (buck teeth). A small lower jaw may be the cause. Pacifier use or thumb-sucking can also create this condition by pushing the teeth outward, sometimes causing the roof of the mouth to change shape (upper palate).
  • Spacing or crowding problems. Too much or too little room for the teeth can cause spacing or crowding problems. Crowding can prevent permanent teeth from coming in properly or at all (impaction).
  • Misplaced midline. In people who have a misplaced midline, the front center line between the upper front teeth doesn't match up with the center line of the lower front teeth.
  • Open bite. Although the molars fit together in a person who has an open bite, the upper and lower front teeth don't overlap. This creates an opening straight into the mouth. An open bite can also be present on one or both sides of the mouth.
  • Overbite. In a person who has an excessive overbite, the upper front teeth reach too far down over the lower front teeth and, in severe cases, can cause the lower teeth to bite into the roof of the mouth.
  • Underbite. An underbite is present when the lower front teeth are farther forward than the upper front teeth.
  • Cross bite. A cross bite occurs when any or all of the upper teeth fit into the wrong side of the lower teeth.
  • Rotation. Rotation is present when a tooth turns or tips out of its normal position.
  • Transposition. Transposition occurs when teeth grow (erupt) in one another's place.

A normal fit is when the upper teeth are slightly forward of the lower teeth. Malocclusion, when there isn't a normal fit, is classified by how the upper and lower teeth fit together. The bones of the jaw are also checked for proper position in relation to the teeth.

  • Class I. Although the upper and lower molars are properly positioned, the teeth are crowding together or have too much space. Cross bites, rotations, and overlapping can also occur in severe cases.
  • Class II. The lower molars fit the upper molars but are positioned toward the throat, drawing the chin back.
  • Class III. The lower molars are far forward and do not fit into their corresponding upper molars. This arrangement creates a jutting jaw and jutting lower front teeth, which are in a cross bite with the upper teeth.

A jaw structure problem that children are born with can cause malocclusion. Malocclusion can also cause the jaw joint to move out of place.

Related Information


ByHealthwise Staff
Primary Medical ReviewerAdam Husney, MD - Family Medicine
Martin J. Gabica, MD - Family Medicine
Specialist Medical ReviewerWilliam F. Hohlt, DDS - Orthodontics

Current as ofMay 7, 2017

Are you sure you would like to cancel?

All information will be lost.

Yes No ×

About the provider search

This search will provide you with WellSpan Medical Group and Northern Lancaster County (Ephrata) Medical Group primary care physicians and specialists. If we don’t have a WellSpan Medical Group physician to meet your criteria, the search will expand to include community physicians who partner with WellSpan Medical Group physicians through the WellSpan Provider Network or provide care to patients on the Medical Staffs of WellSpan’s Hospitals.


Schedule Your Next Appointment Online with MyWellSpan

Use your MyWellSpan patient portal any time to view available appointments, and pick the date and time that best suits your schedule.

Go to MyWellSpan

New to this practice?

If you don't have a WellSpan primary care provider and would like to schedule a new patient appointment with a provider who is accepting patients, just log into your MyWellSpan account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to see the offices that are accepting new patients in relation to your zip code. If you are not enrolled in MyWellSpan, go to https://my.wellspan.org, call 1-866-638-1842 or speak with a member of the staff at a participating facility to sign up. New patient scheduling not available at all practices/programs.

Already a patient at this practice?

If you already have a relationship with a WellSpan practice, simply log into your account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to schedule an appointment with any provider or practice that already counts you as a patient. Online scheduling varies by practice/program.