What does “Posterior crossbite” mean?
A posterior crossbite occurs when the upper and lower back teeth meet in a reversed side-to-side relationship rather than the normal relationship.
Problems with left and right width and tooth tilt
Examine the relationship between the molars, such as the upper molars biting inward than the lower molars. It may appear on one or both sides, in some or several teeth. Distinguish between problems with tilted teeth and differences in the width of the upper and lower arches.
Check whether the jaw moves when closed
Check whether the jaw moves sideways from the position where the teeth first contact to a comfortable biting position. The width, eruption, and growth stage of the dentition are also evaluated. Even if only one side appears opposite on the outside, it does not always mean that the problem is with only one side of the jawbone.
Correction tailored to the area and cause
The assessment determines whether movement of individual teeth can improve the bite or whether the width of the dental arch needs to be changed. The appliance and extent of treatment depend on growth and the condition of the bone and gums. Posterior crossbite does not mean the same thing as anterior crossbite or a Class III relationship.
Frequently Asked Questions
Does a posterior crossbite mean the lower jaw protrudes?
Posterior crossbite mainly refers to the left-right relationship of the molars. It is evaluated separately from the skeletal relationship in which the lower jaw is forward.
If my child has a posterior crossbite, should we wait until all the permanent teeth have erupted?
Whether to wait or evaluate first depends on growth/eruption and functional movement of the jaw. If you see a crossbite, it is a good idea to schedule an appropriate evaluation with your dentist.
Questions to help you understand posterior crossbite
Learn what the term means and how it relates to your dental condition.
- Sufficient understanding
Which side and how many teeth does it appear on?
Explanation and evidenceWe examine the issues of single tooth tilt and overall arch width separately.
American Association of Orthodontists · Glossary of Orthodontic Terms - A choice suited to your condition
How do growth and movement during closure affect the timing of treatment?
Explanation and evidenceEvaluate the eruption stage and differences in contact location to determine the need and timing of treatment.
NHS England Orthodontic Assessment and Referral
