What does “Posterior crossbite” mean?
A posterior crossbite usually means upper back teeth bite inside the lower back teeth. It may affect one or both sides. Assessment considers tooth inclination, the width of the upper and lower dental arches and jaws, and jaw movement during closure.
Distinguish tooth contacts from a functional shift
Tooth inclination may produce a crossbite involving a few back teeth, several teeth or both sides. Examination also checks whether the jaw shifts sideways to avoid an interfering contact, making the crossbite appear one-sided. Appearance in a photograph alone cannot establish the cause.
Choose treatment according to width, growth and movement needs
Assessment determines whether to adjust tooth positions, expand the dental arch or obtain further skeletal evaluation. A review supports expansion appliance treatment in children, but the same findings do not apply to every appliance, age or skeletal problem. Appliance choice and timing are individualized.
Review the bite and retention after treatment
Checks include not only the direction in which teeth meet but also jaw movement, the overall bite and tissue condition. Follow appliance use and cleaning instructions and report discomfort or breakage. Growth, eruption, retention and the need for later alignment treatment are also reviewed.
Frequently Asked Questions
If only one side has a crossbite, is only that side expanded?
Not necessarily. Actual arch width, skeletal relationships and functional jaw movement during closure must be distinguished before setting the scope of movement.
Is a molar crossbite different from a posterior crossbite?
In this context, the terms refer to the same condition. The important details are which teeth meet in which direction, the cause and growth status.
Checking the cause and scope of a posterior crossbite
Learn what the term means and how it relates to your dental condition.
- Sufficient understanding
Is the problem tooth inclination, width or jaw movement?
Explanation and evidenceAsk about the teeth and sides involved, jaw movement during closure, and the findings of dental, skeletal and growth assessment.
AAPD: Assessment and management of developing dentition, occlusion and crossbite (2024 revision) - A choice suited to your condition
What will change, when, and what needs later review?
Explanation and evidenceConfirm appliances and alternatives, possible changes and limitations, eruption and whole-bite checks, and the retention plan.
Cochrane: Orthodontic treatment for posterior crossbites (2021)
Further reading and references
Further reading
References
- AAPD: Assessment and management of developing dentition, occlusion and crossbite (2024 revision)aapd.org (opens in a new tab)
- Cochrane: Orthodontic treatment for posterior crossbites (2021)cochrane.org (opens in a new tab)
- NHS: Orthodontic appliance components, care and retentionnhs.uk (opens in a new tab)
