What does “Class III malocclusion” mean?
Class III malocclusion describes a front-to-back bite relationship in which the lower dental arch is positioned ahead of the upper dental arch.
Distinguishing front-tooth position from the jaw relationship
The lower front teeth may bite ahead of the upper front teeth. However, tooth inclination and jaw position must be assessed separately. A crossbite affecting one or two front teeth alone does not establish an overall Class III relationship or an enlarged lower jaw.
Factors checked in diagnosis
The assessment includes where the teeth meet, jaw movement during closure, the stage of growth, and the relationship between the upper and lower jaws. Photographs of the teeth, models or scans, and any necessary radiographs are considered together to distinguish dental from skeletal problems.
Treatment plan according to condition and growth
Treatment goals and available approaches differ between growing patients and adults. The dentist assesses what can be addressed through tooth movement; when a substantial skeletal discrepancy remains, orthodontics combined with jaw surgery may be considered. The Class III label alone does not determine whether surgery is needed.
Frequently Asked Questions
Does every crossbite mean Class III malocclusion?
No. A crossbite may affect only some teeth, so the overall molar relationship and jaw condition must also be assessed.
Is Class III caused only by a large lower jaw?
The relative position and size of the upper jaw as well as the lower jaw, tooth position and functional movement, etc. may be related.
Questions to help you understand Class III malocclusion
Learn what the term means and how it relates to your dental condition.
- Sufficient understanding
How does an overall Class III relationship differ from a crossbite affecting only some teeth?
Explanation and evidenceThe molar relationship and front tooth position are viewed together to determine classification and scope of the problem.
American Association of Orthodontists · Glossary of Orthodontic Terms - A choice suited to your condition
Can skeletal differences be compensated by tooth movement alone?
Explanation and evidenceGrowth, the jaw relationship, and the amount of tooth movement required guide consideration of orthodontic treatment alone or treatment combined with surgery.
British Orthodontic Society · Orthognathic Treatment
