Why do back teeth sometimes not meet after orthodontic treatment?

First, establish the cause

Your teeth look straight after orthodontic treatment, but some back teeth do not seem to meet when you close your mouth. This can occur after orthodontics, including clear aligner therapy. It does not automatically mean treatment was incorrect or that a tooth should immediately be built up with composite or ceramic.

The first question is why the contact is missing. Some situations require orthodontic finishing. In others, tooth position is satisfactory but shape, size or wear prevents suitable contact. Restorative treatment may then be considered.

Tooth position and tooth shape are different

Orthodontics moves teeth within biological limits: it can change their position, rotation and vertical level. It cannot replace tissue lost through wear or independently rebuild an unusually small tooth.

If a tooth still needs repositioning, the orthodontic plan should be reassessed. If its position is satisfactory but its anatomy is deficient, a restoration may be appropriate. Restorations should not simply conceal an unresolved positional problem. Some patients need both approaches.

What is a posterior open bite?

A posterior open bite describes a lack of contact between opposing posterior teeth in a particular clinical relationship. One isolated missing contact does not establish this diagnosis. A 2026 narrative review describes posterior open bite as a recognised issue in clear aligner therapy and discusses possible causes and management.

Assessment may consider unwanted intrusion of posterior teeth, the aligners’ occlusal coverage, incomplete expression of planned movements, premature contacts elsewhere, arch coordination, final vertical position, tooth anatomy and wear. Simply observing that a molar does not touch is insufficient to choose treatment.

Can contacts improve after orthodontics?

Occlusal settling refers to changes in contacts after active treatment. It should be monitored by the orthodontist; do not change or stop wearing retainers on your own.

A study of 39 patients treated with aligners or fixed appliances followed contacts for six months of retention. Contact distribution changed, but marked force asymmetry persisted in some patients. Settling is therefore not a universal solution.

Additional orthodontic finishing may be needed. A 2026 prospective study assessed vertical settling elastics for posterior open bite during clear aligner finishing. Such techniques are selected and supervised by the orthodontist; they are not instructions for self-treatment.

When can the problem be restorative?

Suppose joint assessment confirms satisfactory premolar and molar positions, but wear has reduced a tooth’s cusp height. Tooth wear, erosion or abrasion, fractures, previous restorations, atypical shape and loss of tooth structure may contribute to deficient anatomy.

Further movement solely to obtain contact is not always the preferred option. In selected cases, restoring lost anatomy may be appropriate. This requires an individual assessment rather than assuming every missing contact needs added material.

How is the cause assessed?

Assessment can include clinical examination, photographs, intraoral scans, contacts during closure and jaw movements, tooth shape and wear. A diagnostic wax-up may support restorative planning. In extensive rehabilitation, the whole masticatory system is considered rather than one isolated contact.

Tooth position, anatomy, supporting tissues and function are evaluated together. Orthodontic finishing and restorative treatment may both form part of the plan.

What can be added to a tooth?

Depending on the indication, options include direct composite, indirect composite, glass ceramics such as lithium disilicate, or other ceramics, including zirconia in selected situations. Restoration designs may include onlays, overlays and occlusal veneers (table-tops). A crown may be considered when remaining structure does not support a suitable partial restoration.

Material choice is not based on strength alone. Available enamel and dentine, defect size, required thickness, bonding substrate, margin location, functional loading and repairability all matter.

Does the tooth need moving or rebuilding?

A tooth that does not contact its antagonist after orthodontic treatment should not automatically be made taller. If position remains the issue, orthodontic reassessment comes first. If position is satisfactory but anatomy is deficient, restorative treatment may complement orthodontics. Combined problems may need a combined plan.

More about rehabilitation

Post-orthodontic rehabilitation · Complex rehabilitation