How Long Does Orthodontic Treatment Take in the UK?

Typical duration ranges by case type

Simple alignment cases — mild crowding, minor spacing, or single-arch treatment — typically take 6 to 12 months. Moderate cases involving multiple tooth movements, bite correction, or both arches usually take 12 to 18 months. Complex cases — severe crowding requiring extractions, significant bite problems, skeletal discrepancies managed orthodontically, or cases requiring additional appliances — commonly take 18 to 30 months. Cases requiring pre-surgical orthodontics for jaw surgery take 12 to 18 months for the pre-surgical phase alone, followed by a further 6 to 12 months of post-surgical finishing. These ranges assume good compliance and no significant delays. Your orthodontist will provide a personalised estimate after taking records; this estimate should be treated as a projection, not a guarantee.

How case complexity affects duration

The primary driver of treatment length is the amount of tooth movement required. Crowding, spacing, rotations, crossbites, deep bites, open bites, and overjet all require planned movements that take biological time — bone must remodel to allow teeth to move safely. The more movements required, and the greater the distances involved, the longer treatment takes. Cases where extractions are needed add time because the spaces must then be closed. Multiple bite problems occurring simultaneously (for example, crowding combined with a deep bite and a crossbite) take longer than single-problem cases because movements must be sequenced to address each issue without compromising another. Your treatment plan will explain the movement sequence and give you a sense of the complexity involved.

Compliance — elastics, aligner wear time, appointments

Patient compliance is the single most controllable factor in treatment duration. For fixed brace patients, wearing elastics (rubber bands) as directed — typically 22 hours per day — is critical for bite correction; patients who wear elastics inconsistently can add months to treatment. For clear aligner patients, wearing trays for at least 20 to 22 hours per day is essential; below this threshold, planned tooth movements may not be achieved and additional aligners or refinements will be needed. Missing appointments delays the treatment plan because the orthodontist cannot progress to the next stage without assessing your response. In the UK, NHS practices typically schedule appointments 6 to 8 weeks apart; private practices may offer shorter intervals, which can reduce total duration.

How age affects treatment speed

Younger patients — teenagers and young adults — tend to move teeth somewhat faster than adults over 30 due to higher bone turnover and metabolic activity. However, the difference is less pronounced than is often assumed. Adult orthodontics takes longer on average not because teeth move more slowly but because adult cases are typically more complex, may involve greater bone density, and often come with pre-existing dental work (crowns, bridges, implants) that constrains movement. Adults over 50 can achieve excellent results, though their treatment plans may need to be more conservative and periodontal health must be carefully managed throughout. Age alone should not be a barrier to treatment.

What delays treatment — breakages, poor hygiene

Several avoidable factors can significantly extend treatment duration. Broken brackets or wires require an emergency appointment to repair and the tooth attached to the broken bracket stops moving in the planned direction until it is fixed — recurring breakages from eating hard foods add weeks or months to treatment. Poor oral hygiene can cause gum inflammation and bone loss that makes it unsafe to continue active tooth movement until the problem is addressed. Missed appointments leave teeth stationary for longer than planned. Whitespots (early decay around brackets) may require the orthodontist to pause treatment to allow remineralisation. For aligner patients, losing or breaking aligners requires reordering, which takes time and may require new impressions.

Does appliance type affect speed?

Appliance type has a modest effect on treatment duration. Fixed metal braces provide continuous force and typically progress efficiently for most tooth movements. Self-ligating braces (a type of fixed brace) were marketed as faster but clinical evidence for a meaningful speed advantage is limited. Clear aligners are comparable in duration for moderate cases but may take longer for complex movements, particularly extrusion and torque, where their biomechanical efficiency is lower than fixed braces. Lingual braces have a similar duration to labial fixed braces. Functional appliances (for growing patients with jaw discrepancies) add a phase to treatment before fixed braces can be used, extending overall duration but addressing problems that could not otherwise be treated non-surgically. The biggest determinant of duration remains case complexity and patient compliance, not appliance choice.

Useful related pages

This guide is for general information only. It is not a diagnosis, treatment plan, or substitute for advice from a registered dentist or orthodontist.