Phased Orthodontics: Phase 1 and Phase 2 Explained

What is phase 1 orthodontics?

Phase 1 orthodontics — also called interceptive or early orthodontic treatment — involves treating specific problems while a child still has a mix of baby and adult teeth, typically between ages 6 and 10. It is not the same as full orthodontic treatment. Phase 1 uses appliances such as expanders, functional devices, or partial braces to address issues that are easier to correct while the jaw is still growing. The goal is to reduce the severity of problems that would otherwise require more invasive treatment in phase 2.

What problems phase 1 is used to treat

Phase 1 is most often recommended for children with a significantly narrow upper arch that is causing crossbite, a skeletal class III bite where the lower jaw protrudes ahead of the upper, a deep overbite where upper teeth significantly overlap the lower, severe crowding that is likely to prevent adult teeth from erupting correctly, and certain habits such as thumb-sucking that are actively affecting jaw development. Phase 1 is generally not used for minor crowding or alignment issues that can be treated efficiently once all adult teeth are through.

What happens between phase 1 and phase 2?

After phase 1 is complete, most children enter a resting period while the remaining adult teeth erupt. This can last 12 to 18 months or longer. During this time, a simple retainer may be worn to hold any space or position gains made in phase 1. The orthodontist monitors progress at intervals. Phase 2 — full braces or aligner treatment — typically begins between ages 11 and 14, once most or all of the adult teeth are through.

What is phase 2 orthodontics?

Phase 2 is the full active treatment that addresses remaining alignment, bite, and spacing issues once all adult teeth are in place. For most children, this is the only treatment they receive — phased treatment is not the default approach. Phase 2 uses fixed braces or clear aligners and typically lasts 12 to 24 months depending on case complexity. It is usually followed by a retention period with removable or fixed retainers.

Does every child with phase 1 treatment need phase 2?

Not always. In some cases, phase 1 treatment resolves enough of the underlying problem that phase 2 is minimal or not required. In the majority of phased cases, however, phase 2 is still needed — phase 1 reduces the complexity rather than eliminating the need for further treatment. Your child's orthodontist should give a realistic assessment of the likelihood of needing phase 2 before starting phase 1.

How to evaluate a recommendation for phase 1 treatment

Phase 1 is not appropriate for all children and not all providers offer it. Questions worth asking before agreeing include: what specific problem is phase 1 addressing, what happens if treatment starts at phase 2 instead, what is the expected phase 1 duration and cost, what is the likely phase 2 timeline and total combined cost, and what monitoring happens between phases. Getting a second opinion is reasonable if you are unsure whether the recommendation reflects genuine clinical need or practice preference.

Cost of phased orthodontic treatment

Phased treatment involves two separate courses of active treatment with separate fees. Phase 1 typically costs between £1,000 and £3,000 depending on appliance type and duration. Phase 2 costs are comparable to standard full treatment — £2,500 to £5,500 for private braces. The combined cost can therefore be significantly higher than a single-phase treatment starting at age 12. Some practices offer a combined fee for both phases if treatment is confirmed at the outset. NHS treatment may cover phase 2 for eligible children, but phase 1 is less consistently covered under NHS criteria.

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.