Two-Phase Orthodontic Treatment Decatur, GA For Kids & Teens

Medically reviewed by Dr. Noam Green, DMD and Dr. Anne Gordon, DMD | Last updated September 2026

At Green Orthodontics, we spend a lot of time thinking about timing. There is a window in a child’s development, opening around age seven, where certain bite and jaw problems are far easier to correct than they will ever be again. Two–phase orthodontic treatment is our approach to using that window when it matters, and staying out of the way when it does not. At our Decatur office and upcoming Buford location, Dr. Noam Green and Dr. Anne Gordon build every Phase 1 recommendation around a simple question: is there something happening right now that will get harder to fix if we wait? Most of the time, the answer is no, and we say so. When the answer is yes, this page is about what we do next.

What Is Two-Phase Orthodontic Treatment?

Two-phase orthodontic treatment is a two-part approach that corrects specific bite, jaw, and eruption problems in a targeted early stage, then completes alignment in a second stage once the rest of the adult teeth erupt. Phase 1 is delivered during the mixed-dentition years, typically starting around age 8 or 9. Phase 2 is delivered in the early-to-mid teens once the remaining adult teeth are in place. The idea is not to do more orthodontics. The idea is to do targeted work at the moment it is most effective, so that the second phase, if it is needed at all, is shorter and less complex.Teeth move best under the right amount of force, often around 50 grams for a given movement. Too much can actually slow a tooth down, and too little does nothing, so every weekly tray is designed to hit that sweet spot. Think of it like watering a plant: pouring on more does not make it grow faster, it simply needs the right amount at the right time.

What Age Should My Child Have Their First Orthodontic Screening?

The American Association of Orthodontists recommends a first orthodontic evaluation at age 7. At that age, a child’s front eight adult teeth and four adult first molars are typically in, and the mix of baby and adult teeth gives an orthodontist enough information to see whether growth and eruption are on track. Age 7 is the screening age, not the treatment age. Most children screened at 7 do not need treatment at 7, and some do not need treatment at all.

When Does Phase 1 Actually Begin?

Phase 1 treatment itself typically begins around age 8 or 9, and the decision is based on dental age rather than the calendar. We look for the front eight adult teeth and the four adult first molars to be in. Those twelve teeth give us the anchorage we need to render meaningful skeletal or dental correction, and just as important, the remaining twelve baby teeth are not close to falling out yet. That gives us a stable environment to work in. Miss that window and the environment changes. The adult canines and premolars begin to erupt. Baby teeth begin to fall out. Anchorage becomes harder. 

Phase 1 and Phase 2 blend together into one long stretch of treatment. That blending is exactly what we work to avoid, because it is where you get the “I had braces for four years” experience some adults describe from their own childhood.

What Problems Does Phase 1 Actually Address?

Phase 1 is targeted at specific issues that are progressive, meaning they get harder to correct as time passes. Not every bite problem calls for early treatment. The ones that often do include:

• Posterior crossbites, which often signal a narrow upper jaw and can cause the lower jaw to shift consistently to one side. Left untreated in children, a unilateral posterior crossbite is associated with measurable mandibular condylar asymmetry and altered skeletal growth that becomes progressively harder to reverse.
• Anterior crossbites, where an upper front tooth sits behind a lower front tooth. The traumatic contact can push the lower incisor forward through its supporting bone, and is associated with gingival recession and periodontal damage. Early correction improves both the periodontal outcome and the growth of the upper jaw.
• Excessive overbites where the lower front teeth risk damaging the roof of the mouth, or the upper front teeth are exposed to injury.
• Underbites that respond well to orthopedic guidance while the jaw is still growing.
• Ectopic teeth, meaning adult teeth erupting in the wrong direction. Impacted or ectopic maxillary canines are a well-known example, and interceptive management is supported by decades of evidence including Ericson and Kurol’s foundational work on primary canine extraction.
• Severe crowding and tooth size or arch length discrepancies that will trap incoming adult teeth if not addressed.

Each of these tends to compound rather than resolve on its own.

Signs Your Child May Benefit From an Early Screening

• Baby teeth falling out much earlier or later than expected
• Difficulty biting or chewing, or a jaw that shifts to one side when your child bites down
• Thumb-sucking or pacifier use continuing past age three
• Mouth breathing or snoring
• A noticeable overbite, underbite, or crossbite
• Crowded, overlapping, or widely spaced front teeth
• Speech difficulty related to tooth or jaw position

If any of these sound familiar, it does not automatically mean your child needs Phase 1 treatment. It means a screening will tell us for certain.

Why Timing Matters: What Changes When Phase 1 Is Missed

We are conservative about recommending Phase 1. When we do recommend it, we mean it, and the reason usually comes down to what happens if we wait.

Skeletal expansion becomes harder, then impossible without surgery. The upper jaw is joined at the midpalatal suture, which fuses gradually with age. In children before the pubertal growth spurt, rapid maxillary expansion produces true skeletal expansion, and there is consensus in the orthodontic literature that expansion is predictable up to about age 14. After that, individual variation is wide, and by adulthood the midpalatal suture typically begins obliteration between ages 15 and 18 and may be completely fused between 25 and 35. Miss the window and expansion moves from a routine appliance to a surgically assisted procedure.

Asymmetrical growth continues while the crossbite continues. A child with a posterior crossbite compensates by shifting the lower jaw to one side to make the bite fit. That shift becomes the growth pattern. Children with unilateral posterior crossbite have significantly increased mandibular condylar asymmetry compared to controls, and every year we wait is another year the face grows around the asymmetry.

Impaction risk goes up, and extraction risk goes up with it. Expanding the arch early makes the parking lot bigger before the remaining adult teeth arrive. That lowers the chance a canine or premolar becomes impacted. The maxillary canine is one of the most commonly impacted teeth, and an impacted canine may damage the roots of adjacent adult teeth, require surgical exposure, or ultimately require extraction. Ericson and Kurol showed that timely extraction of a primary canine normalizes eruption of a palatally displaced permanent canine in up to 91% of favorable cases, which is one of orthodontics’ clearest examples of “early is genuinely different.”

Anterior crossbite damages the lower incisor as long as it goes uncorrected. Every day an anterior crossbite goes uncorrected, the upper front tooth is pushing the affected lower incisor forward through cortical bone. That translates over time to gingival recession, deepening of the bite, and a harder correction later. Studies show correction of the anterior crossbite improves the gingival recession clinically once traumatic occlusion is eliminated, but tissue that has already receded does not fully regrow.

Airway and nasal breathing benefit from expansion in the right window. A narrow upper jaw is also the floor of the nasal cavity. Multiple systematic reviews now show that maxillary expansion in pediatric patients decreases nasal resistance and increases nasal airflow, and a more recent 2025 systematic review concluded rapid maxillary expansion is efficacious in improving nasal breathing in pediatric patients. We are careful not to over-promise here: airway diagnosis is a multidisciplinary decision that involves your pediatrician, ENT, and sometimes a sleep study, and we do not diagnose sleep-disordered breathing as orthodontists. What we can say is that when a narrow upper jaw is one of the contributors, expanding at the right age can help.

The four-year braces experience is what happens when Phase 1 waits too long. If Phase 1 is delayed until baby teeth are already falling out and adult teeth are already erupting, Phase 1 blends into Phase 2. Treatment stretches on.

What Phase 1 Does Not Do

We are careful here because the evidence matters and the honesty matters more. For anteroposterior Class II problems specifically, where the lower jaw sits behind the upper, the long-term evidence from randomized trials shows early treatment does not meaningfully change final occlusal outcomes, skeletal position, or overall treatment complexity compared to a single phase of treatment delivered in adolescence. In practical terms, for a straightforward Class II case with no other concerns, waiting for a single phase of treatment during the adolescent growth spurt is often the right call. That is why our approach is targeted. Phase 1 is for problems that are progressive or complicating in their own right: crossbites, expansion needs, ectopic teeth, protruding incisors at risk of injury, or space issues that will trap adult teeth. If a screening does not turn up one of those, we tell you so and we watch.

What Is Interceptive (Phase 1) Treatment?

Interceptive orthodontic treatment is targeted care delivered during the early window, aimed at problems that will get worse without intervention. Mechanics stay proportional to the issue. We are deliberately selective:

• Too conservative and we miss a window that will not return.
• Too aggressive and we treat unnecessarily and stretch the child’s total time in appliances.
• Too early and treatment becomes unnecessarily long.
• Too late and we miss the boat for value, meaning problems that would have been guided at the right age now require extraction, surgery, or extended treatment.

Phase 1 timing is not a mechanical decision based on tooth eruption alone. Dr. Green and Dr. Gordon weigh a child’s dental age, skeletal development, the social implications of the smile, maturity, family logistics, severity, and how time-sensitive the issue is before recommending treatment. It is a multifactorial call, not a mechanical one, and it is one of the real differences in how we practice.

How Long Does Two-Phase Treatment Take?

No two teen cases are the same, which is why Invisalign is constantly advancing its Invisalign Teen digital treatment solutions. This allows our office to deliver a unique, customized teeth-straightening solution that’s more precise and keeps your teen moving forward.

With the Invisalign system’s proprietary innovations, your teen’s smile can transform up to 50% faster. And as your teen becomes the person you’ve always seen, he or she will continue to enjoy the things that make your teen unique.

In need of straighter teeth but don’t want to wear braces? Green Orthodontics in Decatur is the Invisalign Teen orthodontist for you!

How Long Does Two–Phase Treatment Take?

• Phase 1 usually runs under twelve months, as short as three months or as long as eighteen depending on the case.
• A break of several years typically follows Phase 1, while the rest of the adult teeth erupt.
• Phase 2 generally runs twelve to twenty-four months, depending on which issues remain.

Phase 1 vs Phase 2 at a Glance

Phase 1

• Typical age | Around 8-9, based on dental age 
• Goal | Guide erupting teeth and jaw growth; correct progressive bite problems
• Typical duration | Usually under 12 months (3-18 months depending on case)
• Typical cost | $3,000 to $4,000

Phase 2

• Typical age | Early to mid teens, once remaining adult teeth erupt
• Goal | Complete alignment; address back-to-front issues, Class II correction, and remaining bite discrepancies
• Typical duration | 12-24 months depending on what remains
• Typical cost | $4,000 to $5,500

Common Parent Questions