The Tostado Take: Phase I Orthodontic Treatment by Dr. Julia Tostado

When early intervention makes a difference

by Dr. Julia Tostado

The Tostado Take is written by Dr. Julia Tostado with AI assistance and developed under her direction to ensure it reflects her authentic voice and expertise.

Phase I orthodontic treatment has always been one of those topics that can turn a casual orthodontic conversation into a surprisingly passionate debate. Ask 10 orthodontists when a child should begin treatment and you may get 10 slightly different answers. Some clinicians strongly believe in taking advantage of growth and intervening early. Others prefer to monitor development and reserve comprehensive treatment for the permanent dentition whenever possible. Many fall somewhere in between.

So, two questions: Has your Phase I treatment philosophy changed over the last decade? Are you doing more early intervention, less, or about the same?

My own view of Phase I treatment is that the question should not simply be, “Can I treat this now?” It should be, “What am I accomplishing by treating this now that I cannot accomplish as effectively later?” That distinction matters.

The American Association of Orthodontists recommends that children have an orthodontic evaluation no later than age 7.¹ But an orthodontic evaluation at age 7 does not mean every 7-year-old needs braces, an expander, or another appliance. In many cases, the most appropriate treatment at that age is observation.

The value of the early visit is opportunity. It gives us a chance to recognize developing problems while growth, eruption, and the mixed dentition may still provide options that become more complicated later.


Phase I is not just early braces
Phase I treatment, also called early or interceptive orthodontic treatment, generally occurs during the mixed dentition, before eruption of all permanent teeth. The objective should not necessarily be to create a miniature version of the final orthodontic result. Instead, treatment should address a specific developing problem.

That may include transverse maxillary deficiency, posterior crossbite, anterior crossbite, functional shift, significant overjet with trauma risk, developing Class III relationship, ectopic eruption, space problems, harmful oral habits, or another condition in which timing influences our options. Current pediatric dentistry guidance similarly emphasizes diagnosis, treatment priorities, and appropriate timing rather than simply treating according to chronological age.²

This is where Phase I treatment is sometimes misunderstood by parents. Parents may hear “early orthodontic evaluation” and assume that treatment needs to begin immediately. On the other side, some hear “two phases” and assume that Phase I is simply a way of turning one orthodontic treatment into two. Neither assumption is fair. The real issue is whether early intervention provides a meaningful clinical benefit.


Cases that make the argument for Phase I
Some developing problems are difficult to ignore. A child with a unilateral posterior crossbite and functional mandibular shift is very different from a child with mild crowding and otherwise normal development. The first patient may have a problem worth correcting while the dentition is developing. The second may simply need monitoring.

Posterior crossbite is one of the classic indications for interceptive treatment. Expansion can correct transverse discrepancies and functional crossbites during growth. Systematic reviews support successful correction with several expansion approaches, although the evidence does not establish one appliance as universally superior and the quality of evidence varies considerably among studies.^3,4

Sometimes we orthodontists debate quad helix versus rapid palatal expander versus removable expansion as if the choice of appliance were the hard part. In a crossbite with a functional shift, it rarely is.


Class III is where timing gets interesting
Developing Class III malocclusion is another situation where early evaluation can significantly influence treatment planning. A young patient with maxillary deficiency and an anterior crossbite may have opportunities for orthopedic correction that are not available in the same way after growth progresses.

The most recent Cochrane review of orthodontic treatment for Class III malocclusion in children found moderate-certainty evidence that nonsurgical orthodontic treatment can improve the bite and jaw relationship immediately after treatment. However, long-term stability is less certain.⁵ We can improve a young Class III patient’s relationship, but we cannot hand parents a guarantee about future mandibular growth.

That conversation can be challenging. Parents understandably want to know, “If we do this now, will my child avoid jaw surgery later?”

The most responsible answer may be that early treatment can improve the current relationship and potentially create a more favorable growth environment, but future growth cannot be perfectly predicted. Severe skeletal Class III growth may still eventually require surgical treatment. Sometimes informed consent means explaining what our appliance can do and being equally honest about what we cannot predict.


What about Class II?
Class II treatment is where the argument for routine two-phase treatment becomes much less convincing. For children with prominent upper incisors, a major Cochrane review comparing early two-phase treatment with treatment beginning later in adolescence found a split result. Early treatment reduced the incidence of new incisor trauma, but after comprehensive treatment there was little evidence of additional benefit in final overjet or skeletal relationship compared with treatment performed in adolescence.⁶

In the included functional appliance studies, new incisor trauma occurred in approximately 19% of patients receiving early treatment compared with 30% of those receiving later treatment.⁶ That gives us a practical reason to consider early intervention in children with severe overjet, especially the patients who seem to find every playground, basketball, scooter, and countertop with their maxillary incisors.

But it does not mean every Class II patient needs Phase I treatment. Severity matters, and so do trauma risk, psychosocial concerns, growth pattern, and whether the patient will actually wear the appliance.

The diagnosis should drive the timing.


The canine we wish we had found earlier
Another advantage of early orthodontic evaluation is eruption monitoring. Few things make an orthodontist appreciate interceptive treatment quite like discovering a significantly displaced maxillary canine later than we would have liked.

Identifying an abnormal eruption path during the mixed dentition can allow relatively conservative intervention in selected patients. Systematic review and meta-analytic evidence suggests that extraction of the primary canine can increase the likelihood of spontaneous eruption of a palatally displaced permanent canine in appropriately selected cases.⁷ Other interceptive approaches, including expansion and space management, have also demonstrated potential benefits, although case selection remains important.⁸

Phase I treatment, therefore, does not always mean an expander and braces. Sometimes the most valuable interceptive procedure is creating space, removing a primary tooth, maintaining space, correcting an eruption obstacle, or simply monitoring closely enough to intervene at the right moment.

Early treatment can sometimes be surprisingly small.


Crowding is more complicated than ‘make more space’
Crowding is probably one of the areas where treatment philosophy varies most. A parent sees crooked incisors and understandably wants them straight immediately. We see much more.

We see arch length, skeletal pattern, incisor position, periodontal boundaries, facial profile, eruption sequence, leeway space, missing teeth, ectopic teeth, transverse dimensions, and future treatment objectives. Creating space is not automatically the same thing as creating the right space.

Expansion may be appropriate when true transverse deficiency exists. Space maintenance or regaining may be valuable when premature primary tooth loss has altered eruption. Serial extraction may still have a role in carefully selected severe tooth size and arch-length discrepancies. But expanding every crowded child simply because expansion creates room can turn treatment planning into appliance planning.

The goal should not be to make the panoramic radiograph look less crowded for six months. The goal is to improve the eventual outcome.


Habits and the human side of Phase I
Oral habits are another common reason children arrive for early consultation. Thumb sucking, finger habits, abnormal tongue posture, and other persistent behaviors can contribute to developing dentoalveolar changes when sufficient frequency, duration, and intensity are present. Current guidance recommends assessing those factors and considering intervention when the habit is associated with unfavorable dentofacial development.²

But this is also where patient communication becomes incredibly important. Putting an appliance into the mouth of a child who is not emotionally ready to stop a habit means you end up with an appliance the child works around instead of with.

Before reaching for an appliance, we need to understand the child. Counseling and positive reinforcement are often enough. Some children simply need more time, and some do eventually need the appliance.

Phase I treatment is performed on growing children, not growing cephalometric tracings.


The psychosocial indication matters too
Not every indication fits neatly into a skeletal measurement. Children can be remarkably aware of their teeth. Significant anterior malocclusion has been associated with poorer oral health-related quality of life, particularly in emotional and social well-being.⁹

That does not mean every rotated incisor requires immediate treatment because someone at school made a comment. It does mean we should listen. If a child has a severe anterior problem affecting confidence, social interaction, or willingness to smile, that information belongs in the diagnostic discussion along with the cephalometric measurements.

Sometimes improving a child’s smile during an important developmental period has value that is difficult to capture in millimeters.


The biggest Phase I mistake
Perhaps the biggest mistake is starting Phase I without defining where Phase I ends. Before placing an appliance, I think we should be able to answer four questions:

• What specific problem are we treating?

• Why is now better than later?

• What is the endpoint of this phase?

• What will probably still need to be treated in Phase II?

If those answers are unclear, treatment can easily drift. A planned nine-month intervention becomes 18 months. Then a few permanent teeth erupt, so we add brackets. Then another tooth is almost in, so we wait. Suddenly the child has been an orthodontic patient for three years and comprehensive treatment has not technically started.

That is exhausting for the patient, the parents, the team, and probably the orthodontist too. Phase I should have an exit strategy.


The parent conversation
Communication may be as important as biomechanics in early treatment. When I recommend Phase I, I want parents to understand that we are treating a specific problem, not completing all orthodontic treatment early. I also want them to understand that Phase II may still be necessary.

One of the easiest ways to create disappointment is to allow parents to believe that early treatment guarantees their child will never need braces again. Early treatment may reduce complexity later, improve skeletal or dental relationships, protect incisors, redirect eruption, or make the second phase more manageable.

But Phase I is not a coupon guaranteeing a shorter Phase II. Setting that expectation before treatment makes the entire process easier.


More Phase I or less?
Has Phase I philosophy changed? I think the evolution many orthodontists experience is not necessarily toward doing more or doing less. It is toward becoming more selective.

Technology has made early treatment easier in some ways. Digital scanning, improved imaging, aligners designed for mixed dentition, skeletal expansion options, eruption guidance, and better monitoring have expanded what is technically possible. But being able to do something earlier is not a reason to.

The question I keep coming back to: What happens if I wait? If waiting allows normal eruption and does not compromise the eventual outcome, observation may be the best treatment. If waiting allows a functional shift to persist, an ectopic tooth to become more difficult, trauma risk to remain high, or a skeletal discrepancy to progress beyond an important growth window, early intervention becomes much more compelling.

Phase I treatment is at its best when it solves tomorrow’s problem while it is still a smaller problem today.


The goal is better timing, not earlier treatment
Phase I orthodontics should not be defined by age alone. The goal is not to treat every 7-year-old. The goal is to evaluate children early enough that we do not miss the patients who genuinely benefit from intervention.

There will always be orthodontists who lean toward early treatment and others who prefer to wait. Healthy disagreement is valuable because the evidence itself is nuanced. Some conditions have meaningful evidence supporting interception. Others show little long-term advantage over well-timed comprehensive treatment.

Perhaps the best Phase I philosophy is neither aggressive nor conservative.

It is intentional.

Treat when timing provides a biological, functional, preventive, or meaningful psychosocial advantage. Monitor when it does not. Know the objective before placing the appliance, know when to stop, and make sure parents understand what Phase I can and cannot accomplish.

Because sometimes the best early orthodontic treatment is an expander, facemask, limited braces, space management, or habit intervention. And sometimes the best decision at age 7 is a recall appointment.

Has your Phase I treatment philosophy changed over the last decade? Are you treating more children early, fewer, or about the same, and what clinical experiences have changed your mind?

References

1. American Association of Orthodontists. Why kids should see an orthodontist by age 7. aaoinfo.org/whats-trending/when-should-my-child-see-an-orthodontist-age-7/. Published June 24, 2026.

2. American Academy of Pediatric Dentistry. Management of the developing dentition and occlusion in pediatric dentistry. The Reference Manual of Pediatric Dentistry. Chicago, Ill.: American Academy of Pediatric Dentistry; 2024:475–93.

3. Alsawaf DH, Almaasarani SG, Hajeer MY, Rajeh N. The effectiveness of the early orthodontic correction of functional unilateral posterior crossbite in the mixed dentition period: a systematic review and meta-analysis. Progress in Orthodontics. 2022;23(1):5. doi:10.1186/s40510-022-00398-4.

4. Caroccia F, Moscagiuri F, Falconio L, Festa F, D’Attilio M. Early orthodontic treatments of unilateral posterior crossbite: a systematic review. Journal of Clinical Medicine. 2021;10(1):33. doi:10.3390/jcm10010033.

5. Owens D, Watkinson S, Harrison JE, Turner S, Worthington HV. Orthodontic treatment for prominent lower front teeth (Class III malocclusion) in children. Cochrane Database of Systematic Reviews. 2024;4(4):CD003451. doi:10.1002/14651858.CD003451.pub3.

6. Batista KBSL, Thiruvenkatachari B, Harrison JE, O’Brien KD. Orthodontic treatment for prominent upper front teeth (Class II malocclusion) in children and adolescents. Cochrane Database of Systematic Reviews. 2018;3(3):CD003452. doi:10.1002/14651858.CD003452.pub4.

7. Alyammahi AS, Kaklamanos EG, Athanasiou AE. Effectiveness of extraction of primary canines for interceptive management of palatally displaced permanent canines: a systematic review and meta-analysis. European Journal of Orthodontics. 2018;40(2):149–156. doi:10.1093/ejo/cjx042.

8. Baccetti T, Mucedero M, Leonardi M, Cozza P. Interceptive treatment of palatal impaction of maxillary canines with rapid maxillary expansion: a randomized clinical trial. American Journal of Orthodontics and Dentofacial Orthopedics. 2009;136(5):657–661. doi:10.1016/j.ajodo.2007.10.065.

9. Dimberg L, Arnrup K, Bondemark L. The impact of malocclusion on the quality of life among children and adolescents: a systematic review of quantitative studies. European Journal of Orthodontics. 2015;37(3):238–247. doi:10.1093/ejo/cju046.

Dr. Julia Tostado earned her DDS from Universidad Autónoma de Nuevo León and completed her Master of Science in orthodontics at Centro de Estudios Superiores de Ortodoncia. She currently practices at the family-owned clinic Tostado Ortodoncia and shares insights with the orthodontic community through her contributions on Orthotown’s social media.