Upper front teeth that stand out whenever a child smiles
are often dismissed as “just genetics,” but that’s not always the whole story.
Protruding front teeth in children have been linked to up to a 3-fold higher risk of front tooth injury compared with children who don’t have this trait, according to research.
In this article, we’ll look at a case where protruding front teeth and overbite occurred together, and walk through how 6 months of growth orthodontics with Preortho played out.
Key Summary
Protruding front teeth in children are often a form of Class II malocclusion caused by slower lower jaw growth, and may appear alongside an overbite.
Both the Korean Association of Orthodontists and the American Association of Orthodontists (AAO) recommend a first orthodontic checkup around age 6–7, and related research reports a lower rate of new front tooth injury in early-treatment groups compared with delayed-treatment groups (19% vs. 30%).
This article covers a case in which overjet and overbite were observed to improve over 6 months using a Preortho Type1 appliance.
Why Do Children Get Protruding Front Teeth?
Protruding front teeth in children are reported to result more often from slower lower jaw growth than from an oversized upper jaw.
In orthodontics, this condition is called Class II malocclusion.
The front-to-back gap between the upper and lower front teeth is called overjet.
A normal range is generally when the upper front teeth sit about 2–3mm ahead of the lower front teeth.
As this gap increases, the front teeth appear to stick out more.
Jaw shape is strongly influenced by genetics, and oral habits such as thumb sucking, lip sucking, and mouth breathing can also negatively affect tooth alignment.
There’s one more thing to note.
A systematic review found that when overjet exceeds 3–3.5mm, the risk of front tooth injury roughly doubles, and beyond 6mm it can rise to about 3 times higher.
(Kids really do fall a lot…)
Is It Okay to Leave an Overbite in Children Untreated?
If left untreated, a severe overbite can lead to gum damage or excessive tooth wear, so a proper diagnosis is needed.
An overbite (deep bite) refers to a condition where the upper front teeth overlap the lower front teeth so much that, when biting down on the back teeth, the lower front teeth are barely visible.
It’s a common type of malocclusion that often appears together with protruding front teeth and a recessed chin.
In severe cases, the lower front teeth can dig into the palate gum tissue or cause excessive tooth wear.
Many parents worry about a link to TMJ (jaw joint) disorders. While some reports note an association, there isn’t yet enough evidence to conclude that an overbite directly causes TMJ disorders. If there is jaw joint pain or clicking, we recommend a separate consultation with a specialist.
When and How Should Growth Orthodontics Start?
The honest answer is “it depends on the child,” which is exactly why getting an orthodontic checkup around age 7 matters.
Starting treatment as early as possible isn’t automatically right, and neither is simply waiting.
That’s why the timing of permanent front teeth eruption is used as a reference point.
“See an orthodontist for a checkup at age 7”
The Korean Association of Orthodontists is reportedly running a public awareness campaign with this message, recommending a first orthodontic checkup around age 7. The American Association of Orthodontists (AAO) similarly recommends a first checkup no later than age 7.
An international systematic review (a Cochrane-affiliated study) found that the rate of new front tooth injury was 19% in the group that received first-phase treatment at ages 7–11, compared with 30% in the group treated only once during adolescence.
However, there was no clear difference in final outcomes between the two groups once all treatment was complete.
That’s why the principle is to diagnose first, and choose the appliance afterward.
| Item | Details |
|---|---|
| First orthodontic checkup | Around age 7 |
| Checking for a recessed-chin tendency | Typically during the late-elementary growth spurt, or earlier in severe cases |
| Age range for Preortho use | From about age 5–6 up to around age 12 |
| Preortho treatment duration | Typically 6 months to 1 year |
| Daily wear time | Manufacturer recommendation: 1+ hour during the day plus 8+ hours at night (our clinic recommends 12+ hours) |
| After all permanent teeth erupt | Second-phase orthodontics if needed |
✅ Has your child had an orthodontic checkup around age 7?
✅ Does your child have oral habits like thumb sucking or lip sucking?
✅ Do the front teeth look more protruded as the permanent ones come in?
✅ Do the upper teeth appear to cover the lower teeth significantly?
What Actually Changed After Wearing Preortho?
This is the case of an elementary school patient who came in concerned about protruding front teeth and difficulty closing the lips fully.
The intraoral photos showed the upper front teeth positioned excessively ahead of the lower front teeth, with an overbite in which the upper teeth covered almost all of the lower teeth.
The occlusal view also suggested limited space for the permanent teeth to erupt.
Since the first molars and lateral incisors had not yet erupted, it was a bit early for a removable appliance or clear aligners (Invisalign First).
So the appliance chosen was Preortho, a silicone mouthguard-type appliance.
Preortho is broadly divided into Type1 and Type3.
Type3 is used for underbite/crossbite cases, while Type1 is used for protruding front teeth and overbite.
What Does Preortho Type1 Aim to Achieve?
Type1 targets five goals.
- Reducing protruding front teeth
- Improving overbite
- Encouraging lower jaw growth
- Mild arch expansion
- Mild front teeth alignment
For this patient, all five goals aligned with what was needed, so treatment began right away.
By around the 3-month mark, the upper front teeth appeared to move inward, with overjet appearing to decrease and the overbite appearing to improve as well.
Preortho wear was then completed at the 6-month mark.
The lower front teeth, previously more than half hidden by the overbite, appeared to become more visible.
The upper front teeth, which had been excessively advanced relative to the lower front teeth, were also observed to have moved inward.
The occlusal view appeared to show that both the upper and lower arches had widened, and the previously spaced-out upper front teeth appeared more aligned.
Growth-phase treatment is less about finishing orthodontics and more about guiding the direction of growth.
Even in cases where extraction would be unavoidable for an adult, guiding growth in the right direction can sometimes achieve adequate results without extraction.
However, once all permanent teeth have erupted, second-phase orthodontics for tooth alignment may still be needed.
Cheongnyangni Yonsei Dajeonghan Orthodontic Clinic, located in Cheongnyangni, Dongdaemun-gu, Seoul, is an orthodontic specialty clinic where the director — board-certified in both orthodontics and integrated dentistry — personally handles everything from the initial consultation to appliance removal.
Frequently Asked Questions
1. At what age should a child with protruding front teeth get checked?
We recommend an orthodontic checkup around age 7. A checkup doesn’t mean treatment starts immediately — the right timing varies by child.
2. How many hours a day should Preortho be worn?
The manufacturer recommends at least 1 hour during the day and 8+ hours while sleeping. Our clinic recommends at least 12 hours of wear per day.
3. If a child does growth orthodontics, will they need braces later?
Second-phase orthodontics for tooth alignment may still be needed once all permanent teeth have erupted.
4. What happens if an overbite is left untreated in children?
In severe cases, it can cause the lower front teeth to dig into the gums or lead to excessive tooth wear, so a proper diagnosis is important.
References
· Thiruvenkatachari B, et al., Cochrane-affiliated systematic review (early Class II treatment vs. front tooth injury rate, 19% vs. 30%), Evidence-Based Dentistry/PubMed, 2014. View source
· Arraj GP, et al., “The association of overjet size and traumatic dental injuries: a systematic review and meta-analysis,” Dental Traumatology, 2019. View source
· American Association of Orthodontists, “Child Orthodontics” (recommends a first checkup by age 7). View source
· News coverage of the Korean Association of Orthodontists’ age-7 checkup campaign, Dental Today. View source
This article is intended for general health information purposes only and cannot replace individual diagnosis or treatment. If you notice symptoms, please consult a specialist.