What Age Should You Correct an Underbite?

The Short Answer: Ages 7–10 Is the Ideal Window

According to the American Association of Orthodontists (AAO), the ideal age to begin correcting an underbite is between 7 and 10 years old. At this stage, the jaw is still actively growing, which means orthodontists can guide bone development with much less invasive — and far less expensive — treatments than would be needed in adulthood.

Waiting too long can turn a manageable problem into one that requires jaw surgery. Acting early, on the other hand, can often resolve an underbite entirely using simple appliances like a palate expander or reverse-pull headgear.

What Is an Underbite?

An underbite (also called a Class III malocclusion) is when the lower jaw protrudes forward so that the lower front teeth sit in front of the upper front teeth when biting down. It can range from mild (a few teeth out of alignment) to severe (the entire lower jaw visibly jutting forward).

Underbites affect roughly 5–10% of the population and can be caused by:

• Genetics (a family history of underbites)
• Prolonged thumb sucking or pacifier use past age 3–4
• Tongue thrusting habits
• Mouth breathing during childhood
• Early loss of baby teeth
• Jaw injury

Why Early Treatment (Ages 7–10) Works Best

Children's jaws are still developing through their early teens. Between ages 7 and 10, the bones are soft and responsive — meaning an orthodontist can actually redirect jaw growth using gentle, non-surgical appliances. This is called Phase 1 (or interceptive) orthodontic treatment.

The benefits of treating an underbite early include:

• Avoiding jaw surgery: Underbites corrected in childhood rarely require surgical intervention. Adults who missed early treatment often need orthognathic (jaw) surgery.
• Shorter, simpler treatment: Phase 1 treatment typically lasts 9–12 months. Adult correction can take 2–3 years.
• Better long-term results: Correcting jaw growth early creates a stable foundation for permanent teeth.
• Improved self-confidence: Children with corrected bites smile more freely and experience fewer social difficulties.
• Reduced wear on teeth: An untreated underbite causes abnormal wear on tooth enamel, leading to chips, cracks, and sensitivity over time.

Treatment Options by Age

Ages 7–10: Phase 1 / Interceptive Treatment

This is the golden window. At this age, orthodontists can use growth modification appliances to guide the jaw into the correct position. Common options include:

• Reverse-pull (facemask) headgear: Worn at home for 12–14 hours per day, this device gently pulls the upper jaw forward to match the lower jaw. Highly effective in children under 10.
• Palate expander: Widens the upper jaw to improve the bite relationship between upper and lower teeth.
• Chin cup: Applies gentle pressure to slow the growth of the lower jaw in cases where the lower jaw is growing too fast.
• Partial braces: Sometimes used alongside appliances to align specific teeth.

Ages 11–14: Phase 2 / Full Braces

After Phase 1 treatment (or if Phase 1 was not needed), most children receive full braces during this phase. By now, most permanent teeth have erupted and the bite can be fully corrected. Braces at this stage address tooth alignment and any remaining bite issues.

Ages 15+: Braces + Possible Surgery

Once the jaw has finished growing (typically around age 16–18 for girls and 18–21 for boys), growth modification is no longer possible. Moderate to severe underbites in older teens and adults often require a combination of braces and orthognathic (jaw) surgery to achieve a stable correction. This is why early evaluation is so important — it can prevent the need for surgery entirely.

Signs Your Child May Have an Underbite

Watch for these signs and schedule an evaluation if you notice any of them:

• Lower front teeth sit in front of upper front teeth when biting
• Lower jaw appears to jut forward
• Difficulty biting into food (especially sandwiches or apples)
• Speech difficulties, especially with "s" and "f" sounds
• Mouth breathing or snoring
• Jaw pain or clicking sounds when opening/closing the mouth
• Uneven facial appearance (asymmetry)
• Teeth wearing down unevenly

What Happens If an Underbite Is Left Untreated?

An untreated underbite doesn't just affect appearance — it can cause real health problems over time:

• Accelerated tooth wear: Misaligned teeth grind against each other abnormally, wearing down enamel faster.
• TMJ (jaw joint) problems: The unnatural bite position stresses the temporomandibular joint, leading to pain, clicking, and headaches.
• Chewing and digestion issues: Difficulty chewing properly can affect nutrition and digestion.
• Speech problems: Certain sounds are harder to produce with a misaligned bite.
• Sleep apnea risk: Jaw misalignment can contribute to airway obstruction during sleep.
• Self-esteem impact: Children and teens with visible underbites often experience social anxiety and reduced confidence.

Underbite Treatment at Cool Smilez in Hialeah & Miami Gardens

At Cool Smilez Family Dentistry & Orthodontics, our orthodontic team is experienced in treating underbites in children of all ages — from early Phase 1 intervention to full braces in teens and adults.

We offer free orthodontic consultations including digital X-rays at both our Hialeah and Miami Gardens locations. During your child's consultation, we will:

• Take digital X-rays to assess jaw development and tooth positioning
• Evaluate the severity of the underbite
• Recommend the best timing and type of treatment
• Provide a transparent treatment plan with clear pricing
• Answer all your questions — no pressure, no obligation

We accept Medicaid, all major insurance plans, and offer no-credit-check financing starting at $99.88/month so that cost is never a barrier to getting your child the care they need.

Frequently Asked Questions

Can a 5-year-old be treated for an underbite?

In some cases, yes. If a child has a very pronounced underbite caused by a habit (like thumb sucking or tongue thrusting), breaking the habit early — ideally before age 5 — can allow the bite to self-correct. For structural underbites, most orthodontists prefer to wait until age 7–8 when there's enough jaw development to assess the problem accurately and begin effective treatment.

Is an underbite genetic?

Yes, underbites often run in families. If one or both parents have an underbite, their children have a higher likelihood of developing one. However, habits like prolonged pacifier use, thumb sucking, and mouth breathing can also cause or worsen an underbite regardless of genetics.

Will my child need surgery for their underbite?

Not if treated early. Children treated with Phase 1 appliances between ages 7 and 10 rarely need surgery. Surgery is typically only considered for adults or older teens whose jaws have finished growing and whose underbite is severe. This is the strongest argument for early evaluation.

How long does underbite treatment take?

Phase 1 treatment (ages 7–10) typically lasts 9–12 months. After a rest period, Phase 2 braces (ages 11–14) usually take an additional 18–24 months. Total treatment time is often less than treating an underbite in adulthood, which can take 2–3+ years including surgery.

Does insurance cover underbite treatment?

Many dental insurance plans cover a portion of orthodontic treatment, including underbite correction. Medicaid covers orthodontic treatment for children when it is deemed medically necessary — and underbites often qualify. At Cool Smilez, we'll help you understand your coverage and maximize your benefits.