An underbite is a bite where the lower front teeth sit in front of the upper front teeth when the mouth is closed. It’s usually caused by the lower jaw growing too far forward, the upper jaw being underdeveloped, or the position of the teeth themselves. Underbites are most easily corrected in childhood while the jaws are still growing, but they can be treated at any age.
At Solana Orthodontics, Dr. Sandra Nairooz looks at how the jaws and teeth work together for every Solana family member, because an underbite is as much about function as it is about the smile.
What causes an underbite?
- Jaw growth: a lower jaw that grows longer than the upper jaw (often genetic).
- Underdeveloped upper jaw: the top jaw doesn’t grow forward enough.
- Tooth position: the lower front teeth tip forward or the uppers tip back.
- Childhood habits: prolonged thumb sucking or tongue posture can contribute.
Why should an underbite be treated?
Beyond appearance, an untreated underbite can cause:
- Difficulty biting and chewing efficiently.
- Uneven, accelerated tooth wear.
- Jaw strain and TMJ-related discomfort.
- Speech challenges in some cases.
How is an underbite treated?
The right approach depends heavily on age:
- Children: growth-guiding appliances (like a palate expander or reverse-pull headgear) can steer the jaws while they’re developing — a major advantage of early evaluation.
- Teens and adults: braces or clear aligners reposition the teeth; elastics help coordinate the bite.
- Severe skeletal cases: a combination of orthodontics and jaw surgery may be recommended for adults.
Because early treatment can be so effective, the American Association of Orthodontists recommends a first orthodontic visit by age 7. Our overview of common bite problems like overbite explains how these issues relate. If you suspect an underbite in your child, early interceptive orthodontics is often where treatment begins.
Correcting underbites at Solana Orthodontics
As a board-certified orthodontist and diplomate of the American Board of Orthodontics, Dr. Sandra evaluates the teeth, jaws, and airway together before recommending a plan. In our practice we often find that catching an underbite early makes correction simpler and less invasive. Our team of experts at Solana Orthodontics in San Antonio can assess it and outline your options.
What are the signs and symptoms of an underbite?
The most obvious sign is that the lower front teeth sit in front of the upper front teeth when the mouth is closed, sometimes giving the chin a prominent appearance. But underbites affect function as well as looks. You might notice difficulty biting or chewing certain foods, jaw fatigue or discomfort, uneven wear on specific teeth, or even changes in speech such as trouble with certain sounds. In children, an underbite may become more noticeable as the permanent teeth and jaws develop, which is one reason early evaluation is so valuable.
How is an underbite diagnosed?
Diagnosis involves more than looking at the front teeth. We examine how the full bite fits together, take digital scans or images, and often use X-rays or 3D imaging to see the jaw relationship. This reveals whether the underbite is primarily dental (from tooth position) or skeletal (from jaw size or position) — a crucial distinction, because a skeletal underbite in a growing child is treated very differently than one discovered in an adult. A thorough diagnosis is what allows a treatment plan that actually addresses the cause.
Can an underbite be fixed without surgery?
Often, yes — especially when caught early. In children, growth-guiding appliances can correct a developing underbite without surgery by steering how the jaws grow. In teens and adults with mild to moderate underbites, braces or clear aligners with elastics can reposition the teeth effectively. Surgery is generally reserved for severe skeletal underbites in adults, where the jaw discrepancy is too large to resolve by moving teeth alone. The earlier an underbite is evaluated, the more likely a non-surgical option will be on the table.
How long does underbite treatment take?
It depends heavily on the type and severity. Early interceptive treatment in a child may run several months to guide growth, often followed later by a second phase to align the permanent teeth. Comprehensive treatment for teens and adults commonly falls in the 1-to-2-year range, similar to other bite corrections. Severe skeletal cases involving surgery are staged and take longer. At your consultation we’ll outline a realistic timeline for your specific situation and explain what’s driving it.
Why treating an underbite protects your long-term health
An underbite isn’t just cosmetic. Left uncorrected, it can cause accelerated and uneven tooth wear, strain on the jaw joints that may contribute to TMJ discomfort, difficulty chewing efficiently, and in some cases speech challenges. Correcting the bite improves how your teeth function and distributes chewing forces more evenly, which protects your teeth and jaw for the long run. As a board-certified orthodontist and diplomate of the American Board of Orthodontics, Dr. Sandra Nairooz evaluates the teeth, jaws, and airway together to build a plan that lasts.
What causes an underbite to develop?
Underbites usually stem from a combination of genetics and development. The most common driver is inherited jaw proportions — a lower jaw that grows longer than average, an upper jaw that grows too little, or both. Childhood factors can contribute as well: prolonged thumb sucking, extended pacifier or bottle use, tongue-thrusting, and mouth breathing can all influence how the jaws and teeth develop. In some cases, the tilt of the front teeth alone creates the appearance of an underbite even when the jaws are fairly balanced. Because several factors can be at play, pinpointing the cause is part of what shapes the right treatment.
Can an underbite be prevented?
You can’t change genetics, but you can reduce contributing habits and, most importantly, catch a developing underbite early. Discouraging prolonged thumb sucking and pacifier use, addressing chronic mouth breathing with your child’s physician, and bringing your child in for an evaluation by around age 7 all help. Early detection doesn’t guarantee prevention, but it dramatically widens the options — a jaw that’s still growing can often be guided in ways that aren’t possible once growth is complete. That’s the single biggest reason not to wait.
Underbite treatment in adults versus children
The difference comes down to growth. In children, we can influence how the jaws develop, so appliances that guide growth can correct the underlying skeletal issue relatively simply. In adults, the jaws are set, so treatment focuses on repositioning the teeth with braces or aligners; when the skeletal discrepancy is large, orthodontics is combined with jaw surgery for a stable, healthy result. Neither age is “too late” — adults achieve excellent outcomes — but the earlier an underbite is addressed, the more conservative the treatment tends to be.
Underbite and quality of life
Beyond the physical effects, an underbite can affect confidence and daily comfort. Some people feel self-conscious about the appearance of their profile, while others simply want to chew and speak without difficulty. Correcting an underbite often brings a meaningful boost in self-assurance alongside the functional improvements — patients frequently tell us they smile more freely afterward. Because treatment addresses both how the bite works and how the smile looks, the results tend to be deeply satisfying, which is part of why we love helping patients through this particular correction.
What to expect at an underbite consultation
At your visit, we examine how your bite fits together, take digital scans or images, and often use X-rays or 3D imaging to determine whether the underbite is dental or skeletal. This shapes everything about the plan, since a growing child, a teen, and an adult are each treated differently. You’ll leave understanding the cause of your underbite, the realistic options, and the expected timeline. As a board-certified orthodontist, Dr. Sandra Nairooz makes sure you feel fully informed before any treatment begins.
Frequently Asked Questions
Can an underbite be fixed without surgery?
Often yes — especially in children and in mild to moderate adult cases treated with braces or aligners. Surgery is reserved for severe skeletal underbites in adults.
What is the best age to treat an underbite?
Early — ideally caught around age 7 — because the jaws can still be guided as they grow. That said, adults can absolutely be treated too.
Can Invisalign fix an underbite?
Aligners can correct many mild to moderate underbites. More severe or skeletal cases may need braces, appliances, or surgery. A consultation determines the best path.