Underbite, Overbite & Open Bite
Medically reviewed by Dr. Sergio Calleja, DDS, MPH — Board-Certified Oral & Maxillofacial Surgeon · Last reviewed 2026-06-30
When your teeth do not meet the way they should, everyday things get complicated: biting into a sandwich, chewing evenly on both sides, closing your lips comfortably, even speaking clearly. Dentists call this malocclusion — a "bad bite" — and it comes in several patterns: the lower jaw ahead of the upper (underbite), the upper teeth far ahead of the lower (excess overbite/overjet), or front teeth that do not touch at all when the back teeth close (open bite).
The key question for treatment is not what the bite looks like — it is where the mismatch lives. Sometimes the teeth are simply tilted or crowded in jaws that match well; braces or aligners fix that. But when the jaws themselves are different sizes or sit in different positions, moving teeth alone cannot close the gap. This page helps you understand which situation you are in.
Teeth Problem or Jaw Problem?
Orthodontists and oral surgeons draw a line between dental malocclusion (the teeth are misaligned in well-matched jaws) and skeletal malocclusion (the jawbones themselves are mismatched — one too far forward, too far back, too long, or too short).
The distinction matters because it determines what treatment can honestly achieve. Braces and aligners move teeth through bone; they cannot move the bones themselves in an adult whose growth is complete. Orthodontics can camouflage a mild skeletal mismatch by tilting teeth into contact — a reasonable choice in some cases — but a significant skeletal discrepancy corrected with tooth movement alone tends to trade one compromise for another.
In growing children and teens, orthodontists have an extra tool: growth-guiding appliances that can influence jaw development. That window closes when growth ends — which is why the same underbite might be treated with an appliance at 9, and with coordinated orthodontics and jaw surgery at 25.
Signs Your Bite Problem May Be Skeletal
- Your lower teeth sit in front of your upper teeth when you bite (underbite)
- Your front teeth do not touch at all when your back teeth are closed (open bite) — biting through pizza or lettuce with your front teeth is impossible
- A noticeably receded or very prominent chin or lower jaw in profile
- Your lips do not close comfortably at rest without straining
- You chew on one side, avoid certain foods, or tire when chewing
- A previous round of braces "relapsed" — the bite drifted back after treatment
- You snore heavily or have been told you may have sleep apnea alongside a small or set-back lower jaw
How an Uncorrected Bite Affects Daily Life
A significant bite discrepancy is a function problem, not just an appearance one. Chewing becomes less efficient and lopsided, which some patients feel as jaw-muscle fatigue or soreness. Teeth that meet at the wrong angles wear each other unevenly and can chip. Certain speech sounds are harder to produce with an open bite. Lips that cannot close at rest lead to mouth-breathing and chronic dry mouth.
There is also a structural connection to sleep: a small or set-back lower jaw leaves less room for the airway behind the tongue, and this anatomy is one of the recognized contributors to obstructive sleep apnea. It is one of the reasons a bite evaluation sometimes turns into a broader airway conversation.
What Evaluation Looks Like
Sorting dental from skeletal takes measurement, not guesswork: a clinical exam, photographs, a 3D CBCT scan, and a bite analysis. From those, the team can show you precisely — in millimeters — where the mismatch lives and model what different treatments would achieve.
This evaluation is a team effort between an orthodontist and an oral & maxillofacial surgeon. If you already have an orthodontist, we work with them; if not, we can coordinate the full evaluation. A good evaluation ends with options, not a sales pitch — including, where honest, the option of orthodontic camouflage or no treatment at all.
Seek Care Promptly If
- A sudden change in how your teeth fit together — especially after an injury (this suggests a fracture or joint problem, not a slowly developing bite issue)
- Bite changes accompanied by jaw joint pain, locking, or swelling
- In a child: a developing underbite or crossbite — earlier orthodontic evaluation (around age 7) preserves growth-guidance options
Office: (301) 645-6911 (Waldorf) · (301) 863-8107 (California, MD). For emergencies, call 911.
The Treatment: Corrective Jaw Surgery
When the jaws themselves are mismatched, coordinated orthodontics plus corrective jaw surgery (orthognathic surgery) repositions the jaw bones so the teeth, lips, and airway all work the way they were designed to. Our complete guide covers the procedure, the orthodontics timeline, recovery, and insurance.
Read the Jaw Surgery Guide →Frequently Asked Questions
Can braces fix an underbite in adults?
It depends on the cause. If the underbite comes from tooth position, braces or aligners can correct it. If the lower jaw itself is too far forward relative to the upper — a skeletal underbite — braces alone can only camouflage a mild mismatch, and significant cases are treated with orthodontics plus jaw surgery. A 3D evaluation tells you which one yours is.
What causes an open bite?
In adults, an open bite is usually skeletal — the jaws grew in a pattern that leaves the front teeth apart — sometimes shaped by long-childhood habits like thumb-sucking or persistent tongue posture. Adult open bites are among the least stable problems to treat with tooth movement alone, which is why surgery is often part of the honest answer.
How do I know if I need jaw surgery instead of just braces?
The dividing line is where the mismatch lives: teeth versus jawbones. Signs pointing toward the skeletal side include a strong family-trait jaw profile, lips that strain to close, front teeth that cannot touch, and a bite that relapsed after previous braces. The definitive answer comes from a coordinated orthodontist-surgeon evaluation with 3D imaging.
Is a bad bite just cosmetic?
No. Significant malocclusion affects chewing efficiency, tooth wear, speech, lip closure, and jaw-muscle comfort — and a set-back lower jaw narrows the airway behind the tongue, a recognized contributor to obstructive sleep apnea. Insurance often recognizes this: functional jaw discrepancies frequently qualify orthognathic surgery for medical coverage.
My child has an underbite — when should we act?
Early. An orthodontic evaluation around age 7 is the standard recommendation, because growth-guiding appliances work while the jaws are still developing. Some skeletal patterns still end up needing surgery after growth finishes, but early evaluation keeps every option open.
Did my wisdom teeth cause my bite to shift?
Almost certainly not — the popular belief that wisdom teeth push the other teeth out of line is not well supported by evidence. Adult bites shift for other reasons: natural mesial drift, gum disease, tooth loss, or a skeletal growth pattern that continued subtly. A proper exam finds the actual cause.
Not Sure What You're Dealing With?
A consultation with imaging gives you a real answer — and a plan, even if the plan is simply to watch and wait.
Related Guides
This page is general patient education, not a diagnosis. Only an in-person examination can determine what is causing your symptoms and which treatment, if any, is right for you. For emergencies, call 911.