Not every underbite requires surgery — but when the jaw itself is the problem rather than just the teeth, surgery is often the only way to achieve a lasting correction.
The key distinction is whether the underbite is dental (teeth positioned incorrectly on normally aligned jaws) or skeletal (the lower jaw is structurally too far forward, or the upper jaw is too far back). Dental underbites can often be corrected with braces or clear aligners. Skeletal underbites — particularly moderate to severe ones — typically require jaw surgery, technically called orthognathic surgery, to reposition the jaw itself.
This guide explains when surgery becomes necessary, exactly what it involves, what recovery looks like, and how orthodontic treatment fits into the process before and after the procedure.
What Is Jaw Surgery for Underbite?
Jaw surgery for underbite — formally called orthognathic surgery — is a procedure performed by an oral and maxillofacial surgeon (OMFS) to physically reposition the bones of the jaw. For an underbite, this typically means moving the lower jaw backward, moving the upper jaw forward, or both — depending on what's causing the misalignment.
The two main surgical procedures used for underbite correction are:
Mandibular osteotomy — the lower jaw (mandible) is cut and repositioned backward. This is used when the lower jaw is the primary source of the underbite — when it protrudes too far forward relative to the upper jaw.
Maxillary osteotomy — the upper jaw (maxilla) is repositioned forward. This is used when the upper jaw is set too far back, making the lower jaw appear to jut forward even if its position is actually normal.
Bimaxillary osteotomy (double jaw surgery) — both jaws are repositioned simultaneously. This is used when both the upper and lower jaw contribute to the misalignment, or when a single jaw movement would create an imbalance elsewhere in the bite or facial profile.
The repositioned bone is held in its new location with small titanium plates and screws, which are designed to remain permanently without causing any issues.
When Is Jaw Surgery Necessary for an Underbite?
This is the question most patients and parents want answered first, and the answer depends on the degree of skeletal involvement.
Surgery is typically necessary when:
-
The underbite is skeletal — meaning the jaw positions themselves, not just the tooth angles, are outside the normal range
-
The degree of jaw discrepancy is too large to be fully compensated by orthodontic tooth movement alone
-
Braces or aligners have been assessed and cannot fully correct the bite to a stable, functional result
-
The underbite is causing significant functional problems — difficulty chewing, speech issues, jaw pain, or sleep-related breathing problems
-
The patient's jaw growth is complete (typically late teens to early 20s), since surgery on a still-growing jaw risks the underbite returning as growth continues
Surgery is usually not necessary when:
-
The underbite is mild and primarily dental rather than skeletal
-
Orthodontic treatment can successfully correct the bite without repositioning the jaw
-
The patient is still growing — in which case growth modification appliances, expansion, or camouflage orthodontics are used to manage the bite until growth is complete
Learn more about non-surgical underbite treatment options at Diamond Braces
Can Invisalign fix an underbite without surgery?
The Role of Orthodontics Before and After Surgery
This surprises many patients: jaw surgery is almost never done without orthodontic treatment surrounding it. Surgery and orthodontics are two phases of the same treatment plan, and they work in a specific sequence.
Before Surgery — Pre-Surgical Orthodontics
Before jaw surgery can be performed, an orthodontist moves the teeth into the positions they need to be in after the jaw has been repositioned. This sounds counterintuitive — it often makes the bite look worse temporarily, because teeth are being positioned for where they'll end up post-surgery, not for where the jaw is right now. This phase typically takes 12 to 18 months.
Pre-surgical orthodontics are necessary because surgery repositions the jaw bones, not the teeth. If the teeth aren't properly positioned before surgery, even perfect jaw repositioning won't result in a good bite afterward.
Surgery
Once the orthodontist and surgeon agree that the teeth are in the right pre-surgical positions, surgery is scheduled. The joint coordination between your orthodontist and oral surgeon throughout this phase is what determines the quality of the outcome — they need to be working from the same treatment plan.
After Surgery — Post-Surgical Orthodontics
After the jaw has healed in its new position (typically 6–8 weeks for initial healing), orthodontic treatment continues for another 6–12 months to fine-tune the bite, close any remaining spaces, and ensure the upper and lower teeth meet correctly in the new jaw relationship. This phase is usually less intensive than the pre-surgical phase but is essential for the final result.
Braces vs Invisalign — understanding your orthodontic options
What Happens During Jaw Surgery: Step by Step
General anesthesia — all orthognathic surgery is performed under general anesthesia. The procedure takes place entirely inside the mouth, so there are no visible facial scars.
Osteotomy — the surgeon makes precise cuts in the jaw bone (upper, lower, or both) to allow the segments to be repositioned. The specific cuts are planned in advance using 3D imaging and virtual surgical planning software, which allows the surgeon to simulate and map the entire procedure before entering the operating room.
Repositioning and fixation — the jaw bone segments are moved to the planned new positions and held in place with small titanium plates and screws. These are permanent and do not need to be removed.
Closure — incisions are closed with dissolvable sutures inside the mouth. There is no external cutting.
The procedure typically takes 2–4 hours for single jaw surgery, or 4–6 hours for double jaw surgery. Most patients stay in hospital overnight and are discharged the following day.
Recovery: What to Expect
Recovery from jaw surgery is significant and should be planned for carefully. Here's a realistic timeline:
First 1–2 weeks: the most intensive recovery period. Swelling peaks around day 3–4 and then gradually subsides over several weeks. A liquid diet is required — nothing that requires chewing. Most patients take 2 weeks off work or school.
Weeks 3–6: swelling continues to reduce, and soft foods (nothing that requires significant chewing) are gradually introduced. Energy levels improve. Most patients feel reasonably normal by week 4–5.
6–8 weeks: the bone has healed sufficiently for post-surgical orthodontics to resume. Full chewing capacity typically returns around this point, though the jaw may still feel different from before for several months.
3–12 months: final swelling resolves gradually — some patients notice continued improvement in facial contour for up to a year post-surgery. The final bite and facial appearance become clearer during this period.
Pain management: prescription pain medication is typically needed for the first 1–2 weeks, transitioning to over-the-counter pain relief after that. Your surgeon will provide specific guidance.
What Jaw Surgery Can and Cannot Fix
Surgery can correct:
- The underlying skeletal jaw discrepancy causing the underbite
- Functional problems with chewing and biting efficiency
- Speech issues related to jaw position
- Facial balance and profile
- In some cases, sleep-disordered breathing related to jaw anatomy
Surgery alone cannot correct:
- Individual tooth positions — this is why orthodontics surrounds the surgery
- TMJ issues that are not directly related to jaw position (though correcting the bite can sometimes improve TMJ symptoms)
- Soft tissue (lips, chin) changes beyond what follows naturally from the jaw repositioning
Can braces fix TMJ — understanding the relationship between bite and jaw pain
The Orthodontist's Role in the Decision
For most patients, the jaw surgery conversation begins with an orthodontist rather than a surgeon. An orthodontist evaluates your bite, analyzes your skeletal structure with X-rays and scans, and determines whether your underbite can be corrected orthodontically or whether a surgical referral is appropriate.
If surgery is recommended, your orthodontist manages the pre- and post-surgical orthodontic phases and coordinates the treatment plan with the oral surgeon throughout. Choosing an experienced orthodontic team that regularly works with oral surgeons on orthognathic cases is one of the most important decisions in this process.
Schedule a consultation with Diamond Braces
Frequently Asked Questions
Do I need jaw surgery for an underbite?
It depends on whether the underbite is primarily dental or skeletal. Mild, dental underbites can often be corrected with braces or clear aligners. Significant skeletal underbites — where the jaw positions themselves are outside the normal range — typically require jaw surgery to achieve a stable, lasting correction. An orthodontic evaluation with X-rays is the reliable way to determine which applies to your case.
What is jaw surgery for underbite called?
Jaw surgery for underbite is called orthognathic surgery. The specific procedure depends on which jaw needs repositioning: mandibular osteotomy (lower jaw moved back), maxillary osteotomy (upper jaw moved forward), or bimaxillary osteotomy (both jaws repositioned simultaneously).
How long is recovery from jaw surgery for underbite?
Most patients return to work or school within 2 weeks. A liquid to soft-food diet is required for 4–6 weeks. The bone heals sufficiently for post-surgical orthodontics to resume around 6–8 weeks. Final swelling and the full facial result continue to develop over 3–12 months post-surgery.
Do you need braces before jaw surgery?
Yes — almost always. Pre-surgical orthodontic treatment, typically lasting 12–18 months, positions the teeth correctly for where they'll be after jaw repositioning. Without this preparation, surgery cannot produce a correct bite result. Post-surgical orthodontics continues for another 6–12 months after jaw healing to refine the bite.
Can Invisalign fix an underbite without surgery?
For dental underbites — where tooth positioning is the primary issue on structurally normal jaws — Invisalign can be effective. For skeletal underbites involving significant jaw discrepancy, Invisalign can address the orthodontic component but cannot reposition the jaw itself. Your orthodontist will evaluate whether your underbite can be fully corrected without surgery.
Is jaw surgery for underbite permanent?
Yes — once the jaw has healed in its new position, the correction is permanent. The titanium plates and screws holding the bone in position remain in place long-term without causing issues. Continued orthodontic retention (wearing a retainer) is still needed to maintain tooth positions, as with any orthodontic treatment.
What are the risks of jaw surgery for underbite?
As with any surgery, risks exist — including temporary numbness or altered sensation (nerve involvement during jaw surgery is common and typically resolves over months), infection, bleeding, and in rare cases, relapse of the jaw position. These are discussed in detail during your surgical consultation, where your specific anatomy and case complexity are reviewed.
Schedule a consultation at Diamond Braces to discuss your underbite treatment options
