Jaw surgery, formally called orthognathic surgery, works by cutting specific bones in the upper jaw, lower jaw, or chin, physically repositioning them, and securing them in place with titanium plates and screws. The entire process typically spans one to three years when you include the braces worn before and after the procedure, though the surgery itself takes a few hours under general anesthesia. It’s performed when the jaws are misaligned in ways that braces alone can’t fix, such as significant overbites, underbites, open bites, or asymmetry that affects chewing, breathing, or facial balance.
Why Jaw Surgery Is Needed
Braces move teeth within the jawbone, but they can’t move the jawbone itself. When the upper and lower jaws don’t line up properly because of how the bones grew, the mismatch is skeletal, not just dental. Jaw surgery repositions the actual bone so the teeth, jaws, and airway all function together correctly.
The most common reasons people undergo jaw surgery include difficulty biting and chewing, speech problems, chronic jaw pain from temporomandibular joint disorders, obstructive sleep apnea caused by a narrow airway, and facial imbalance from a receding chin or protruding jaw. It’s also used to repair birth defects and facial injuries. In some cases, a person’s front teeth don’t touch even when their back teeth are fully closed (an open bite), making it impossible to bite through food normally.
Months of Braces Come First
Before surgery happens, you’ll wear braces for a preparatory phase that lasts a median of about 17 months, though it can range from 7 months to nearly 4 years. This might seem counterintuitive: the orthodontist is often making your bite look and feel worse before surgery, not better. The goal is to align the teeth within each jaw so that when the surgeon repositions the bones, the upper and lower teeth will fit together precisely. Without this step, the surgeon would have no way to lock the jaws into a stable new position.
During this phase, your surgical team also creates a detailed plan using 3D imaging software. CT scans of your skull are loaded into planning programs that let the surgeon simulate every bone cut, predict how your soft tissue will respond, and design custom surgical guides. These guides, often made from titanium or medical-grade plastic, act as templates during the actual operation, reducing guesswork and improving precision. Physical 3D-printed models of your skull may also be produced so the surgeon can rehearse the procedure.
How Upper Jaw Surgery Works
When the upper jaw (maxilla) needs to be moved, the surgeon performs what’s called a Le Fort I osteotomy. All incisions are made inside the mouth, so there are no visible scars on the face. The surgeon cuts through the bone on both sides of the upper jaw using a surgical saw under continuous irrigation to prevent heat damage. Additional cuts separate the nasal septum from the upper jaw and disconnect the back of the upper jaw from the skull base.
Once these cuts are complete, the entire upper jaw is freed as a single piece that can be shifted forward, backward, upward, downward, or tilted to correct a canted smile. The surgeon uses a prefabricated splint (made during the planning phase) to guide the jaw into its new position, then secures it with titanium plates bent to match the bone’s contours. Typically four small plates are screwed into the bone, two near the nose and two at the cheekbone area. These plates are permanent and rarely need removal.
How Lower Jaw Surgery Works
The most common lower jaw procedure is a bilateral sagittal split osteotomy. Again, all cuts are made through incisions inside the mouth. The surgeon uses a saw to cut along the inner surface of the jawbone behind the back molars, then continues that cut forward along the outer ridge of the bone. A final vertical cut is made through the outer surface of the jaw near the second molar, extending down to the lower border.
This pattern of cuts essentially splits the back portion of the jawbone into two layers, like opening a book. The inner piece stays connected to the jaw joint, while the outer piece (carrying all the teeth) can slide forward or backward. A prefabricated splint positions the tooth-bearing segment precisely, and the surgeon secures the two layers together using either three screws on each side that pass through both layers of bone, or a small plate with screws. Throughout this process, the surgeon checks that the jaw joint (condyle) remains properly seated in its socket, since even a small displacement can cause long-term bite problems.
Chin Repositioning
Sometimes the chin needs independent adjustment even after the jaws are corrected. A sliding genioplasty addresses this by cutting a horizontal section of chin bone through an incision inside the lower lip. The freed bone segment can be moved forward, backward, or sideways depending on what’s needed. To shorten a long chin, the surgeon removes a slice of bone entirely. To lengthen a short chin, the surgeon shifts the segment downward and leaves a gap that fills in with new bone over time. The repositioned piece is held with plates, screws, or wire.
Many patients have upper and lower jaw surgery performed in the same session. Adding a genioplasty to the same operation is also common, since it requires relatively little additional time and avoids a second round of anesthesia and recovery.
What Recovery Looks Like
Hospital stays average about 4 days, though they range from just over 1 day to about 8 days depending on the complexity of the surgery and how quickly you stabilize. The main concerns in those first days are airway management (the tissues inside your mouth and throat swell significantly), pain control, and making sure you can take in enough fluids. Your jaws may be held together with elastic bands to guide your new bite, and your face will be noticeably swollen.
Diet progression follows a predictable pattern:
- Weeks 1 to 2: Liquids and pureed foods only. Everything goes through a syringe or straw at first.
- Weeks 2 to 3: Soft foods you can squish between your fingers, nothing crunchy or hard.
- Weeks 4 to 6: Soft chewing resumes. Most foods are fine if cut small and easy to chew.
- Weeks 7 to 8 and beyond: Gradual return to normal eating, though hard foods like raw carrots, nuts, and pizza should wait another month or two.
Most people take two to four weeks off work or school. Swelling peaks around day three and gradually subsides over several weeks, though subtle puffiness can linger for months. You’ll continue wearing braces after surgery, typically for another 6 to 12 months, to fine-tune the final bite alignment.
Numbness and Nerve Risks
The most talked-about risk of jaw surgery is nerve injury, particularly to the inferior alveolar nerve, which provides sensation to the lower lip, chin, and gums. This nerve runs directly through the path of the lower jaw cuts, making some degree of temporary numbness almost universal. Studies report nerve disturbance rates ranging from 20% to 98% in the early postoperative period. For most people, sensation gradually returns over weeks to months. Persistent numbness (lasting a year or more) occurs in a smaller but significant subset of patients, with reported rates varying widely from near zero to as high as 82% depending on the study and how “persistent” is defined.
In practical terms, you should expect your lower lip and chin to feel numb or tingly for weeks after lower jaw surgery. Most people regain functional sensation, but some are left with a permanent patch of reduced feeling. Upper jaw surgery carries less nerve risk but can cause temporary numbness in the upper lip and cheeks.
Insurance and Medical Necessity
Jaw surgery can cost tens of thousands of dollars, and insurance coverage depends on proving the procedure is medically necessary rather than cosmetic. The general standard requires showing that the jaw is structurally deformed, that the deformity impairs health (through problems like inability to chew, airway obstruction, or chronic pain), and that no simpler treatment would work.
In practice, insurance criteria can be frustratingly rigid. Many plans use specific measurement thresholds, such as requiring at least 5 millimeters of overjet (horizontal gap between upper and lower front teeth) to qualify. A patient with 4 millimeters of overjet and significant functional problems could still be denied. Most guidelines rely entirely on dental measurements and ignore skeletal measurements from imaging, even when those show clear deformity. Some insurers classify facial disfigurement as cosmetic, and several major carriers don’t account for certain types of jaw problems at all. If your initial claim is denied, appeals with additional documentation from your surgeon and orthodontist are common and sometimes successful.