How Orthognathic Surgery Is Performed: Repositioning the Jaws From Inside the Mouth

The mirror has never been the problem. What bothers him is the sandwich: bite down, and only the back molars meet, so the lettuce slides out and the bread tears instead of cutting. Years of braces straightened his teeth, but the jaws that hold them still do not line up, and his orthodontist has finally said the phrase he has been half-expecting: the orthognathic surgery procedure.

The word sounds heavier than it needs to. Orthognathic simply means “straight jaw.” The operation moves one or both jaws so that the teeth, and the face that surrounds them, sit in a functional relationship. What surprises most people is where it happens: almost entirely inside the mouth, with no visible cut on the face.

This explainer walks through the operation as a surgeon would describe it, from the planning appointments to the moment the plates go in, then through the honest parts: the swelling, the numb lip, the weeks of soft food, and the questions worth asking before you agree to anything.

What the orthognathic surgery procedure actually does, in plain language

Think of the teeth as passengers and the jaws as the two vehicles carrying them. Orthodontics can rearrange passengers within a vehicle. When the vehicles themselves are parked in the wrong places, too far forward, too far back or tilted, no amount of rearranging fixes the ride. Orthognathic surgery moves the vehicles.

The technical word for cutting bone in a planned way is an osteotomy. During the operation the surgeon creates one or more osteotomies through the upper jaw (the maxilla), the lower jaw (the mandible) or both, frees the tooth-bearing segment, slides or rotates it into the position worked out in advance, and holds it there with small plates and screws while the bone knits. The mouth heals around the cuts, and because the incisions run along the inside of the lips and cheeks, scars stay hidden.

The condition being corrected is usually a skeletal malocclusion. Malocclusion means the teeth do not meet correctly when the mouth closes; the skeletal part means the cause sits in the bone rather than the teeth alone. According to Mayo Clinic, jaw surgery is considered when the mismatch affects chewing, speech, breathing, the ability to close the lips at rest, or causes uneven wear and jaw joint strain, and when orthodontics alone cannot correct it.

One point matters more than any other: this is a functional operation with facial consequences, not a cosmetic operation with functional side effects. The bite is measured to the millimeter. Facial changes follow because the bone that carries the teeth is the same bone that shapes the lower face.

Who is usually offered jaw surgery, and who is usually asked to wait

Most candidates have lived with the problem for years. A lower jaw that sits well behind the upper one, a chin that recedes, an open bite where the front teeth never touch, a crossbite where the upper jaw is narrower than the lower, or a face that is visibly asymmetric because one side of the mandible grew longer than the other. Some have obstructive sleep apnea, a condition in which the airway collapses repeatedly during sleep, and their surgeon has judged that advancing the jaws would widen the space behind the tongue; MedlinePlus lists jaw surgery among the options for selected patients when other treatments are unsuitable.

Timing is decided by growth, not by the calendar age on a form. Operating on a jaw that is still lengthening risks the correction being outgrown. Mayo Clinic notes that surgery is usually done after growth stops, roughly 14–16 years for females and 17–21 for males, though a surgeon confirms this with imaging rather than assuming it from age.

Who is asked to wait, or steered elsewhere? Adolescents whose growth plates are still active. People whose orthodontic preparation is incomplete, because the teeth must be positioned so they will interlock once the bones move. Anyone with uncontrolled gum disease or untreated dental decay, since infection and surgery are a poor mix. Smokers are commonly asked to stop well beforehand because tobacco impairs bone and soft-tissue healing. People whose main goal is a change in appearance are often referred for a frank discussion about what the operation can and cannot alter.

None of this is a checklist you can score yourself against. The decision rests with an orthodontist and an oral and maxillofacial surgeon working together, and it is normal for that conversation to take several visits.

Months before the operation: braces, scans and the surgical plan

The operation itself takes hours. The preparation takes most of a year. Mayo Clinic describes a typical sequence in which an orthodontist places braces 12–18 months before surgery, not to straighten the smile in the usual sense but to move the teeth into positions that will fit together only once the jaws are repositioned. This is the counterintuitive phase: the bite may look worse before surgery than it did at the start, because the teeth are being decompensated, moved out of the crooked compromises they drifted into over years of adapting to the skeletal mismatch.

Alongside the braces comes imaging. A cone-beam CT scan (a three-dimensional X-ray of the skull) captures the bone; digital scans or plaster models capture the teeth. Many teams now combine these on a computer and rehearse the operation virtually, sliding the jaw segments on screen until the airway, the profile and the tooth contacts all fall into place. From that plan they produce surgical splints: thin plastic wafers, shaped to the exact planned bite, that sit between the teeth during the operation and tell the surgeon where the moved jaw should stop.

Expect a general medical assessment as well. Blood tests, a review of medications and any bleeding tendency, and a discussion with the anesthetic team about the airway, since the surgeon needs full access to the mouth. If you take any regular medicine, the team will tell you what to continue and what to pause; that decision belongs to them, not to a blog.

Photographs are taken from several angles and, in many units, a second full consent conversation happens once the virtual plan exists, so you can see the intended movements before agreeing.

The day of surgery: anesthesia, the airway and the first incision

You will be asleep for all of it. Orthognathic surgery is performed under general anesthesia, a medically induced unconscious state maintained by an anesthesiologist who monitors breathing, heart rate and blood pressure throughout, as Mayo Clinic explains in its overview of anesthesia. Because the surgeon works inside the mouth, the breathing tube is passed through the nose rather than the mouth, then secured so it stays out of the field.

Before the first cut, several quiet steps happen. The anesthetic team may lower blood pressure slightly, within safe limits, to reduce bleeding from the bone. A drape covers everything except the lower face. Local anesthetic with a small amount of a blood-vessel-narrowing agent is injected into the gums to further limit bleeding and to blunt pain signals for the hours after you wake. Antibiotics are usually given through the drip as a single preventive measure; the choice and timing are the team’s.

Then the surgeon retracts the lip and makes an incision along the fold where the inside of the upper lip meets the gum, or along the ridge behind the last lower molars, depending on which jaw is being moved. The soft tissue is lifted off the bone in a sheet, exposing the maxilla or the outer surface of the mandible. Nerves that supply sensation to the lip and chin are identified and protected.

The operation from here on is measured rather than fast. A single-jaw procedure commonly takes a few hours; moving both jaws takes longer. Family members waiting outside should ask the team for a realistic estimate rather than watching the clock.

Repositioning the upper jaw: the Le Fort I osteotomy step by step

The upper jaw operation is named after a French surgeon who mapped the natural fracture lines of the face. A Le Fort I osteotomy is a horizontal cut through the maxilla above the roots of the upper teeth and below the eye sockets, allowing the entire tooth-bearing part of the upper jaw to be moved as one piece.

With the gum lifted, the surgeon marks the cut line, staying clear of the tooth roots that sit just below. A fine reciprocating saw or a piezoelectric device (an instrument that cuts bone with ultrasonic vibration while sparing soft tissue) scores the bone from one side of the face to the other, passing the wall of the nose and the cheekbone on each side. The nasal septum is separated from the top of the maxilla. Small chisels then complete the cut behind the last molars, where the maxilla joins the bones of the skull base.

The moment that follows is called the downfracture. The surgeon applies steady pressure and the maxilla hinges downward, still attached by its blood supply through the soft tissue of the palate, but free of the skull. This is deliberate and controlled; the blood supply is what keeps the segment alive.

Now the jaw can travel. Forward to correct an underdeveloped midface, upward to shorten a long face and reduce a gummy smile, downward with a bone graft placed in the gap to lengthen a short face, or tilted to level a canted smile. The pre-made surgical splint is seated on the upper and lower teeth, locking the maxilla into its planned relationship with the mandible, and the plates go on.

Repositioning the lower jaw: the bilateral sagittal split osteotomy

The lower jaw poses a different engineering problem. The mandible is a single horseshoe of dense bone hinged at the two jaw joints, and the nerve that gives feeling to the lower lip and chin runs in a canal right through it. The standard solution is the bilateral sagittal split osteotomy, usually shortened to BSSO: a cut on each side that splits the back of the jaw lengthwise into an inner and an outer plate, so the tooth-bearing front section can slide while the joints stay where they are.

Through an incision behind the last molar, the surgeon exposes the outer surface of the ramus, the vertical part of the jaw below the ear. Three connected cuts are made: a short horizontal one on the inner surface above the point where the nerve enters the bone, a long one running forward along the top of the jaw, and a vertical one down the outer surface near the molars. Only the outer layer of bone is cut. Chisels are then gently advanced and twisted so the jaw splits along the plane between the layers, leaving the nerve resting in the inner segment.

Once both sides are split, the front section is free. It can slide forward to correct a retruded jaw and chin, or be set back if the mandible is too long, or rotated to correct asymmetry. The surgical splint guides the teeth into the planned bite, the surgeon confirms that both jaw joints are seated properly in their sockets, and the segments are fixed.

When both jaws are moved in one operation, the maxilla is generally done first and the mandible is then matched to it. Mayo Clinic notes that surgery on both jaws at the same time is common when the problem involves both.

Single jaw, double jaw surgery procedure or chin only: how the options compare

Not every case needs both jaws moved. Some need a third, smaller procedure, a genioplasty, in which the chin bone is cut horizontally below the roots of the lower front teeth and slid forward, backward, up or down, independently of the bite. The table below summarizes what each option involves. It is descriptive, not a menu; the combination is chosen by the surgical team from the plan.

Procedure	What is cut and moved	Typical reasons	Points to know
Le Fort I (upper jaw)	Maxilla above the tooth roots, moved as one piece	Underdeveloped midface, open bite, gummy smile, canted smile	Nose width and lip position can change slightly; sinuses are entered
BSSO (lower jaw)	Each side of the mandible split lengthwise; front segment slides	Receding or protruding lower jaw, asymmetry	Lip and chin numbness is common early because the nerve runs through the cut area
Bimaxillary (both jaws)	Le Fort I plus BSSO in one anesthetic	Mismatch involving both jaws, some sleep apnea cases	Longer operation and more swelling; avoids a second recovery
Genioplasty (chin)	Chin bone below the front tooth roots	Chin position that the jaw movement alone would not correct	Can be done alone or added to the above; does not change the bite

Two honest observations about the table. First, swelling and recovery scale with the number of cuts, so a bimaxillary operation asks more of the patient than a chin procedure. Second, a chin operation on its own is sometimes offered to someone who wanted jaw surgery, because the bite is acceptable and only the profile bothers them; that is a legitimate outcome of a candid consultation, not a consolation prize.

Plates, screws, splints and elastics: how the new jaw position is held

Once the bone has been moved, gravity, chewing muscles and time all want to pull it back. Something must hold it while the cut surfaces knit. Mayo Clinic describes the tools as small bone plates, screws, wires and rubber bands, and it is worth understanding what each one does.

Rigid fixation is the term for plates and screws. The plates are thin strips of titanium, a metal the body tolerates well, each about the thickness of a fingernail and perforated with holes. The surgeon bends a plate to bridge the cut, then drives screws a few millimeters long through the holes into bone on each side. In the upper jaw, four plates typically sit at the corners of the maxilla. In the lower jaw, a plate or a set of screws passes through the overlapping inner and outer segments on each side. These are usually left in place permanently; they do not set off airport scanners in any meaningful way and rarely need removal unless they become irritating or infected.

The splint may stay wired to the upper teeth for a few weeks as a guide for where the lower teeth should close. Small hooks on the braces let the team run light elastics between the jaws, a technique called guiding elastics, which trains the muscles into the new bite without fully wiring the mouth shut. Fully wiring the jaws together for weeks, once standard, is now uncommon because rigid fixation does the mechanical work.

Where a gap has been created, for example when the maxilla is moved downward or far forward, a bone graft fills it. This may be bone taken from the hip or chin, or a processed graft material; the choice is the surgeon’s and is discussed beforehand.

Is orthognathic surgery major surgery? The honest answer on risks

Yes. It is a planned operation on healthy people, which makes it feel less alarming than emergency surgery, but it is carried out under general anesthesia, involves cutting and moving facial bone, and Mayo Clinic lists a hospital stay of roughly two to four days afterward. By any reasonable definition that is major surgery, and a good surgeon will say so plainly.

The risks listed by Mayo Clinic fall into a few groups. Bleeding is the first; the maxilla in particular has a rich blood supply, and while transfusion is unusual it is not impossible, which is why the anesthetic team works to keep blood pressure controlled. Infection is the second, kept low by sterile technique, the preventive antibiotic and, above all, meticulous mouth hygiene afterward.

Nerve injury deserves its own paragraph. The nerve running through the lower jaw and the branches supplying the upper lip and cheek are inevitably stretched, and altered sensation in the lower lip and chin is common in the early weeks after a BSSO. For most people it improves over months; for a minority some patch of numbness is permanent. The nerve that moves the face is not in the surgical field and weakness of facial movement is rare.

Other listed complications include an unplanned fracture pattern during the split, relapse (the bone drifting partly back toward its old position), a bite that does not settle as planned and needs further orthodontics or a second operation, new or worsened jaw joint discomfort, and damage to the roots or blood supply of individual teeth, occasionally requiring root canal treatment. Loss of a portion of jaw from failed blood supply is rare but described.

Alternatives exist for many patients: orthodontics alone with a compromise bite, camouflage with dental restorations, or no treatment. Weighing those is exactly what the consultation is for.

How painful is orthognathic surgery? What the first days really feel like

Ask people who have had it and a consistent answer emerges: the dominant sensation is not sharp pain but pressure, tightness and an almost surreal amount of swelling. The face feels like it belongs to someone else. This is partly because the nerves that would normally report pain from the lower jaw and lip are themselves bruised, so the area is numb rather than sore. The upper jaw tends to ache more than the lower for the same reason.

Pain is managed in layers. Local anesthetic given during the operation carries most people through the first hours. In hospital, the team uses a combination of analgesic classes, adjusting to your needs, and sends you home with a plan; the specifics are theirs to decide and vary with your history. Anti-inflammatory medicines are often part of that plan because swelling, not incision pain, drives much of the discomfort. Corticosteroids given around the time of surgery are commonly used to limit swelling, again at the surgeon’s discretion. Cold packs over the cheeks and sleeping propped upright do more than most people expect.

The first three days are the low point. The nose is congested from the breathing tube and from blood in the sinuses; you breathe through a mouth that does not open far. Swelling peaks around day two or three and then begins, slowly, to recede. Drinking is awkward and a syringe or a cup with a spout helps. Fatigue is profound.

What frightens people most is often not pain but the sense of being unable to communicate. A notepad on the bedside table, agreed in advance, removes much of that anxiety.

None of this is a reason to avoid surgery. It is a reason to plan for it honestly.

Jaw surgery recovery timeline: weeks one to twelve

Recovery is not a straight line, but it has recognizable stages. Mayo Clinic gives two anchors: initial healing takes about six weeks, and complete healing of the bone may take up to twelve. Everything below fits between those markers as typical ranges, not promises.

Week one is about breathing, fluids and rest. You are home from hospital by the end of it, living on liquids and purees, rinsing gently after everything you swallow, and sleeping with your head raised. Swelling is dramatic and bruising may track down the neck. Speech is thick because the lips and tongue are numb and the mouth barely opens.

Weeks two and three bring the first noticeable turn. Swelling has fallen enough that the face looks recognizably yours, though still puffy. The surgeon may remove the splint or loosen the elastics. Many people return to desk work or study around this point, tired by mid-afternoon. Food is still soft: scrambled eggs, mashed vegetables, yogurt, well-cooked pasta.

Weeks four to six are about function returning. Mouth opening improves with gentle stretching exercises the team shows you. Sensation in the lip begins to return as tingling, often before it returns as normal touch. Light exercise is usually permitted; Mayo Clinic advises avoiding strenuous activity during the initial healing period, and contact sports wait longer.

Weeks six to twelve bring the orthodontist back into the picture. The braces stay on to fine-tune the bite in its new position; Mayo Clinic indicates this finishing orthodontics often continues for some months after surgery. Residual swelling in the cheeks and under the chin can linger, and the final facial shape settles gradually rather than appearing on a particular day.

What people often get wrong about corrective jaw surgery

“They cut the face open.” They do not. Nearly all incisions are inside the mouth. A few surgeons make a tiny puncture on the cheek to angle a screw into the lower jaw; it heals to a dot. There are no lines along the jaw or under the chin.

“Your jaws are wired shut for six weeks.” That was true a generation ago, before rigid plate fixation became standard. Today most people can open the mouth a little from the first day and rely on light guiding elastics rather than wires. Some surgeons still use brief periods of tighter fixation for specific cases, so ask what applies to you.

“The braces come off at surgery.” The opposite. The braces are the anchors the surgeon uses for the splint and elastics, and the orthodontist needs them afterward to settle the bite. Mayo Clinic notes orthodontic treatment continues after the operation.

“It fixes jaw joint pain.” Jaw surgery is not a treatment for temporomandibular disorders, the group of conditions affecting the jaw joint and its muscles. The NIH’s dental research institute stresses that most TMD is managed conservatively, and Mayo Clinic lists jaw joint problems among the possible complications of orthognathic surgery rather than its indications. Some people find their joints more comfortable after a balanced bite; others do not.

“Numbness means something went wrong.” Altered sensation in the lip and chin is an expected early feature of lower jaw surgery, not a sign of error. It usually improves over months, and permanent numbness in a small area is a known, disclosed risk rather than a surprise.

“It is cosmetic surgery.” Appearance changes, sometimes considerably, but the operation is planned around the bite and airway. People whose only concern is appearance are usually counselled toward a different conversation.

Questions to ask your care team before agreeing to the orthognathic surgery procedure

A good consultation should leave you able to describe your own operation in a sentence. If you cannot, ask again. These questions tend to draw out the answers that matter.

• Which jaw or jaws will move, in which direction, and by roughly how many millimeters? Can I see the virtual plan or the models?
• Is my growth complete, and how have you confirmed that?
• How long will I wear braces before surgery, and roughly how long afterward?
• Will I have a splint or elastics after the operation, and for how long will my mouth opening be limited?
• What is your plan for the nerve to my lower lip, and what has been your own experience with numbness that does not fully recover?
• Will I need a bone graft, and if so, where will it come from?
• How many nights do you expect me to stay in hospital, and who do I call at 2 a.m. if something worries me at home?
• What will my face look like in profile after this, and what will it not change?
• What happens if the bite does not settle as planned? Would that mean more orthodontics or a second operation?
• Which of my regular medicines should I continue, pause or discuss with my prescribing doctor before surgery?
• What are my alternatives, including doing nothing, and what would you expect to happen to my teeth and bite over the next twenty years without surgery?

Take someone with you. Ask whether the team will put the key points in writing. A surgeon who welcomes these questions is telling you something reassuring about how they will handle the unexpected.

When to call your doctor: red-flag signs after jaw surgery

Most of what you experience in the first fortnight is expected: swelling, bruising, congestion, a numb lip, oozing that stains the pillow pink, a low mood around day three. The list below is different. These are signs the team wants to hear about the same day, and some warrant emergency care.

Call the surgical team promptly if you notice bleeding from the mouth or nose that does not slow after twenty minutes of steady pressure or that soaks through gauze repeatedly; a fever that develops or climbs after the first two days; a sudden increase in swelling on one side, especially if the skin becomes hot, red or tense; a foul taste or pus from an incision; pain that is escalating rather than easing after the first few days, or that is not controlled by the plan you were given; a plate or screw you can feel through the gum or that has become exposed; a bite that suddenly shifts or teeth that no longer meet the way they did on discharge; or numbness that spreads to new areas after initially improving.

Seek emergency care without waiting for a callback if you have difficulty breathing or a sense that your airway is closing, which can follow rapid swelling or bleeding; chest pain, a racing heart or sudden breathlessness, which can signal a blood clot after any operation and period of reduced mobility; a calf that becomes painful, swollen or warm; persistent vomiting with an inability to keep fluids down; or confusion, fainting or an inability to stay awake.

Trust the instinct that something is off. Surgical teams would far rather answer an unnecessary call than miss a necessary one, and every decision about what to do next belongs to them.

Frequently asked questions

How painful is orthognathic surgery?

Most people describe pressure, tightness and heavy swelling rather than sharp pain, partly because the nerves in the area are bruised and the lip and chin feel numb. Discomfort peaks around the second or third day and eases as swelling falls. Pain is managed with a layered plan chosen by the surgical team, plus cold packs and sleeping upright. Congestion and difficulty opening the mouth often bother people more than the incision pain itself.

Is orthognathic surgery major surgery?

Yes. It is performed under general anesthesia, involves cutting and repositioning facial bone, and Mayo Clinic lists a hospital stay of roughly two to four days. It is planned surgery on generally healthy people, which makes it less frightening than emergency operations, but the risks of bleeding, infection, nerve injury and relapse are real and should be discussed openly with the surgeon before consent.

Is jaw surgery a difficult surgery?

It is technically demanding for the surgeon, which is why it is carried out by oral and maxillofacial surgeons with specific training and planned months in advance using three-dimensional imaging and surgical splints. For the patient, the difficulty lies less in the operation, which happens under anesthesia, than in the recovery: several weeks of soft food, swelling, limited mouth opening and altered sensation before the new bite feels natural.

What is the best age for jaw surgery?

The best age is whenever jaw growth has finished, because operating on a still-growing jaw risks the correction being outgrown. Mayo Clinic gives approximate ranges of 14–16 years for females and 17–21 for males, but surgeons confirm maturity with imaging rather than relying on age alone. Adults of any age can be candidates provided their general health, gum condition and dental status allow safe surgery.

What does the double jaw surgery procedure involve?

Double jaw, or bimaxillary, surgery combines a Le Fort I osteotomy of the upper jaw with a bilateral sagittal split osteotomy of the lower jaw in one anesthetic. The upper jaw is usually repositioned first and fixed with plates, then the lower jaw is matched to it using a pre-made splint. It takes longer and produces more swelling than single-jaw surgery but avoids two separate recoveries when both jaws contribute to the problem.

What is the jaw surgery recovery timeline?

Mayo Clinic describes initial healing over about six weeks and complete bone healing taking up to twelve. The first week is dominated by swelling, liquids and rest; by weeks two to three many people return to desk work on soft food; between weeks four and six mouth opening and sensation improve and light exercise is usually allowed. Orthodontic finishing continues for months afterward. These are typical ranges, not guarantees.

Will I have visible scars after orthognathic surgery?

Almost never. The incisions run along the inside of the upper lip and behind the lower back teeth, entirely within the mouth, and heal into the natural gum folds. Some surgeons make a pinpoint puncture on the cheek to angle screws into the lower jaw, which fades to a barely visible dot. Facial appearance changes come from the moved bone, not from external cuts.

Will my jaws be wired shut after surgery?

Usually not for any length of time. Titanium plates and screws now hold the repositioned bone rigidly, so most patients can open their mouth a little from the first day and use light elastics between the braces to guide the bite. Some surgeons use a splint wired to the upper teeth for a few weeks, and specific cases may need tighter fixation briefly. Ask your surgeon what applies to your plan.

Does orthognathic surgery fix TMJ pain?

It is not a treatment for temporomandibular disorders. The NIH’s dental research institute notes most TMD is managed conservatively, and Mayo Clinic lists jaw joint problems among possible complications of jaw surgery rather than among its purposes. Some people find their joints more comfortable once the bite is balanced; others notice no change or new discomfort. Raise any existing joint symptoms with your surgeon before deciding.

Do the plates and screws stay in forever?

In most cases, yes. The titanium plates and screws are well tolerated and are usually left in place permanently once the bone has healed around them. They occasionally need removal if they become irritating, exposed through the gum, or infected, which is a smaller procedure. They do not typically interfere with airport security screening or with medical scans, though you should mention them before any imaging.

References

• MedlinePlus: Malocclusion of teeth
• NIH National Institute of Dental and Craniofacial Research: TMD (Temporomandibular Disorders)
• MedlinePlus: Obstructive sleep apnea – adults

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.