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Orthognathic surgery at North Austin Campus

Conditions

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In craniofacial conditions, such as cleft lip and palate, Treacher Collins syndrome, and craniofacial microsomia the jaws and teeth often do not line up correctly (“malocclusion”). Malocclusion can also occur in teenagers without craniofacial conditions. If your teenager’s jaws do not line up properly, they may have trouble chewing or biting into food, and can develop jaw pain and worn-down teeth as they get older. 

We use orthognathic surgery to correct the position of the jaws when orthodontic treatment (braces) alone cannot treat the problem. We typically perform this corrective jaw surgery after the facial bones have stopped growing, which is usually around 16 years for a female and 18 years for a male. 

At Texas Children’s North Austin Campus, we have experts in orthognathic surgery as well as a fellowship-trained craniofacial orthodontist to help plan and perform your teenager’s surgery safely and accurately. We use state-of-the-art 3D imaging and virtual surgery planning to ensure the treatment plan meets all the goals. 

  • Your teenager will need orthodontic treatment with braces for approximately one year before corrective jaw surgery (“pre-surgery orthodontics”). Although the jaw surgery can move the position of the jaws, the orthodontic treatment before surgery is needed to align the teeth, so they bite together well after the surgery. You can choose to either have the pre-surgery orthodontic treatment done at the North Austin Craniofacial Clinic, or by a community orthodontist closer to home. If you have the braces done by a local orthodontist, our craniofacial orthodontist will communicate with them during the treatment to make sure they understand the plan for the surgery. 
  • We will recommend removal (extraction) of your teenager’s wisdom teeth (third molars) in the lower and upper jaw 9 to 12 months before corrective jaw surgery. This is necessary since they are usually in the way of the bone cuts that your surgeon needs to make during surgery. We can arrange for the wisdom teeth extractions at the hospital in North Austin, or we can work with your local dentist to find an oral surgeon to remove the teeth closer to home.
  • Imaging is important for surgical planning. For single jaw movements that are not complex, the imaging is often a plain x-ray taken at a dental office (lateral cephalogram and panorex). For surgery on both jaws (double jaw surgery) or for complex movements of the bone, we will order a CT scan so that we can perform detailed 3D virtual surgical planning. 

There are several different types of orthognathic surgery that your surgeon can use depending on your child’s specific condition. Overall, corrective jaw surgeries can be divided into “single jaw procedures”, when only one jaw is moved into a new position, and “double jaw procedures” when both the upper jaw (maxilla) and lower jaw (mandible) need to be adjusted. 

There are three basic techniques that are used in single and double jaw surgeries:

  • The Le Fort 1 osteotomy is a cut in the upper jaw made above the tooth roots from left to right. Your surgeon will make an incision inside the mouth close to where the upper lip meets the gums. We use a special saw to make the cut, called a Piezoelectric saw, that is less traumatic and more accurate than a traditional saw.
  • Once the Le Fort 1 osteotomy is complete, your surgeon will be able to adjust the position of the upper jaw using a plastic splint that lines up the upper and lower teeth. Once the upper jaw is in the new position, your surgeon will use small metal plates and screws to hold the bone in place while it heals over the next 2 months. The plates are made of titanium, which is the same metal as artificial knee joints or dental implants. They do not rust, do not set off airport alarms, and usually do not need to be removed after the bone heals.
  • Occasionally, your surgeon may need to use a bone graft to secure the Le Fort 1 segment if the movement is big. In some cases, they will recommend using bone available on the shelf (cadaver bone), or in some cases the bone will come from another part of your child’s body, such as the hip crest. 
  • Bilateral sagittal split osteotomy (BSSO) is a surgery to change the position of the lower jaw. “Bilateral” means on both sides of the jaw, “sagittal” means a cut along the length of the lower jaw, and “split” means that the surgeon creates two overlapping pieces in the bone so they can slide over each other but still touch.
  • Your surgeon will make incisions in the gums behind the bottom molars. After the bone is carefully “split” using a special tool known as a Piezoelectric saw, the part of the lower jaw holding the teeth can be advanced and rotated to properly align with the upper jaw using a plastic splint made by our orthodontist to line up the teeth.
  • Once the lower jaw is in the new position, your surgeon will use small metal plates and screws to hold the bone in place while it heals over the next 2 to 3 months. The plates are made of titanium, which is the same metal as artificial knee joints or dental implants. They do not rust, do not set off airport alarms, and usually do not need to be removed after the bone heals.

Genioplasty is a surgery on the chin bone. It allows your surgeon to adjust the position of the chin point to improve facial balance. The surgeon places the incision inside the lower lip and uses a special saw to release the bottom edge of the chin bone below the teeth. The surgeon will then move the chin bone based on the surgical plan. Usually the chin is moved forward and upwards to create a more prominent chin. This movement can also give a minor improvement to some breathing conditions such as obstructive sleep apnea. The moved bone is held in place with metal plates and screws.  

 

Figure 1: Orthognathic surgery

  1. Example of a patient with negative overjet, where the upper jaw is pushed back. This is the typical jaw deformity that may occur in children with cleft lip and palate
  2. Jaw position after orthognathic surgery. LeFort 1 advancement was performed to move the maxilla (yellow) forward, and bilateral sagittal split osteotomy was performed to move the mandible (red) back
  • It is important to plan enough time for your child to recover from jaw surgery. They usually feel very tired, and sometimes a little down for two weeks after surgery. They will not want to do their usual activities, and often stay close to home. After two weeks, they will start to feel better and better, but usually do not start to say they are feeling more like normal until 6 weeks after surgery. Since it takes this time to recover, families often choose to schedule the jaw surgeries during a school break or during summer. 
  • Time in the operating room can range from half a day (4 hours) to a full day (6-8 hours). The length of the surgery will depend on how many bones the surgeon needs to move, how far they need to move them, and if your child has a craniofacial syndrome.
  • In almost all cases, the anesthesia team will remove the breathing tube that was used during surgery when the procedure is over, and your child will go to a regular hospital room overnight. 
  • In rare cases where our team decides it is safer to leave the breathing tube in place after surgery, such as in jaw surgeries treating obstructive sleep apnea, your child will go to the intensive care unit (ICU) overnight. The team will remove the tube safely after the swelling has decreased. 
  • Even though the incisions are small, and inside the mouth, you should expect swelling of the cheeks and lips that is slightly more than after wisdom teeth removal. The most swelling will be the evening of the first day after surgery. The swelling will then last for 2 to 3 days before starting to go away. We will use ice packs and keep your child slightly sitting up in the bed overnight to keep the swelling to the least possible. Most swelling goes away in the first week after surgery, but some slight swelling can still be around one month later.
  • You should expect your child to say that their lips feel numb, and they will often drool for a few days. This is because the nerves that give feeling to the lips are close to the surgery, and are stretched during the surgery. Numbness of the upper lips usually comes back quickly, within a week or two. Numbness of the lower lip usually improves quickly, but research studies have shown it can take up to one year before it feels completely normal. 
  • To help guide the healing bones, your surgeon or our orthodontist will place small elastic bands from the upper braces to the lower braces. We will place the elastics either immediately after the surgery or sometimes we wait until some swelling has gone down. 
  • Time in the hospital usually ranges from 1 to 2 nights for a surgery on one jaw, and 2 to 3 nights for a surgery on both jaws. 
  • After you leave the hospital, your surgeon will recommend that your child follow a “soft chew” diet for six weeks while the bones are healing. A “soft chew” diet is anything you can easily squish between your fingers, such as yogurt, scrambled eggs, oatmeal, soft pasta, pancakes and ground beef. You may need to add food with high calories, such as ice cream or protein shakes. Your teenager may lose up to 10 pounds after jaw surgery, but with careful planning of small, frequent meals, this weight loss can be kept to a minimum. 
  • You will come back to see your surgeon and the craniofacial orthodontist 7 to 10 days after discharge from the hospital. At this first visit we will check all the stitches and adjust the elastics on your braces. 
  • There should be no contact sports, no weightlifting, and no swimming for 6 weeks after surgery. Your surgeon will let you know after that when your child is ready to return to their normal activities. 
  • Your orthodontist will usually need to continue to adjust your child’s braces for up to one year after surgery (“post-surgery orthodontics”).
  • There is a risk of infection after any surgery, but the risk is slightly higher after jaw surgery due to the type of bacteria we have inside our mouths. The signs of infection after jaw surgery are swelling that occurs after the immediate post-surgery swelling goes away (usually 1 to 2 weeks later), a persistent bad smell coming from your child’s mouth, drainage of fluid around the stitches inside the mouth, or a fever. 
  • We will use antibiotics during the surgery to keep this risk as low as possible. We will give you special mouthwash for your child to use for two weeks after surgery. Keeping the stitches as clean as possible after eating will also help. 
  • If an infection happens after surgery, we will see you in clinic and give you a prescription for antibiotics.  Infection can cause the incisions inside your child’s mouth to open. If this happens, we will show you how to wash the wounds with a special syringe that we will give you. Once the infection goes away, the wounds usually heal by themselves. 
  • In rare cases, infection can interfere with bone healing, and additional surgery may be required.
  • Although your surgeon will use special planning tools and splints to line up your child’s teeth during surgery, occasionally the bite will change after your child wakes up and they start to use their chewing muscles, and the joints of their lower jaw settle into place. In most cases this can be adjusted using the elastics that we will place from the upper to lower braces. In very rare cases, we may need to take your child back to the operating room to reset their jaw position and correct their bite by adjusting the positions of the plates and screws. 
  • Decreased feeling in the upper and/or lower lip is common immediately after surgery due to stretching of the nerves during the procedure. Permanent numbness of the upper lip after upper jaw (Le Fort 1) surgery is very rare, since the surgeon can see the nerves and avoid them during the surgery. Permanent numbness of the lower lip after lower jaw (BSSO) surgery is unlikely but research studies have shown that changes in the degree of feeling can occur in 1 out of every 10 patients. The reason the risk is higher in lower jaw surgery is that the nerve that gives feeling to the lower lip runs inside the bone and the surgeon cannot see it until after the bone cuts are complete and the jaw is split. We keep this risk as low as possible by using digital technology to know where the nerve is located using the CT scan taken before surgery, and by using a special saw known as a piezoelectric saw, which is less traumatic to the nerve than a traditional saw.