Orthognathic and Jaw Surgery

Orthognathic surgery, or corrective jaw surgery, is used to correct severe jaw malocclusion (misalignment) that cannot be fully corrected with orthodontics.

Surgery involves changing the position of the maxilla (the upper jaw), the mandible (the lower jaw) and/or the alveolar bones (the bones that support the teeth).

Proper alignment of the jaws and teeth can improve your child’s ability to chew, speak and breathe. It can also improve the appearance of a person’s smile and facial profile.

At Children’s Hospital of Philadelphia, your child’s treatment and orthognathic surgery will be customized to address their unique needs and is based on recommendations from our top maxillofacial and plastic surgeons, orthodontists and dentists.

What causes jaw abnormalities?

A number of medical diagnoses can cause problems with jaw and facial growth including cleft lip and palate, isolated cleft palate, hemifacial microsomia, Pierre Robin syndrome, craniosynostosis, Treacher Collins syndrome, ectodermal dysplasia, and jaw injury or fracture. However, children without an underlying medical diagnosis can also develop jaw anomalies.

Who is a candidate for orthognathic surgery?

In proper jaw alignment, the upper jaw and teeth project slightly farther than the lower teeth. If the jaws are not properly aligned, your child may experience difficulty chewing food, difficulty biting into food, breathing problems or jaw pain. Misalignment of the jaw can also put the teeth at risk for becoming worn down.

Orthognathic surgery may be recommended for your child if they have one or more of the following jaw abnormalities:

  • Severe underbite, meaning the lower jaw projects forward beyond the upper teeth. This can be due to a small or underdeveloped upper jaw (common in children with a cleft palate) or a large or overdeveloped lower jaw.
  • Severe overbite, meaning the upper jaw projects abnormally forward beyond the lower teeth, causing the lower jaw to appear receded. This can be due to an underdeveloped lower jaw (common in children with Treacher Collins and Pierre Robin syndromes) or an overdeveloped upper jaw.
  • Open bite, when the upper and lower jaws grow at an outward angle, which prevents the teeth from touching each other properly.
  • Uneven or asymmetrical jaws, meaning one side of the jaw grows at a faster or slower rate than the other, causing jaw or facial asymmetry. The chin may deviate to the left or right (common in children with hemifacial microsomia).

Preparing for corrective jaw surgery

Typically, corrective jaw surgery is performed after the face and jaw have stopped growing. This is necessary to ensure that your child does not outgrow the correction. In most cases, the jaw and face have completed growth around 15 to 18 years of age.

Most children require about 6 to 12 months of orthodontic treatment before surgery to properly align the teeth as well as an additional 612 months of orthodontic treatment after surgery to finalize the bite. At Children’s Hospital of Philadelphia, our team of orthodontists specialize in treating children and teenagers with complex jaw abnormalities.

Prior to surgery, your child’s orthodontist will work with your child’s surgeon to plan the surgical movements. Planning is performed with the aid of 3D X-rays and computer software to ensure that the jaw movements are customized and precise.

Surgical procedures

At the time of surgery, your child may require one or more of these procedures to properly align the jaws, maximize function of the jaw and teeth, and improve outward appearance. Surgery can range from two to six hours, and all of the incisions are located inside the mouth. Once the jaws are properly aligned, the surgeon will secure the bones of the jaw into place with small plates and screws.

Le Fort I 

This is a surgical manipulation of the upper jaw. The surgeon will make an incision into the upper jaw bone above the teeth. Then, the upper jaw and teeth will be moved forward and rotated to properly align with the lower teeth.

Bilateral Sagittal Split Osteotomy (BSSO)

This is a surgical manipulation of the lower jaw. The surgeon will make incisions to the lower jaw behind the bottom molars. The lower jaw can then be advanced and rotated to properly align with the upper jaw.


This is surgical manipulation of the chin bone. This is commonly performed in conjunction with one of the above procedures to promote midline position of the chin and improved facial aesthetics. 

Distraction osteogenesis

Sometimes, the upper or lower jaw is so severely underdeveloped that it cannot be safely advanced in one surgery. In these cases, a surgical technique called distraction osteogenesis is used to gradually lengthen the bone. This is particularly beneficial in young children or babies whose lower jaw is so small that it affects their ability to safely breathe and eat.

Distraction osteogenesis involves making a cut in the lower jaw bone (mandible) or upper jaw bone (maxilla) and applying an expansion device called a distractor.

The distractor is secured to either side of the bone cut and held in place with screws. A small portion of the distractor is visible on the outside of the body.

The device is turned daily for two to three weeks, slowly increasing the gap between the bone to promote new bone growth.

Once the appropriate length is achieved, distraction is complete. This distractor devices are surgically removed about 12 weeks later to allow for adequate healing of the bone.

When distractor devices are involved, the surgeon must make incisions in the skin. The child, therefore, will have visible scars, typically located under the jaw close to the ear.

What to expect after surgery

Following surgery, the jaw is stabilized with orthodontic rubber bands. In rare cases, the jaw will be wired shut. Most patients remain in the hospital for one or two nights to monitor pain and swelling.

Facial swelling and bruising is expected. This will improve significantly over the first two weeks. However, some swelling may take up to four weeks to completely to resolve.

Numbness of the lips, cheeks, and chin is normal following surgery. This will improve over several weeks and does not interfere with movement of the face.

Your doctor will recommend that your child follow a soft foods diet for four to six weeks while the bone of the jaw are healing. This diet includes foods such as yogurt, oatmeal, scrambled eggs, soft pasta, pancakes and ground beef.

At Children's Hospital of Philadelphia, we offer a wealth of ongoing support and services for your child and family at our Main Campus and throughout our CHOP Care Network.