Orthognathic and Jaw Surgery

Children with severe jaw discrepancies resulting in a poor bite that cannot be fully addressed with orthodontics may need orthognathic surgery, also known as corrective jaw surgery. Orthognathic surgery may be recommended for teens who have an upper or lower jaw that is too small, too large, or if the upper and lower jaw do not fit together properly.

Children with cleft lip and palate, isolated cleft palate, craniofacial microsomiaPierre Robin syndromecraniosynostosisTreacher Collins syndrome, and ectodermal dysplasia are most likely to exhibit altered jaw growth patterns that require orthognathic surgery. However, children with no medical diagnoses can also develop jaw anomalies.

Jaw surgery can dramatically alter a child’s appearance and improve their ability to chew, speak and breathe. Treatment takes time, however. In most cases, patients will need 6 to 12 months of orthodontics to prepare for surgery, then an additional 6 to 12 months of post-surgical management to finalize the bite after surgery.

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.

Candidates for orthognathic surgery

Orthognathic surgery is performed to correct a wide range of skeletal and dental anomalies, including the misalignment of the jaws and teeth.

In normal jaw alignment, the upper jaw and teeth project slightly further than the lower teeth. Problems arise when the jaws or teeth don’t fit together properly because of the size and alignment of the jaw, or position of the teeth.

Your child may be a candidate for orthognathic surgery if they have:

  • A severe underbite (maxillary retrusion), which may include a smaller-than-usual upper jaw (maxilla). This is often the case for children born with cleft palate.
  • A severe overbite (mandibular retrusion), which may include a smaller-than-usual lower jaw (mandible). This is more common in children with craniosynostosis and Treacher Collins syndrome.
  • An open bite, in which the upper and lower teeth are forced outward at an angle so the upper and lower jaw do not touch each other properly.
  • A combination of these conditions.

Preparing for corrective jaw surgery

If orthognathic surgery is indicated, our orthodontic specialists will work with your child’s surgeon to plan the surgical movements and prepare the teeth to fit together well after jaw surgery.

At Children’s Hospital of Philadelphia, orthognathic surgical planning is often performed with the aid of 3-D X-rays and computer software. These tools help oral and maxillofacial surgeons, orthodontists and dentists determine the best approach to correct your child’s condition.

Orthognathic surgery is generally performed at skeletal maturity — when your child is 14 to 18 years old — to ensure your child does not outgrow the correction.

Younger children with severe jaw anomalies may undergo distraction osteogenesis as an intermediate phase before jaw surgery. This procedure is generally reserved for younger patients with a severe maxillary retrusion (underbite) that prevents the upper jaw from being moved forward in a single stage.

Surgical procedures

There are several different types of reconstructive jaw surgery. Depending on your child’s condition, they may need one or more of these surgeries to properly align their jaw, maximize functional use of their jaw and teeth, and improve outward appearance. Your child’s surgeon will discuss the best treatment plan to address your child’s condition.

Le Fort I advancement

The LeFort I advancement procedure, sometimes called an upper jaw advancement, is performed when your child reaches skeletal maturity to do a final correction of the bite.

The procedure requires orthodontics before and after surgery. A plastic surgeon and specialized craniofacial orthodontist will work together to pre-align your child’s teeth to ensure maximum improvement upon completion of the procedure.

During the two- to three-hour LeFort I procedure, an oral or maxillofacial surgeon will cut the bone above the teeth in the upper jaw so the upper jaw and teeth can be moved forward to properly align with the lower teeth. Once the jaw is realigned, the surgeon will secure it in place with small screws and plates to keep it in the new position. All incisions for this procedure are inside the mouth.

In some children with severe facial anomalies, the LeFort I may be accompanied by an osteotomy of the lower jaw or mandible. In patients where the midface has been adequately positioned by a prior LeFort III or Monobloc advancement, a LeFort I procedure may not be needed. Most patients will still require orthodontic treatment.  

teen post le fort 1 and asymmetric genioplasty

Adolescent with significant maxillary retrusion with dental malocclusion (top) and after LeFort I and asymmetric genioplasty (bottom). Note improvement in location of upper jaw and dental relations.

Bilateral Sagittal Split Osteotomy (BSSO)

A bilateral sagittal split osteotomy (BSSO) is most commonly performed when repositioning the lower jaw is required due to misaligned teeth (malocclusion) and functional issues with biting or speech.

In this procedure, an oral surgeon makes lengthwise cuts on the lower jaw behind the bottom molars so the jawbone can be repositioned and lengthened to improve occlusion and position. Small screws are used to hold the jaw in place as it heals.

BSSO can be performed symmetrically (both sides) or asymmetrically (one side) to obtain the best position.


A genioplasty (chin surgery) is most commonly performed in conjunction with a LeFort I and BSSO to promote midline position of the chin and improved facial aesthetics.

In this procedure, an oral surgeon cuts into the chin bone, moves it to a more cosmetically pleasing position, and then secures it with tiny screws and plates in the new position. Chin reconstruction can be completed at the same time as genioplasty.

Demonstration of LeFort I, BSSO and genioplasty

demonstration of Le Fort I advancement, bilateral sagittal split osteotomy (BSSO) and genioplasty

Demonstration of LeFort I advancement, bilateral sagittal split osteotomy (BSSO) and genioplasty. While any of these procedures can be performed independently, often to correct a malocclusion properly, all three are performed during one surgery.

Mandibular osteotomy

A mandibular osteotomy may be needed in patients with severe craniofacial conditions in which the mandible (lower jaw) is abnormally situated. This may be done in combination with the LeFort I procedure or as a separate approach.

The mandibular osteotomy involves making an incision inside the mouth near the gums (intraoral incision), cutting the bone, repositioning the jaw, and affixing it with screws and plates. 

Mandibular distraction osteogenesis

Mandibular distraction osteogenesis (MDO) is used when a child’s severely small jaw or facial bones are causing misaligned teeth, obstructive sleep apnea, and functional issues with chewing and speech. 

MDO involves making a cut in the lower jaw bone (mandible) and applying an expansion device that is secured on either side of the bone cut and held in place with surgical screws. At the direction of your child’s surgeon, the device is turned and the gap between the sides of the bone is slowly increased to promote new bone growth that will lengthen the jaw bone. The period of growth is called the distraction phase.

Once the appropriate increase in length is achieved, the bone is allowed to heal. This is called the consolidation phase. After the bone has healed, the distractor devices are removed.

Distraction can be performed on one or both sides of the mandible at the same time and can be repeated if needed.  

Follow-up care

After corrective jaw surgery, your child will remain in the Hospital for a day or two, then will be discharged to recover at home. For the first few days post-op, your child will be on a liquid diet and will take prescribed pain medication to keep them comfortable.

One of the most important things to remember in the days and weeks after jaw surgery is to keep your child’s mouth clean. They should rinse with warm salt water, use a soft toothbrush and an anti-bacterial mouthwash. Facial swelling and bruising is normal and expected after surgery. Bruising usually disappears within two weeks, although some swelling may take longer to resolve.

Teens are encouraged to get out of bed and walk around as soon as possible after surgery as this will reduce swelling and stimulate circulation. No strenuous activity or physical exercise should be attempted in the first week after surgery.

Your child’s surgeon and care team will regularly monitor your child in the months following orthognathic surgery. Most teens can return to school two to four weeks after surgery, and begin eating soft foods soon after.

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.

As your teen enters adulthood, we will help coordinate any continuing treatment with Penn Medicine or a facility near you. Our team works closely with your child’s other care providers to manage ongoing, coordinated care that will be best for each patient’s individual needs.