What is orthognathic surgery?

This surgery makes it possible to realign the jaws in an ideal position when there is a discrepancy between them. Orthognathic surgery is recommended to align both the upper and lower jaw when orthodontics alone is not sufficient. Orthodontic treatment combined with surgery will provide superior results to conventional orthodontic treatment to maximize aesthetics and function.

Why is orthognathic surgery performed?

The lack of balance between the two jaws can cause difficulty chewing, headaches, speech or breathing (sleep apnea); pain in the teeth, jaw joint (snaps, cracking, chronic blockages) or masticatory muscle as well as esthetic defects in the case of an important discrepancy in the position of the jaws.

What are the different steps to orthognatic surgery?

Clinical examination and diagnosis

The maxillofacial surgeon will perform a clinical examination based on the progression of the malocclusion anomaly, dental condition, phonation, swallowing and respiration, as well as front, profile, a panoramic x-rays or 3D tomography. Moldings make it possible to better analyze the relationships between the teeth and to simulate surgical movements. Thus, when a proper diagnosis is made, the surgeon will determine if treatment is necessary and will adapt it to the particular case of each patient. The magnitude and complexity of the malalignment will determine the length of treatment and the type of surgery proposed in the treatment plan.

Preoperative orthodontic treatment (modifying the position of the teeth)

Prior to surgery, orthodontic treatment is often required in order to prepare the patient’s dental arches for surgery. In general, it will last 9 to 18 months. The aim is to modify the position of the teeth in order to allow an ideal surgical gesture. Monitoring of changes in tooth positioning is assessed on a regular basis.


The surgery is performed in a hospital setting under general anesthesia. Hospitalization of 24 to 48 hours may be necessary following surgery. A convalescent period of 1-2 weeks is expected for the majority of patients.

The surgery, called osteotomy, is intended to move the bones of the jaws. The facial bone architecture is thus modified and will allow the teeth to coincide. The different bone segments are then fixed to each other by means of implants, such as plates and screws. These plates are not visible but sometimes palpable. They can be left in place for life and they are only removed if they cause injury (infection). The incisions are made inside the mouth so as not to leave visible external scars. The procedure can last from one to four hours, depending on the complexity of the movements to be made in the jaws.

Post-surgical time (hospitalization, postoperative orthodontic treatment, follow-up)

In order to facilitate healing and consolidation of the bones, the diet will first be liquid on the following days of the procedure, then purée and finally soft. After a period of 1-2 weeks, it is possible to resume normal academic or professional activity.

Postoperative follow-up will be performed until the end of orthodontic treatment. The appointments will be more frequent immediately after the surgery and will subsequently spread out according to the progression and improvement of symptoms. About 4-6 weeks after surgery your orthodontist will be able to continue orthodontic treatment; in order to carry out the finishing phase and finalize the treatment.

Complications of orthognathic surgery

  • Pain
  • Nausea, vomiting
  • Swelling
  • Loss or altered sensation
  • Infection
  • Sinusitis
  • Bleeding
  • Movement within the new position of the jaws
  • Limitation in the opening of the mouth

It is important to note that the result of the dental repositioning can be seen instantaneously, but the final facial esthetic results can only be fairly evaluated 2 months after surgery (awaiting complete dissipation of the swelling).

Your Maxillofacial Surgery Specialist

Dr. Nadia Rizkallah

DMD, FRCD(c), Oral and Maxillofacial Surgeon

Dr. Nadia Rizkallah obtained a doctorat in dentistry at the University of Montreal in 2008.  She then went on to complete her studies in oral and maxillofacial surgery at Montefiore Medical Center of the Albert Einstein College of Medicine located in New York City. She is a Fellow of the Royal College of Dentists of Canada in her specialty.

She teaches dental students as an oral surgery clinician at the University of Montreal as well as general practice residents in the Notre-Dame Hospital – CHUM (catered mostly for medically compromised patients as well as trauma patients). She now works in private practice and is affiliated with the Hôtel-Dieu Hospital in St-Jérôme as well as Notre-Dame hospital – CHUM.

In her spare time, Dr. Rizkallah enjoys biking outdoors, spinning, hiking and trekking, improvising new cooking recipes without forgetting the most important part of savouring them.

Dr. Nadia Rizkallah is a member of the following dental associations: