What is Orthognathic Surgery? Treatment Definition

Jaw misalignment is a condition that can affect facial appearance and cause a variety of functional problems. Orthognathic surgery realigns the jaw to improve aesthetics and function. In this article, the maxillofacial surgeons at Clinique MFML in the Greater Montreal area provide an overview of this type of surgical treatment.

What is orthognathic surgery?

The term orthognathic is a combination of the Greek words orthos, meaning “straight”, and gnathos, meaning “jaw”. Orthognathic surgery is a procedure that realigns the upper and lower jaws.

The jawbones support the teeth and affect speech, chewing and swallowing. Orthognathic surgery can rectify jaw anomalies to improve oral health, chewing function and facial aesthetics.

Orthognathic surgery can also correct some types of dental misalignment such as class 2 malocclusion. It is often accompanied by orthodontic treatment.

What problems can be treated with orthognathic surgery?

Orthognathic surgery can be used to treat a number of problems. Here are the three most common ones.


Dentoskeletal malocclusion is a pathology that covers several types of jaw and dental misalignment. Patients with dentoskeletal malocclusions often experience problems that lead them to consult a dentist or orthodontist. Malocclusions can be detrimental to facial aesthetics, and patients may experience difficulty chewing or breathing.

Malocclusion is one of the conditions that orthognathic surgery can correct in the majority of cases.

Facial disharmony

Facial disharmony can stem from dentoskeletal malocclusion, a congenital or acquired facial malformation, bone spurs or the results of a facial trauma or tumour. Types of facial disharmony include facial asymmetry and micrognathia (an undersized chin). Orthognathic surgery is often the treatment of choice for correcting facial disharmony.

Sleep apnea

Sleep apnea is a disorder that can affect people of any age and sex. People with sleep apnea experience regular breathing interruptions while sleeping. If left untreated, sleep apnea can have significant consequences on health and quality of life. Obstruction is one of the main factors that contributes to sleep apnea, so orthognathic surgery is used to increase the size of a patient’s airway.

The steps of orthognathic surgery

Orthognathic surgery is a procedure that involves four well-defined steps.

1. Exam and diagnosis

Well before the surgery, the maxillofacial surgeon will examine the patient. The purpose of the exam is to assess the progression of the anomaly, the state of the patient’s teeth and their ability to speak, swallow and breathe. The surgeon will also take 3D dental x-rays in order to better plan the surgery.

Once the surgeon has arrived at a diagnosis, they will determine whether any orthodontic treatment is necessary and if so, how long it should last, before proceeding with surgery. The parameters of the treatment are determined on a case-by-case basis according to the extent and complexity of the misalignment.

2. Preoperative orthodontic treatment

Surgeons often recommend 9-18 months of orthodontic surgery to prepare the dental arches for orthognathic surgery. The purpose of the treatment is to move the teeth into the optimal position for surgery.

3. Surgery

Orthognathic surgery is performed under general anaesthesia and requires hospitalization for 24 to 48 hours after the procedure.

The surgery involves a mandibular osteotomy, which is done to move the jawbones into the correct position and modify the facial architecture. Plates and screws are then used to reattach the bone segments. Unless there is a risk of infection, the plates and screws are usually left inside the patient. The surgery leaves no visible scars, because all of the incisions are made inside the mouth.

The procedure generally takes 1 to 4 hours, depending on the extent of the misalignment and the complexity of the adjustment. Recovery takes 1 to 2 weeks for most patients.

4. Postoperative care

Following orthognathic surgery, patients must start with a liquid diet, then transition to a soft diet in order to facilitate healing and bone consolidation.

Patients can return to their normal lives after recovering for 1 to 2 weeks.

Patients are followed by an oral surgeon after the operation until the end of their orthodontic treatment. The frequency of the follow-up appointments will decrease as the postoperative symptoms subside.

Generally, orthodontic treatment resumes 4 to 6 weeks after surgery in order to fine-tune the adjustments.

Postoperative symptoms and complications

After orthognathic surgery, patients may experience the following symptoms:
• Pain
• Facial swelling
• Nausea and vomiting
• Bleeding, especially from the sinuses
• Limited ability to open one’s mouth

Complications may also occur:
• Infection
• Jaw shifting
• Sensitivity problems

Although the effects of the adjustment are visible immediately after the operation, it takes 2 months for the swelling to disappear and reveal the final aesthetic and morphological results. For more information, please visit our postoperative instructions page.


Orthognathic surgery is a procedure that can correct jaw misalignment and other health problems. If you think you may be in need of this surgical procedure, contact our team immediately for medical advice on your situation.

The maxillofacial surgeons at Clinique MFML are at your disposal to treat your oral pathologies and prescribe the appropriate treatments.

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