The definition of Orthognathic means “straight jaw”. Often a patient may visit the orthodontist to have their teeth straightened and obtain a better and healthier bite. However there is a small group of patients that will require the expertise of the oral surgeon to help the orthodontist get the bite correct. This is because not only are the teeth crooked but also the jaw itself is not in correct alignment. A growth problem, traumatic injury, or pathologic process of the upper, lower or both jaws are common causes of this problem. Thus even if the orthodontist would get the teeth straight the bite would still not come together because the upper and lower jaw bones are not aligned.
Here are some examples of what this may appear like:
- Lower jaw too big - “Prognathism”
- Lower jaw too small - “Micrognathia”
- Lower jaw crooked - “Asymmetry”
- Upper jaw too big - “Maxillary procumbency”
- Upper jaw too small “Maxillary/midface deficiency”
- Cannot close teeth together - “Apertognathia/open bite”
Do you fit into one of these categories?
To find out if the skeleton is not in proper position the Oral and Maxillofacial surgeon will examine several areas of data to develop a plan to analyze the problem at hand. This exam includes special radiographs that allow us to measure the sizes of the bones, clinical photographs use to overlay on the x-rays, models of the teeth, and actual measurements of the face and teeth. This data will allow us to make an “architectural” analysis of the skeletal discrepancies. Then a surgical plan is created to determine which jaw will need to be repositioned to correct the problem.
Several surgical techniques have been developed to allow the surgeon to repositioning the upper or lower jaw or sometimes both. The goals of the surgery are to balance the skeleton and the bite thereby improving function, speech, breathing, chewing and esthetics. Once the bone is in the correct position then the orthodontist can properly finish aligning the teeth. This type of surgery is typically done once skeletal growth is complete.
- LeFort I Maxillary osteotomy: Moving the upper jaw in any position.
- Sagittal Split Mandibular osteotomy : Used to move the lower jaw forward or backward
- Vertical Ramus Mandibular osteotomy: Used to move the lower jaw backward.
- Anterior Mandibular horizontal osteotomy: used to adjust the chin to stay in alignment with the profile.
Other members of the Dental team are necessary to make it all fall into place. Thus the patient that requires corrective jaw surgery to align the bite will require:
- DENTIST: To make sure that the teeth and supporting structures are in excellent health.
- ORTHODONTIST: To straighten the teeth prior to moving the bones with surgery and then refine the bite once the bones are healed.
- ORAL AND MAXILLOFACIAL SURGEON: To reposition the jaws.
From a timeline perspective:
First an evaluation by the maxillofacial team is done. This typically takes about an hour at your initial visit. This is the time when all of the data is collected such as radiographs, photography, models, facial measurements and a health history. It is important to discuss with the surgeon previous surgery, hospitalizations and medications as this may impact on your surgical care and planning for a safe anesthetic. This includes any herbal or holistic therapies.
A second follow up visit to the office will allow us the necessary time to compile the data and create the analyses necessary to determine if corrective jaw surgery is appropriate for you. This will be discussed at length with you and any family members that may come. A demonstration of computer generated surgery on you at that time may be available. This also takes about an hour.
To move forward with the surgery then a visit to the orthodontist is next. The doctor will place appliances (braces) on your upper and lower teeth to align and level them into the correct position within the bone. Typically it takes any where from 6 to 12 months of preparation. During that time we will be checking on you periodically to see the progress of tooth alignment so that we may plan ahead for your surgical date.
Once the alignment of the teeth is accomplished you will come back to us for a final surgical work up. At this time we will be taking new records. We will create a scale model of your jaws and perform the surgery to create guides to use in the operating room. This allows us to navigate through your surgery smoothly and precisely position the bones into the correct position.
The operation takes place in one of the many hospitals we are affiliated with. The average length of stay for two jaw surgery is two nights.
Once the surgery is completed the bones that have been repositioned at this point are healing into their new location. It takes 8 weeks for the bone to be hard enough to return to full function. Thus a diet of liquid to soft consistency is necessary so as not to traumatize the delicately healing bone. Along the same lines your activity will be limited to no strenuous activity for at least 4 months. These are things like contact sports, heavy weight lifting, and any activity that can lead to falling or getting hit in the face.
When the bones are stable the orthodontist can resume aligning the teeth for a perfect fit. Typically, this takes about 6 more months. The teeth are placed into retainers to maintain stability of the bone and the bite.
Thus the total treatment time once growth is completed takes on average 18 – 24 months of comprehensive care.
Commonly asked Questions:
Do I have to wear braces?
The answer is yes and no. To be specific, in order to align the skeleton in the operating room we need to make sure that the teeth remain in a good bite. We use the braces to connect the teeth into a good bite before setting the bones into their final position. If we do not use regular braces then we typically have surgical braces.
Do we have to wait until growth is completed before proceeding with surgery?
Once again another tricky question is asked. Now we are going to say it depends. It depends upon how much of a functional deficit the child has whether emotionally or physically are both taken into account. This poses us with the problem of usually having to do another touch up procedure at the end of skeletal maturity if the jaws become misaligned with further growth.
I had braces as a child, how will this affect my surgery?
The adult patient typically has had some form of orthodontic therapy that has either changed because your jaws kept on growing or because the teeth were compensated to a misaligned skeleton. Sometime this is not stable and the bite changes. Once the teeth are realigned appropriately in the upper and lower jaw then the surgery should be the same for adult and child with the exception that the adult cannot have their teeth moved as quickly as a child, and may need some type of long term retainers.
I am planning to have cosmetic nasal surgery; can it be done at the same time?
The upper jaw supports the sub structures of the nose. If the upper jaw is to be moved then the nose will also have some subsequent changes that may make simultaneous cosmetic surgery less predictable. We have found that the best results were achieved once the swelling from the jaw surgery have gone away and the bone is well healed. Typically about 6 months.
Do I have to have my jaw wired shut?
NO!!! However, the inconvenience of wiring you shut comes with some advantages too. The most important one being that there is less risk of having sensory changes with this type surgery. This type of surgical procedure is done typically when the jaw needs to be moved back (made smaller).
What happens if I get sick to my stomach with my teeth wired together?
However unpleasant this may be it is safe for you as long as you have your reflexes. It will all come out fine. We use medications especially in the postoperative period to help deal with nausea.
What are the risks of surgery?
- Non healing bone in incorrect position
- Further growth
- Bone healing with scar tissue and not calcifying
Will it affect my speech?
Often times patients with skeletal deformities cannot articulate properly and have speech intelligibility problems. Speech therapy can only go so far to teach the compensations needed to help the patient’s speech be intelligible. However, once the jaws and teeth are in proper position, it will be easier to achieve a better result. With appropriate post operative speech therapy patients can achieve a better articulation of sounds.
Will I be able to breathe better?
In the immediate post surgical period all patients have some nasal congestion that is related to the manipulation of the soft tissues of the nose and jaw during surgery. Decongestant medications and topical sprays to keep the swelling down will be used to help the nasal passages stay clear.
The airway itself usually improves after corrective jaw surgery for several reasons. The floor of the nose is opened more and air passes more easily, the lower jaw if advanced will bring the tongue forward and open the posterior airway as well as the upper jaw if advanced for any reason.
Patients will Obstructive Sleep apnea fall into a special category of airway problems. If you would like to read further go the section on sleep apnea surgery.
Can I travel?
Not for the first 4-6 weeks post op.