Orthognathics is surgically moving facial jaw structure to correct deformities caused by growth, development, trauma or syndromes. Orthognathic surgery is done in a partnership of the orthodontist and the oral-maxillofacial surgeon. From the Greek: ortho-straighten, gnathic –jaws. Dr. Bentele has a unique experience set in orthognathic surgery. His first exposure to orthognathics was in the operating room as a hospital resident after dental school. His orthodontic residency included collaboration with the legendary oral-maxillofacial surgeon Dr. Larry Peterson at Ohio State. The next 7 years provided the experience of approximately 200 cases as the orthodontist for RAF Lakenheath and the US Air Force Academy. Orthognathic surgery is not something well recognized by patients as a solution to their problem before they arrive for evaluation. It is rather a treatment option that must be explored when a case is discovered to be beyond the limits of what orthodontics can provide.
Orthodontic problems are defined as either “dental” or “skeletal”. If totally dental or related to the teeth then the solution will be an orthodontic one. If the proportions of the facial skeletal structure are off moderately then the orthodontist can either correct the problem orthopedically by differentially modifying the growth of parts of the facial structure or the other option is to camouflage the skeletal problem. Camouflage is accomplished by moving the teeth to mask the discrepancy between the upper and lower jaw. For example if the lower jaw is too short then the upper incisors are tipped back and the lower incisors are tipped forward to meet in the middle. There is an envelope of discrepancy within which the orthodontist is able to reliably achieve the goals for a great smile, bite and facial appearance. Beyond this envelope the oral-maxillofacial surgeon may be involved to accomplish an ideal outcome.
In a growing patient the orthognathic surgery option may be explored early on but not definitely prescribed due to the uncertainties of growth and treatment response. In the more severe cases that are definite cases for orthognathics, then it may be best to monitor growth and time treatment towards the end of the growth period. Orthodontic camouflage of severe, clearly orthognathic cases is to be avoided as the outcome will not be acceptable, treatment time and expense are extended and some of the orthodontic treatment will then need to be reversed if orthognathic surgery is eventually decided upon. The orthodontist and oral surgeon work in partnership to achieve dramatic results and collaborative planning is essential. It is possible with the Dolphin Imaging program to predict the eventual facial appearance after the surgery. Even though orthognathics is reserved for the most severe cases, experienced planning and execution can mean completion in the same amount of time as a routine orthodontic case.
The orthodontic portion of treatment consists of aligning the teeth and matching the arches so that they fit together after the surgery. Coordination with the surgeon occurs several times during this process and at least once and possibly several times orthodontic records will be taken to check the fit. When the patient is ready for surgery a set of models is taken for the surgeon to build a splint. This will act like a cast for a broken arm. The orthodontist will attach surgical hooks onto the archwires that the surgeon will use during the surgery to tie the upper and lower jaws together. The surgery will reposition one or both jaws so that the teeth fit together and the facial appearance is enhanced. An osteotomy or bone cut is accomplished to separate parts of bone. For some people modification of the nose appearance, cheek prominence or projection of the chin may be accomplished at the same time to enhance the overall facial appearance. Double chins can be reduced by liposuction. The jaw(s) is then fixed into place with either surgical plates or screws. Only rarely are the jaws wired together as was common 20 years ago. After 6 weeks of healing the splint is removed and the patient returns to orthodontic treatment. There are usually 4- 6 months of treatment remaining to finalize tooth positions and to assure that healing is complete before the braces are removed.
Types of orthognathic surgery and related procedures:
Bilateral Sagittal Split Osteotomy (BSSO): the posterior part of the mandible is split allowing advancement or retraction of the tooth containing portion of the mandible
Surgically Assisted Rapid Palatal Expansion (SARPE): much like an RPE in a younger patient but the surgeons cut the maxilla and the fused growth suture to allow expansion
LeFort: the maxilla is moved in either one or multiple pieces to expand or correct an underbite or open bite
Advancement or reduction genioplasty: a section of the bony chin is moved to enhance the profile appearance
Submental lipectomy: fat deposits are removed from the double chin area
Distraction osteogenesis: instead of moving the bone structure all at once distracters are placed across a cut bone. Screws are activated to move the bones apart a half millimeter per day thus growing bone. This technique is used when the change would be too great for the soft tissue to adapt to the stretching.
The Association of Oral and Maxillofacial Surgeons provides a good overview here: