Corrective jaw surgery or orthognathic, surgery is performed to correct a wide range of minor and major skeletal and dental irregularities, including the misalignment of jaws and teeth. This can improve chewing, speaking and breathing. Orthognathic surgery combines orthodontic treatment with surgery of the jaw to correct or establish a stable, functional balance between the teeth, jaws, and facial structures. This procedure involves diagnosis, treatment planning, and execution of treatment by combining orthodontics and maxillofacial surgery to correct musculoskeletal, dento-osseous, and soft tissue deformities of the jaws and associated structures.
Orthognathic surgery is needed when jaws do not meet correctly and/or when the teeth do not seem to fit with the jaws. The teeth are straightened with orthodontics, and corrective jaw surgery repositions the mal-aligned jaws. This not only improves the facial appearance, but also ensures that teeth meet correctly and function properly.
There are many different types of abnormalities of the jaw structures that can result in facial deformity and improper bite. These abnormalities in the jaws and facial bones may be congenital (present at birth) or developed during growth and development. They may also be acquired after birth as a result of hereditary, environmental influences, or trauma/illness to the face. It has been estimated that dentofacial (involving the teeth and face) deformities affect approximately 20 percent of the population.
While orthodontics can usually correct bite, or "occlusion," problems when only the teeth are misaligned, corrective jaw surgery may be necessary to correct misalignment of the jaws.
Following are some of the conditions that may indicate the need for corrective jaw surgery:
- difficulty chewing, or biting food
- chronic jaw or jaw joint (TMJ) pain and headache
- excessive wear of the teeth
- open bite (space between the upper and lower teeth when the mouth is closed)
- unbalanced facial appearance from the front, or side
- facial injury or birth defects
- receding chin
- protruding jaw
- inability to make the lips meet without straining
- chronic mouth breathing and dry mouth
- sleep apnea (breathing problems when sleeping, including snoring)
Despite being of multiple origin, maxillary and/or mandibular facial skeletal deformities can be classified as
- Overjet of teeth
- Protrusion of the upper or the lower jaw or the chin
- Retrusion of the upper or the lower jaw or the chin
- Presence of a vertical facial skeletal deformity (differing from published norms for accepted skeletal landmarks)
- Open Bite
- Presence of a transverse skeletal discrepancy (differing from published norms for accepted skeletal landmarks)
- Antero-posterior, transverse or lateral asymmetries greater than 3 mm with concomitant occlusal asymmetry.
The most important aspect of overall patient management is a thorough evaluation and diagnosis.
Patient evaluation for orthognathic surgery can be divided into four main areas:
- patient concerns or chief complaints
- clinical examination
- radiographic and imaging analysis (x-rays)
- dental model analysis
After an examination by each of the orthognathic surgery team members (orthodontist and maxillofacial surgeon), a diagnosis is made and a coordinated treatment plan is prepared. The complete process usually takes place in several stages over the course of one to two years.
The treatment process occurs in stages. Any general dental maintenance, prevention, or restoration should be performed prior to orthodontic and surgical intervention. Then, the first stage of treatment is the alignment of the teeth into a stable relationship with the underlying jaw by orthodontics, which prepares the dental arches for the surgical repositioning. This stage usually takes the longest, from a few months to over a year. At this stage, the abnormal bite (malocclusion) may become more noticeable.
Once ready for the surgical procedures, the orthodontist and maxillofacial surgeon will review photographs, x-rays, CT scans and dental models to finalize the surgical plan. This procedure called the work-up, which is a higly important part of the treatment. Nowadays, 3D prediction planning is available to facilitate preoperative analysis and decision making procedure.
All surgeries are meticulously planned through the use of skeletal analyses, sketches, mock up surgeries on plaster models and computer imaging. From this pre-operative work-up, precise templates are fabricated with 3D printing technology that are utilized during surgery to position the jaws. The proposed surgery is always a carefully thought out and pre-planned event requiring only routine surgical skills to complete the task. With the use of highly technical instrumentation along with tried and true surgical techniques (Le Fort I type osteotomy, bilateral sagittal split osteotomy, malar sandwich osteotomy) the jaws are then precisely repositioned and stabilized using tiny screws, plates and/or wires. These screws and plates are only temporarily necessary after which the jaw mends itself into its new position. Because of their long standing history of biocompatibility, it is hardly ever necessary to remove them at a later date.The operation may involve a single jaw or both jaws (maxilla and mandible). The surgery may also be combined with other procedures, such as rhinoplasty (nose correction) or genioplasty (chin correction) to improve the general appearance of the face. Incisions are usually made inside the mouth to reduce visible scarring; however, some cases do require small incisions outside of the mouth. When this is necessary, care is taken to minimize their appearance.
Corrective jaw surgery is performed under general anesthesia in a hospital. Surgery may take from one to several hours to complete.
- Swelling – Simply a result of the trauma of surgery, most swelling from surgery of this kind will peak in visible size over the course of two to five days. Approximately 85% of the swelling resolves within a ten day period after which the remaining percentage often requires several months of maturation.
- Nasal and sinus congestion – As a consequence of the techniques utilized at surgery and associated swelling at the operative site, most patients will experience a five to seven day period of significant nasal and sinus congestion. Resolution of these symptoms is generally parallel with the abatement of visible facial swelling.
- Difficulty eating and chewing food – Although modern surgical techniques have freed the patient of the burdens of being wired shut, the first week following surgery is still fraught with moderate frustrations in the eating department. Swelling and the fear of moving one’s jaw too much tend to self-limit the diet to something of a more blenderized category.
- You may also be asked to refrain from using tobacco products and avoid strenuous physical activity.
Only a short period of convalescence is necessary before the patient can return to a normal activity. Even patients presenting with the most complex of scenarios, are able to return to work or a school environment within ten days of the surgical date. The only prolonged and prescribed physical restriction may occur in the patient involved in “contact sports,” who may be asked to refrain from such activity for approximately three months. The surgeon will monitor the healing, and review the changes in the facial structures and occlusion (bite). The orthodontist will adjust the braces to fit the new repositioned jaw. Orthodontic treatment may continue for several months to ensure optimal positioning of the teeth.
Orthognathic surgery is not a new technique or area of maxillofacial surgery. The conceptualization and early practice of this form of surgery have been around for many decades and the most recent technology has been practiced for nearly thirty years. Due to the continuing modernization of instruments and techniques of stabilization the elective treatment of a patient with this form of surgery has become safer, more comfortable, and more reliable. Procedures that once demanded nearly ten hours of surgery have been shortened to as little as three to four hours.
Orthognathic surgery is nowadays accepted as a safe and predictable treatment modality for functional and aesthetic facial discrepancies.
The information listed above is the opinion of the doctors of the Department of Maxillofacial Surgery, AZ Sint Jan Bruges, Belgium and does not necessarily reflect the opinion of the specialty as a whole.