What are jaw deformities?
Jaw deformities are abnormalities in the shape and structure of the jaw that have adverse effects on physical appearance and dental health. The most common are mandibular retrognathia, which is an overslung (jutting) lower jaw, and mandibular micrognathia, which is a receding lower jaw.
- A jutting or receding chin.
- Difficulty chewing.
- Irregular or poorly aligned teeth.
- An over or underbite.
Most jaw deformities are minor, affecting appearance more than health. Severe jaw deformities, however, can interfere with normal chewing and speaking.
What causes jaw deformities?
The problem is often a hereditary trait that runs in some families. Injuries during early childhood can cause jaw deformities, particularly when the end of a developing jawbone is broken and heals improperly. Severe trauma such as a gunshot wound can cause jaw deformities, as can bone infections and certain diseases involving hormonal imbalances. Radiation and surgical treatments for oral cancer may also produce jaw deformities.
How are jaw deformities diagnosed and treated?
Generally, jaw deformities are readily apparent to the doctor, and often painfully obvious to the patient. Treating them, however, depends both on the severity of the problem and on the patient's desire for a change in appearance. As a rough guideline, plastic surgeons assume that the most protuberant parts of the chin and lips should be in the same vertical plane as the forehead, and that the lips should meet easily over the teeth. The upper and lower teeth should meet
each other naturally and evenly, a characteristic known as dental occlusion.
Before any corrective treatment, a series of x-rays of the skull are taken to show the relationship between the upper and lower jaws. The x-rays are combined with studies using cephalometry, a technique of measuring and evaluating the spatial relationships among different parts of the face. Photographs of the face and profile should also be analyzed, and molds of the teeth are made to use as models in planning possible surgery and braces (orthodontia).
In some cases, orthodontia is the only treatment required to achieve proper dental occlusion. Often, however, braces alone cannot solve the underlying problem of a jaw that is too small, too large, or out of proper alignment. In such cases, plastic surgery may be necessary.
What can I do myself?
There is no specific self-treatment for jaw deformities.
When should I see my doctor?
Other deformities can be corrected as soon as the permanent teeth come in. In either case, it's a good idea to consult a plastic surgeon and orthodontist as soon as the problem becomes apparent.
Some jaw deformities, particularly mandibular retrognathia, cannot be surgically corrected until after the jawbone has stopped growing in late adolescence.
What will the doctor do?
The first step entails determining whether corrective surgery and/or dental work is needed. In most instances, a plastic surgeon works in consultation with an orthodontist to plan the best approach. If the jaw juts forward, the operation generally involves removal of part of the bone from the lower jaw. Depending upon the nature of the deformity, orthodontia may be carried out before and/or after the operation. Special devices or wiring may be
needed to hold the reconstructed jaw in place until it is fully healed.
When the lower jaw is set too far back or is simply too short, the corrective operation is more complicated than the one for an overslung jaw. One approach entails dividing the jawbone on one or both sides and inserting a bone graft taken from a pelvic bone. To protect the graft, the surgeon makes an overlying skin graft from tissue inside the mouth.
In either type of surgery, the surgeon usually approaches the jawbone by making an incision in the mouth. Patients often need to have some teeth removed before the surgery to accommodate the incision and to keep the teeth symmetrical.
The course of jaw deformities
Some jaw deformities worsen over time, particularly those that begin to develop during childhood. Once the child stops growing, however, the progression should stop as well. In severe cases, the jaw joint becomes immobile. This condition always requires treatment because it interferes with normal eating.
Are jaw deformities dangerous?
Jaw deformities are more inconvenient than dangerous. Some, however, interfere with eating and lead to dental problems.
What can I do to avoid jaw deformities?
- Follow good dental hygiene.
- If you accidentally lose a tooth or teeth, see your dentist as soon as possible. Oftentimes, the tooth can be reimplanted.
- If your baby falls and hits the side of his or her face, be sure to check for a possible jaw injury.
- Avoid injuries to the jaw by always wearing protective headgear during contact sports.