Impact of Recessed Jaw and Overbite (Retrognathia)

Mandibular retrognathia is the condition of having a visibly recessed chin and overbite. It is a common condition that can affect more than just a person's self-image. In some cases, it can lead to:

• Jaw misalignment
• Eating pain
• Orthodontic problems
• Sleep disorders

Some people might remember when in 1983 the comedian and actress Carol Burnett underwent jaw surgery to correct her visibly recessed chin, which she considered problematic.

Retrognathia Symptoms

Retrognathia is when the lower jaw (mandible) is set back from the upper jaw (maxilla). It doesn't necessarily mean that the mandible is small, just that it appears recessed when the face is viewed in profile.

Retrognathia is often referred to as an "overbite." The feature is not considered abnormal or unattractive and is generally proportionate to the rest of the face.

Causes

The anatomical structure of the face is based, at least in part, on a person's genetics. So, people with retrognathia will often have a jaw structure similar to that of other family members. (Burnett herself referred to her overbite as the "Burnett family lip.")

Rare genetic conditions also can cause severe malformations of the jaw, including Pierre-Robin sequence, a disorder characterized by an abnormally small mandible and associated breathing problems.

Facial trauma in early childhood development can also cause jaw displacement, often resulting in an asymmetrical, "set back" appearance.

Complications

Retrognathia may cause problems from as early as birth, with some babies unable to adequately to properly latch onto a nipple when feeding.

As the person gets older, misalignment of the teeth may affect the ability to bite or chew food, If the lower jaw is smaller, the teeth may also become crowded or irregularly positioned.

These features can contribute to a disorder known as temporomandibular joint disorder (TMJ), an often painful condition characterized by muscle spasms and tension in the jaw. Retrognathia can also cause disrupted breathing, especially during sleep or when lying on one's back.

Treatment

Depending on the severity of retrognathia, treatment may or may not be necessary.

If identified in early childhood, orthodontic treatments that may be effective in minimizing the recessed appearance of the jaw. One method involves the use of special headgear to slow the growth of maxilla (upper jaw) so the upper and lower jaws can become better aligned.

In late adolescence or adulthood, once growth is completed, a surgical procedure known as maxillomandibular advancement (MMA) can be used to move both jaws forward. The advantage of this technique is that braces aren't needed to realign the teeth.

By contrast, Burnett's surgery employed mandible osteotomy in which the jaw is actually detached and moved forward in a single unit.

If retrognathia is causing sleep apnea, standard treatments such as continuous positive airway pressure (CPAP) or an oral appliance will typically help.

TMJ, by contrast, is often more difficult to treat and may involve anti-inflammatory drugs, ice packs, massage, relaxation techniques, and the avoidance of excessive grinding or chewing. Oral appliances (known as dental splints or bite plates) are also available to treat more severe cases.

If ever you feel concerned about the health impact of your jaw positioning, speak with a doctor or dentist who may be able to offer advice on both surgical and non-surgical treatment options.