Retrognathia (Recessed Jaw)

When a Simple Overbite Can Becomes a Big Problem

Carol Burnett
Michael Loccisano/Getty Images

Some people might remember when comedian and actress Carol Burnett underwent jaw surgery in 1983 to correct a facial feature she considered problematic: a visibly recessed chin.

The condition, known as mandibular retrognathia, is a common condition which can affect more than just person's self-image. In some cases, it can lead to jaw misalignment, eating pain, orthodontic problems, and even sleeping disorders.

Retrognathia Feature

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 appears recessed when the face is viewed in profile.

We will often to a person with retrognathia as having an "overbite." The feature is not considered in any way abnormal or unattractive and is generally proportionate to the rest of the face.

However, when the jaw is abnormally small and out of proportion, the person is said to have micrognathia, a condition which can have more serious consequences.

Causes of Retrognathia

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.")

There are rare genetic conditions that can cause severe malformations of the jaw, including Pierre-Robin syndrome, 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.

Problems Associated With Retrognathia

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. Snoring and sleep apnea are not an uncommon problem in people with retrognathia, caused when the recessed position of jaw allows the tongue to slip back toward the airway. This can lead to abnormal pauses in breathing, gasping, and choking.

Treating Retrognathia

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 so that 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.)

(The main downside to the surgeries is the cost: anywhere from $50,000 to $100,000 and sometimes even higher.)

If retrognathia is causing sleep apnea, standard treatments such as continuous positive airway pressure (CPAP) and 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.

Sources:

Al-Hashmi, A. and Al-Saadi, N. "Surgical correction of mandibular retrognathia as a treatment for temporomandibular joint disorders." Oral Maxillo Surg. 2015; 44(Suppl 1):e25.

Joshi, N.; Hamdan, A.; and Fakhouri, W. "Skeletal Malocclusion: A Developmental Disorder With a Life-Long Morbidity." J Clin Med Res. 2014; 6(6):399-408.

Continue Reading