Micrognathia

What is micrognathia?

Micrognathia is when your lower jaw is underdeveloped or smaller than usual. Most cases of micrognathia are congenital, which means people are born with the condition.

Micrognathia can result in breathing or feeding problems in babies. Most of the time, the condition corrects itself as children grow older. In some cases, however, it’s associated with underlying genetic conditions, such as cleft lip and palate, Pierre Robin syndrome and Treacher Collins syndrome.

What’s the difference between retrognathia and micrognathia?

Retrognathia and micrognathia both describe conditions of the lower jaw (mandible) and are often used to describe similar features. Technically, with retrognathia, the lower jaw is in an abnormal position in relation to the upper jaw. Micrognathia, on the other hand, is characterized by a jaw that’s smaller than it should be. The clinical presentation is often very similar.

Who does micrognathia affect?

Micrognathia is most common in babies who are born with certain genetic conditions, such as Pierre Robin syndrome, progeria or cri-du-chat syndrome. Sometimes it occurs as a random genetic mutation.

People can develop micrognathia later in life, though this is less common. Micrognathia in adults typically occurs due to trauma (such as a broken or dislocated jaw) or ankylosis (stiffening) of the temporomandibular joint (TMJ).

How common is micrognathia?

Micrognathia in newborns is quite common. In fact, a slightly recessed jaw is a normal part of development among babies. Micrognathia can correct itself over time in many infants but less often when associated with a genetic condition.

What are the symptoms of micrognathia?

Common micrognathia symptoms in babies and children include:

• Noisy breathing.
• Sleep apnea or other breathing difficulties.
• Trouble with feeding.
• Poor weight gain.
• Inability to sleep well.

Micrognathia in adults can lead to obstructive sleep apnea. Some people successfully treat their symptoms with a CPAP machine, while others may need braces or corrective jaw surgery.

What is the cause of micrognathia?

People can inherit micrognathia, meaning it’s passed down through genes. It can also occur because of a random genetic mutation. Sometimes there’s no known cause for micrognathia.

What is micrognathia associated with?

Micrognathia is associated with a number of genetic syndromes and conditions. Genetic causes of micrognathia include:

• Cleft lip and palate.
• Pierre Robin syndrome.
• Treacher Collins syndrome.
• Trisomy 13.
• Trisomy 18.
• Beckwith-Wiedemann syndrome.
• Stickler syndrome.
• Progeria.
• Achondrogenesis.
• Cri-du-chat syndrome.
• Turner syndrome.
• Marfan syndrome.
• Seckel syndrome.
• Russell-Silver syndrome.
• Hallermann-Streiff syndrome.
• Hemifacial microsomia.

How is micrognathia diagnosed?

Your healthcare provider will examine your child’s facial structures. Specifically, they’ll:

• Look at the relationship between your child’s upper and lower jaws.
• Determine if there are any facial asymmetries.
• Look for signs of cleft lip and palate.
• Check the position of your child’s tongue.
• Look to see if your child has a tongue-tie.

Sometimes your healthcare provider can diagnose micrognathia before your baby is born. A prenatal ultrasound can show if the lower jaw is underdeveloped.

What tests will be done to diagnose micrognathia?

If you or your child has micrognathia, your healthcare provider may recommend further testing, including:

• Imaging tests, such as X-rays or CT scans.
• A sleep study, which measures breathing, oxygenation, heart function and brain stimulation during sleep.

How do you fix micrognathia?

In some cases, micrognathia improves on its own. If this is going to happen, it usually gets better by the time your child is 18 months old. In the meantime, your healthcare provider will monitor your baby’s progress.

There are nonsurgical and surgical treatments for micrognathia. What’s right for your child depends on the severity of the condition.

Nonsurgical micrognathia treatment

The most common nonsurgical treatments for micrognathia include:

• Positional therapy. To help keep your baby’s airway open, your healthcare provider may recommend specific sleeping positions.
• Nasopharyngeal tube. This device is inserted into your child’s nostril and through their nasal passageway to keep the airway open.
• Positive airway pressure. A bilevel positive airway pressure (often known under the trade name BiPAP®) or CPAP device sends air through a tube and into a mask that fits over your child’s nose. This continuous air pressure keeps your child’s airway open.

Surgical micrognathia treatment

If nonsurgical options don’t work, then micrognathia surgery may be necessary. Surgical treatments include:

• Tongue-lip adhesion. Your surgeon attaches the base of your child’s tongue in a more favorable position so it doesn’t obstruct their airway.
• Mandibular distraction osteogenesis (MDO). This procedure involves surgically lengthening your child's lower jaw to open their airway.
• Tracheostomy. Reserved for rare instances, this procedure creates an opening through your child’s neck and into their windpipe. This bypasses the airway obstruction.

Can I prevent micrognathia?

Because micrognathia is typically a congenital condition, there’s no way to prevent it. There’s also no way to prevent most of the underlying conditions associated with it.

What can I expect if my child has micrognathia?

If micrognathia doesn’t improve on its own by the time your child is 18 months old, your healthcare provider may recommend treatment. They’ll talk with you about your options and find a plan that works for you and your child.

The overall outlook for children with micrognathia largely depends on the underlying condition. Your healthcare provider can tell you what to expect based on your child’s specific situation.

When should I see my healthcare provider?

If your child has a small or underdeveloped lower jaw, it’s a good idea to schedule an appointment with your healthcare provider. Additionally, you should call your provider if your child develops noisy breathing, feeding problems or other concerning symptoms.

What questions should I ask my healthcare provider?

If your child has been diagnosed with micrognathia, you’ll want to learn all you can about the condition. Here are some questions to ask your healthcare provider:

• How severe is the condition?
• Is there a chance my baby could outgrow micrognathia?
• Does my baby have other conditions that are associated with micrognathia?
• What are some sleeping positions that will help open my baby’s airway?
• Is treatment necessary? If so, what kind?
• What’s the overall outlook?

A note from Cleveland Clinic

Micrognathia is fairly common in newborns, and the condition often improves on its own. In some cases, however, it can block their airway and interfere with proper breathing and feeding. If your child has micrognathia, your healthcare provider can talk with you about treatment options and determine which one is most appropriate.