Micrognathia — also known as mandibular hypoplasia — is a condition in which the lower jaw is smaller than usual. Common in babies, micrognathia can potentially block their airway. Micrognathia often corrects itself as children grow older. Depending on the severity of the condition, surgery may be necessary.
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.
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.
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).
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.
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Common micrognathia symptoms in babies and children include:
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.
Micrognathia is associated with a number of genetic syndromes and conditions. Genetic causes of micrognathia include:
Your healthcare provider will examine your child’s facial structures. Specifically, they’ll:
Sometimes your healthcare provider can diagnose micrognathia before your baby is born. A prenatal ultrasound can show if the lower jaw is underdeveloped.
If you or your child has micrognathia, your healthcare provider may recommend further testing, including:
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.
The most common nonsurgical treatments for micrognathia include:
If nonsurgical options don’t work, then micrognathia surgery may be necessary. Surgical treatments include:
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.
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.
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.
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:
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.
Last reviewed by a Cleveland Clinic medical professional on 04/28/2022.
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