What is micrognathia
Micrognathia is a condition in which the lower jaw is undersized. It is a symptom of a variety of craniofacial conditions. Sometimes called mandibular hypoplasia, micrognathia may interfere with your child’s feeding and breathing.
Micrognathia is fairly common in infants, and can often corrects itself as your child grows. In some children, micrognathia can cause abnormal tooth alignment because there is not enough room in your child’s mouth for the teeth to grow.
Micrognathia can present as a birth defect in numerous syndromes, including cleft lip, cleft palate, Pierre Robin sequence or syndrome, Stickler’s syndrome, Beckwith-Wiedemann syndrome, hemifacial microsomia, Treacher Collins syndrome and others.
Causes of micrognathia
Micrognathia can be inherited (passed on through genes) or caused by a genetic mutation. In rare cases, the cause of micrognathia is unknown.
Symptoms of micrognathia
Children with micrognathia often show signs of “failure to thrive,” a term medical professionals use when children begin to fall off their growth curve.
Symptoms of micrognathia can vary from child to child but may include:
- Apneic spells (a temporary stop in breathing)
- Feeding difficulties including prolonged feeding, inability to feed, and poor weight gain
- Noisy breathing
- Poor ability to sleep
In rare case, parents will report that their child turns blue (cyanosis) when feeding or sleeping due to breathing difficulties.
Diagnosis of micrognathia
We begin your child’s evaluation with a thorough medical history and physical exam by one of our craniofacial specialists.
During the physical exam, we look at:
- The relationship between your child’s tongue and lower jaw
- If your child has a cleft palate
- If your child has any facial asymmetries
- The relationship of your child’s upper jaw to their lower jaw
- Presence of a tongue tie (lingual frenulum)
- The overall health of your child
After the exam, we may order diagnostic tests including:
- Imaging studies such as X-rays or CT scan which help us define the anatomy of your child’s jaw, face and head.
- A 16-lead polysomnogram, commonly called a sleep study, which measures your child’s breathing, brain stimulation, heart function, and oxygenation levels during sleep.
Other specialists involved in the evaluation and treatment of children with micrognathia include neonatologists, geneticists, otolaryngologists, pulmonologists and feeding specialists. Your child may be examined by a variety of specialists before a definitive diagnosis and treatment plan is made.
Your child’s care will be managed through CHOP’s multidisciplinary Craniofacial Program, which brings together all of these specialists to provide coordinated care for your child.
Treatment for micrognathia
Most children with micrognathia are able to be treated without undergoing surgery.
Non-surgical therapies to treat micrognathia include:
- Prone positioning — If your child sleeps on his stomach, the positioning thrusts his tongue base forward and clear his airway.
- Nasopharyngeal airways — This flexible tube with a flared end can be inserted into your child’s nostril and into the nasal passageway to create an open airway.
- Non-invasive positive pressure ventilation, such as CPAP (continuous positive airway pressure) or BiPAP (Bi-level positive airway pressure) that is managed by pulmonology for obstructive sleep apnea.
If these minimally-invasive measures do not work, your child may require surgery.
Surgical treatments for micrognathia include:
- A tongue-lip adhesion procedure, in which the base of your child’s tongue is tied to the lower jaw closer to the chin, effectively moving the tongue-base forward to clear the airway.
- A mandibular distraction osteogenesis (MDO), which makes the lower jaw larger by slowly lengthening the lower jaw bone and relieving airway obstruction.
- A tracheostomy, which creates an opening though the neck into the trachea to bypass the airway obstruction caused by a small jaw. This procedure is only rarely performed to treat micrognathia.
Long-term outcomes for children with micrognathia
Outcomes for children with micrognathia are generally good, but can vary depending on the severity of the condition, how quickly it was diagnosed, and how it was treated. Additional surgeries may be necessary dependent upon your child’s jaw growth and development. We will continue to monitor patients with micrognathia until they have reached skeletal maturity in adolescence.
Early diagnosis and ongoing monitoring help clinicians determine the best time to medically or surgically intervene to give your child the best long-term quality of life.
Why choose us
At CHOP, children with micrognathia have access to the nation’s top pediatric specialists and coordinated care through our Craniofacial Program. While we tailor therapy to each individual child, this multidisciplinary program streamlines care and makes sure you child has access to all the specialists and services he may need before, during and after treatment.
The craniofacial experts at CHOP are world leaders in the treatment of micrognathia. Our innovative approaches are being adopted by other leading children’s hospitals, and we are committed to improving the quality of life for your child.
Our dedication to excellence will be apparent to you, not only in our practice, but in all the experts who help us diagnose and treat children with micrognathia. Our goal is to minimize your child’s interaction with us — we want them home with you, healthy!
Reviewed by: Scott Bartlett, MD and Jesse Taylor, MD
Date: March 2014