Micrognathia

Micrognathia Causes

Micrognathia can be inherited, meaning it's passed down from a parent. It can also occur due to a change in the genes associated with a genetic condition or for an unknown reason.

Other causes are:

• Crowded positioning of the baby in the womb.
• A problem with a baby's muscles or nerves.
• A connective tissue disorder such as, Stickler syndrome.

Micrognathia Symptoms

Sometimes children with this condition have a hard time breathing and eating. This is because the small jaw pushes the tongue back into the throat causing obstruction of the airway. If this is severe and present at birth, these individuals are typically admitted to the Neonatal Intensive Care Unit (NICU) for comprehensive evaluation and treatment.

Your child may have significant micrognathia if they:

• Stop breathing while sleeping, also known as sleep apnea.
• Have feeding or swallowing problems. These can lead to problems with growth or aspiration of food and liquid into the lungs.
• Breathe noisily while awake and during sleep.
• Have problems sleeping.
• Turn blue while eating or sleeping due to lack of oxygen.

Micrognathia Diagnosis

Some micrognathia cases are diagnosed before the baby is born, during a mother's routine ultrasound exams. Otherwise, the condition can usually be diagnosed on sight after birth, meaning your doctor may simply notice that your baby's jaw looks smaller than normal. If your child has a small jaw, their doctor will perform a full physical examination, including looking inside their mouth.

Some tests may be needed in order to determine how serious the condition is. These tests may include:

• CT scan of the facial bones: A CT scan takes pictures in "slices" and puts them together to make a highly detailed 3D picture
• A sleep study: This can help identify the severity of any sleep and breathing problems.
• An airway endoscopy.
• A swallowing study.
• Blood tests: These allow the doctor to identify any genetic causes of the condition.

Your child may need to be evaluated by several specialists, including a craniofacial surgeon, an otolaryngology (ENT) surgeon, a genetic specialist, and a speech pathologist who is also a feeding specialist.

Your child's treatment at UPMC Children's Hospital of Pittsburgh will be guided by the severity of their condition. While some children grow out of their micrognathia, they may need extra care in the meantime. If your child has more severe problems, like breathing and feeding issues, they'll need to be treated in infancy so their growth, development, and safety aren't affected. This care in infancy is typically provided in the NICU and involves a team of specialists.

Some of the methods we used to treat micrognathia include:

• Sleep positioning: Your baby may need to be placed in certain positions during sleep so that they're able to breathe freely. Your child's care team can show you how to do this.
• A tube in the airway: A tube called a nasopharyngeal airway can be placed through your child's nose to keep the nasal passage open.
• Tracheostomy: If your child's breathing problems are very severe, they may need to have a tracheostomy, which creates an airway opening through the neck.

If other, more conservative measures aren’t successful, surgical interventions may be required. These can include one of the following based on the child’s needs:

• Tongue-lip adhesion: This is a surgery that attaches the tongue to the inside of the lip to keep the tongue from blocking the back of the throat.
• Mandibular distraction osteogenesis surgery: In this procedure, the lower jawbone, or mandible, is made longer by separating it and then elongating the jaw. After the jaw is split, a special device called a distractor is implanted in the jaw. This device is adjusted over time to lengthen the lower law by increasing the space where the jaw is split. This will pull the tongue forward and out of the airway. The jawbone grows to fill the space that is created. Approximately three or four months later, the device is removed during a second surgery.