Clinical Focus: Pierre Robin Syndrome
Pierre Robin syndrome (PRS) is a congenital condition that affects the lower jaw and palate. PRS is characterized by three main features: a small lower jaw, displacement of the tongue toward the back of the oral cavity (glossoptosis), and cleft palate (an opening in the roof of the mouth).
PRS is believed to be caused by multiple contributing factors which lead to a series of physical changes within the oral cavity. The condition is also called Pierre Robin sequence, because it is believed when the lower jaw does not grow enough, it begins a sequence of events which leads to the tongue being displaced and the formation of a cleft palate. These changes occur during pregnancy, leading to craniofacial abnormalities that are typically detected at birth.
The exact causes of Pierre Robin syndrome are unknown, though there is a higher incidence in twins. This leads some experts to believe one cause may be due to crowding in the uterus, restricting the growth of the lower jaw. PRS can occur in isolation but it can also be part of an underlying disorder or syndrome, the most common being Stickler Syndrome.
In PRS, the lower jaw characteristically has an altered shape and position. Anatomic anomalies of PRS also frequently include a U-shaped cleft palate, which affects the dynamics of breathing and speech development.
Specifically, the displacement of the tongue toward the back of the mouth predisposes it to fall toward the throat. This may obstruct the airway and cause difficulty breathing. This can vary in severity, ranging from mild disturbance to life-threatening respiratory distress. Airway obstruction can also occur during the night, in the case of a related condition called obstructive sleep apnea.
Since air and food both pass through the mouth and down the throat, breathing and feeding problems are common.
Other possible manifestations of PRS include cardiovascular and lung conditions, such as heart murmurs, high blood pressure in the arteries of the lungs (pulmonary hypertension), and narrowing of the opening between the lung artery and the right ventricle of the heart (pulmonary stenosis). Inflammation of the middle ear usually accompanied by repeat ear infections occurs in about 80% of patients, and eye defects are noted in about 10% to 30% of patients. Teeth present at birth are another frequent finding.
Infants with severe airway obstruction may present with respiratory distress at birth and may require medical intervention. In moderate cases, the child will need to have a tube placed through the nose and into the airway to avoid airway blockage. In severe cases, surgery is needed to prevent a blockage in the upper airway by moving the jaw forward. In rare cases of patients with severe breathing problems, surgery may be needed to make a hole in the windpipe (tracheostomy). Surgery to repair the cleft palate is usually done between 9 and 12 months of age.
Feeding must be done very carefully to avoid choking and breathing liquids into the airway. The child may need to use a feeding tube to prevent choking.
Children affected by PRS usually reach full development and size, and most children will have normal speech after palate repair. Some may need speech therapy or a second operation later on to improve speech. Parents and doctors should continue to monitor the child’s development, particularly tooth development, growth, and speech as the child ages.