Physician: Education: Descriptions of Disorders

The prime features of this condition are a small jaw (micrognathia) and a cleft of the posterior soft palate. The cleft is typically rounded, sometimes called "U-shaped", in comparison to the more common "V-shaped" cleft seen in other conditions. In the newborn period, the main concern for someone with this condition is for respiratory problems. Because the tongue is positioned in the back of the mouth, it tends to block the airway and cause respiratory distress. In severe cases, a tracheostomy may be required to provide a stable airway for the patient.

The Pierre-Robin sequence can occur for many reasons. It may be an isolated finding, meaning that there are no other unusual features present on physical examination. Even as an isolated finding, the Pierre-Robin sequence may be inherited, and other family members may be identified with the same condition. It may also occur as part of a genetic syndrome. A syndrome is a group of features which regularly occurs together in a recognizable pattern. For example, someone with the Stickler syndrome may have the Pierre-Robin sequence in addition to nearsightedness and arthritis. Lastly, the Pierre-Robin sequence may be caused by external factors which do not allow for normal movement of the developing jaw. For example, constraint of the fetus by factors such as a large fibroid, or by multiple fetuses (i.e., twins, triplets, etc.) can lead to the same clinical picture. Certain neurological abnormalities which lead to decreased jaw movement in utero can also have the same result. If an individual has the Pierre-Robin Sequence because of the influence of external factors while in utero, his or her risk of passing on the condition is minimal, because the genetic information governing jaw and palate development has not been altered. If the condition has occurred because of a new or inherited genetic mutation, there is a risk of recurrence for the patient. New dominant mutations are associated with a 50% risk of passing the same condition on to one's children.

Development of the palate occurs between the fifth and twelfth week of gestation. The palate forms in two portions, called the primary (anterior) and secondary (posterior) segments. The primary palate forms first, beginning at approximately the fifth week of gestation. It encompasses a small portion of the mature palate, and includes the four incisor teeth. This segment is formed by the fusion of two tissue ridges (called the medial nasal prominences) which also contribute to normal formation of the nostrils and upper lip. Interruption of normal development in this region often leads to clefting of both the lip and palate. Formation of the posterior palate is somewhat more complex, and is generally not complete until around the twelfth week. This portion is formed by two tissue structures called the lateral palatine processes. They are structures which originate in the area of the upper jaw and grow downward on either side of the developing tongue. When the two lateral palatine processes have completed their downward growth, they begin to rotate towards each other (similar to the closing of a gate). As development progresses, the face and oral cavity elongate to allow room for development of the oral structures. Specifically, this elongation causes the tongue to move downward and out of the way of the palatal processes. This allows the palatal processes to then meet in the midline, and begin to join together to form what we know as the secondary palate. They join together in a fashion similar to a zipper, which begins at the front of the mouth and proceeds to the back. The secondary palate also fuses with the primary palate to make one continuous tissue structure. In the Pierre-Robin sequence, however, this normal development is disrupted. The primary defect is that the jaw is too small. Because of this, the developing tongue is located further back in the mouth than normal, and in a somewhat "heaped up" or higher position. The tongue, then, blocks the joining of the lateral palatine processes in the posterior section of the palate. Since the tissues are not able to come together, the palate cannot close, and rounded cleft of the posterior palate results. The Pierre-Robin deformity is called a sequence because of this cascade effect where one abnormality (the small jaw) leads to other features in a stepwise progression.

The diagnosis of the Pierre-Robin sequence is a clinical one, meaning that it is based on the physical features rather than on a diagnostic test. The Pierre-Robin sequence may be given as a diagnosis (when no other unusual features are found), or may be only one feature of a larger genetic syndrome which includes this condition among its findings.

The treatment of Pierre-Robin sequence involves an assessment of the patient's airway and of the palatal cleft. In most cases, there is only mild respiratory compromise and no surgical intervention is required to provide an airway. In fact, the micrognathia becomes less evident with time as the small jaw tends to show catch-up growth. In these milder cases, all that may be required is care in positioning the baby. By placing the child on his or her stomach, gravity will help to keep the tongue out of the airway. These children should not be placed on their backs, because the tongue will fall to the back of the throat and make breathing more difficult. Moderate cases are sometimes treated by surgically attaching the tip of the tongue to the lower lip, preventing the tongue from falling to the back of the throat. This is maintained for a limited period of time until the jaw has grown sufficiently. In severe cases, a tracheostomy may be needed. The cleft palate is generally addressed surgically. The timing of repair will depend on the size of the cleft, the health of the child, and other factors. Because a cleft palate can affect speech and feeding behaviors, a speech therapist is often involved in the care of these children. Persistent cleft can increase the likelihood of ear infections and retained ear fluid, and other specialists such as otolaryngologists (ear, nose and throat specialists) and audiologists may be involved. Due to the multispecialty needs of children with oral clefting, they are often best evaluated by a group of experts who function as a Cleft and Craniofacial Team.

American Cleft Palate-Craniofacial Association
Wide Smiles
Prescription Parents
OMIM 261800

Bath AP, Bull PD.
Management of upper airway obstruction in Pierre Robin sequence.
J Laryngol Otol 111(12):1155-7, Dec 1997. abstract

Caouette-Laberge L, Bayet B, Larocque Y.
The Pierre Robin sequence: review of 125 cases and evolution of treatment modalities.
Plast Reconstr Surg 93(5):934-42, Apr 1994 . abstract

Elliott MA, Studen-Pavlovich DA, Ranalli DN.
Prevalence of selected pediatric conditions in children with Pierre Robin sequence.
Pediatr Dent 17(2):106-l 1, Mar-Apr 1995. abstract

Handzic-Cuk J, Cuk V, Risavi R, Katusic D, Bagatin.
Pierre Robin syndrome: characteristics of hearing loss, effect of age on hearing level and possibilities in therapy planning.
J Laryngol Otol 1l0(9):830-5, Sept 1996. abstract

Laitinen S, Heliovaara A, Pere A, Ranta R.
Growth in children with Pierre Robin sequence and isolated cleft palate.
Acta Paediatr 83(11):1161-4, Nov 1994. abstract

Olney AH, Kolodziej P, MacDonald MR, Schaefer GB.
Robin sequence.
Ear Nose Throat J 76(9):620, Sept 1997. abstract

Gorlin RJ, Cohen MM Jr, Levin LS (eds).
Syndromes of the Head and Neck (3rd ed).
Oxford University Press, New York. p 15-20, 1990 .

We subscribe to the HONcode principles
of the Health On the Net Foundation