Craniosynostosis CRANIOSYNOSTOSIS

Home , Craniosynostosis, Dysostosis, Hypertelorism, Synostosis, Trigonocephaly

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Craniosynostosis can be defined as the sure has been found to be present in approxi- premature closing of one or more of the mately 13-23% of patients. normally present bony gaps between the different bones of the skull. These linear The surgical treatment of craniosynostosis areas where the bones have not yet healed has been transformed by the development and together are called cranial sutures. They applications of craniofacial techniques to intersect in certain areas of the skull form- reshape the skull and upper face in the infant. ing “soft spots” or fontanelles. The cranial Functionally, the goal in treatment is to release suture lines or non-ossified zones accom- the fused sutures to prevent any problems asso- modate the brain’s growth and expansion ciated with increased intracranial pressure as during the first years of life. The brain well as creating the potential for normal growth. increases in volume about 2-1/2 to 3 times Cosmetically, the goal is to obtain normal shape the first two years of life with these non- of the skull and face, thus minimizing psychoso- ossified areas of bone remaining open for a cial problems. variable length of time and then closing in a predictable manner. Premature synostosis or closure of the suture will stop the growth of the skull in the direction perpendicular to that suture; however, growth will contin- ue in the direction parallel to the suture. The result is that synostosis of a particular suture will alter the shape of the skull in a predictable manner with recognizable patterns. With multiple suture involvement, increased intracranial pressure can occur since the skull cannot sufficiently expand to accommodate normal brain growth. In moderate craniosynostosis with only one suture involved increased intracranial pres- 3-D Scan of Sagittal Synostosis

©1997 Erlanger Health System Tennessee Craniofacial Center 1(800) 418-3223 Approximately one infant in every one together to insure that the patients are evalu- thousand births will have a premature clo- ated and treated in a coordinated manner and sure of a cranial suture associated with a that all their needs, both physical and psy- skull deformity. Infants born with abnormal chosocial, are met. The team combines the skull shapes should be suspected of having expertise of each specialist to provide a level craniosynostosis. However, abnormal skull of comprehensive care that cannot be provid- shapes at birth may be related to fetal head ed by a single physician. The primary physi- position or birth trauma; this type of defor- cian or pediatrician plays a key role in early mity will usually correct itself in several diagnosis and referral so that a successful months. True craniosynostosis will not treatment is accomplished. improve with time and usually worsens with Surgical Treatment: Tremendous growth. On examination palpation of the advancements have been made in the treat- abnormal portion of the head often reveals a ment of infants with isolated craniosynostosis ridge in the area of the fused suture. Once due to the application of craniofacial surgery craniosynostosis is suspected, the diagnosis principles. Past treatments such as strip can be verified with plain skull radiographs craniectomies which remove only the fused and CT scans. We routinely obtain CT scans suture have resulted in unpredictable results. with three-dimensional reconstructions to These procedures have often resulted in skull confirm the diagnosis, rule out other intracra- and facial deformities that are difficult to cor- nial abnormalities, and to fully assess the rect in the older child. Current surgical treat- deformity. The 3-D scans can very clearly ment involves a team approach with a show the skull shape and help in pre-opera- combined expertise of a neurosurgeon and tive planning. Isolated craniosynostosis must craniofacial surgeon. The goal of surgery is to be distinguished from a syndrome that has as establish normal contour of the brow, fore- one of its components craniosynostosis. The head and skull; and to allow the brain to specific diagnosis is an important starting grow and expand in a normal manner with point in treatment planning. release of synostosis. The timing of surgical Etiology: While the pattern of embryonic correction depends on the age at diagnosis craniofacial development has been well and referral. In our experience we feel that defined through extensive research, very lit- the best results are obtained when infants tle is known about the etiology of many cran- undergo surgical repair between 4 and 8 iofacial anomalies. There is strong evidence months of age. This period has several for a genetic role in the occurrence of some advantages: craniosynostosis. An inherited tendency or (1) remodeling is easier because the bone is family history has been reported in many very malleable; cases in the literature, however, most cases of (2) rapid brain growth benefits bone isolated craniosynostosis are usually spo- remodeling; radic in occurrence with no known etiology. (3) bone defects heal rapidly. Team Evaluation: Patients with cran- Early correction also prevents further iosynostosis need to be evaluated and treated deformity caused by unreleased, fused at a recognized craniofacial center with a sutures. Therefore, early diagnosis and refer- team approach. We have a multidisciplinary ral to a craniofacial center is crucial. We advo- team at our center to provide the comprehen- cate extensive release of the fused suture, sive care necessary to adequately evaluate total reshaping of the brow, superior orbits, and treat craniofacial patients and their fami- and skull as necessary between 4 and 8 lies. Members of the craniofacial team work months of age. Older patients will require

SAGITTAL SYNOSTOSIS Premature closure of the sagittal suture, the longitudinal suture on the top of the head, stops growth laterally producing a narrow head. There is a compensatory growth in the anteroposterior direction with elongation of the skull and a bulging of the front and back of the head. This particular deformity is called scaphocephaly due to the skull’s boat shaped appearance. Synostosis of the sagittal suture is the most frequent type of single suture craniosynostosis. It makes up 50-60% of all patients within North America with craniosynostosis. The particular infants with sagittal synostosis characteristically have normal intelligence. In sagittal synostosis or scaphocephaly we most frequently perform Scaphocephaly total skull reshaping. In this type of synostosis the forehead and back of the skull are usually bulging, over- projected, and the width of the skull too narrow. The front, back and lateral bone plates are removed and then reshaped to a more normal contour. The forehead is tilted back (as well as the occiput) and the entire anteroposterior dimension of the skull is short- ened. The reshaped bones are secured in position with wires and/or Preoperative Postoperative microplates. Certain gaps between the bones are left unsecured to avoid restriction of growth. The dura, or outer covering of the brain, may be plicated in the frontal region to decrease the prominence. Barrel stave cuts are made in the lateral bone at the base of the skull to allow more projec- tion of the skull laterally, increasing the transverse width. This type of procedure gives a more definitive and immediate improvement in skull shape. Preoperative Postoperative

©1997 Erlanger Health System Tennessee Craniofacial Center 1(800) 418-3223 METOPIC SYNOSTOSIS The metopic suture runs down the midline of the forehead. Premature fusion of this suture results in a triangular shaped forehead called trigonocephaly. A bony ridge is usually palpable that extends from the bridge of the nose to the upper part of the forehead. This premature fusion pro- duces a prominent midline keel with lateral recession of the brows. From the frontal view these patients typically have the appearance of hypotelorism or decreased distance between the eyes. The incidence of metopic synostosis in most cases of craniosynostosis is between 5-10%. This deformity is usually obvious at birth, but the severity of the anomaly may vary. We prefer to correct these deformities between 4 and 8 months of age. Our current surgical treatment consists of frontal bone remodeling and supralateral orbital Trigonocephaly advancement. The triangular or keel- shaped forehead is removed and recon- toured to the appropriate shape or bone may be taken from another area of the skull to replace this bone. The entire bony supraorbital bar is removed and reshaped with supralateral orbital advancement to restore the normal brow contour. Microplates are used to secure the frontal bar to the facial bones and maintain the Intraoperative photograph of triangular shaped forehead normal contour. (left) and brow (right).

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©1997 Erlanger Health System Tennessee Craniofacial Center 1(800) 418-3223 UNILATERAL CORONAL SYNOSTOSIS Premature fusion of one of the coronal sutures results in an asymmetric forehead and brow. On the affected side the forehead is flattened and recessed with the brow and supraorbital rim both elevated and recessed. The contralateral forehead may exhibit compensatory bulging or bossing. This ultimately results in a very asymmetric malformation called plagiocephaly. Technically, plagiocephaly refers to any type of asymmetric skull deformity. However, many authors have used this synonymously with unilateral Plagiocephaly coronal synostosis. The incidence of unilateral coronal synostosis in most series of craniosynostosis is between 10-20%. If untreated, this type of synostosis may result in a severe deformity of the forehead, orbit, and nose that persists or worsens with growth. We feel the best treatment for plagiocephaly should involve a bilateral approach with remodeling of the entire forehead and brow between the ages of 4 and 8 months. Our cur- Preoperative Postoperative rent surgical treatment consists of extended bicoronal craniectomies with bilateral frontal bone reconstruction. The supraorbital bar is completely removed, reshaped, and straightened. The supraorbital bar is advanced and lowered as necessary on the affected side and rigidly fixed in position to the face. The reconstructed forehead is then secured to the supraorbital bar. We feel that the bilateral approach obtains a more symmetric forehead and brow than the unilateral approach.

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©1997 Erlanger Health System Tennessee Craniofacial Center 1(800) 418-3223 BICORONAL SYNOSTOSIS Bicoronal suture fusion results in a flat retruded forehead with increased height to the skull. This condition is also called brachycephaly due to the short anteroposterior diameter. As a result of this shortening there is a compensatory bulging of the transverse diameter or width of the skull. The brow is usually recessed and elevated with the deformity being symmet- Brachycephaly ric. The incidence of bicoronal synostosis or brachycephaly is between 10-20% in most series of craniosynostosis. This may occur as an isolated occurrence or part of a more complex syndrome with facial retrusion such as Apert’s or Crouzon’s. Surgical treatment consists of extended bicoronal craniectomies with reconstruction of the forehead. Intraoperative lateral view of skull The supraorbital bar or Intraoperative lateral view of skull after before remodeling. remodeling. brow is reshaped and advanced forward with the forehead. The reconstructed forehead and brow are rigidly fixed to the nose and lateral orbits with microplates. If there is excessive height to the skull then total calvarial remodeling is also performed, decreasing the height of the skull.

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©1997 Erlanger Health System Tennessee Craniofacial Center 1(800) 418-3223 POSTERIOR PLAGIOCEPHALY There has been a significant increase in the past several years of infants referred for evaluation of occipital deformities. This increase in occurrence of posterior skull deformities appears to be related to the 1992 recommendation for supine sleep positioning by The American Academy of Pediatrics to avoid Sudden Infant Death Syndrome. Occiput deformities can be divided into lambdoid synostosis and deformational or positional plagiocephaly. The lambdoid suture is a paired structure that transverses in a symmetric Posterior Plagiocephaly

Preoperative photo showing left Postoperative result after posterior Postoperative result after posterior posterior skull flattening. skull remodeling. skull remodeling.

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©1997 Erlanger Health System Tennessee Craniofacial Center 1(800) 418-3223 fashion across the posterior aspect of the CRANIOFACIAL DYSOTOSIS skull. Premature fusion or synostosis of this suture is rare but may be unilateral or bilat- Craniofacial dysotosis (Crouzon’s and Apert’s eral. diseases) are characterized by craniostenosis with cranial dysmorphia and facial deformities Characteristically in unilateral synosto- (hence, the term craniofacial dysotosis). sis the posterior skull is flattened on the involved side. Displacement of the ear with compensatory skull changes may be present APERT SYNDROME in severe cases. Bilateral synostosis is char- Apert syndrome or acrocephalosyndactyly acterized by extensive flattening across the syndromes are rare conditions. In 1906, Apert posterior skull and increased vertical described the skull, facial, and hand deformities growth to accommodate brain enlargement. of several patients characteristic of this syn- In mild cases the deformity can be covered drome that now bears his name. The incidence of by hair and surgical repair may not be indi- infants born with Apert syndrome is one for cated. When there is significant flattening every 100,000 to 160,000 live births. Many of the or asymmetry, we recommend release of the infants born with this syndrome show a sporadic fused sutures and posterior skull remodel- transmission, which means that a family may ing. Surgical treatment consists of extensive have a child with Apert’s when no other mem- posterior skull craniectomies with remodel- bers of the family are affected. The recurrent risk ing of both sides of the occiput and posteri- of having another child with Apert’s for two or advancement of the affected side. Rigid unaffected parents is negligible. However, if the fixation with microplates is used to hold the parent is affected there is a 50% chance of each reconstructed bones in position and main- offspring having Apert syndrome with both tain the contour until healing takes place. males and females affected equally. Occipital plagiocephaly without synos- Clinical Features: Patients with Apert syn- tosis must be distinguished from lambdoid drome have very distinct facial and extremity synostosis. Most patients referred to our features. Abnormal skull shape is due to cran- center for posterior skull deformities are iosynostosis or premature fusion of the sutures deformational or positional plagiocephaly. or soft spots. The skull usually demonstrates a In these infants, the skull becomes mis- short anteroposterior diameter (brachycephaly) shaped from repeated pressure on the same and may be excessively tall (turricephalic) or position, without the premature fusion of abnormally wide (euryprosopia). The forehead the lambdoid suture. Positional plagio- is generally always retruded, but this may not be cephaly usually improves without surgery. obvious due to the hypoplasia of the midface. Once the child’s sleep patterns change and The orbits or bony sockets which contain the he spends more time awake, the brain’s nor- eyes are very shallow causing a bulging or prop- mal growth forces help to reshape the poste- tosis. The orbits are usually rotated downward rior skull. Some centers recommend a and lateral causing a downward shape to the lat- custom fitted helmet to mold the head back eral corners of the eyes. There may be a moder- into position over a period of several ate increased distance between the eyes months. However, in cases where the poste- (hypertelorism) with muscle imbalance. rior skull deformity progresses or is severe, we recommend surgical remodeling as The middle of the face in Apert’s is both described, even though a true synostosis retruded and very hypoplastic. This causes the may not be present. central midface to have a characteristic sunken-

©1997 Erlanger Health System Tennessee Craniofacial Center 1(800) 418-3223 in appearance with the nose being Apert Syndrome thick and beaked. The upper jaw or maxilla characteristically shows a narrow arch with an open bite and dental crowding. The maxilla is significantly retruded compared to the mandible with the teeth of the lower jaw projecting in front of the upper teeth. Other possible clinical features include moderate hearing loss, speech impairment, acne, and decreased mental capability in some individuals. Intellectual potential may be difficult to evaluate due to communication problems. Some patients with Apert Preoperative photo of infant Postoperative result after fore- syndrome may have normal intelli- with Apert syndrome. head and brow advancement. gence. All patients with Apert syndrome demonstrate a unique hand malformation. This is characterized by a complex syndactyly or fusion of the skin, soft tissue, and bones of the fingers. Both hands are affected equally, as are the feet. This unusual variation of syndactyly can be used to identify Apert’s from other similar syndromes. Treatment: The treatment of patients with Apert syndrome is not uniform due to significant variations in the facial anomalies, age of patients when first seen, and Preoperative Postoperative previous operations. Our primary concern of the infant born with this syndrome is: compression of the brain, breathing problems, pro- truding eyes with corneal exposure, and lack of facial growth. The surgical plan must be flexible and individualized to the patient. Multiple stages or operations at different ages are usually necessary. When we see these patients as infants, the first stage is treatment of the craniosynostosis with total Characteristic appearance of complex syndactyly of hand.

©1997 Erlanger Health System Tennessee Craniofacial Center 1(800) 418-3223 calvarial reshaping. We prefer to do this hypertelorism or lateral rotation of the orbits. procedure at four to six months of age. A This procedure, as described by Tessier, is called frontal-orbital advancement is per- a facial bipartition and corrects several deformi- formed which increases the intracranial ties at once. It effectively widens the maxilla and space and size of both orbits. Total skull derotates the orbits, and narrows the upper face. reshaping helps correct the tower skull In milder cases an extracranial LeFort III problem which is not addressed by advancement may be used. frontal-orbital advancement alone. A ventriculo-peritoneal shunt may be The final steps in the reconstruction are max- needed for treatment of a hydro- illary/mandibular osteotomies to complete the cephalus. This is performed prior to correction of any further dental discrepancies. skull remodeling. Occasionally a repeat These procedures are usually performed after craniotomy is needed to further reshape eruption of permanent dentition and completion the calvarial vault and advance the of growth (teen years). Additional procedures orbits. The next stage of the reconstruc- such as rhinoplasty, genioplasty and eyelid tion is midfacial advancement. We usu- surgery may be beneficial. Surgical separation of ally perform this procedure between the the fingers is usually started in the first year of ages of four to six years old prior to life and completed by three to four years of age. starting school. If necessary, an The patient with Apert syndrome represents intra/extracranial advancement of the a complex combination of multiple deformities. entire face and forehead (monobloc) can Our goal is to treat not only the function and be performed with correction of mild physical problems but the psychosocial issues as

Apert Syndrome

This little girl has the character- Preoperative Postoperative result after facial istic facial appearance of Apert advancement. Syndrome which is also associated with complex syndactyly.

©1997 Erlanger Health System Tennessee Craniofacial Center 1(800) 418-3223 Apert Syndrome CROUZON SYNDROME This syndrome was originally described in 1912 by a French neurosurgeon. He described four essential characteristics: exorbitism, retromaxil- lism, inframaxillism and parodoxic retrogenia. The incidence of this syndrome appears to be approximately one in 25,000 in the general popula- tion. It is inherited as an autosomal dominant pattern with variable expression. However, approximately 25% of reported cases have no family history and represent a new mutation. Postoperative result after Four year old girl with Apert Clinical Features: Patients with syndrome. monobloc facial advancement Crouzon syndrome have very distinct with facial bipartition (medial rotation of orbits). facial features with craniofacial bone morphology similar to Apert syndrome. Premature fusion of the bicoronal suture is the most common type of craniosynostosis with a brachycephalic or oxycephalic appearance to the skull. The extent of the craniosynostosis may be variable as well as the age at onset. There is retrusion of both the forehead and brow, with midface hypoplasia and shallow orbits with bulging eyes (proptosis). Orbital hypertelorism is less commonly seen in Crouzon’s than Apert’s syndrome. The lateral canthi may be slanted downward with some degree of upper eyelid ptosis. The proptosis is usually more prominent Preoperative Postoperative in Crouzon’s than Apert’s; however, in Apert syndrome, the other craniofacial deformities are more complex and severe. In addition, hydrocephalus well. We feel these individuals are best evaluated and and developmental delay are less fre- treated by a craniofacial center that utilizes the multi- quently seen in Crouzon’s than disciplinary team approach providing a coordinated, Apert’s. The nasomaxillary retrusion comprehensive, long-term treatment plan with careful may cause some degree of nasal air- monitoring of growth and development. way obstruction with mouth breath-

©1997 Erlanger Health System Tennessee Craniofacial Center 1(800) 418-3223 ing. The chin is usually large with Crouzon Syndrome increased vertical height but often retruded resulting in a paradoxical retrogenia. The maxillary teeth are retruded compared to the mandible with a class III malocclusion. Other possible abnormalities include con- ductive hearing loss, inverted V- shape to palate and exposure keratitis. Variations of this type of craniofacial dysostosis are seen in the syndromes of Carpenter, Pfeiffer and Saethre-Chotzens. Treatment: Our approach to the treatment of Crouzon syndrome is Young woman with Crouzon’s Result after correction of similar to that described for Apert Syndrome. orbital hypertelorism, maxil- syndrome. The first stage involves lary advancement, mandibular treatment of the craniosynostosis setback and chin reduction. with total calvarial reshaping as needed and frontal-orbital advancement. This procedure is usually performed at four to six months of age and is effective in increasing the intracranial space and enlarging the orbits. It is not unusual for a ventriculo-peritoneal shunt to be needed for treatment of a hydrocephalus. Occasionally, a repeat craniotomy will be needed in infancy to further reshape the calvarial vault and advance the orbits. The next stage of reconstruction is midface advancement performed at four to six years of age. This type of advancement can Two year old boy with Postoperative appearance after be accomplished with either a LeFort Crouzon’s syndrome who forehead-brow advancement. A III or a monobloc (entire face and exhibits severe proptosis. Lefort III advancement will be needed in the future. forehead) osteotomy. The position of the forehead and brow determines which procedure would be the best alternative. If necessary, the monobloc osteotomy can be further split in the midline to correct orbital osteotomy is used to correct the dental discrepancies in hypertelorism (facial bipartition). combination with orthodontic intervention. This is usually performed after facial growth is completed and may be The final stage of the reconstruc- combined with a genioplasty (chin reduction/advance- tion is management of the dental ment). Additional procedures such as rhinoplasty may be class III malocclusion. A LeFort I needed.