Syndromic Craniosynostosis

anterior cranial fossa. The sella is enlarged and the greater wings of the sphenoid are protruded. There is an expanded ethmoidal labyrinth, with orbital hypertelorism and shallow orbits, with proptosis. Down-slanting palpebral fissures and strabismus are frequently present. The ocular motility disturbances may be due to mechanical factors or structural alterations of the extraoc-cular muscles.

Mid-face hypoplasia is also characteristic of this syndrome, resulting in a depressed nasal bridge, mandibular prognathism and a class III malocclusion, along with maxillary arch constriction. This results in a V-shaped maxillary dental arch, dental crowding and thickening of the alveolar ridges. Consistent with these deformities, there is often a posterior cross-bite and an anterior open bite. There is often delay of dental eruption and frequent supernumerary teeth. The palate is short, highly arched and often has a median furrow. The incidence of cleft palate is also high, occurring in 30% of those afflicted [11]. This results in eustachian tube dysfunction and frequent otitis media. Congenital stapedial foot plate anomalies, along with frequent middle-ear infections, result in an increased risk of hearing deficits. The soft palate is longer and thicker than in normal subjects. The nasopharynx is also reduced in size, placing these patients at risk of airway obstruction.

Mental retardation occurs in a significant number of those with Apert syndrome. The average IQ in one series was 73, with a range of 52-89 [12]. Structural CNS malformations may be partly responsible for the mental deficiencies, such as absence of the corpus callo-sum, hypoplasia of the cerebral white matter and abnormalities of the limbic structures and pyramidal tracts [13]. Progressive hydro-cephalus is uncommon and is often confused with non-progressive ventriculomegaly, due to an embryonic malformation or abnormal brain shaping by the malformed skull [14].

Other findings in this patient population are four-limb symmetric complex syndactylies of the hands and feet, with brachydactyly and joint stiffness. Malformations of other joints, including the elbows and shoulders, may also be found. At birth, height and weight are increased; however, final height is below average due to deceleration of limb growth. Cardiovascular defects can also occur, as well as other visceral anomalies. Lastly, acne vulgaris, extending to the forearms, chest, back and upper arms, commonly occurs.

The initial surgical procedure for Apert syndrome is cranio-orbital decompression and reshaping. It consists of bi-coronal suture release and osteotomies of the anterior cranial vault and orbits, with reshaping and advancement. The purpose is to decompress the brain and increase orbital volume, to decrease globe protrusion. This is usually performed at 6-12 months, unless signs of elevated ICP are evident, in which case a strip craniectomy, limited cranial vault expansion and/or shunt is placed within the first month of life. The child is then followed clinically at intervals and further decompression with reshaping is performed if there is evidence of elevated ICP. Commonly in Apert syndrome, there is need for posterior cranial vault decompression and reshaping. Correction of the mid-face hypopla-sia, along with final cranial vault reshaping, are best performed no sooner than at 5-7 years of age. These can be performed through a LeFort III, monobloc or facial bipartition. The facial bipartition allows for more complete correction of the deformities of the orbits (exorbitism and hypertelorism), forehead and mid-face. These procedures are most often performed through distraction osteogenesis, in order to decrease the incidence of post-operative relapse. Final correction of the malocclusion should be reserved until skeletal maturity, to avoid recurrence of the malocclusion and also creation of severe enophthalmos in an attempt to correct the bite at an early age.

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