Craniosynostosis Definition 1. A syndrome is the association of several clinically recognizable signs and symptoms, which can occur together in an affected individual. A large number of syndromic conditions involve the craniofacial region (Gorlin et al, 2001). 2. Abnormal growth pattern of the skull o skull cannot expand perpendicular to the fused suture o compensates by growing more in the direction perpendicular to the open sutures (Virchow’s Law= Virchow's Law, during craniosynostosis, skull growth is restricted to a plane perpendicular to the affected, prematurely fused suture and is enhanced in a plane parallel to it. ) o growth pattern provides the necessary space for the growing brain, but results in an abnormal head shape and facial features Classification according to mode of inheritance 1. Familial syndrome: Those that occur as part of a characterized Mendelian disorder, resulting from a single gene defect: • Autosomal dominant • Autosomal recessive; • X-linked dominant • X-linked recessive 2. Sporadic syndrome: Those arising from structural abnormalities of the chromosomes; due to teratogenic agents like: • Teratogen: eg Drugs (alcohol, phenytoin, thalidomide); Physical agents (radiation, intrauterine mechanical restraint). • Maternal illness: eg Infections (cytomegalovirus, rubella, syphilis); • Nutritional 3. Idiopathic Classification according to clinical features I. Craniosynostoses • Isolated craniosynostosis 70% • Syndromic craniosynostosis a. Apert's syndrome b. Crouzon's syndrome
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Craniosynostosis Definition
1. A syndrome is the association of several clinically recognizable signs and symptoms,
which can occur together in an affected individual. A large number of syndromic
conditions involve the craniofacial region (Gorlin et al, 2001).
2. Abnormal growth pattern of the skull
o skull cannot expand perpendicular to the fused suture
o compensates by growing more in the direction perpendicular to the open
sutures (Virchow’s Law= Virchow's Law, during craniosynostosis, skull growth is
restricted to a plane perpendicular to the affected, prematurely fused suture and is
enhanced in a plane parallel to it.)
o growth pattern provides the necessary space for the growing brain, but results
in an abnormal head shape and facial features
Classification according to mode of inheritance 1. Familial syndrome: Those that occur as part of a characterized Mendelian disorder,
resulting from a single gene defect:
• Autosomal dominant
• Autosomal recessive;
• X-linked dominant
• X-linked recessive
2. Sporadic syndrome: Those arising from structural abnormalities of the chromosomes;
D. Plagiocephaly (fusion of coronal and lambdoidal
sutures unilaterally), Lambdoid synostosis was a focus of
interest after the impact of the Back to Sleep campaign
(supine sleeping is better than prone sleep as it has less
effect on cranium, less SID and longer stage 3 Non-REM
and shorter REM which all good) initiated by the American
Academy of Pediatrics in 1994 resulted in an epidemic of
infants with posterior plagiocephaly.
E. Oxycephaly conical or pointed skull, delayed onset bilateral coronal synostosis.
II. Deformational Plagiocephaly
o No fusion of the sutures o Skull changes shape due to extrinsic forces o No bulging of the mastoid o Skull base not affected o Position of the ears is level and displacement of one ear to the front is characteristic
for deformational plagiocephaly.
III. Primary microcephaly
o Absence of growth of the brain → rendering the sutures of the cranial vault useless → the sutures close
o Pansynostosis like image. o Differentiation between these two conditions can be made with a computed
tomography (CT) scan. o
Medical history
Risk factors during pregnancy
Familial rate
Presence of symptoms of elevated intracranial pressure (ICP).
Physical examination
Fundoscopy → papilledema (optic disc swelling 2° to ↑ICP)
Measurement of the head circumference + growth curve
Assess skull deformity
Supplemental analysis
3D CT - gold standard for diagnosing craniosynostosis
Allows for surgical planning and 3D reconstruction/stereolithographic modeling as
required
MRI scans
Genetic testing
Apert's syndrome
Aetiology:
• acrocephalopolysyndactyly type I (typoe II and III are below)
• Autosomal dominant
• It is due to paternal mutation
• Defect in the FGF receptor 2 gene
• Prevalence of the disease (1 in 100,000)
Extraoral sign and symptoms
• Premature fusion of the coronal and frontosphenoidal sutures and the sphenoethmoidal
synchondrosis
Syndactyly of hand and feet (soft tissue and bone). Syndactyly of the hands and feet = Failure of programmed cell death or apoptosis which normally causes separation of the digits → skin, and rarely bone, between the fingers and toes fuses. Especially mediated great toes and thumbs. Fusion of fingers or toes with an equal number on both sides of the body.(symmetrical). It is typical for the middle 3 fingers to be fused together. The thumb and big toe may be broad and malformed. Abnormal shortness is called brachydactyly. Cohen (1984) Classification