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Craniosynostosis (from ''cranio'', cranium; + ''syn'', together; + ''ostosis'' relating to bone) is a condition in which one or more of the fibrous sutures in an infant skull prematurely fuses by turning into bone (ossification), thereby changing the growth pattern of the skull. Because the skull cannot expand perpendicular to the fused suture, it compensates by growing more in the direction parallel to the closed sutures.〔 Sometimes the resulting growth pattern provides the necessary space for the growing brain, but results in an abnormal head shape and abnormal facial features.〔 In cases in which the compensation does not effectively provide enough space for the growing brain, craniosynostosis results in increased intracranial pressure leading possibly to visual impairment, sleeping impairment, eating difficulties, or an impairment of mental development combined with a significant reduction in IQ. Craniosynostosis occurs in one in 2000 births. Craniosynostosis is part of a syndrome in 15 to 40% of the patients, but it usually occurs as an isolated condition. ==Signs and symptoms== Children born with craniosynostosis have a distinct appearance, otherwise known as the phenotype. The features of the phenotype are determined by which particular suture is closed. The fusion of this suture causes a certain change in the shape of the skull; a deformity of the skull.〔 Virchow’s law dictates that, when premature suture closure occurs, growth of the skull typically is restricted perpendicularly to the fused suture and enhanced in a plane parallel to it, thus trying to provide space for the fast-growing brain. Using this law, the pattern of skull deformity in craniosynostosis often may be predicted.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Craniosynostosis」の詳細全文を読む スポンサード リンク
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