The fusion of this suture causes a certain change in the shape of the skull; a  deformity of the skull.Virchows 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. Scaphocephaly
An illustrative example of this phenomenon is scaphocephaly; the name providing a direct hint regarding the deformity of the skull. The literal meaning of the Greek derived word scaphocephaly is boat-head. A synonymous term is dolichocephaly (the prefix dolicho- means elongated).Premature sagittal suture closure restricts growth in a perpendicular plane, thus the head will not grow sideways and will remain narrow. This is best seen in a view standing above the child looking downward at the top of the head. Compensatory growth occurs forward at the coronal suture and backward at the lambdoid suture giving respectively a prominent forehead, called frontal bossing, and a prominent back portion of the head, called coning. This is the most common form of craniosynostosis. Trigonocephaly
Trigonocephaly is a result from the premature closure of the metopic suture. Using Virchows law again to predict the resulting deformity, this fusion will result in a narrow forehead, which is even further emphasized by ridging of the suture. Compensatory growth occurs at both the coronal sutures, thereby pushing the forehead forwards.
The points to look at are: eye position, eye symmetry and twisting of the nasal tip.The implications of the deformities that are seen are extensively discussed under phenotype. Syndromal craniosynostosis presents with a skull deformity as well as deformities affecting other parts of the body. Clinical examination should in any case include evaluation of the neck, spine, digits and toes. Medical imaging
Radiographic analysis by performing a computed axial tomographic scan is the gold standard for diagnosing craniosynostosis.Plain radiography of the skull may be sufficient for diagnosing a single suture craniosynostosis and should therefore be performed, but the diagnostic value is outweighed by that of the CT-scan. Not only can the sutures be identified more accurately, thus objectively demonstrating a fused suture, but also evaluation of the brain for structural abnormalities and excluding other causes of asymmetric growth are possible at the same time. In addition to this, CT-scanning can visualize the extent of skull deformity, thereby enabling the surgeon to start planning surgical reconstruction. Classification
There are several ways to classify craniosynostosis. For example, one can consider the number of closed sutures. If only one of the four sutures is prematurely closed (single suture craniosynostosis), the craniosynostosis is referred to as simple (or isolated). Whereas when two or more sutures are no longer open, the craniosynostosis is complex. A second classification scheme gives a clinical description of the resulting shape of the skull. This will be further discussed under phenotype. A third classification involves the presence or absence of an identified craniofacial syndrome.