[9] Premature sagittal suture closure restricts growth in a perpendicular plane, thus the head will not grow sideways and will remain narrow.

[10][11] Children born with unilateral coronal synostosis develop due to compensatory mechanisms a skew head; a plagiocephaly.

[10][11] An increase in growth at the metopic and the sagittal suture accounts for the parallel plane and will result in bulging at the temporal fossa.

[12] Assessment of the skull from a frontal view will show asymmetrical features of the face, including a displacement of the chin point of the jaw and a deviation of the tip of the nose.

[10][11] The chin point is located more to the contralateral side of the head, due to the ipsilateral forward displacement of the temporomandibular joint together with the ear.

Findings include elevation of the intracranial pressure; obstructive sleep apnea (OSA); abnormalities in the skull base and neurobehavioral impairment.

[11] When the ICP is elevated the following symptomes may occur: vomiting, visual disturbance, bulging of the anterior fontanel, altered mental status, papilledema and headache.

[5] A theory regarding the involvement of OSA as a causative agent for elevated intracranial pressure suggests an association with the auto-regulation of blood flow in the brain.

[36] Neurobehavioural impairment includes problems with attention and planning, processing speed, visual spatial skills, language, reading and spelling.

[10] It has been suggested that these problems are caused by a primary malformation of the brain, rather than being a consequence of the growth restriction of the skull and elevated intracranial pressure.

Some evidence for this statement has been provided by studies using computed tomographic (CT) scans and magnetic resonance imaging (MRI) to identify differences between the structures of the brains of healthy children and those affected with craniosynostosis.

[10] Advances in the fields of molecular biology and genetics, as well as the use of animal models have been of great importance in expanding our knowledge of suture fusion.

[3] Research in animal models has led to the idea that the dura mater plays an important role in determining closure or patency of the suture.

[3] Detailed work by Sahar et al at Stanford University using chip microarray and quantitative real-time PCR on samples of suture junctions during development, reveals cranial suture fusion in mammals is a tightly orchestrated expression of genes in specific temporal order, leading to endochondral ossification.

[37] Sox9, Slug, Osteocalcin, growth factors and multiple Collagen type genes are upregulated in this coordinated and specific sequence (see Figure).

[38] Multiple potential causes of premature suture closure have been identified, such as the several genetic mutations that are associated with syndromic craniosynostosis.

[39] It has been found by Jacob et al. that constraint inside the womb is associated with decreased expression of Indian hedgehog protein and noggin.

[47] This finding is highly suggestive of a genetic cause, which has possibly been found in the fibroblast growth factor receptor 3 (FGFR3) and TWIST genes.

[6] The transcription factor gene TWIST is thought to decrease the function of FGFR, thus also indirectly regulating fetal bone growth.

[50][51] Craniosynostosis is therefore likely the result of a disturbance in the fine balance that regulates the multiplication and maturation of the precursor bone cells in the cranial sutures.

[3] The fibrous sutures specifically allow the deformation of the skull during birth[3] and absorb mechanical forces during childhood[6] They also allow the necessary expansion during brain growth.

[55] Medical history should in any case include questions about risk factors during pregnancy, the familial rate and the presence of symptoms of elevated intracranial pressure (ICP).

[58][59] Plain radiography of the skull may be sufficient for diagnosing a single suture craniosynostosis and should therefore be performed,[58][59] but the diagnostic value is outweighed by that of the CT-scan.

[60] In addition to this, CT-scanning can visualize the extent of skull deformity, thereby enabling the surgeon to start planning surgical reconstruction.

[62] There are a few basic elements involved in surgical intervention which is aimed at normalization of the cranial vault: The prevention of post-surgical complications, including those mentioned above, plays an important role in discussions over the timing of potential surgery.

[citation needed] It is important that families seek out a Pediatric Craniofacial Physician who has experience with craniosynostosis for proper diagnosis, surgical care, and followup.

[54] The matter of which procedure is superior is still heavily debated amongst the surgeons treating this condition,[54] however it is generally agreed upon that the cephalic index should be used to assess the efficacy of the preferred surgical intervention.

[54] Retrospective analysis has given an indication that the use of total cranial vault remodelling provides children with a better cephalic index than does the extended strip craniectomy.

[11] The treatment of unilateral coronal synostosis is typically performed in two parts: the forward advancement of the supraorbital bar and the correction of the orbital asymmetry.

[54] A two-dimensional sagittal image is used to pre-operatively determine the extent of movement, which can vary between seven and fifteen millimetres depending on the severity of the deformity.