= 4 cm + 4 cm + 4 cm = 12 cm. A square and an equilateral triangle are both examples of regular polygons. Another method for finding the perimeter of a regular polygon is to multiply the number of sides by the length of one side. Let's revisit Examples 3 and 4 using this second method.
Cranial vault expansion is a surgery to correct and reduce the risk of future craniofacial deformities caused by a condition called pediatric craniostenosis. Pediatric craniosynstenosis is the name of a condition where pediatric sutures, which are bony plates in an infantâs head, fuse together too early.
As the cranial vault is essentially a closed, fixed bony box, its volume is constant. This volume is described by the Monro-Kellie doctrine, proposed in the early part of the 19th century: v.intracranial (constant) = v.brain + v.CSF + v.blood + v.mass lesion. As all these components are fluids, and non-compressible, once the cranial vault is filled, it's pressure rises dramatically.