Observations on the ultrastructure of the pericranium.

The pericranial membrane is of great interest in corrective and reconstructive procedures of the craniofacial region. A close look at its ultrastructure reveals that the outer layer is made up of loose areolar tissue and fibroblasts, and the inner layer of osteoblasts. A network of vessels near the inner layer accounts for the ability of the pericranial layer to be used as a flap based on a narrow pedicle.