Skull Subsidence due to Periosteum Defect following Craniotomy in a Child.

We report a case of a 7-year-old child with a cranial deformity secondary to a craniotomy for an intracranial hematoma. He suffered from an acute epidural hematoma with a lineal fracture of the right temporal bone following a severe head injury. A large question mark-shaped skin flap with the periosteum and temporal muscle was created for a decompressive craniectomy; however, neither the acute epidural hematoma nor brain swelling was severe, and we performed a small craniotomy compared with the skin flap without a decompressive craniectomy. Eighteen months after the operation, he complained of skull deformity with a mild depression of the forehead. Axial and 3-dimensional computed tomography showed thinness and subsidence of the frontoparietal bone around the replaced bone flap, corresponding to the skin flap with the periosteum defect. We suggest that the periosteum defect following creation of the skin flap during surgery prevented normal growth of the skull, which caused the thinness and subsidence of the frontoparietal bone. Preservation and cooptation of the periosteum should be performed during neurological surgeries in babies and children to prevent skull deformity.