Preformed nonalterable cranioplasty plate.

(a) Identification. A preformed nonalterable cranioplasty plate is a device that is implanted in a patient to repair a skull defect and is constructed of a material, e.g., stainless steel or vitallium, that cannot be altered or reshaped at the time of surgery without changing the chemical behavior of the material. (b) Classification. Class II (performance standards).