Abstract: A cranial deformation orthosis device for a head of an infant, including a rigid outer shell with an anterior portion detachably connected to a posterior portion. The anterior portion is shaped and configured to be donned on a forward portion of the head of the infant. The posterior portion is shaped and configured to be donned on an aft portion of the head of the infant. Each of the anterior portion and the posterior portion can include an inner surface having at least one lined zone having selectively positioned padding to prevent head growth and at least one unlined zone having a plurality of ventilation holes extended through the inner surface to an outer surface and selectively configured to allow growth or movement of the head to reshape the head of the infant.