The following conditions of the head are causes for rejection of membership:

(1) Abnormalities which are apparently temporary in character resulting from recent injuries until a period of three months has elapsed. These include severe contusions and other wounds of the scalp and cerebral concussion;

(2) Deformities of the skull in the nature of depressions, exostoses, etc., of a degree which would prevent the individual from the wearing of a gas mask or headgear;

(3) Deformities of the skull of any degree associated with evidence of disease of the brain, spinal cord, or peripheral nerves;

(4) Depressed fractures near central sulcus with or without convulsive seizures;

(5) Loss or congenital absence of the bony substance of the skull, except that the examiner may find individuals acceptable when—

(a) The area does not exceed 2.5 centimeters square, and does not overlie the motor cortex or a dural sinus;

(b) There is no evidence of alteration of brain function in any of its several spheres (intelligence, judgment, perception, behavior, motor control, sensory function, etc.);

(c) There is no evidence of bone degeneration, disease, or other complications of such a defect;

(6) Unsightly deformities, such as large birthmarks, large hairy moles, extensive scars, and mutilations due to injuries or surgical operations; ulcerational fistulae, atrophy, or paralysis of part of the face or neck.