The Determination of Surface Area of Living Children

Abstract

Three major methods for obtaining surface area have been applied to both the living body and the cadaver. The first is the geometric. The second is to cover the body with pieces of paper of known area or with a thin sheet of pliable but non-elastic substance which is later measured with a planimeter, by direct weighing or by weighing pieces of paper of the same area as the coating. The third method is the application of the surface integrator.

A variation of the coating method has been devised and applied to plaster of Paris casts of living children. 1 This use of the intermediate stage of a model permits a check on the reliability of the coating method through seriatim measurements.

The casts were obtained as follows: The child, after having his body coated with stearine and his hair covered with a close-fitting silk stocking top, was placed on his back in a thick layer of semisolid, quick-setting plaster of Paris with his legs apart, arms away from the sides and the fingers spread apart. The child was removed when the plaster was sufficiently set to hold its form. While the half-matrix cooled and hardened, its rough edges were smoothed, and its entire surface greased. Then the child was replaced in it and a thick layer of plaster of Paris spread over the body to the chin. This upper matrix was removed in several segments. To obtain the face, the neck segment was refitted leaving the rest of the body free, the closed eyes covered with vaseline and soft tissue paper, and then thick plaster spread over the face, leaving only the anterior nares uncovered. It is essential to grease the child thoroughly, to remove him before the plaster becomes uncomfortably hot, and to keep him sufficiently interested so that he will remain quiet voluntarily.