The present invention is a simple, adaptable orthotic device that can correct and/or prevent deformational posterior plagiocephaly, especially if used before the infant is 4 months of age. The manufactured article provides an anatomically correcting, adjustable, concave-shaped resting surface for an infant's head in a manner that effectively eliminates uneven pressure on the infant's occiput. The orthotic device has a module design which permits easy adjustments of the devices' head cavity to accommodate differences in individual infant head size and shape, thereby providing the infant's head with a custom fit. Also, as the infant continues to grow in size, the adjustable head cavity and torso recess features of the orthotic device allow the contoured spatial volume and dimensions of the molded supporting surfaces to expand as the infant's calvaria grow, and thereby facilitate a progressive, normalization and rounding of the infant's occiput.