Three techniques combining the shaping of calvarial and facial bone with onlay of methyl methacrylate are presented for use in the late treatment of unilateral coronal synostosis deformities. The procedures described are suggested as possible alternatives to extensive bone repositioning procedures. They have the advantage of being quicker and are therefore potentially safer operations. Acrylic is malleable and does not resorb; thus, permanent superior esthetic results may be achieved. The two most serious risks when using this technique are infection and limitation of growth. The risk of infection may be reduced by attaching the acrylic implant securely to surrounding bone, under sterile conditions, beneath well-vascularized skin. Growth limitation may be obviated by not placing acrylic across sutures in children with enlarging skulls.