Hemifacial Hyperplasia, also known as hemifacial hypertrophy, is related to plagiocephaly and saethre-chotzen syndrome. An important gene associated with Hemifacial Hyperplasia is EFNB1 (Ephrin B1), and among its related pathways/superpathways are MAPK signaling pathway and Regulation of actin cytoskeleton. The drugs Acetylcholine and Cholinergic Agents have been mentioned in the context of this disorder. Affiliated tissues include bone and eye, and related phenotypes are dental malocclusion and facial asymmetry