Some homeobox genes, such as MSX1, MSX2,PAZ 9 and TGFA, have an important role in the development of dentition and incraniofacial morphogenesis.7 Moreover, hypodontia of permanent maxillarylateral incisors or other teeth are often associated with other tooth anomalies inthe same patient: microdontia, delayed eruption, ectopic eruption, and others. The gene discussed is MSX1; the disease is Microdontia.