Hypodontia is the condition at which the patient has missing teeth as a result of the failure of those teeth to develop (also called tooth agenesis). Hypodontia describes a situation where the patient is missing up to five permanent teeth, excluding the3rd molars. In primary dentition the maxilla is more affected, with the condition usually involving the maxillary lateral incisor. The cause of isolated missing teeth remains unclear, but the condition is believed to be associated with genetic or environmental factors during dental development. Hypodontia is often familial, and can also be associated with genetic disorders.