In dentistry, 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 the 3rd molars. Missing third molars occur in 9-30% of studied populations. In primary dentition the maxilla is more affected, with the condition usually involving the maxillary lateral incisor.