Variations in the number of human permanent teeth: hypodontia

The partial absence of teeth germs is a hereditary or acquired congenital defect called hypodontia. The present report analyses and discusses hypodontia in permanent dentition on the basis of eleven clinical cases. In these, the hypodontia corresponded to mandibular central incisors, maxillary lateral incisors, maxillary canines, or maxillary and mandibular premolars and molars. All these cases of hypodontia were recorded by photographs of the oral cavity and/or by orthopantomographic studies. Together with the most-frequent types of hypodontia already reported in the literature, other unusual anomaliesthe lack of permanent canines, central incisors, or molars from both the maxillary and mandibular alveolar archeswere also detected.