Following a short review of the main aetiopathogenetic theories on dental agenesia, a personal statistical study of this pathology is reported. 1529 orthopantomographs of juveniles aged between 7 and 14 were examined. 79 cases of hypodentia were observed (5.2%), 32 in males (4.05%) and 47 in females (6.78%). The most interesting tooth was the second premolar with an incidence of 58.9% followed by the lateral incisor, with an incidence of 26.38%. This is in agreement with the international literature.