The dentition of 116 patients with a non-syndromic form of oligodontia was characterized. For this purpose use was made of the so-called Tooth Agenesis Code (TAC), with which the various patterns of missing teeth can be indicated with a unique number. Oligodontia can present itself in very diverse ways. Only 3 patterns were seen (2 times) among these 116 patients. Considered per quadrant, in the upper jaw, on the one hand, agenesis of both premolars and the lateral incisor was most common and, on the other, the absence of all teeth except the central incisor and the first molar. In the lower jaw, agenesis of the second or of both premolars was most common. Evaluating treatments and formulating standards of restoration in the treatment of patients with severe oligodontia are methodological challenges. Homogeneous, comparable sub-groups of patients of any size are difficult to construct due to the low prevalence of severe oligodontia and the diversity of patterns of agenesis when the whole mouth is taken into consideration.