[Ossiculum terminale (Bergmann). Differential diagnosis of an odontoid fracture of the Anderson I type].

We describe a case of the rare entity of a persistent ossicle on the top of the odontoid process. In a short review of the literature, we show developmental abnormalities of the odontoid process and its etiologies. The terminal ossicle (Bergmann) plays an important role in the differential diagnosis of a fracture of the odontoid process type I in adults using the classification of Anderson and D'Alonzo. If fracture and instability is excluded by plain radiographs, computed tomography and/or MRI, there is no need for additional therapy.