Bergmann's ossicle (ossiculum terminale persistens): a brief review and differentiation from other findings of the odontoid process.

PURPOSE: The purpose of this paper was to review the literature on Bergmann's ossicle and provide an overview on its development, etiology, and clinical presentation while also differentiating it from similar structural anomalies.
METHODS: A thorough review of the literature available on Bergmann's ossicle was performed.
RESULTS: Bergmann's ossicle, also referred to as ossiculum terminale persistens, was defined as a developmental anomaly of the odontoid process in which an ossification center that gives rise to the tip of the dens fails to fuse properly with the body of the axis.
CONCLUSION: Bergmann's ossicle is most often a benign condition, although it rarely may present with clinical symptoms such as neck pain and neurological signs. It may be associated with Down's syndrome and contribute to atlantoaxial instability.