Abnormal odontoid process morphology Duplicated odontoid process 2017-04-08T13:00:41Z The odontoid process forms from different ossification centers. Two centers normally appear on each side of the midline around the fifth or sixth month of fetal life. These two centers usually fuse by one year of age. When there is a delay in fusion, a longitudinal midline cleft may be seen. Duplication of the odontoid process most likely is the result of a lack of fusion of these two centers of ossification [from PMID:9367321]. The presence of two distinct odontoid processes. The odontoid process, also known as the dens of the axis, is a protuberance of the C2 vertebral body around which the first vertebra rotates.