| Type | Description | Diagnosis | Incidences | Treatment |
| I | Instability | Reducible in dynamic X-rays | 52.2 | Posterior fusion procedure |
| II | Reducible | Reducible with skeletal traction under general anesthesia | 17.7 | Posterior fusion procedure |
| III | Irreducible | Irreducible with skeletal traction under general anesthesia | 29.6 | Transorally released anteriorly before posterior fusion |
| IV | Bony dislocations | Dislocation with bony anomalies that are visualized by reconstructive computed tomography scan | 0.4 | Transoral odontoidectomy |