The odontoid process: a comprehensive review of its anatomy, embryology, and variations

The odontoid process is a critical component of the cranio-cervical junction. Therefore, clinicians who diagnose, treat, or operate this region need a strong background in regard to the embryology, anatomy, and anatomical variations that may be seen for the odontoid process. A literature review was performed, using standard search engines, to explore the morphology, embryology, and anatomical variants of the odontoid process. A sound understanding of the development of the odontoid process, both in normal and in variant forms, as well as its phenotypical morphology is a prerequisite for the diagnosis and treatment of patients presenting with disorders affecting the cranio-cervical spine.