ObjectivesWe calculated the prevalence of unsuspected retro-odontoid pseudotumor (ROP) as detected in cone beam computed tomography examination. Additionally, we examined patient age, sex, and presence and severity of cervical osteoarthritis (OA) as potential risk factors for ROP. Study DesignWe retrospectively analyzed de-identified CBCT scans of 455 patients from the Division of Oral and Maxillofacial Radiology at the University of Connecticut School of Dental Medicine. Identification of likely ROP was completed through a likelihood scoring scale (1-4) due to the lack of magnetic resonance images. Severity of cervical OA was determined using 5 osteoarthritic features. An ordinal logistic regression model was used to link potential risk factors to ROP. ResultsIn total, 18 patients (3.9%) were classified with probable [11 patients (2.4%)] or definite [7 patients (1.5%)] likely ROP. Older age and the presence and severity of OA were significantly associated with higher ROP scores (P<0.001). There was no significant association of ROP likelihood and patient sex (P=.637). An increase of one year of age increased the chance of a patient having a higher ROP likelihood score (P<0.001). The age-adjusted chance of having a more severe ROP increased with moderate to severe OA (P≤ 0.017). ConclusionsPrevalence of likely ROP increases with age and OA but is not associated with sex. Individuals with moderate or severe OA are more likely to have ROP. Statement of Clinical RelevancePatients with retro-odontoid pseudotumor may experience spinal cord compression, which can result in adverse health effects. Clinicians should be aware of the appearance of this lesion on CBCT scans and be knowledgeable of the associations with increasing age and osteoarthritis.