Background: Ponticulus posticus (PP) is an abnormal bony bridge on the atlas. It plays a significant role in patients undergoing C1 lateral mass screw procedure. Patients with cleft lip and palate (CLP) have higher risk than patients in general population for the appearance of cervical vertebral anomalies. The purpose of the this study was twofold: to determine the prevalence and characteristics of PP in patients with CLP, and to compare the findings with patients in general population using cone beam computed tomography.