Cone beam computed tomography evaluation of ponticulus posticus in patients with cleft lip and palate: a retrospective radio-anatomic study

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. Materials and methods: Cone beam computed tomography images from 54 individuals who had undergone surgical repair of cleft lip and/or palate were ana-lysed as the study group. For comparison purposes a control group was randomly selected from 108 patients and matched with the CLP subjects. Results: Although 12 of the 54 (22.3%) patients with surgically repaired cleft lip and/or palate in the study group were identified to have PP, only 10 of the 108 (9.2%) patients in the control group had PP. The distribution of the presence of PP between the groups was statistically significant. Conclusions: Ponticulus posticus is an important anomaly and the presence of PP is important for patients. PP can have clinical significance in cervical spine surgery as this study has indicated that the likelihood of encountering PP is higher in patients with CLP. We suggest that PP should be taken into account prior to cervical vertebral surgery in patients with CLP.