Prevalence of Ponticulus Posticus (PP): A Cross-Sectional Study Using Digitized Lateral Cephalograms

Background: Ponticulus Posticus (PP) is described as an anomalous malformed bony bridge between the posterior portion of the superior articular process and the posterolateral portion of the superior margin of the posterior arch of the atlas. Many terms, including foramen sagittale, Kimmerle anomaly, foramen arcuale, and arcuate foramen, have been used in the literature to describe this anomaly. Presence of this anomaly can result in occlusion of vertebral artery which can lead to various head and neck symptoms. Objectives: The purpose of this study was to investigate the prevalence of PP in digitized lateral cephalograms. Methodology: The presence and types of PP were assessed in 212 digitized cephalograms. Presence of PP in 64 digitized lateral cephalograms was confirmed after using Adobe Photoshop® (for image enhancement). Results: PP was found in 30.18% (64 out of 212) subjects out of which 31.45% (39 out of 124) were females and 28.41% (25 out of 88) were males in an age group of 8 to 44 years (mean age = 26years, SD+/- 18years). Significant difference in number of PP cases in males and females was tested by Chi square test (p-value=0.003). Out of 64 patients, bilateral complete were 5 (7.81%), bilateral partial 40 (62.50%), unilateral complete 6 (9.37%), unilateral partial 12 (18.75%) and complete partial 1 (1.56%). Conclusion: Lateral cephalogram can act as a baseline screening tool for detection of PP. Detecting a PP in lateral cephalogram has an importance as it can prove beneficial for the diagnosis of head and neck symptoms and can be sent for further investigations. Also, digitized Lateral cephalograms had an edge over the conventional lateral cephalograms in detecting PP.