Journal of Medicine, Radiology, Pathology & Surgery ● Vol. 3:6 ● Nov-Dec 2016 1 Journal of Medicine, Radiology, Pathology & Surgery (2016), 3, 1–4 ORIGINAL ARTICLE The prevalence of ponticulus posticus among patients visiting JSS dental college - A radiographic study Karthikeya Patil, Mahima V. Guledgud, Athira Joshy, Poornima Chandran, Bharathi Penumatsa Department of Oral Medicine and Radiology, JSS Dental College and Hospital, JSS University, Mysuru, Karnataka, India Abstract Objective: The objective of this study was to estimate the prevalence of ponticulus posticus among patients visiting JSS Dental College. Methods: The occurrence of ponticulus posticus and its forms were assessed in 435 lateral cephalograms (LCs) by 2 independent examiners. Data obtained were subjected to statistical analysis using Chi-square and κ analysis. Results: The prevalence of ponticulus posticus among patients visiting JSS Dental College was found to be 31.8%, with no signifcant gender predilection. Conclusion: Ponticulus posticus has been found to be a common anomaly in the population of Mysuru. Due to its clinical signifcance during surgical intervention and the association with headaches and migraines, patients must be educated on the consequences of its presence. It must also be recorded as a fnding in the LC taken. Introduction Atlas is the frst cervical vertebra. Historically, named after a Greek myth, Atlas had to carry the weight of the sky on his shoulders for eternity. Similarly, even the atlas bears the weight of the entire head. It is a ring-shaped structure which comprises two lateral masses, transverse process as well as anterior and posterior arches. The two lateral masses consist of superior and inferior articular facets. The superior articular facet forms the atlanto-occipital joint whereas the inferior articular facet forms a lateral atlanto-axial plane joint. The anterior arch forms anterior 2/5 th while the posterior arch forms 3/5 th of the circumference of the atlantal ring. The superior surface of posterior arch consists of a groove through which the vertebral artery passes. A bridge of ossifcation named “ponticulus posticus” is seen on the vertebral groove which extends from the lateral mass to posterior arch of atlas. In Latin, ponticulus posticus means little bridge. [1] Ponticulus posticus is defned as an abnormal small bony bridge which is formed between the posterior portion of the superior articular process and the posterolateral part of the superior margin of the posterior arch of the atlas. It is also known as atlantal posterior foramen, sagittal foramen, a variant of Kimmerle’s anomaly, arcuate foramen, canalis vertebralis, upper retro-articular foramen, retro-articular vertebral artery ring, retro-articular canal, and retrocondilar vertebral artery ring. However, ponticulus posticus is the most accepted terminology. [2] Also called as the arcuate foramen, it is a bony arch on the atlas vertebra. It converts from a groove on the upper surface of the arcus posterior Atlantis to this foramen. It comprises signifcant anatomic structures, such as the vertebral artery and the suboccipital nerve. It is also attached to the atlanto-occipital membrane, which is linked to the dura. Hence, any compression to the vertebral artery or suboccipital nerve might cause symptoms such as migraine, vertigo, diplopia, shoulder pain, and neck pain. It has been reported that it could cause severe complications such as stroke and even death during insertion of C1 lateral mass screws due to the compression of vertebral artery. [3] With this background in mind, this study has been designed to estimate the prevalence of ponticulus posticus among patients visiting JSS Dental College. Materials and Methods This study was conducted in the Department of Oral Medicine and Radiology, JSS Dental College and Hospital, Mysuru. The archived lateral cephalograms (LCs) were recovered from the Keywords: Atlas, arcuate foramen, cervical vertebrae, ponticulus posticus Correspondence: Dr. Mahima V. Guledgud, Department of Oral Medicine and Radiology, JSS Dental College and Hospital, JSS University, Mysuru, Karnataka, India. E-mail: mahimamds@gmail.com Received: 14 october 16; Accepted: 28 November 16 doi: 10.15713/ins.jmrps.72