e-ISSN: 2320-7949 p-ISSN: 2322-0090 36 RRJDS | Volume 5 | Issue 3 | September, 2017 Research & Reviews: Journal of Dental Sciences INTRODUCTION Panoramic imaging is also called pan tomography. It is a technique for producing a single image of facial structures that includes both maxillary and mandibular dental arches and their supporting structures [1] . certain peculiarities of the panoramic system result in unique projection of many anatomic structures in the image [2] . This produces numerous anatomic relationships in the image that are not found in any other kind of radiographic projection. The word panoramic radiography which means an unimpeded view of an area in every required direction [3] . Placement of mandibular endosseous implants can be problematic especially in the area of neurovascular bundles. The complications, such as altered sensation, numbness and pain, often occurred if these vital structures, such as inferior alveolar nerve (IAN) and mental foramen (Figure 1), incisive foramen (Figure 1) if they are not properly identifed. Hence, it is critical to determine the location and confguration of the mandibular canal (MC) and related anatomical structures so these types of damages can be minimized [4] . The mental canal (Figure 2) which rises from the mandibular canal and runs outward, upward and backward to open at the mental foramen has an anatomical variation called anterior loop (Figure 3). Prevalence of the anterior loop is quite variable in literature, occurring in between the range of 28% and 71% [5] . While examining the posterior wall of the sinus, we also look at the zygomatic process of the maxilla and pterygomaxillary fssure (Figure 2). These are thin radiopaque lines produced by these structures which run roughly parallel to the posterior wall of the maxillary sinus, and may be confused with it. Destructive disease affecting the maxillary sinus mayerode the posterior wall, which can be easily missed if all three lines are not identifed [6] . Visibility of Maxillary and Mandibular Anatomical Landmarks in Digital Panoramic Radiographs: A Retrospective Study Srisha Basappa, Smitha JD, Nishath Khanum*, Santosh Kanwar, Mahesh MS and Archana Patil Department of Oral Medicine and Radiology, Farooqia Dental College and Hospital, Mysore, India Research Article Received: 23/08/2017 Accepted: 29/08/2017 Published: 06/09/2017 *For Correspondence Nishath Khanum, Department of Oral Medicine and Radiology, Farooqia Dental College and Hospital, Mysore, India, Tel: 0821-2494890. E-mail: nishkhan7@yahoo.co.in Keywords: Mandibular, Radiograph, Tomography ABSTRACT Aims: To determine frequency, visibility and gender variation of pterygomaxillary fssure, incisive foramen, mental foramen, mandibular canal, anterior loop of mental nerveand elongated styloid process in different age groups. Materials and methods: The study was conducted in 200 ortopantomographs (OPG) which was taken using digital Sirona machine. The maxillary and mandibular anatomical land marks were analysed and scores were recorded. Results: A total of 200 OPGs were analysed. Pterygomaxillary fssure was visible in 58%. Incisive foramen showed good visibility in 25%. Mental foramen showed good visibility in 77%, mandibular canal was visible in 74% on OPG. Anterior looping was perceptible in 20% of cases. Elongated styloid process was visible in 25% of cases. Gender does not exert effect on the appearance of the anatomical structures and the study also revealed signifcant statistical difference between visibilities of anterior looping, which was better in males as compared to females. Conclusion: Orthopantomographs provided suffcient information of mental foramen and mandibular canal and are reliable to visualise pterygomaxillary fssure. But for better visualization, detection of structures like incisive foramen anterior looping and elongated styloid process for performing surgery, for implant placement in this region it may require to be replaced with three-dimensional imaging like cone-beam computed tomography.