CDA Essentials 2019 • Volume 6 • Issue 4

33 Issue 4 | 2019 | S upporting Y our P ractice Test your radiograph interpretation skills by applying a systematic approach to the following case studies. Please refer to the Radiology Observation Checklist (see p. 39).  Observations • Mandibular and maxillary bony borders appear normal although the maxillary sinuses are a little smaller than I would expect. • There is a particularly good example of right and left inferior alveolar canals. • The internal bone structures are normal although I see something coronal to the unerupted maxillary right third molar (cannot see the follicle space here and there appears to be some radiopacity on the coronal aspect of this tooth). • There are some punctate areas of opacity above the maxillary left cuspid and second premolar/molar that I have decided are a variation of normal. • There may be caries on the mesial of the second molars in the maxilla but once again I think this is due to the arrangement of the maxillary soft tissue structures overlying this area. • I cannot clearly see the apices of the maxillary central incisors. • I have counted the teeth and the count is not normal. There are two missing incisors in the lower arch. I would, in light of the reason the patient presented, expose a periapical film that confirms this. • At this point, I would test the vitality of the maxillary central incisors and might also expose bitewings to check for caries that I might not be able to detect with an explorer. I might expose a periapical of the maxillary right third molar and the maxillary central incisors, pending vitality testing. At the same time, I would have a look at the left maxillary molar (and indeed other places) for the presence of calculus. Case Studies Landmarks of the Maxilla • Inferior orbital rim • Hard palate • Maxillary sinus boundaries • Maxillary sinus loculations • Maxillary sinus septae • Nasal septum • Canine fossa • Inferior nasal concha • Nasal cavity and floor • Nose • Nasolabial fold • Zygomatic bone and process • Pterygoid plates (look like triangular wings that stick out). • Hamular process • Intermaxillary suture • Incisive foramen • Nasopalatine canal • Anterior nasal spine Case 1: Patient presents prior for orthodontic management of crowding in the lower anterior. ( Figures 1a and 1b ) Fig. 1a