Quiz 6: Oral and Maxillofacial Radiology


D Early periodontitis is evidenced radiographically as a cupping-out or blunting especially in the anterior regions of the lamina dura at the crest of the interdental septum. Radiographically, crestal bone levels that are 2 mm apical to the adjacent cemento-enamel junction ( CEJ ) are indicative of periodontal bone loss. This client's radiographs indicate a blunted pattern in the mandibular anterior sextant with a crestal bone level 2 mm apical to the CEJ of these teeth.

B The se root s appear unnaturally shortened. Given the age of this client, beyond the formative years, and the closed root canal appearance , the cause seems to be external resorption. The presence of orthodontic wires indicates that force is being applied to teeth. While resorption is often idiopathic, physical resorption, indicated by the presence of a force on the tooth structure, seems evident in this case.

B The error that rendered this radiograph undiagnostic is horizontal overlapping , which resulted from not directing the x-ray beam precisely perpendicular through the teeth embrasures to the image receptor. Therefore , a shift in the horizontal angulation is the corrective action. On the radiograph, the overlap appears to get more severe in the posterior, or distal. Therefore , the corrective action is to shift the tube head so that the x -ray beam will intersect the image receptor from the distal.