Dental Radiology and Imaging 1 Flashcards
6 cards from real MJDF practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Dental Radiology and Imaging 1 flashcards as text
Which imaging modality provides three-dimensional data and is MOST appropriate for assessing the relationship between an impacted mandibular third molar and the inferior alveolar canal?
Answer: Cone beam computed tomography (CBCT)
CBCT generates volumetric 3D data that allows precise assessment of the spatial relationship between an impacted third molar and the inferior alveolar canal in all planes, information that cannot be reliably obtained from 2D projections.
The paralleling technique for intraoral periapical radiography is preferred over the bisecting angle technique primarily because it:
Answer: Produces less geometric distortion of the tooth image
In the paralleling technique the receptor is placed parallel to the tooth's long axis with an increased target-to-receptor distance, minimising foreshortening and elongation and yielding a more dimensionally accurate image than the bisecting angle method.
On a periapical radiograph, the lamina dura is correctly described as:
Answer: A radiopaque line of cortical bone lining the tooth socket
The lamina dura is the compact cortical bone that lines the alveolar socket; it appears as a continuous radiopaque (white) line surrounding the root. Its absence or discontinuity can indicate periapical pathology or systemic bone disease.
Which of the following BEST describes the radiographic appearance of an acute periapical abscess?
Answer: A diffuse radiolucent area at the root apex with poorly defined margins
An acute periapical abscess reflects rapid, active bone destruction and typically presents as a diffuse, ill-defined radiolucency at the apex. A well-corticated border suggests a more chronic, organised lesion such as a radicular cyst or granuloma.
The SI unit that expresses effective radiation dose — incorporating both radiation weighting and tissue weighting factors — is the:
Answer: Sievert (Sv)
The Sievert (Sv) quantifies effective dose by accounting for the biological effectiveness of different radiation types (radiation weighting factor) and the differential radiosensitivity of various tissues (tissue weighting factor). The Gray measures absorbed energy per unit mass only.
Which of the following is a recognised inherent limitation of panoramic (orthopantomographic) radiography compared with intraoral periapical radiography?
Answer: It has lower spatial resolution, making fine detail assessment less reliable
Panoramic radiography sacrifices spatial resolution compared with intraoral films because of the longer object-to-receptor distance, larger receptor size, and geometric factors inherent in the rotating-beam technique. This makes it less suitable for detecting early interproximal caries or subtle periapical changes.