MJDF Part 1 - Membership of Joint Dental Faculties Dental Radiology and Imaging 1

Question 1

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?

Accepted Answer

Cone beam computed tomography (CBCT)

Answer

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.

Question 2

The paralleling technique for intraoral periapical radiography is preferred over the bisecting angle technique primarily because it:

Accepted Answer

Produces less geometric distortion of the tooth image

Answer

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.

Question 3

On a periapical radiograph, the lamina dura is correctly described as:

Accepted Answer

A radiopaque line of cortical bone lining the tooth socket

Answer

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.

Question 4

Which of the following BEST describes the radiographic appearance of an acute periapical abscess?

Accepted Answer

A diffuse radiolucent area at the root apex with poorly defined margins

Answer

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.

Question 5

The SI unit that expresses effective radiation dose — incorporating both radiation weighting and tissue weighting factors — is the:

Accepted Answer

Sievert (Sv)

Answer

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.

MJDF Part 1 Practice Test

MJDF Part 1 Practice Test

MJDF Part 1 - Membership of Joint Dental Faculties Dental Radiology and Imaging 1