Radiographic Technique — ORE Part 1 MCQ

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EasyRadiology & ImagingRadiographic TechniqueORE Part 1

Which feature is an advantage of the bisecting-angle technique compared with the paralleling technique for an intraoral periapical radiograph?

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Correct answer: E — It permits imaging when anatomy prevents parallel receptor placement

Explanation lettering: D = shown as A · E = shown as B · B = shown as D · A = shown as E

A is correct. The bisecting-angle technique is useful when anatomy, particularly a shallow palatal vault, makes it impracticable to place the receptor parallel to the tooth's long axis. Long-cone paralleling is the usual preferred technique because its geometry generally gives less magnification and distortion and permits more reproducible root-length assessment. Thus, B and C describe relative advantages of paralleling, not bisecting-angle imaging. D is incorrect because bisecting-angle imaging is an alternative when paralleling cannot be achieved, rather than the routine preference. E is incorrect because the technique does not inherently require a lower radiation exposure; exposure factors should be optimised to produce a diagnostic image at the lowest appropriate dose.

Reference: Yen M, Yeung AWK. The Performance of Paralleling Technique and Bisecting Angle Technique for Taking Periapical Radiographs: A Systematic Review. Dent J (Basel). 2023;11(7):155. https://pubmed.ncbi.nlm.nih.gov/37504221/