Which intraoral radiographic technique provides the most accurate, distortion-free view of tooth structure for posterior teeth?

• A. Bisected angle technique
• B. Paralleling technique
• C. Occlusal technique
• D. Vertical bitewing

Answer: (B)

Achieving an undistorted, true-to-size image depends on the geometry of how the tooth, film, and x-ray beam are aligned. The paralleling technique places the receptor parallel to the long axis of the tooth and directs the central ray perpendicular to both the tooth and the film. This alignment minimizes geometric distortion, so magnification is consistent and the detail is sharp. For posterior teeth, where the crowns are broader and accurate dimensions are essential for diagnosis and treatment planning, this setup provides the most faithful representation of tooth structure.

Other methods introduce angulation or viewing planes that can alter magnification and shape. The bisected angle technique relies on angulation that can produce foreshortening or elongation if not precise. The occlusal technique is intended for broad, topographic views rather than precise posterior tooth anatomy. Vertical bitewings change the projection compared to standard horizontal bitewings and can introduce distortion in tooth dimensions while focusing more on interproximal spaces and bone height.