What causes overlapping of inter-proximal contacts on dental radiographs?

Overlapping of inter-proximal contacts on dental radiographs primarily occurs due to incorrect horizontal angulation. When the X-ray beam is not directed parallel to the plane of the teeth, it can lead to distortion and superimposition of adjacent tooth contacts on the radiograph. Proper horizontal angulation ensures that the X-ray beam is directed straight through the contacts of the teeth, allowing for an accurate representation without overlap. This is essential for proper diagnosis as overlapping can obscure potential dental caries and other issues, making it difficult for practitioners to evaluate dental health accurately.

In contrast, incorrect vertical angulation can lead to foreshortening or elongation of dental images, which affects the overall image morphology but does not specifically cause inter-proximal overlapping. Similarly, incorrect positioning of the patient may induce various distortions, but it is not directly linked to the overlaps of contacts. Additionally, inadequate film processing might result in poor quality images overall but does not specifically target the issue of overlapping contacts, as this is more about beam direction than film quality.