What likely happens if a film is placed in the mouth backwards with the foil next to the teeth?

When a film is placed in the mouth backwards with the foil side facing the teeth, the result is a characteristic herringbone pattern visible on the developed film. The foil side of dental film is designed to reflect and absorb X-rays in a specific way, usually containing a pattern that aids in proper film orientation during processing. If this foil side is facing the source of the X-rays (the teeth), it obstructs the X-rays from properly penetrating the film. This results in an insufficient exposure and creates a distinct pattern on the film.

This indicates that proper positioning is essential in radiography to ensure clear and diagnostic images. Such a mistake leads to the inability of the film to capture a proper image, hence the herringbone appearance which is a hallmark of improper film placement rather than normal development or overexposure.