Which statement is true about a rectangular collimator compared to a circular collimator?

A rectangular collimator is designed to emit a beam of X-rays that is more precisely aligned with the area of interest, usually the dental arch, resulting in better image quality. One of the essential features of a rectangular collimator is that it restricts the beam more than a circular collimator. This restriction means that less radiation is directed toward the surrounding tissues, which can significantly reduce patient exposure to unnecessary radiation.

The shape of the beam emitted by a rectangular collimator is closely matched to the shape of the dental film or sensor, leading to improved coverage of the area being imaged while minimizing the exposure of adjacent structures. This is in stark contrast to a circular collimator, which tends to produce a wider beam that can expose more of the surrounding tissues, thus increasing the radiation dose to the patient.

Therefore, the combination of greater beam restriction and resultant reduction in patient exposure makes the statement about the rectangular collimator being more effective in these respects accurate. This highlights the importance of using a rectangular collimator in dental radiography for enhancing safety and image quality.