Proximal caries on x-rays typically appear how in relation to their clinical size?

Proximal caries, which refers to decay located between teeth, often appear smaller on x-rays than they are when clinically observed. This discrepancy arises because x-rays provide a two-dimensional representation of three-dimensional structures. As a result, advanced decay can occupy a significant volume in reality but may only register as a small shadow or radiolucency on the film.

The nature of caries development also plays a role; initial carious lesions can begin small and become more extensive before they are noticeable to the naked eye. By the time a clinician sees the lesion clinically, it may have progressed more significantly than what is visible radiographically. Therefore, when interpreting x-rays, it is essential to consider that the severity of proximal caries can often be underestimated based on their appearance in radiographic images.

In contrast, clinically observable caries take into account the totality of its impact on the tooth structure, reflecting its true size and extent that may not be fully represented on x-ray films.