cavity

Each participant underwent dental exams to determine whether they had gum disease, cavities, or both.

These tiny cavities act as miniature light traps, causing light to reflect back and forth and produce vivid colors.

In optics, a similar process occurs when two mirrors trap light between them, creating a standing wave inside what scientists call a cavity.

Pink-tinted cavities - capillaries of the tooth that send blood into the teeth - would confirm what officers had suspected, that Karen's death had been caused by violence.

Which means the movie winds up feeling like the mouthful of cavities Jeffrey gets from living on M&Ms.