What is an extraoral film commonly referred to as?

An extraoral film is commonly referred to as a cassette because it is housed within a protective casing that holds the film and/or image receptor outside of the mouth during radiographic imaging. The cassette ensures that the film is properly positioned and shielded from light prior to exposure, allowing for the capture of images of the dental structures. Cassettes are typically used for panoramic or cephalometric radiographs, capturing a broad view of the mouth and jaw.

The other terms, while related to dental radiography, describe different components or products. A film holder is a device used to secure the film during an exposure but does not encompass the idea of housing a film for extraoral imaging. A film packet usually refers to the packaging containing intraoral films, which are used within the mouth, and a radiographic plate pertains to digital imaging systems that utilize imaging plates instead of traditional film. Therefore, in the context of extraoral imaging, "cassette" is the most accurate term.