The interdental plate refers to the bone-filled mesial-distal region between the teeth.[1] The word "interdental" is a combination of "inter" + "dental" (meaning "between the teeth") which originated in approximately 1870.[2] In paleobiology, the presence or absence of the interdental plate can determine the place of an animal in the evolutionary scale, and paleontologists use the interdental plate when trying to classify a new specimen. Thecodont reptiles and theropod dinosaur fossils have an interdental plate, whereas acrodont reptiles such as Sphenodontia do not.[3] Its presence in Archaeopteryx, an extinct avialan, resulted in the proposal of the dinosaur-bird connection.[citation needed]
The term can also be used to refer to a manufactured object designed to be placed or worn between the teeth. An example would be a dental prosthetic designed to prevent contact between the teeth while the wearer is sleeping.[4] A 2004 patent relates to an apparatus designed to measure the pressure exerted by the tongue as a means of diagnosing ailments related to swallowing.[5]