Deciduous teeth important for the development of the child's speech, for the child's smile and play a role in chewing of food, although children who have had their primary teeth removed (usually as a result of Dental caries) can still eat and chew to a certain extent. In almost all European languages the primary teeth are called "baby teeth" or "milk teeth". In the United States and Canada, the term "baby teeth" is common. In some Asian countries they are referred to as "fall teeth" since they will eventually fall out. Various cultures have customs relating to the loss of deciduous teeth.
Dentition rare in theropod dinosaurs. The majority of dinosaurs had teeth that were similarly shaped throughout their jaws but varied in size. Dinosaur tooth shapes included cylindrical, peg-like, teardrop-shaped, leaf-like, diamond-shaped and blade-like. A dinosaur that has variety of tooth shapes is said to have heterodont dentition. An example of this are dinosaurs of the group Heterodontosauridae and the enigmatic early dinosaur, "Eoraptor". While most dinosaurs had a single row of teeth on each side of their jaws, others had dental batteries where teeth in the cheek region were fused together to form compound teeth. Individually these teeth were not suitable