Dentition is the development of teeth and their arrangement in the mouth. All mammals except the monotremes, the xenarthrans, the pangolins, and the cetaceans have up to four distinct types of teeth, with a maximum number for each. These are the incisor (cutting), the canine, the premolar, and the molar (grinding). Mammals that have distinct types of teeth are heterodont; others are homodont. The number of teeth of each type is written as a dental formula for one side of the mouth, with the upp… (More on Dentition)