Cheek teeth across the globe. Cheek teeth Cheek teeth or post-canines comprise the molar and premolar teeth in mammals. Cheek teeth are multicuspidate (having many folds or tubercles). Mammals have multicuspidate molars (three in placentals, four in marsupials, in each jaw quadrant) and premolars situated between canines and molars whose shape and number varies considerably among particular groups. Cheek teeth are sometimes separated from the incisors by a gap called a diastema. Cheek teeth in reptiles are much simpler as compared to mammals. Apart from helping grind the food to properly reduce the size of substrates for stomach enzymes, their minor role
Hinge teeth sides). This arrangement is characteristic of the venus clams (Veneridae), the cockles (Cardiidae) and several other important groups. In the "desmodont" hinge, also known as an "asthenodont" hinge, the hinge consists of a large ligamentous resilifer (or chondrophore) which replaces the cardinal teeth, as in the soft-shell clams (Myidae). The "anodont" hinge is characterized by a strong ligament (or a series of transverse ligamental grooves as in the "Isognomonidae"), however, true teeth are absent in adults as is the case in the pen shells (Pinnidae), tree oysters (Isognomonidae), the pearl oysters (Pteriidae), and some freshwater mussels such as the genus