Deciduous teeth Middle Eastern countries (including Iraq, Jordan, Egypt and Sudan). It may originate in a pre-Islamic offering and certainly dates back to at least the 13th century, when Izz bin Hibat Allah Al Hadid mentions it. In premodern Britain, lost teeth were commonly burnt to destroy them. This was partly for religious reasons connected with the Last Judgement and partly for fear of what might happen if an animal got them. A rhyme might be said as a blessing: <poem style="margin-left:2em"> "Old tooth, new tooth" "Pray God send me a new tooth" </poem> Deciduous teeth Deciduous teeth, commonly known as milk
Dentition on the skin of basal Gnathostomes (i.e. Chondrichtyans). Since the origin of teeth some 450mya, the vertebrate dentition has diversified within the reptiles, amphibians, and fish: however most of these groups continue to possess a long row of pointed or sharp-sided, undifferentiated teeth ("homodont") that are completely replaceable. The mammalian pattern is significantly different. The teeth in the upper and lower jaws in mammals have evolved a close-fitting relationship such that they operate together as a unit. "They "occlude", that is, the chewing surfaces of the teeth are so constructed that the upper and lower teeth are able to fit