Deciduous teeth first teeth seen in the mouth are the mandibular centrals and the last are the maxillary second molars. The primary teeth are made up of central incisors, lateral incisors, canines, first molars, and secondary molars; there is one in each quadrant, making a total of four of each tooth. All of these are gradually replaced with a permanent counterpart except for the primary first and second molars; they are replaced by premolars. The replacement of primary teeth begins around age six, when the permanent teeth start to appear in the mouth, resulting in mixed dentition. The erupting permanent teeth cause
Deciduous teeth be thrown straight down to the ground and lower teeth straight up into the air or onto the roof of a house; the idea is that incoming teeth will grow in straight. Some parts of China follow a similar tradition by throwing the teeth from the lower jaw onto the roof and burying the teeth from the upper jaw underground, as a symbol of urging the permanent teeth to grow faster towards the right direction. The Sri Lankan tradition is to throw the baby teeth onto the roof or a tree in the presence of a squirrel ("Funambulus palmarum"). The