Close-up of the mouth of a young person (aged about 8 years) showing gross decay of the top set of deciduous teeth (milk teeth). The adult mid- incisor (large tooth at top) is developing crookedly as a result of decay. Normally, when the time comes for the milk teeth to be shed (the 1st molar teeth are first, at between 6-7 years), the fang (lower portion of tooth) of the milk tooth is gradually absorbed & the growing adult tooth pushes out the milk tooth crown (ie top part of tooth). Interruptions in the fang absorption process & the loss of decidual crowns lead to crooked deformations of the adult teeth.