Notches in animal teeth - artifical or natural/pathological?

Animal teeth with notches at the root are sometimes found in archeological contexts. The notches are often considered to have been artificially engraved and the teeth regarded as artifacts of personal adornment. However, one has to differentiate between teeth with engravings at the apex or in the middle of the root, where cut marks are to be seen in the notches (these represent adornment) and those with notches at the collum of the tooth, where the dentine appears to be polished. The latter is a pathological phenomenon of natural origin called a "wedge-shaped defect." Examples of these two distinct types of notches are given, and different theories for the development of wedge-shaped defects are discussed.