Enamel spindles are "short, linear defects, found at the dentinoenamel junction (DEJ) and extend into theenamel, often being more prevalent at thecusp tips."[1] The DEJ is theinterface of the enamel and the underlyingdentin. Because they are "formed by entrapment ofodontoblast processes betweenameloblasts prior to and duringamelogenesis," they cannot be found at the enamel surface protruding inward, asenamel lamellae are often located.
Enamel spindles are often confused with two other entities:enamel lamellae andenamel tufts. Lamellae are linear enamel defects that extend from the surface of the enamel towards the DEJ, or vice versa. Enamel tufts are "small, branching defects that are found only at the DEJ, protruding into the enamel towards the enamel surface. Enamel spindles however, are in fact odontoblast processes that extend into the enamel.[1][2]
