Enamel spindles

Enamel spindles are "short, linear defects, found at the dentinoenamel junction (DEJ) and extend into the enamel, often being more prevalent at the cusp tips." The DEJ is the interface of the enamel and the underlying dentin. Because they are "formed by entrapment of odontoblast processes between ameloblasts prior to and during amelogenesis," they cannot be found at the enamel surface protruding inward, as enamel lamellae are often located.