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."Histology Course Notes: "Mature Enamel", New Jersey Dental School, 2003-2004, page 2. The DEJ is the interface of the enamel and the underlying

dentin Dentin () (American English) or dentine ( or ) (British English) ( la, substantia eburnea) is a calcified tissue of the body and, along with enamel, cementum, and pulp, is one of the four major components of teeth. It is usually covered by ena ...

. 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 Enamel lamellae are a type of hypomineralized structure in teeth that extend either from the dentinoenamel junction (DEJ) to the surface of the enamel, or vice versa. In essence, they are prominent linear enamel defects, but are of no clinical co ...

are often located. Enamel spindles are often confused with two other entities:

and

enamel tufts Enamel tufts are hypomineralized ribbon-like structures that run longitudinally to the tooth axis and extend from the dentinoenamel junction (DEJ) one fifth to a third into the enamel. They are called ‘‘tufts’’ due to their wavy look wit ...

. 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. Oral Biology Course Notes: "Dentine and Pulp", Otago University School of Dentistry, 2006-2007, pg 109.

References

Dental enamel Acquired tooth pathology {{dentistry-stub