Enamel lamellae are a type of hypomineralized structure in teeth that extend either from the dentinoenamel

Dentin

Dentine is a calcified tissue of the body, and along with enamel, cementum, and pulp is one of the four major components of teeth. Usually, it is covered by enamel on the crown and cementum on the root and surrounds the entire pulp...

 junction (DEJ) to the surface of the enamel

Tooth enamel

Tooth enamel, along with dentin, cementum, and dental pulp is one of the four major tissues that make up the tooth in vertebrates. It is the hardest and most highly mineralized substance in the human body. Tooth enamel is also found in the dermal denticles of sharks...

, or vice versa. In essence, they are prominent linear enamel defects, but are of no clinical consequence. These structures contain protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

s, proteoglycan

Proteoglycan

Proteoglycans are proteins that are heavily glycosylated. The basic proteoglycan unit consists of a "core protein" with one or more covalently attached glycosaminoglycan chain. The point of attachment is a Ser residue to which the glycosaminoglycan is joined through a tetrasaccharide bridge...

s, and lipids.

Enamel lamellae should not be confused with two similar entities, enamel tufts

Enamel tufts

Enamel tufts are hypomineralized ribbon-like structures that run longitudinally to the tooth axis and extend from the dentinoenamel junction one fifth to a third into the enamel...

and enamel spindles

Enamel spindles

Enamel spindles are "short, linear defects, found at the dentinoenamel junction 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...

. Enamel tufts are small, branching defects that are found only at the DEJ, and so differ from lamellae which can be facing either direction and are strictly linear. Enamel spindles are also linear defects, but they too can be found only at the DEJ, because they are formed by entrapment of odontoblast

Odontoblast

In vertebrates, an odontoblast is a biological cell of neural crest origin that is part of the outer surface of the dental pulp, and whose biological function is dentinogenesis, which is the creation of dentin, the substance under the tooth enamel....

 processes between ameloblast

Ameloblast

Ameloblasts are cells, present only during tooth development, that deposit tooth enamel, the hard outermost layer of the tooth that forms the chewing surface....

s prior to and during amelogenesis

Amelogenesis

Amelogenesis is the formation of enamel on teeth and occurs during the crown stage of tooth development after dentinogenesis, which is the formation of dentine. Although dentine must be present for enamel to be formed, it is also true that ameloblasts must be present in order for dentinogenesis to...

.