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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 consequence. [1] These structures contain proteins, proteoglycans, and lipids.
Enamel hypocalcification is a defect of tooth enamel in which normal amounts of enamel are produced but are hypomineralized. [ 1 ] [ 2 ] In this defect the enamel is softer than normal. Some areas in enamel are hypocalcified: enamel spindles, enamel tufts, and enamel lamellae.
Enamel tufts should also not be confused with the similar enamel spindles. Enamel spindles are also linear defects, similar to lamellae, but they too can be found only at the dentinoenamel junction, similar to enamel tufts. This is because they are formed by entrapment of odontoblast processes between ameloblasts prior to and during amelogenesis.
Enamel spindles are often confused with two other entities: enamel lamellae and enamel 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 ...
Enamel is the hardest substance in the human body and contains the highest percentage of minerals (at 96%), [2] with water and organic material composing the rest. [3] The primary mineral is hydroxyapatite, which is a crystalline calcium phosphate. [4]
Produced during the second stage of enamel calcification, also known as the maturation stage, ameloblasts produce matrix and enamel at the rate of 4 micrometers per day; however every fourth day there is a change in development. Brownish lines, the striae of Retzius, develop as a result of a change in the growth process.
Lamellae can also describe the layers of atoms in the crystal lattices of materials such as metals. In surface anatomy, a lamella is a thin plate-like structure, often one amongst many lamellae very close to one another, with open space between. In chemical engineering, the term is used for devices such as filters and heat exchangers.
As the prisms in the enamel grow in thickness but not length, proteins (amelogenins and most non-amelogenins) are removed from the matrix to give more space for hydroxyapatite deposition - mature crystals are hexagonal and 25x75nm and can run the whole length of the enamel (up to 2.5mm). [3] The mineralising enamel becomes progressively less ...