Cementoenamel junction

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The CEJ is the more or less horizontal demarcation line that distinguishes the crown (A) of the tooth from root (B) of the tooth.

The cementoenamel junction, frequently abbreviated as the CEJ, is an anatomical landmark identified on a tooth. It is the location where the enamel, which covers the crown of a tooth, and the cementum, which covers the root of a tooth, meet. The border created by these two dental tissues has much significance as it is usually the location where the gingiva attaches to a healthy tooth by fibers called the gingival fibers.

Active recession of the gingiva reveals the cementoenamel junction in the mouth and is usually a sign of an unhealthy condition.

There exists a normal variation in the relationship of the cementum and the enamel at the cementoenamel junction. In about 60-65% of teeth, the cementum overlaps the enamel at the CEJ, while in about 30% of teeth, the cementum and enamel abut each other with no overlap. In only 5-10% of teeth, there is a space between the enamel and the cementum at which the underlying dentin is exposed.^[1]

[edit] References

^ Carranza, FA; Bernard, GW: The Tooth-Supporting Structures. In Newman, MG; Takei, HH; Carranza, FA; editors: Carranza’s Clinical Periodontology, 9th Edition. Philadelphia: W.B. Saunders Company, 2002. page 43.