The cementoenamel junction, frequently abbreviated as the CEJ, is an anatomical border identified on a tooth. It is the location where the enamel, which covers the anatomical crown of a tooth, and the cementum, which covers the anatomical root of a tooth, meet. Informally it is known as the neck of the tooth. 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.
Famous quotes containing the word junction:
“In order to get to East Russet you take the Vermont Central as far as Twitchell’s Falls and change there for Torpid River Junction, where a spur line takes you right into Gormley. At Gormley you are met by a buckboard which takes you back to Torpid River Junction again.”
—Robert Benchley (1889–1945)