Crown-of-thorns starfish Health Dictionary

The cuticular extension to fine pointed processes in the nematodes which have no lip; extension from the rim of the mouth called “external leaf-crown”, from the rim of the buccal capsule called “internal leaf-crown” as in Strongyloidea.... leaf-crown

An artificial replacement for the crown of a tooth that has become decayed, discoloured, or broken. A porcelain crown is usually used on front teeth, but back teeth require the greater strength of a crown made from gold or porcelain fused to metal.

A crown may be fitted by filing the natural tooth to form a peg and cementing the crown over the top. If the tooth is... crown, dental

n. 1. the part of a tooth normally visible in the mouth and usually covered by enamel. 2. a dental *restoration that covers most or all of the natural crown of a tooth. It may be made of porcelain (sometimes bonded to a metal substructure), gold, a combination of these, or less commonly other materials. Most crowns are like thimbles and are custom made to fit over a trimmed-down tooth. Preformed metal crowns may be used on primary teeth. A post crown is used to restore a tooth when insufficient of the natural crown remains. A post is inserted into the root and the missing centre of the tooth is built up as a core; over it is fitted a thimble-like crown to restore the natural shape of the tooth. *Root canal treatment is required before a post crown can be made.... crown

(CRL) the longest measurement of the fetus from end to end. Measurement of the CRL of the embryo in the first trimester has been shown to be the most accurate parameter for assessment of gestational age; the measurement is less accurate at the end of the first trimester because of fetal flexion.... crown–rump length