A text-book of dental histology and embryology, including laboratory directions . «H 4 The dental ridge and denal lamina. The Tooth Germ.âThe tooth germ is composed of theenamel organ, made up of the outer tunic, the inner tunic,and the stellate reticulum, covering the dental papilla?.From the base of the papilla? fibrous tissue develops, growingupward around the entire tooth germ and enclosing it in adefinite wall or sac of fibrous tissue. This is known as thedental follicle, or the follicle wall. The Dental Follicle.âThis term has been used to indicatenot simply the connective-tissue wall, b
A text-book of dental histology and embryology, including laboratory directions . «H 4 The dental ridge and denal lamina. The Tooth Germ.âThe tooth germ is composed of theenamel organ, made up of the outer tunic, the inner tunic,and the stellate reticulum, covering the dental papilla?.From the base of the papilla? fibrous tissue develops, growingupward around the entire tooth germ and enclosing it in adefinite wall or sac of fibrous tissue. This is known as thedental follicle, or the follicle wall. The Dental Follicle.âThis term has been used to indicatenot simply the connective-tissue wall, but all of the structure TOOTH GERMS OF THE PERMANENT TOOTH 365 nL~ enclosed in it. This use of the term, however, is confusing,and the term should be confined to the fibrous sac. By theend of the twelfth week the follicle wall has grown up so asto enclose the enamel organ, and the epithelial cord whichhas connected it with the surface is broken. Tooth Germs of the Permanent Tooth.âBefore the epithelialcord is broken, from some point on the lingual surface of the Fig. 279. A section through the mandibular arch: E, enamel organ; D, beginning of thedental papilla; B, bone; F, fold from the side of the mandible to the base of thetongue covering the beginning of the sublingual gland; T, tongue. outer tunic or along the cord a bud of epithelial cells growsout and turns down into the mesoderm, passing over thefollicle wall (Fig. 283). This continues to grow downwarduntil it has reached the position below and to the lingualof the tooth germ for the temporary tooth, where it developsinto the enamel organ for the corresponding permanenttooth. It goes through the same changes of form as hasbeen seen in the temporary teeth. 36G THE DEVELOPMENT OF THE TOOTH GERM Beginning of Calcification.âAbout the sixteenth weekthe tooth germs of all the temporary teeth have been com-pletely enclosed in their follicles and the enamel organ for Fig. 280
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectteeth, bookyear1912
