Principles and practice of operative dentistry . iouserrors in the order of the genesis of thedental tissues, the most conspicuous ofwhich was the statement that the dentin First rudiments of a hair from the bulb WaS the first part of the folliclC tOhuman embryo of sixteen weeks, a, b, -k^ formed layers of cuticle ; m, m, cells of the rudi- ?-, ^ mentary hair ;i, hyaline envelope. It WaS UOt, hoWCVCr, Until the appear- ance of the treatise The Origin and For-mation of the Dental Follicle, by Legros and Magitot, that the Goodsirtheory was fully overthrown. The teaching of these authors has stoo
Principles and practice of operative dentistry . iouserrors in the order of the genesis of thedental tissues, the most conspicuous ofwhich was the statement that the dentin First rudiments of a hair from the bulb WaS the first part of the folliclC tOhuman embryo of sixteen weeks, a, b, -k^ formed layers of cuticle ; m, m, cells of the rudi- ?-, ^ mentary hair ;i, hyaline envelope. It WaS UOt, hoWCVCr, Until the appear- ance of the treatise The Origin and For-mation of the Dental Follicle, by Legros and Magitot, that the Goodsirtheory was fully overthrown. The teaching of these authors has stood the test of more than fortyyears of investigation without a single important statement having beensuccessfully controverted. Many facts, however, in relation to the develop-ment of the individual dental tissues have since been discovered and be-come a part of dental histology. We may, therefore, feel fairly certainthat in so far as the evolution of the dental follicle is concerned, we areresting upon a solid, scientific foundation. Fig. 28 OPERATIVE DEXTTRTRY. Before proceeding to a study of tlie accepted theory of the evolutionof the teeth let us briefly review the theory of Goodsir. Goodsir stated that at a very early period of foetal existence a depres-sion or groove, which he termed the _/;ri»uYire dental groove, was formed inthe mucous membrane along the entire circumference of the alveolar borderof both jaws; that from the bottom of this groove in each jaw papillaearose, ten in number, isolated and uncovered, which represented the futuredeciduous teeth ; that later these papillae became closed in by the approach-ing of the walls Of the groove and by the formation of separate septabetween the papillae, thus enclosing each of them in an independentfollicle. The permanent teeth, except the molars, were formed in like manner,within what he termed the secondary dental groove, which he located behindthe primitive dental groove, and formed from the inner or lingual lip o
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectdentist, bookyear1920
