Principles and practice of operative dentistry . s. The average length of the inferior third molar is inch ( centi-metres), of the crown inch ( centimetre), and of the root inch( centimetre). THE DECIDUOUS TEETH. The deciduous teeth resemble in every way the same class of teeth in thepermanent set, with the exception of the first molars. They are, however,all much smaller than the permanent teeth, and are much whiter in color. The incisors and cuspids of both jaws are similar in form to the teethwhich succeed them. The cervix, however, is more constricted, and theena
Principles and practice of operative dentistry . s. The average length of the inferior third molar is inch ( centi-metres), of the crown inch ( centimetre), and of the root inch( centimetre). THE DECIDUOUS TEETH. The deciduous teeth resemble in every way the same class of teeth in thepermanent set, with the exception of the first molars. They are, however,all much smaller than the permanent teeth, and are much whiter in color. The incisors and cuspids of both jaws are similar in form to the teethwhich succeed them. The cervix, however, is more constricted, and theenamel ends more abruptly. The process of resorption of the roots of the 24 OPERATIVE DENTISTRY. deciduous teeth, wliich allows their crowns to fall away, begins in the cen-tral incisors at about the fourth year, and is completed at about the the lateral incisors this process begins at about the Jifth year, and iscompleted at about the eighth; while in the cuspids it is delayed until theninth year, and completed at the twelfth. Fig. The superior first deciduous molars are unlike the molars of thepermanent set in that the crown has but three lobes or cusps, mesial, distal,and lingual, which are divided by three developmental grooves, the mesial,distal, and buccal. The cusps converge towards the centre of the crown,giving the morsal surface the appearance of being smaller than the base ofthe crown. The cervix is constricted, while the enamel ends so abruptly atthe bucco-cervical margin as to form a prominent ridge, —the buccal ridge. Another distinctive feature is that the marginal ridges, triangularridges, and angles are more acute than in the permanent molars. Itsgreatest diameter is bucco-lingually. The superior second deciduous molars are larger than the first;the morsal surface is wider, and is surmounted by four cusps, and in otherways the prototype of the superior second permanent molar. The inferior deciduous molars are similar in general form and out-line
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectdentist, bookyear1920
