. The Dental cosmos. re arrangedwith their cutting edges forming a continuous 668 THE DENTAL COSMOS. curved line from cuspid to cuspid, and thisline is continued over the cusps of the cuspidsand the buccal cusps of the bicuspids andmolars to the distal surfaces of the thirdmolars. From the first bicuspid to the thirdmolar, the lingual cusps of these teeth form asecond line of elevations. Between these two,the lingual and buccal cusps, there is a con-tinuous, but irregular, valley or sulcus. Fig. 1 is an illustration from a typicalnormal skull. The general shape, size, very obtuse (see Fig. 2).
. The Dental cosmos. re arrangedwith their cutting edges forming a continuous 668 THE DENTAL COSMOS. curved line from cuspid to cuspid, and thisline is continued over the cusps of the cuspidsand the buccal cusps of the bicuspids andmolars to the distal surfaces of the thirdmolars. From the first bicuspid to the thirdmolar, the lingual cusps of these teeth form asecond line of elevations. Between these two,the lingual and buccal cusps, there is a con-tinuous, but irregular, valley or sulcus. Fig. 1 is an illustration from a typicalnormal skull. The general shape, size, very obtuse (see Fig. 2). As the boneincreases in size the alveolar process de-velops, and the permanent teeth takethe place of the deciduous ones; the man-dible, being forced apart from the max-illa, causes this angle to lose its markedobtuseness (see Fig. 3). forming almosta right angle in adult life. As the teethwear away, or when they are extracted,the alveolar process is resorbed, the hori-zontal planes of the jaws approach each Fig. Skull of a fully developed embryo cut vertically through the first deciduous molars, theorbit, and nasal chambers. (Crver.) and position of this maxilla stand indefinite relationship with the skull. (SeeFig. 29, a.) MANDIBLE. The mandible is made up of the bodyand the ramus, the teeth, and the alve-olar process. The teeth and the alveolarprocess are placed on the upper portionof the body of the bone. At the upperand posterior end of the ramus is thecondyloid process, which articulates withthe glenoid fossa of the temporal angle of the mandible at birth is other more closely, and the angle againbecomes obtuse. (See Fig. 4.) Whenthe jaws can be kept apart with the fullcomplement of teeth and allowed to per-form their duties, no such changes occurin the angle. Fig. 5 is an illustrationof a mandible of a typical Caucasianskull about twenty-five years of age. Themental process gives prominence to thechin and lower part of the face. Theteeth are set back, the t
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Keywords: ., bookcentury1900, bookdecade1910, bookiddent, booksubjectdentistry
