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The anatomy, physiology, and diseases of the teeth
The anatomy physiology and diseases of the teeth Author:Thomas Bell Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: THE NUMBER, ARRANGEMENT, AND USES OF THE ADULT TEETH. The total number of teeth in the adult is thirty-two. Mr. Hunter1 speaks of considerable variations ... more »in this respect, arising as he says, from the occasional absence of the last grinder above or below, on one or both sides. There is, however, every reason to believe that this tooth is as constantly formed in the jaw as the others, and still more so than some to which I shall hereafter refer; but in the cases related by him, they probably had not yet made their appearance; as I have known them, in some instances, come through the gums as late as sixty and even seventy years of age. The teeth are arranged. in perfect uniformity in each jaw, eight on each side of the symphisis of the lower, and of the maxillary suture in the upper, those of one side exactly corresponding with those of the opposite. They are divided into four distinct classes ; namely, on each side of either jaw two incisores, one cuspidatus, two bi- cuspides, and three molares ; and these classes differ from each other in size, form, articulation, and use. OF THE INCISOKES." The incisores, or cutting-teeth, are situated in the anterior part of the jaw, forming the centre of themaxillary arch. Each has but one root. The body of an incisor, viewed laterally, is wedge-shaped ; it has an anterior and posterior flattened surface, which converge and form a cutting edge at the extremity. The anterior surface is somewhat convex, and perpendicular to the edge of the alveolus; the posterior more or less concave, but with the concavity interrupted by a projecting tubercle, and sloping forwards from the neck to the edge. In a front view, the edge is the broadest part: it decreases in breadth towards the neck, and continues tapering to the extremity of the root. Bu...« less