Dentition and its derangements : a course of lectures delivered in the New York Medical College / by A. Jacobi.

  • Jacobi, A. (Abraham), 1830-1919.
Date:
1862
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Licence: Public Domain Mark

Credit: Dentition and its derangements : a course of lectures delivered in the New York Medical College / by A. Jacobi. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    its duration, the broader the furrows. Where the dis- ease returns at different periods, there are often furrows at different heights. Prof. Nessel is of the opinion that this abnormal condition is the effect of a severe disease, influ- encing as well the membrane outside the ivory, from which the enamel is deposited, as any other part of the organism, but does not depend on supposed abnormal acidity of the liquid contained in the dental sac. For if this were the cause we should expect the enamel to be defective all over below the line that was formed before the disease occurred. Whichever may be the cause, the anomaly cannot be removed. It would be aggravated by levelling the surface of the tooth, as extensive caries would be the immediate consequence. Another anomaly of the enamel is its discoloration. Brownish spots are the result of original development and composition. White spots are sometimes the effects of mechanical injuries producing local disorganization of the enamel. They consist of carbonate of lime instead of the phosphate and fluate, and from the fragility of the enamel at these places are apt to give rise to carious degeneration. The anomalies described cannot be mistaken for those irregularities of shape, such as furrows extending around a whole tooth, which are sometimes observed as family pecu- liarities. Such teeth are generally hard and solid; have very little tendency to become carious or wear prematurely, and differ widely from those soft and friable teeth which are due to the arrest of development in early infancy, by either hereditary predisposition, or accidentally contracted severe disease, or protracted mal-nutrition. To Mr. Hutchinson, of London, the profession is indebted for a number of good observations on the influence of here- ditary syphilis on the development of the teeth. Although the majority of his remarks relate to the permanent teeth, in which this hereditary malady exhibits itself best, there are some morbid symptoms in the temporary teeth belonging to this class. The temporary teeth, in hereditary syphilis, do not present any peculiarities of form; they are, how- ever, often of bad color, and are very liable to early decay. The central upper incisors are the first to suffer from caries, and often crumble away under its influence, within a year of their being cut The upper lateral incisors soon follow,