Volume 2

The principles and practice of dentistry : including anatomy, physiology, pathology, therapeutics, dental surgery and mechanism / by Chapin A. Harris.

  • Harris, Chapin A. (Chapin Aaron), 1806-1860.
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: The principles and practice of dentistry : including anatomy, physiology, pathology, therapeutics, dental surgery and mechanism / by Chapin A. Harris. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    the lip. The laterals sometimes appear half an inch behind the arch, looking toward the roof of the mouth; at other times they come out in front of the arch, and at other times, again, they are turned obliquely or transversely across it. When any of the upper incisors are transversely inclined toward the interior of the mouth, the lower teeth at each occlusion of the jaws shut before them and become an obstacle to their adjustment. This form of irregularity often interferes with the lateral motion of the jaw. The lower incisors sometimes shut in this manner even when there is no inward deviation of the upper teeth. In this case the irregularity is owing to preternatural elongation of the lower jaw, which arises more frequently from some fault of dentition than from any con- genital defect in the jaw itself. Sometimes the superior maxillary arch is so much contracted, and the front teeth in consequence so prominent, that the upper lip is prevented from covering them. Cases of this kind, however, are rarely met with, but when they do occur it occasions much deformity of the face and forms a species of irregularity very diffi- cult to correct. From the same cause the lateral incisors are sometimes forced from the arch and appear behind the cen- trals and cuspids, the dental circle being filled with the other teeth. An abnormal promi- nence of the superior incisors may be either J Fig. 162. congenital or accidental, and when of the former origin it is almost invariably accompanied with a contracted arch, especially between the bicuspids of the right and left sides of the mouth, the incisors occupying a V-shaped posi- tion (Fig. 162). When this form of irregularity has an accidental origin, it is generally caused by a pernicious habit of thumb, tongue, or artificial nipple-sucking.* * Such a habit as thumb-sucking may be prevented by the application of some bitter substance, such as aloes, to the thumb, tying the arms close to the body at night, or the wearing of coarse, heavy gloves.