A system of dental surgery / by the late Sir John Tomes.

  • John Tomes
Date:
1897
Catalogue details

Licence: Public Domain Mark

Credit: A system of dental surgery / by the late Sir John Tomes. Source: Wellcome Collection.

    80/764 page 68
    Thirty-two being the number of a normal series of permanent teeth, any deviation, whether it be in an excess or in a diminu- tion of that number, will constitute an irregularity ; in other words, there may be irregularity from there being too many or too few teeth. Each of these forms of departure from the normal series is far from rare ; but of the two forms it is perhaps more common to find that in which the teeth are in excess, one or two supernumerary teeth, as they are termed, being present. Supernumerary teeth may spring up during the second dentition in any part of the alveolar arch, and either may resemble those of special members of the normal sei'ies, or may deviate from any of the recognised forms, and assume a some- what irregular conical shape, sufficiently characteristic in itself to enable them to be at once recognised as supernumerary teeth (i). Several cases, occurring either in the first or the second dentition, have come under my own observation in which five equally well-formed incisors occurred in the lower jaw. In neither case was it possible to determine, from an examina- tion of the crowns of the teeth, which was the extra tooth. A third lateral incisor in the upper jaw, undistinguishable from the normal tooth, I have seen in one case only. Instances of a third caniue or of a fifth bicuspid, and also of supplemental molar teeth (the form of the additional tooth being perfectly normal), have been seen even in lower races of mankind, in a gorilla, and in a lion, though they are somewhat rare ; but examples in which an ill-shaped tooth without determined form is found placed between the front teeth or behind them, or even holding the place to the exclusion of the normal member of the set, are met with by all who are engaged in practice. The number is commonly limited to one, or at most two, supernumerary teeth symmetrically arranged ; but I have seen a case in which there were four supernumerary teeth, forming a group with the upper incisors and canines. The (’) Seeing that supernumerary teeth assume two distinct forms, the one being regular, the other irregular, it might, perhaps, be advantageous, when speaking of those which in no respect differ from members of the normal series, to use the term supplemental, reserving supernumerary for the irregular- shaped teeth. As, however, there is every gradation between them, too much stress should not be laid upon this distinction.
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