IRREGULARITIES, either in the form of the arch or the position of the teeth, are very uncommon in the deciduous set. We have seldom seen an irregular arch in a child prior to the eruption of the permanent teeth, unless associated with and correlated to some other deformity. In a few instances there has been observed a slight malposition of one or more of the incisors, sometimes of congenital origin, and sometimes the result of mischievous habits; as, for example, the two centrals may be pulled forward by the prolonged use of an artificial nipple, sucking the thumb, or other similar habit.
Congenital deformities rarely amount to more than a trifling displacement of one or two of the incisors; but, considering the temporary character of the deciduous teeth, and more especially the incisors, no irregularity in their position. that we have ever seen can be regarded as of special importance, or as justifying any interference for its correction. They are to be classed as mere freaks of nature, not associated with nor indicating any other peculiarity in the child. Nor do they prognosticate an irregularity in the development of the second set. This important fact can not be too prominently borne in mind. The deciduous dental arch is always