THE DERANGEMENTS OF TEETHING.
period of active development of the milk teeth is always a time of trial for the young child. Many an infant seems healthy and sturdy up to this point ; but when the time of teething arrives his nutrition falters and he begins to fail. On this account mothers, if they do not look upon the eruption of the teeth as a disease in itself, are at least in the habit of attributing every complaint which occurs during the first two years of life to the influence of this normal physiological process. In the medical pro fession the views held with regard to the influence exercised by teething upon the infant economy were at one time very similar. At the beginning of this century, dental development was looked upon as one of the chief causes of death in the infant. One author classes it amongst the fatal dis eases of childhood. Others estimate the mortality from this cause at one tenth, one-sixth, one-third, and even one-half of the whole number of deaths under the age of two years. Even in the present day it is common to find dentition included in the etiology of almost every variety of nervous disorder occurring in the child.
The period of dentition coincides with that of the most active physical progress. Towards the end of the first year of life the follicular apparatus of the intestines is undergoing considerable development ; the cerebro spinal system is passing through a stage of rapid growth and high func tional activity ; and most organs and tissues of the body are in a state of active change. The evolution of the teeth is not, therefore, a solitary in stance of developmental progress, but corresponds to a similar activity of growth in other parts. No doubt, a period, such as this, of quick transi tion is a period of exceptional susceptibility. Derangements of function are very liable to occur ; but to attribute these exclusively to one of the many physiological processes of which the body is the seat, merely because this process is external and visible to the eye, while the others are inter nal and cannot be seen, is to generalize hastily, and from very insufficient data.
There is another reason why, at the time of teething, various forms of illness are liable to arise. The stomatitis so commonly induced by the
advance of a tooth in the gum, is a cause of pyrexia. A feverish child is very susceptible to chills, and is liable to be disordered by the irritating influence of unsuitable food. In such a state, also, the digestive power of the infant is weakened, so that the food on which he has been thriving may cease to agree. Derangements of the stomach and bowels, thus in duced, if prolonged as they often are by improper treatment, cause serious interference with nutrition and not uncommonly bring the infant to the grave. To say, however, that in such a case the child dies from teething, is incorrect. He dies from mal-nutrition, brought on by persistence in forcing upon him food which is no food, because he cannot digest it. His diet, instead of supplying him with the nourishment he requires, ferments, turns acid, and sets up catarrhal diarrhoea ; so that at last he succumbs, worn and exhausted by purging and starvation. The looseness of the bowels, which is so apt to occur during the period of teething, cannot, be attributed with any justice directly to the process of dentition. The fever ish child is attacked by intestinal catarrh, because his body for the time is mom than usually susceptible to the influences which are capable of ex citing that derangement ; but teething is the cause, not of the purging, but of the fever. So, also, in the case of pulmonary catarrh, which in some subjects is a common accompaniment of the eruption of each separate tooth, it is to the pyrexia, and not to the accidental cause of the pyrexia, that the derangement is to be ascribed. In support of this view, it may be remarked that diarrhoea is a more common complication of dentition dur ing the warmer months, when the weather is liable to sudden and unex pected changes, and the temperature varies rapidly while the dress of the child remains the same ; and is less common during the winter, when more care is taken to guard the child's body from the cold. Again, the pulmo nary accidents are more common in raw, damp weather, at the times when such disorders are especially apt to prevail.