Domestic

New Zealand Tablet, 23 May 1912, Page 57

Domestic

By Maueeen.

THE PROCESS OF DENTITION. The process of cutting the teeth, or teething, or dentition, begins usually between the sixth and seventh month of the infant’s life. There are, however, many cases in which it does not take place till a month or two later; a few in which the teeth are not cut until the child is a year and a-half or two years old; some in which the child has one or more-teeth already cut at birth; and some in which this process commences before the time at which, as we have said, it more usually takes place. It will probably be known to most readers, if not to all, that the teeth are almost wholly formed at birth, and that they have been fashioned and organised in secret some time before birth. This curious workmanship goes on until the cavity of the jaw-bone in which each tooth is lodged can hold it no longer, and it is pressed against the gum by the elongation of its root. The top of the tooth is the first formed, the process extending first to its neck, and then to its root, and as the latter is lengthened by the deposition of general layers of bony matter, the tooth is mechanically forced against the membranes which cover its crown. It is commonly supposed, and the word cutting proves it to be so, that the gum is cut or cleft by the top of the tooth, and a passage in this way forced through it. But this is probably an error. It would rather seem that by the pressure of the tooth against the unyielding gum, the latter is absorbed at that point, and gradually becomes thinner and thinner until at length no longer able to resist the pressure of the tooth against it, the now much thinned gum is broken through and the tooth is cut. Were it true that the apex of the tooth cuts through the whole dense substance of gum that covers it the cutting of the teeth would be a much quicker process than it is, and we should be at no small loss to acount for the high degree of constitutional irritation which the cutting of the teeth so frequently occasions. For the gum is a dense gristly substance, comparatively speaking, almost destitute of sensibility, which may be cut through without occasioning much, if any, pain, and were the teeth merely to pass through it by so dividing it, the constitutional irritation would be, in almost all cases, comparatively trifling. But when we know that the greater number of the teeth are mechanically unfitted to produce such a division of the gum —being intended rather to crush than to divide any substance they may have to act upon — are almost forced to admit that the teeth make their way through the gum by pressing upon it and so effecting its absorption. And when we know that a delicate and highly organised and most sentient pulp is placed under the root of each tooth, consisting of its nerve and its blood-vessels, and feel that in pressing against the gum the tooth must likewise press against this sentient and vascular pulp, we can no longer wonder that the process of dentition should often occasion a high degree of constitutional disturbance. In most cases the teeth are cut in pairs, those of the lower jaw commonly appearing before the corresponding ones in the uper jaw. The two middle teeth of the lower jaw are generally cut first, then the corresponding teeth in the upper jaw, then a tooth on each side of these in the lower jaw,.then the opposing teeth in the upper jaw, then the anterior grinders, first in the lower then in the upper jaw, then the eye-teeth, and then the posterior grinders. These, called the milk teeth, are twenty in number, ten in each jaw. An interval of time, between a week and a month, usually elapses between the cutting of each successive pair of teeth—a merciful ordination to avoid or diminish the risk that would be run in infants, however healthy, by the cutting of all the teeth at one and the same time, and the high degree of constitutional disturbance that in such a case would have been almost necessarily induced.

Maureen