Palatine bone

“ Influence of mastication on the jaw-bones.—It is well known that the size of a bone is largely determined by the degree to which the muscles attached to it are exercised. That the jaws do not grow to their normal size, if not adequately exercised during their period of growth, is strikingly shown by the overcrowding of the teeth, which takes place in those brought up on soft foods, and this even though there be no contraction of the jaws resulting from mouth-breathing. ”

“ In cases of a diseased molar tooth in the upper jaw, food getting firmly impacted in the hollow space, irritates the pulp in the fang and the adjacent bone until the progress in ulceration reaches the nasal chamber or sinuse and a nasal discharge is established. If an upper molar tooth is lost the molar formerly opposed to it in the lower jaw grows out and sets up the same train of symptoms. In all cases then in which nasal gleet is associated with much fœtor and with difficulty in eating, a careful examination of the teeth should be made. ”

“ If the probe slide readily over the bone, it is free from caries, but if it does not so, and yet no inequalities are felt on it, caries has taken place, but it is still smooth: if it feel unequal and rough, the bone is eaten with caries. ”

“ In the first place the condition of the mouth has certainly deranged the digestive organs, and, where there is room for choice, no operation, however simple or apparently safe, should be undertaken while the stomach is out of order. The seat of the disease is known, but the general health is first attended to; and when that has been in some measure re-established, the great object of the surgeon is fit to be accomplished. The question is, which of the teeth are to be interfered with? One is diseased or dead, and there can be no doubt that the diseased tooth should be removed. ”

“ The palate of the skull (plate 15, fig. 2) has been determined by removing the skull bones of one specimen. Anteriorly the premaxillæ and maxillæ are clearly recognizable as large dentiferous elements. The premaxillæ have 4 to 7 teeth, the short maxilla has 3 to 4. All the teeth are of nearly equal size. Smaller teeth seem to be indicated by impressions found between the larger ones. The vomers, which are tolerably large, unite with the premaxillæ behind and inclose at least half of the palatine foramen on the inner side. ”

“ The anterior end of the skull is formed by a pair of rather small bones, the premaxillaries, which carry the incisor teeth; they bound the sides of the nasal opening, or anterior nares, reaching to the nasals, when the latter are of ordinary length; they also form the front end of the hard or bony palate, which divides the nasal passage from the mouth. The maxillaries, or upper jaw-bones, make up nearly all of the facial region on each side and send inward to the median line from each side a bony plate which together constitute the greater part of the hard palate ”

“ In the median line is a well-marked raphe, extending anteriorly to a prominence indicating the position of the anterior palatine canal. The rugose condition of the membrane over the hard palate is not seen in young children; it supervenes later in life. ”

“ This invasion of the palate by teeth, which began in the lizard and the serpent, assumes alarming proportions here. It is not merely the roof of the palate which is spiked with teeth: above, below, at the sides, everywhere to the very limits of the oesophagus, the little fangs triumphantly stick out their slender points. It is impossible, therefore, to state their number. Nature has scattered them broadcast without counting, just as she has done with the hairs of the beard round the human mouth; and the comparison is not so impertinent as you may think. ”

“ The visible part or crown of the tooth is covered with a very hard white ivory-looking substance called enamel, which serves to prevent it from being worn down by friction, and into which neither bloodvessels nor nerves have been observed to penetrate. Owing to this structure, the tooth can be safely exposed without sustaining damage—a privilege on which most persons will be disposed to place a higher value after having experienced the pains consequent upon injury of the nerve from a portion of the enamel being broken off. ”

“ This is a general law, and holds with reference to the teeth as well as to any other organ or set of organs. The proper mastication of healthful and nutritious food constitutes the appropriate exercise of the teeth, and is a condition upon which their health, and the healthy exercise of the function of digestion, alike depend. If from any cause the teeth of one jaw are removed, the corresponding teeth of the other jaw, being thus deprived of that exercise which is essential to their health, are pressed out of the jaw, appear to grow long, become loose in their sockets, and sometimes fall out. ”

“ The brain, the liver, and the intestines, seem among the first to feel the effect of this change, and cerebral excitement is not slow to shew itself, especially if other circumstances combine to favour such determination. Where repulsion takes place, before all the deciduous teeth have made their appearance, the danger is greater, as the nervous as well as vascular system, seems endowed with singular susceptibility during dentition. ”

“ If we are mouth-breathers, our jaws will grow out of shape, so that our teeth are crowded and irregular and do not meet each other properly in chewing. Pressure upon the roots of the teeth, from meeting their fellows of the opposite jaw in firm, vigorous mastication, is one of the most important means of keeping them sound and healthy. Whenever a tooth becomes idle and useless, from failing to meet its fellow tooth in the jaw above or below properly, or from having no fellow tooth to meet, it is very likely to begin to decay. ”

“ There is a lack of proper nourishment of the tissues, due to imperfect digestion, which depends again on the proper "nerve tone." I believe this to be the real cause of the difficulty. It is reasonable to suppose that any tonic, whether taken in the form of exercise in the open air, or in any other form, which affects favorably other portions of the body, will affect the teeth favorably as well. When we have ascertained the functions of the great nerve-centers, and those functions are assured, then we will probably have more perfectly formed teeth.—Items of Interest. ”

“ I am convinced that far more illness than is generally supposed is attributable to dental defects, and this even among the more leisured classes. With regard to pyorrhœa alveolaris, it has to be remembered that it not only does harm by causing loosening, lengthening, and shedding of the teeth, and thus interfering with mastication, but also by contaminating the stomach and the blood and thus upsetting the digestion and causing constitutional diseases, such as anæmia and arthritis ”

“ The food, in consequence of the rugged condition of these teeth, would be imperfectly masticated, the organs of digestion would become impaired, and the whole frame would suffer. To prevent this, the molars are fully cut before the temporary tables are cast off, nor do both the tables leave the mouth at the same time. The one on the upper jaw is first shed, and it is not until [65] this has, by attrition, been rendered somewhat flat, so as to present a surface upon, or against which the food can be ground that the permanent molar of the lower jaw is uncovered. ”

“ When the teeth are carious he directs us to scrape them, and [295] apply to them a mixture of the flowers of roses, galls, and myrrh, and to hold undiluted wine in the mouth. When the teeth are slackened by any accident, he directs us to fasten them to the surrounding ones with a golden thread, and then to hold some stringent decoction in the mouth. When in young persons a second tooth appears before the first has fallen out, he recommends us to scarify around the latter and pull it out, and to endeavour to force the other gradually into its proper place. ”

“ The teeth divide solid food, the glands which line the inside of the mouth moisten it, the tongue mingles the food, presses it against the palate so as to force out the juice, and then collects the elements in the centre of the mouth, after which, resting on the lower jaw, it lifts up the central portion forming a kind of inclined plane to the lower portion of the mouth where they are received by the pharynx, which itself contracting, forces them into the oesophagus. ”

“ Children scarcely ever have occasion to use their teeth. The food in use requires no chewing. Little demand is made upon the salivary glands (for food is hot, moist, and “goes down itself”) ; hence these glands, which consequently fail to develop normally, become at some time acutely diseased, or finally almost if not entirely useless. Hollow, sunken cheeks result from this cause. It was never designed to remedy this defect with fat. The parotid glands and the cheek muscles should be developed and maintained by physiological eating. ”

“ Those, therefore, who swallow a mouthful after two or three turns, forget that they are thereby forcing the stomach to do the work the teeth have neglected to do, and this is very bad economy, I can assure you. You will see hereafter, when we speak about animals, that by a marvellous compensation of nature, the power of the stomach is always great in proportion to the _in_efficiency of the teeth, and that by the same rule, it is weakest when the jaws are best furnished. Now, no jaw is more completely furnished than the human one ”

“ Human teeth are of excellent service in the initial determination of degeneracy in the child. For this purpose the teeth should be studied from the first evidence of their development until they are all in place, which occurs normally, in most cases, by the twenty-second year.
Teeth-enamel is formed from the epiblast, and dentine, cementum, pulp (except as to nerve tissue) from the mesoblast. The enamel organs of the first set appear during the seventh week of fœtal life; the dentine bulb during the ninth week. At this period the tooth obtains its periphery. ”

“ The vascular supply of the palate is free and abundant, a circumstance which is of the greatest surgical importance in that it permits of the free detachment of the soft structures from the hard by long lateral incisions, and the necessary manipulation of these in uranoplastic operations without any fear of loss of vitality, provided that the patient’s health and constitution are tolerably sound, and that sufficient pedicle is left in front and behind. ”

“ An excess of nutrition produces a phlogistic process analogous to that of the soft parts; a defect of nutrition makes the teeth thin, arid, and weak. The first of these pathological states is met with especially in young men and must be fought against with the ordinary antiphlogistic means, designed to eliminate the excess of humors (evacuant, resolvent, revulsive, and astringent remedies) . As to defect of nutrition, this is met with most frequently in old people. ”

“ Infants born with a cleft palate cannot suck from an ordinary bottle, as the deficiency in the hard palate prevents the necessary vacuum being formed in the mouth. Such children are, therefore, usually brought up with a spoon, and often waste and die through insufficient nourishment. ”

“ If these bones are efficiently exercised during the formation of the teeth—and my remarks apply especially to the permanent set—the tooth-germs will be abundantly flushed with blood, while the ample growth of the jaws themselves will provide the germs with plenty of room in which to grow and to develop, and the more perfect their growth and development the more resistant should we expect them to be to the ravages of caries. ”

“ He teaches that the mucous membrane of the gums, tongue, and mouth is provided with nerves from a portion of the third pair of cerebral nerves, and that the teeth, too, by a small hole existing at the end of every root, receive tiny ramifications of sensitive nerves, having the same origin. The nutrition of the teeth is understood by Ætius in the following way: The nourishment which reaches the dental nerves is not entirely assimilated by them ”

“ Into its formation several bones enter; in the adult skull one usually sees posteriorly a cruciform suture indicating the limits of the superior maxillæ and palate bones; but even in the adult, evidence is forthcoming in the existence of traces of sutures to indicate that the anterior part of the palate is formed independently of the part immediately behind it. ”

“ The teeth, which have long sent down immoderate quantities of food, too often of the most abominable composition, for the stomach to grind over again, become visited with pains and penalties by the offended organ, under the vain hope that less work will be done in the upper mill. ”

“ Soft mucous polypus may exist for many years, without depressing the palate, or projecting into the fauces. The anterior nasal cavity is its most frequent seat, and it widens and fills up the fissure between the anterior and posterior cavities: frequently it projects backwards, but is not visible, though it may be felt with the finger behind the soft palate. Its growth is slow. ”

“ They are not only within the stomach, but fixed to a cartilage nearest to its lower extremity, so that the food, unlike that of other creatures, is submitted to the action of the teeth as it is passing from the stomach, instead of being chewed before it is swallowed. ”

“ Paré’s palatine obturator without sponge.
In the last chapter of Book XVIII, first dentition and the treatment required during this period are spoken of. The cutting of teeth, says Paré, is accompanied by pain, itching, and pricking of the gums; often, as well by diarrhea, fever, epileptic convulsions, which sometimes end fatally. The symptoms by which it may be known that teeth are about to come forth are as follows: The wet-nurse feels the mouth of the suckling infant to be hotter than usual; the gums are swollen; the child is restless, crying often and sleeping but little ”