A system of practical medicine. By American authors. Vol. 2

by Unknown

SYNONYMS.—Dentitio difficilis, Pathological dentition, Odontitis infantum.

The correct comprehension of the subject will be facilitated by considering its etiology, pathology, and symptomatology in connection. Indeed, morbid dentition has been assigned so prominent a part in the etiology of various affections elsewhere discussed that a satisfactory consideration of its own causation would require the repetition of much that belongs more appropriately under other titles. While in some infants the teeth erupt so quietly that the parents are astonished by the accidental discovery of their presence above the gum, few children escape a greater or less amount of local and constitutional disturbance while passing through the process of dentition. So severe may these disturbances become that, according to the mortality-tables of London, as cited by West,⁷⁵ teething was assigned as the cause of death of 4.8 per cent. of all children dying under one year old, and of 7.3 per cent. of those who died between the ages of twelve months and three years. It is furthermore well recognized that the period of greatest mortality among children is that of the first dentition. Associating these facts, we see, on the one hand, that while disorders of dentition may act a causative part in the production of systemic diseases or aggravate morbid processes due to ordinary causes, on the other hand they may be but one expression of some profound constitutional disturbance; or both aberration in the eruption of the teeth and systemic disease may be dependent upon the influence of dyscrasia. The period is one of active organic processes; the child is becoming fitted for a new manner of existence; and change and development are going on throughout nervous, vascular, respiratory, and alimentary systems. Hence there exists peculiar susceptibility to morbid influences; and any process, physiological or pathological, once started, goes through its stages with excessive energy.

⁷⁵ Lectures on the Diseases of Infancy and Childhood, Philada., 1860, p. 425.

Although the periods of normal eruption of the deciduous teeth vary within extensive limits, and an invariable order in eruption is not observed in all subjects, it may be stated as a rule that the lower central incisors are cut in quick succession about the seventh month. Some infants get these teeth during the fourth month (Vogel), and others have to wait until the tenth or eleventh month, some even longer. A few weeks after the appearance of these lower incisors—within fourteen days in some subjects, not until nine or more weeks in others—the central incisors of the upper jaw are cut, and its lateral incisors shortly afterward, followed in their turn by the lateral incisors of the lower jaw. In some instances—the majority, according to Vogel—the eruption of the inferior lateral incisors is delayed until the anterior molars are about to become exposed, usually from the twelfth to the fifteenth month. Sometimes the upper molars are cut before the lower, sometimes after them. From the sixteenth to the twentieth, or even the twenty-fourth, month the canine teeth are cut, and the four posterior molars follow between the twentieth and thirtieth months, rarely delayed until the thirty-sixth month,—completing the process of the first dentition.

From this it will be seen that the teeth erupt as a rule in pairs, and that a longer or shorter interval of repose takes place between the eruption of successive pairs.

Variations from the usual order beyond the limits noted above may be considered abnormal. Numerous cases are on record both of precipitate and of tardy dentition. Tanner cites from Haller nineteen examples in which one or more of the central incisors have been found through the gums at birth, and have had to be removed to prevent injury to the mother's nipple; from Crump, a case of full dentition at birth, reported to the Virginia Society of Dentists; and from Ashburner, a case of a child beginning to cut its first tooth, an incisor in the upper jaw, during its twenty-third month, the infant being very delicate, with a large head, tumid abdomen, and peculiarly small-sized extremities. The same author quotes from Serres cases of persons passing through several years of life—in one instance seven—before cutting their first teeth, and mentions on the authority of Tomes that Boxalli and Baumes have each recorded an instance in which the patient reached old age without a single tooth having ever appeared.

Rachitis is often the cause of tardy dentition, and in the subjects of this diathesis not alone are the teeth retarded in development, but they decay early and even fall from their sockets.

The first indication of approaching dentition is the markedly increased production of saliva. For some little time after birth the salivary glands seem to remain wholly inactive, and until the fourth or fifth month of extra-uterine life they furnish very little secretion. At this period a decided change occurs. The mouth is constantly filled with saliva, which dribbles from its corners. To this continual slobbering, wetting the garments covering the chest, has been attributed the bronchial catarrh which attends some infants; and diarrhoea has likewise been referred to the swallowing of large quantities of saliva, acting as a mild laxative by virtue of its saline constituents.

There may be no further manifestation until the seventh month, beyond the broadening of the dental ridge. The exact position of each tooth is usually indicated by greater prominence of the gum above it for some time before it comes through, its entire outline being very distinct in the upper central incisors. As the tooth approaches the surface the gum becomes hot, shining, tense, and tumid, often painful. A slight amount of catarrhal stomatitis is almost invariable. There is some elevation of temperature; flushing of the cheek may occur; the child is restless, peevish, and fretful; its sleep may be broken; it may cry out with pain; its thumb, its fingers, any hard substance it can obtain, are thrust into its mouth to allay the irritation of the gums. Otalgia is not uncommon, and its occurrence may be inferred from the fact that the child pokes its thumb or finger into the auditory canal or firmly presses the tragus down over the external meatus. These may comprise all the disordered manifestations, local or constitutional, or there may be in addition loss of appetite, diarrhoea, vomiting, and the various disturbances of reflex nervous origin to be alluded to later; or, in the not common yet not rare instances already mentioned, there may be absolutely no appreciable disturbance whatever.

Sometimes a disposition exists to the formation of small aphthous ulcerations on the tongue or elsewhere in the mouth, particularly at the duplicature of the lip and the outer surface of the alveoli. Ulceration occurs most frequently at the tip of the tongue, probably occasioned by friction from the new teeth. Usually there is a single flat, round ulcer, its edges somewhat infiltrated, its bed covered with a yellow lardaceous substance. It is extremely painful to the touch, and thus every movement of the tongue occasions distress. It may heal within a few days or continue for weeks. Ulcers in other situations are less obstinate.