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No. 2.

Original Communications.


BY J. F. COLYER, L.R.C.P., M.R.C.S., L.D.S.

THE subject which forms the theme of my remarks to-night was suggested by your Hon. Secretary when he sent me a kindlyworded invitation to read a paper before your Society. The question is, of course, far too extensive to discuss in a single paper and it is therefore my intention in the first place to refer briefly to certain points in the preventive treatment which seem to deserve more attention than has been previously accorded to them, and then to deal more fully with certain lines of remedial treatment that have been found to lead to excellent results.

First, then, as to the all-important question of infant feeding. Clinical experience seems undoubtedly to suggest that breast-fed children have better teeth than hand-fed children. The impressions I have formed are that in the case of the breast-fed child, the physical character of the teeth is more resistant to attack, and that defects in structure, such as fissures on the occluding surfaces, are less frequently met with in them than in the hand-fed child. Pits and fissures on the masticating surface render the teeth more liable to attack. Take, for example, a child where the teeth on examination show marked fissures. No amount of tooth-brush cleaning will succeed in freeing such pits from the solution of food stuff contained in them, and if the food stuff does happen to be of a carbo-hydrate nature, then fermentation will probably occur and structural damage to the tooth follow. Reference is made to this question because a certain school of thought teaches that such defects do not predispose to caries, and argues that defects of structure are frequently met with in animals, such as the gorilla, and yet caries does not appear. This, however, is no argument against such defects rendering the teeth more susceptible to caries, providing the necessary pabulum exists for the production of lactic acid. In the majority of the lower animals this pabulum does not exist. Take for example

*Read before the Manchester Odontological Society, December 6th, 1910.

Discussion on page 96.

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the question of caries in the horse. In the maxillary teeth there is constantly a defect in the structure of the cemental tissue occupying the anterior and posterior "lakes." The defect takes the form of a canal which: persists right through the tooth. When caries attacks the teeth of horses it invariably commences on the occluding surface, and starts in these defects. E. A Merillat states that "the entrance of food into these pits causes more than 95 per cent. of the decayed molars of the horse." Horses kept on a diet of hay or grass are free from caries because the mouth bacteria have but slight action on cellulose material and lactic acid is not formed. With the introduction of corn and other cereals into the diet a material is present from which lactic acid is formed, and caries is liable to occur, and starts as stated above in the defective part of the tooth.

The method of infant feeding also influences the growth of the jaws. The subject was dealt with in detail in a paper before the Odontological Section of the Royal Society of Medicine. Briefly stated, I found that breast-fed children had slightly better developed arches and jaws than hand-fed children, who had had the modern shaped bottle.

In a series of measurements made of children free from adenoids the following data were obtained :


A. 34.85 mm.

34'1 mm.


26.31 mm. 25'61 mm.

These figures, taken from patients in private practice, show that breast-fed children have slightly better developed arches than hand-fed children. Amongst Hospital patients the difference is, however, more marked. The relation of breadth to height showed that in the case of the breast-fed the breadth averaged 2·63 times the height, while in the case of the hand-fed the figures were 2′52.* The tube bottle, however, produces disastrous effects; example, in forty-one patients where the tube bottle had been used, the average measurements were :—

# A.

32'14 mm.

B. 23'05 mm.

The ill effects of the tube feeding-bottle is due to the fact that the constant sucking action produces a lateral compression of the arch, tending to narrow it and at the same time force the anterior teeth forward. The reason why the modern feeding-bottle does not interfere so much with the shape of the arch and palate as the tube bottle is that the former, when properly used, somewhat simulates the action of the nipple. The teat to feeding bottles could, however, with advantage be improved.

Adenoids.-The influence of adenoids leading to nasal obstruction upon the growth of the palate and the hygiene of the mouth is of

*For the purpose of obtaining measurements, the following points were utilized :

(a) The breadth between the first permanent molars, the point chosen for measurement being the gum margin immediately in line with the fissure in the palatine aspect of the tooth. This measurement is denoted by A.

(b) The breadth between the first deciduous molars or first premolars, the point chosen being the gum margin at the point corresponding to the centre of the palatine aspect. This measurement is denoted by B.

the greatest importance.

The interference with growth would appear to occur mainly in the region of the premaxillæ and the molars. Lack of use of the muscles of the anterior nares, in addition to the loss of stimulus to the nasal mucous membrane, inhibits the growth of the premaxillæ. The restriction of growth from this cause would seem to afford an explanation of the almost constant association of crowded incisors in cases where adenoids develop during the first six years of life. The want of growth in the molar region is due to the lack of expansion of the antrum arising from disuse, and the want of growth of the maxilla is correlated with a diminished growth of the mandible.

The slight decrease in the width of the arch seen in patients with adenoids may be due to the general want of growth of the maxilla through lack of expansion of the antrum. Some authors, however, hold the opinion that such narrowing is due to the constant tension of the cheeks on the dental arches, in addition to the absence of pressure of the tongue against the maxillary teeth. It is doubtful whether this pressure of the cheeks actually exerts much influence on arches where all the teeth are present, but where early loss of teeth has occurred, or where there has been rickets, the effect is likely to be more marked.

The high arch of the palate, so often associated with adenoids, has been accounted for in several ways:

(1). It is maintained by some that the high arch is due to the lateral pressure of the cheeks crushing in the arch in the region of the premolars and molars. This view is open to criticism, as the amount of narrowing is extremely slight and would not account for the amount of deformity seen.

(2). Others hold that the flow of air through the mouth on its way to the trachea abstracts the contents of the naso-pharynx, and so produces a negative pressure in that cavity, and an increased pressure on all its walls. In this way, the palate is pushed up, and the sides of the arch approximated. Against this view it is urged that the main obstruction is at the back of the fossa, and not at the front. The anterior part of the palate is of considerable thickness, and the vomer, which is fairly strong posteriorly, would offer some resistance to an upward movement in the middle line. An upward movement of the palate would lead to a deflection of the part of the septum formed by the vomer, but there is not sufficient evidence of this in those with vaulted palates.

(3). Another view, and one which is probably the correct one, is based on the fact that nasal obstruction interferes with the growth of the sphenoid and septum. The hard palate in the infant is normally high arched, and at birth it lies above the level of the Eustachian tubes, but later on becomes considerably lower. This alteration is due to the downward growth of the hard palate, so that one factor in the production of a highly arched palate is a lack of development of the walls of the nose, more especially of the sphenoid and the septum." Any factor, such as adenoids, will interfere with the growth of the nasal septum, and so retard the proper development of the hard palate and consequently its descent. All views considered, it would seem rational that the palatal

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