The Wanganui Chronicle. "NULLA DIES SINE LINEA." FRIDAY, SEPTEMBER 4, 1908. THE MILLS OF THE MOUTH.

Wanganui Chronicle, Volume L, Issue 12145, 4 September 1908, Page 4

The Wanganui Chronicle. "NULLA DIES SINE LINEA." FRIDAY, SEPTEMBER 4, 1908. THE MILLS OF THE MOUTH.

Ik our telegraphic columns.on "Wednesday there appeared a summarised reporc of a speech delivered by Dr Purdy, District Health Officer for Auckland, in which he strongly advocated the teaching of hygiene in the public schools .is a compulsory subject. Dr Furdy particularly emphasized the need for the exercise of greater cafe in the matter of childien's teeth. He declared that at least in each of the principal centres dental dispensaries should be established, to which all children with bad teeth should be sent for treatment. There can be no doubt that Dr Purdy has voiced a popular necessity, although ho is by no means the first to have done so. The poor condition of the teeth of so many children has long been the subject of serious consideration by thoughtful people in all civilised countries. Just here it is interesting to note how inevitably the decay of human teeth follows upon a so-called higher state of human civilisation, or rather increased luxury in living; In a recently published article a Melbourne dentist pointed out that the evolutionist who is able to combine practical experience with scientific theory finds curious results. "One qf them is that bad teeth are inherited with jnuch niore certainty than -good ones, but /the first cause, rather than thb inherited effect, is the more interesting and practical side of the subject. An expert study of a great number of skulls of ancient Britons bhows. less than 3 per cent, of caries, which is the technical name for decay. Amongst the Roman-Britons the percentage increased to nearly 20 per cent., while the ancient Egyptians, at the highest stage •of their glory , when luxury of living probably reached its apex, the astonishing figure of nearly 42 per cent, of decay is disclosed, a result more astounding than anything which has as yet been, discovered in the civilisation of to-day. Both the Romans and: Egyptians,Oiad recourse to artificial • remedies i: and. wooden teeth, which could not possibly last very long, have been found in Egyptian mummies. The other extreme in human experience is found in the r aboriginals of South Australia, v Several skulls which the Melbourne * expert >has heard of show four niolar^ieeth; 'nbticeable in' no. other;branch of. the human race (and unknown;.in the anthropoid apes,: whose teeth i« other respects cor r respond clbeely with those of human beings).Jftow,the tendency here—one which .tlie writer referred to says he constantly discovers in daily practiceis for the third molar or wisdom tooth to disappear altogether, or in other cases to exist, in spA immature a form that it does not comb: into the biting or chewing line, is never developed by uso, and in its earlier decay becomes one, of the .chief troubles with which dentists have to deal. Every dentist knows how frequently he is.required to extract a wisdom tooth—gouging it out,, since it is frequently so stunted as to barely break the gum, yet ' in the formation of abscesses is -the frequent incentive to a fatal form of lockjaw. In the aboriginal; the inferior black, people who are in the dental sense superior^ fh<y'molars are invariably fully developed and perfect, showing ample space between the teeth, while in white races molars, as I have already said, arc either" missing or so imperfectly developed as to be a nuisance rather than an aid. The Reason is shown at a glance in the shape of 'the jaws of the two peoples-^the black having a broad jaw, the white a narrow one, a defect from a dental point of view which seems to increase alarmingly with the. development of- the^race: The result is that nearly all the teeth; in the superior race arie crowded -and irregular; so that the, immediate causes of decay are more easily secreted, and the perfect cleaning ldf' the teeth made more difficult. There is not sufficient backward growth in the jaw to afford room for the third niolar—that which, coming last, of all.in life, finds its natural space already occupied, yet is the most important of thtv three" grinders, with; which a man chews | his 'fpccL In the aboriginal it i? incorruptible. .Buried through the ages, long after the vital fires have burned out and thei machine fallen to decay, it reappears apparently indestructible—a time mark for the geologist, a connecting link for the evolutionist. Apart from what may be called the racial characteristic, tlie breadth of .jaw which gives the Australian aboriginal ample room for 32 fully-developed teeth, and occasionally for an extra molar—while the Australian native has never more though often less than 32, and these! frequently undeveloped "and irregular--the > main cause-:o£.the ; . change so detrimental to whito^men is-the greater care taken in itfre preparation of mixed foods. The once in use required r~±bor,£ugh gpafsticatipn, and the first ab«Wlnt§7fpTiysical law is that no organ .or structure of the body can either attain perfection or continue healthy unless adequate use is made of it. The superior foods now in general use require little mastication /,though they .a'fe of course more readily digested. In this they may be considered a consequence as well as a cause of dental decay.. The-patent digestive foods are a natural sequence to the easily masti-

catod preparations which ask littlo aid from the teeth. It is the more serious cause of decay because its effects are immedite and affect every type of jaw. Singularly few bad teeth are found in the skulls of Australian aboriginals which have been ploughed out by the thousand from the kitchen mounds of tho blacks. Yet on taking impressions recently of .the ..aboriginals at Lake Tyers station, the! writer found that their teeth were as bad, if not worse, than those of the surrounding white settlers, . with whom cleanliness was a greater if not yet a complete virtue. It is further curious in this connection that a lecent examination of the teeth of pupils attending two schools of different classes in Edinburgh showed the ratio of decay amongst children of the poorer and labouring classes to be 158.2 por thousand, while with the children of the wealthier and better class the figures rose to 273.9. Such a Tesult is( not flattering to superior self-esteem, but if there be significance in the. fact, who would wish to live in a fool's paradise when be might dwell in a happy, rational, and realisable Arcadia? The figures just quoted suggest that the decay of the teeth is not a naturat consequence of any widespread degeneracy in the modern man. Upon that point, indeed, there is no need to speculate. Men like Professor Cunningham, Sir Laucler Brunton, and others are emphatic. In reply to an inquiry as to whether his practice as an anatomist of wide experience disclosed any changes in the structure of modern men unfavourable to development, Professor Cunningham said, "No, with the one exception of the teeth." No speculation upon the causes of the decay of experience. And, in adopting the policy that prevention is better than •cure, the dentist may at least claim benevolent motives, because he seeks to anticipate the evils from the correction of which he obtains his living. There is perhaps too great a tendency to blame a deficiency of lime in water as being responsible for decay. To blame the water is. as old a delusion as tho popular belief with regard to a decaying tooth, "Better have it out." The Melbourne writer has no hesitation in saying that if every parent had some knowledge of the chemistry of : the mouth arid the constituents and action of saliva;; if they could be made to realise the slow, inevitable progress towards general decay and deterioration, they would be so impressed, that cleanliness with regard to the teeth would . become n religion rather than a casual practice. To put the position as briefly as possibleT the tooth is mainly composed of two factors—dentine, or the soft, porous inner basis, with its "proportion of organic matter, such as nervo, and the outer casing of enamel. It is the acids created in the mouth, mainly by particles of food, that first make an impression upon the enamel, and this, once breached, the dentine, with its lesser percentage of lime salts, .is more easily peptonised, decalcified, or eaten away. To I;ake a. biscuit or a piece of, bread, a^cKildren so frequently do, before going to bed, without cleaning the teeth afterwards, is one of the first aids to decay. The ' very manner in which teeth usually ..ct g°! J .suggests thenecessity for clean-. ' ; iiness. ' , The. lower front teethj which' from their-shapeliness and absence of "fissures do not easily secrete particles of "food,, are invariably the last of decay. The tip of the tongue, the action of the lips, helps ;tcjT cleanse them naturally, while the irregular molars have not the same aids." '; The more irregular the teeth, of ■cpur^e,':*the greater the necessity. for. frequeiltl cleansing, and the best time, he Repeats, is to clean them on going. to bed: The front teeth have open Ispa-pes^ aftd,:! in the absence of contact ,are preserved. When the molars touch,, decay-is/hastened; when they jam, the-effect is more immediate. Neglected" po^tr^Ssal \; growth in young children, wlVicti-.compels them to breathe through thejjopen: mouth, promotes decay in teeth, la This may be accepted as a fact without:" going into- physiological ;det^il> as, further, the assurance .ihat to.:promote the formation and development of good teeth no food is so valuable to infants and young children Jas a pure> milk supply. Admitting that our'focds of to-day are not the kind '*? i^yflop .perfect teeth, the remedy for -the evil is first, last and always rigid cleanliness. Hygiene has long been suggested as a vital subject for study in school, but the Melbourne writer is quite in accord with Dr Purdy, of | Auckland, that no form of it is more urgent than the knowledge of how to protect and preserve the teeth. Unhappily, the most elemental precautions are still regarded by a great many people as nothing less than snobb:sh affectation ...-.■;■