The Mouth in Backward Children (Imbecile) of the Mongolian Type

Abstract

So much has been said and written about the mouth—the palate and the teeth—that it may be difficult to say anything fresh, perhaps more difficult to reconcile statements already made. We hear from one authority that a highly arched palate and contracted jaws are a sure sign of weak-mindedness; so sure, that imbecility can be diagnosed as congenital or otherwise according to their presence. Another authority regards contracted, badly-developed jaws as an equally certain sign of a higher state of civilization—children of a “well-bred aspect” having the abnormality in about seventy per cent.; those of a “coarse, low, and brutal aspect” manifested the deformity in only seven to eight per cent., whereas those children of doubtful aspect occupied an intermediate position between the other two as regards the frequency of the deformity. The comparative disuse of the organs of mastication among civilized races who cook and soften their food before masticating is probably confirmed by a statement made that irregularities of the teeth and contracted jaws are rare among savage races. It has, at any rate, become very generally acknowledged that a highly-arched palate is a common deformity in imbeciles, and the importance of the teeth as organs of mastication, with their necessity for healthy digestion, has led to certain observations which I shall shortly relate. From an examination of a large number of mouths in imbecile children, I am very strongly convinced that vaulted arches are not so common as has been supposed, and that these high palates occur mostly in two classes of imbeciles, viz., the micro-cephalic and the Mongolian type. As it is much more common in the latter, I shall refer only to this class. It is well-known that there are among imbeciles as a genus several well-defined and distinct species; no species is more clearly defined and more distinct than this, described by one authority in his ethnological classification as the Mongol or Kalmuck type. This species, composed of individuals having a very close resemblance to one another, is not a very large one; the class constitutes about four or five per cent. of the total number of imbecile children. They are generally short in stature—adult males rarely measure over five feet; females rarely over fifty-five inches in height; they have a squat figure, and are either of a very light or dark complexion; the head is small and round, the measurements from the root of the nose to the occipital protuberance and from ear to ear being nearly equal. The hair is never curly, it is straight, lank, and thin, or straight and coarse, sometimes absent, at other times devoid of pigment; the faces are round, length and breadth being nearly equal; the nose is usually flat over the bridge, and upturned and sharp as if bitten off; the eyebrows tend to run outwards and slightly upwards—the eyelids more so—the outer canthus and the opening between the eyelids having a very distinct outward and upward tendency—hence the Chinese, Tartar, or Mongolian features. The eyebrow may have a distinctly arched direction, but the outer canthus has an almost invariable upward direction. The space between the eyes appears wider than normal, owing to the flattened condition of the bridge of the nose. The face is rough, the skin being generally coarse and loose; the tongue is usually deeply transversely fissured; their hands and feet are broad and short, and their joints are very supple, their usual and favourite position at ease being that of squatting, tailor fashion, on their crossed legs, again like the Chinese. Their mental, no less than their physical, features are characteristic, the habits being lethargic, dull, and reserved in company; they are very observant, not easily roused to enthusiasm by others, although very playful and original when not watched; they are very apt mimics of muscular movements, fond of music and colour; they can be educated with advantage up to a certain point, and have a great desire, when it pleases them, to be useful to others. The smaller children of this type will turn over and over again the gaudy pages of a coloured picture book, in appreciation of varied tints. They are often near-sighted. Their articulation is defective; they can rarely pronounce the sibilants, but improve by training; they are usually short-lived, but rarely do any of this class suffer from epilepsy. They are generally the youngest in large families, or there is much disparity in the parents' ages. It is very desirable to know this type in order to give a satisfactory prognosis to anxious parents.