Pedagogical Anthropology, Maria Montessori [online e book reader TXT] 📗

measurement—prosopometry.

Prosoposcopy.—We proceed to inspection according to two norms: A. facial norm; B. lateral norm or norm of profile.

A. Facial Norm.—If it is a question of a living person, we make complete inspection of the visage, from the roots of the hair to the chin. First of all we direct attention to the forehead, which will give us an index of the development of the anterior region of the brain; next, we observe whether a plane passing longitudinally through the median line would divide the face into two equal halves (facial symmetry).

From an æsthetic point of view, the three following vertical distances ought to correspond in length:

Height of forehead (from the roots of the hair to the nasion).

Length of nose (from the nasion to the subnasal point).

Labio-mental height (from the subnasal point to the point of the chin). And in regard to width the three following horizontal distances ought, according to the æsthetic laws of art, very nearly to correspond (especially in the female face):

Width of forehead, between the two external orbital points.

Bimalar width, between the two malar points.

Bigoniac width, between the two gonia.

It should be remembered that the standards of beauty do not necessarily coincide with those of normality.

B. Lateral Norm.—In observing the face according to this norm, three facts should be chiefly noted:

The relative volumetric development between facial and cerebral cranium. The direction of the forehead, which, in the normal profile, ought to be vertical. Whether the facial profile protrudes or not beyond the extreme anterior limit of the forehead.

Prosopometry.—-Many forms of measurements are taken on the skeleton of the face and many total and partial indices are obtained, such, for instance, as the facial index, the orbital index, the nasal index, etc.

Measurements of diameters and angles are also taken on the face of the living subject and indices are obtained.

We, however, shall limit ourselves to indicating only those measurements which are taken most frequently in our special field of application.

The diameters and the height of the face are obtained by the craniometric calipers and Mathieu's compass with sliding branches; the facial angle is measured in projection by means of the double square; and directly, by the goniometer.

One mode of measuring the facial angle in projection is that of drawing the facial profile with the help of special instruments; or else of taking a photograph in perfect profile and tracing and measuring the facial angle on the picture.

Principal Linear Measurements:

Total length of visage: from line of hair root to point of chin.

Total length of face: from the nasion to the point of the chin.

Length of the nose: from the nasion to the subnasal point.

Height of mandible: from the upper edge of the lower incisors to the lower edge of mandible.

Subnase-mental height: from the subnasal point to the point of the chin.

Bizygomatic diameter: between the two bizygomatic arches.

Bimalar diameter: between the two malar points.

Bigoniac diameter: between the two gonia.

Biorbital diameter: between the two external borders of the orbits.

Gonio-mental distance: from the goniac point to the point of the chin.

Auriculo-frontal radius: from the tragus or from the auricular point to the ophryon.

Auriculo-subnasal radius.

Auriculo-mental radius.

(The last four measurements, if compared right and left, give an index of facial symmetry; the radii when compared together serve as an indirect measure of prognathism.)

Width of nose between the external borders of the nostrils (the branches of Mathieu's compass are placed tangent to the nostrils).

(The index of the nose is obtained from the length and breadth, by applying the well-known formula of indices; the nose thereupon receives various names—leptorrhine, mesorrhine, platyrrhine).

Width of orbit: from the inner extremity of the ocular rima (eye-slit) to the external border of the orbit.

Width of the ocular rima: between the two extremities of the rima.

Width of the labial rima: between the two extremities of the rima.

Length of the ear: from the highest upper edge of the auricle to the lower extremity of the lobule.

Index of the ear: this is obtained, by the well-known formula, from the length and breadth. The normal index is 50; the types of ear above 50 are low types.

Anthropologists obtain the facial index from the skeleton, especially for the purpose of determining the proportion of the face in human remains found in the geological strata. In such crania the mandible is wanting, and the teeth are wanting. Consequently, there are several ways of computing the facial index, because, while the transverse or bizygomatic diameter, which is considered as the lesser diameter, always remains constant, the longitudinal, which is considered as the greater, varies. The longitudinal diameter is calculated sometimes from the ophryon to the chin, at others from the ophryon to the point of insertion of the two upper middle incisors. In the first case it is now less, and again greater than the bizygomatic diameter; in the second case, it is always less, and the resulting facial index is notably greater than 100.

The most usual formula for the facial index is the following:

Fi = (bizygomatic diameter×100)/(ophryo-mental diameter)

on the basis of which Pruner Bey gives the following mean averages according to race, for the general facial index:

Arabs 96.7 Chinese 101.7 Hottentots 105.7 Tasmanians 109.9 Laplanders 124.7

This index is not exact and constant, like that for the cranium; in fact, in case a person loses his teeth the index is altered. At the present day, especially in the French school, the anterior or total facial index is taken into consideration, in which the vertical diameter is measured from the vertex of the head to the chin (Collignon), and, consequently, the index is always less than 100. The following is the nomenclature that results for the anterior facial index:

Leptoprosopics 62 and below Mesoprosopics from 62 to 66 Chameprosopics 66 and above

If we take for the measure of length that of the visage, i.e., the distance between the middle point of the frontal line of roots of the hair and the chin, we obtain indices that are higher by 5 than those of the French school, namely:

Leptoprosopics 67 and below Mesoprosopics from 67 to 71 Chameprosopics 71 and above

In many cases this index differs in the individual by as much as 10 from the cranial index, as I proved in my work on the population of Latium. Consequently, anyone who has a cranial index of 81 ought to have a visage index of 71, etc.

Contrary to what happens in the case of the cranium, the index of the face varies according to the age, the face being very short in childhood, and much longer in the adult.

Angles.—The angles distinguished by anthropologists are so numerous that it is impossible for us to take them all under consideration.

In the case of a living person, the angles may be measured directly with the aid of Broca's goniometer; the transverse branch passes across the subnasal point; the two antero-posterior branches are inserted, with the buttons with which they terminate, into the external auricular canals; the vertical branch, swinging on a hinge, is adjusted in such a way that the little rod which it carries at the end rests upon the ophryon.

This complicated instrument resembles an instrument of torture and could not be applied to children; furthermore, it is difficult to adjust, and consequently the angles that it gives are inexact: every muscular contraction causes the angle to vary. For this reason the goniometer is impracticable.

If, by means of an instrument we trace the projection of the facial profile, the facial angle may be taken on such a drawing; it may also be traced and calculated on a photograph taken in profile.

Broca's angle is that included between the auricular foramen, the subnasal point and the ophryon.

Camper's angle is that included between the auricular foramen, the point of insertion of the upper incisors and the metopic point.

We, on the contrary, in judging of the facial angle, or rather of the existence and degree of prognathism, have resorted to inspection, aided by certain facial lines, namely (Fig. 104):

a. Vertical Facial Line.—If the subject holds his head level, with the occipital point in contact with a vertical rod, and his gaze fixed straight before him, then what we call the vertical line is the line perpendicular to the horizontal direction of the gaze, and tangent to the extreme anterior limit of the brain. This line, in the perfect human face, is perpendicular to the horizontal line uniting the auricular point with the subnasal point, and hence forms a right angle with it.

b. Line of Facial Profile.—This is the line uniting the nasal point with the subnasal point. This line is never vertical, and therefore cannot form a right angle with the auriculo-subnasal line, but forms an angle that approximates more or less nearly to a right angle (85°): this is the facial angle.

Transversely there is only one line for us to consider, and it has already been noted:

c. The auriculo-subnasal line, or line of orientation.

Facial Norm.—Our attention should be directed, as we have already said:

1. To the forehead.

This, if anomalous, may be:

Broad (if greater than 133 mm.). Narrow (if less than 100 mm.). High (if over 60 mm.). Low (if under 50 mm.).

2. To the Symmetry of the Face.—If the face is notably asymmetrical, in respect to a plane dividing it longitudinally, the fact is at once perceptible. But a slight asymmetry may fail to be detected either by measurements (trago-mental diameters) or by inspection. Consequently, it will be well to follow certain practical rules in making this observation.

Observe first of all the median line of the face: the bridge of the nose, the nasal septum, the upper labial furrow and the point of the chin ought all to lie in the same vertical line; very often a slight deviation of the nasal septum above the upper labial furrow will betray the asymmetry; furthermore, the two naso-labial plicæ or folds should be noted, for they ought to be symmetrical in direction and in depth; lastly, we must observe the symmetry of the zygomatic prominences. We shall often discover three concurrent facts: a slight deviation in the median line of the face usually corresponding to the nasal septum; a greater depth of one of the naso-labial plicæ; and a greater prominence of the zygoma and the cheek on the same side.

Our attention should next be turned to the correspondence required by æsthetics between the following three diameters:

Minimum frontal. Bizygomatic. Bigoniac.

A very notable difference between these distances may also lead to the discovery of anomalies.

Sometimes we may discover, even by inspection alone, a notable narrowness of the frontal diameter, as compared with the other two.

The bizygomatic diameter may show an exaggerated development, and this is frequently accompanied by a hollowness in the temporal and upper maxillary regions and by a beak-like prognathism (prominence of the middle portion of the upper maxilla); at other times this degenerative sign calls our attention to the mongoloid type.

The bigoniac diameter may also show an exaggerated development due to the enormous volume of the mandible (criminaloid type—Lombroso's assassin type). It is necessary to supplement our observation with the measurement of these three diameters, because it may very often appear to the eye that the minimum frontal diameter is below the normal, merely by comparison with the other two diameters which are overdeveloped; while when measured, it may turn out to be normal. Or, conversely, the other diameters, the bizygomatic or bigoniac, although actually normal, may appear overdeveloped, because of the shortness of the minimum frontal diameter (see "Faces of Inferior Type.")

Meanwhile we must not forget that the following are signs of grave degeneration:

a. The minimum frontal diameter less than 100 mm. (the gravity of this is increased if at the same time the other two diameters are found as described in b).

b. The other two diameters greater than 110 mm. (Lombroso's born delinquents, assassin type).

Lateral Norm, or Norm of Profile.—Our attention ought to be directed, as we have already said:

1. To