FOOTNOTES:
[165] Sliding calipers: Separate measurement of each half of the body, from the lowest point on the posterior border of each ramus not affected by the angle to a point of corresponding height on the line of the symphysis. The anterior point may, in consequence of a lower or higher location of the posterior point, range from the chin to above the middle of the symphysis, but the results are much alike. The measurement leaves much to be desired, but is the best possible if the two halves of the body are to be measured separately.
[166] The length of the whole jaw is measured on Broca's mandibular goniometer, by laying the jaw firmly on the board, applying the movable plane to both rami, and recording the distance of the most anterior point of the chin from the base of the oblique plane. This measurement is easier than the previous, though on account of the variation in the angles and the lower part of the posterior border of the rami it is also not fully satisfactory, and it does not show the differences in the two halves of the body.
[167] Sliding calipers: One branch applied so that it touches the highest points on both the condyle and the coronoid, while the other is applied to the lowest point of the ramus anterior to the angle, if the bone here is prominent; if receding, the branch of the compass is applied to the midpoint on the lower border of the ramus.
[168] Sliding calipers: Maximum external diameter at the angles; the maximum points may, exceptionally, be either anterior to or a little above the angle proper.
The Angle
The angle between the body and the ramus of the lower jaw is known to differ with the age and sex as well as individually. Not seldom it differs also, and that sometimes quite appreciably, on the two sides. Racial differences are as yet uncertain.
The angle, especially in some specimens, is not easy to measure, and the position of the jaw may make a difference of several degrees. Numerous trials have shown that the proper way is to measure the angle on the two sides separately, and to so place the jaw in each case that there is no interference with the measurement by either the posterior or the anterior enlarged end of the condyle.
Leaving out jaws in which extensive loss of teeth has in all probability resulted in changes in the angle, the western Eskimo material gives the following data:
| Male | Female | |
|---|---|---|
| (224) | (217) | |
| Right side | 119.6° | 124.5° |
| (218) | (207) | |
| Left side | 119.5° | 124.3° |