A clinical study of the skull / by Harrison Allen.

  • Allen, Harrison, 1841-1897.
Date:
1890
Catalogue details

Licence: Public Domain Mark

Credit: A clinical study of the skull / by Harrison Allen. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    68/90 (page 62)
    Notk.—H. Welcker (Wachsthum und Bau des menschlichen Schadels, 1862, Fig. 7, p. 17) divides the sagittal suture into five parts. These divis- ions are the same as I suggest in the text. My attention was called to Welcker's work by Dr. Frank Baker after I had delivered the lecture. In- stead of naming the parts separately, Welcker includes them in the numbers 1, 2, 3, 4, and 5. It will be noticed that this writer retains the post-bregmal division, which I have included with some doubt. The reference of Welcker to the entire subject is very brief and is embraced in the follow- ing language : For more accurate examination of the shape of these su- tures I have illustrated (Plate iii, Fig. 7) five regions, of which No. 1 is on the coronali ; No. 5 borders on the lambdoida, while No. 4, which lies be- tween the straight parts of the parietal foramina, is a trifle smaller than the other divisions. Rolleston (British Barrows, 1877, 623), probably influenced by the same authority, speaks of the sagittal suture as divided into fifths. The post- obelial is the posterior fifth of this writer, and the obelial the penulti- mate fifth. REMARKS ON THE SUTURES OTHER THAN THOSE OF THE VERTEX. Sutures often indicate the manner in which the bones have grown. As already stated, the comparatively deep serrations in the middle of the sagittal and coronal sutures correspond to the most preco- cious extensions of growth-force in those directions. Premature union of two opposed portions of bone, namely, at the surfaces of greatest acceleration, may lead to a suture at such portions, being raised above the plane of the adjacent surface. The carinated por- tion of the sagittal suture is an illustration of this peculiarity. A group of instructive examples is seen in the sutures between the maxilla and the bones adjacent; thus the malo-maxiliary at its lower part, where two obtuse processes project, the process pertain, ing to the maxilla being the larger ; the inequality and even rugosity of the same suture, as it aids in denning the lower border of the orbit; the union of the horizontal plates of the maxilkeby means of which an upward extension results, aiding in the composition of the nasal septum ; a downward extension of the same in the form of a thicken- ing and even of an exostosis, which lies upon the roof of the mouth ; and also in the nasal spine, which is formed at the intermaxillary