The etiology of osseous deformities of the head, face, jaws and teeth.

  • Talbot, Eugene S. (Eugene Solomon), 1847-1924.
Date:
1894
Catalogue details

Licence: Public Domain Mark

Credit: The etiology of osseous deformities of the head, face, jaws and teeth. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    CHAPTER V. DEVELOPMENT OF THE CRANIUM AND FACE. In early stages of development the posterior part of the cranium is large in proportion to the anterior part. At about the second month of foetal life the parietal region begins to increase rapidly in volume along with the greater develop- ment of the cerebral hemispheres; the frontal region next begins to increase in size, and toward the latter part of foetal life the occipital region increases as the brain extends back- ward. The face at birth is in surface about one-eighth of the cranium, while in the adult it is fully one-half. At birth the face still shows peculiarities which resemble those of the foetus. The ears are much lower than in the adult, the external opening being but little above the mouth. Racial distinctions are not at all pronounced, the children of the most strongly marked races showing great similarity, according to the law that the farther back we go in develop- ment the more generalized are all the features. After birth there are three distinct periods of develop- ment, the first ending at about the seventh year, the second at about the fourteenth, and the last at about the twentieth year. The transition from the first to the second type is quite a striking one. The skull grows rapidly during the first seven 3^ears. By that time certain parts have reached their definite size: the circumference of the occipital foramen, the body of the sphenoid, the cribriform plate of the ethmoid, and the petrous portion of the temporal bone. The eruption of tem- porary teeth, the gradual modeling of bones by growth, the development of muscular prominences and depressions grad- ually change the infantile character of the physiognomy. The face becomes longer in proportion to its width, and the jaws are shaped with reference to use in mastication. In the second period very many of the forms are already adult,