Congenital malformations of the lower jaw / by Alexander Ogston.

  • Ogston, Alexander, 1844-1929.
Date:
1874
Catalogue details

Licence: Public Domain Mark

Credit: Congenital malformations of the lower jaw / by Alexander Ogston. Source: Wellcome Collection.

    10/42 (page 8)
    thrown on this by Hiiter* than by any other recent author. He has shown that there is little increase of size, between birth and adult development, in the portion bearing the incisor and canine teeth, while the segment bearing the bicuspids and molars is enormously developed in proportion to the rest of the jaw during the like period of time, and this fact has to be kept in mind in the study of congenital smallness, as it is of consequence to observe what relation the jaw bears in each to the number and size of the teeth. Hiiter is of opinion that the increase in the number of the molar teeth at the second dentition, is the cause of the increased growth of the molar segment; while the incisor segment, having always the same number of teeth, does not grow in the same ratio. The ingenuity with which he sup¬ ports his conclusions does not however blind us to the fact, that the lower border of the molar segment, though not influenced by the teeth in any way, grows equally with the upper border, and that the influence of the teeth, if acknow¬ ledged as a sufflcient cause, would lead us to expect an increased obtuseness of the angle of the jaw, instead of the diminished obtuseness which is observed between infancy and manhood. Hiiter attributes the production and growth of the angle of the jaw to the resistance offered to its elonga¬ tion by the temporal bone at one end, and the muscles and integuments of the chin and lower lip at the other, an explanation similar to that which he has applied to the ribs. But the bend produced in the lower jaw is invariably an angle, not a curve, as such pressure would lead us to expect, and takes place at a definite point, a fact which his hypo¬ thesis of increased periosteal activity on the lower, and diminished activity on the upper margin, does not make in the least more intelligible. Of all Huter’s observations, the greater development of the molar than of the incisor portion is the one which chiefly concerns us. Congenital smallness of the lower jaw has been found affecting one or both halves, and these two series of cases will be considered separately. * Hiiter, Virchow’s Archiv. Bd. xxix., p. 21,