A system of dental surgery / by Sir John Tomes.

  • John Tomes
Date:
1887
Catalogue details

Licence: Public Domain Mark

Credit: A system of dental surgery / by Sir John Tomes. Source: Wellcome Collection.

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    of tlie organs of the face to the increasing perfection of their associated functions. Tiie mouth, nose, orliits, and pliarynx, arc all more or less directly influenced, ;ind con- temporanconsly rendered more perfect in form by tlie com- plete dcvelo])ment of this bono. The primary idea, or priuiary intention of the develop- ment of the sphenoid, seems chiefly ■with reference to the masticatory function ; Iiut in the changes that it produces in the direction of the cranial and facial bones, it may not inaptly bo compared to the scaphoid bones of the carpus and tarsus ; for in its growth and final development it effects for the cranium and face precisely the same object that these bones effect for the hand and foot. Like these bones, then, the growtli and completion of the sphenoid, in spreading out the craninm, and in enlarging the cavities of the organs belonging to the face, sui^plies the de- ficiency of tlie nniscular tension which in other jiarts of the body has so large a share in determining the final or perfect forms of the bones. (^) Of tlie different parts of the sphenoid bone, those which undergo the greatest change during the period under con- sideration, as regards size, and which are also the most directly connected with the present inipury, are the Jjtery- goid plates. Tliese parts increase to the extent of one-third of their nltimate length between the age of seven and twenty-one years. In a specimen of seven years, the an- terior surface of the pterygoid process is separated from the first permanent molar by a distance scarcely exceeding a quarter of an inch, and the nascent second molar lies in the tul)erosity, in great part external to the sjihenoidal ]iro- cesscs. Tiie space, at present so inconsiderable, lias, before the adult form is aciiuired, to be increased fully two-tliirds, accompanied l)y an increased length of tlie i)terygoid plates, the general direction of which remains unchanged. The general |ii'inci|>les wiiicli have been ])ointed out as ])ertain- (') Notcxon sdiiu: iil' tlio Dovclninnentul ami Fiiiictioniil Rchibdiis of cer- tiiin Boiics of the Cnuiiuin. Suloctcd by F. \V. Tavy, M.D., from Lectures oil Anatomy Iiy .lolm Hilton, F.K.S. 1855.
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