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45 



HAWAIIAN SKULLS ^^ 



Making allowance for the difference the observer expects to find between 

 the two sides of any skull, the contrasts noted above were of a kind and 

 degree different from what is usually found, and in my opinion should be 

 associated with the gross changes in the upper jaw in the region of the teeth. 

 That absorption should go on in the maxilla of the left side is in full conso- 

 nance with what is known of the laws controlling use and disuse. ' The parts 

 above the alveolus no longer receiving the stimulus arising from impact and 

 not yet entering into the senile state showed the effect of prolonged disuse. 



The presence of the osteophytes on the disused side is of interest, since 

 it shows that they may appear under conditions of disuse. 



The small size of the left external pterygoid plate, the small impression 

 general of the left temporal fossa, the harmonic suture at the posterior part of 

 the temporal fossa, all show weakened left temporal muscle. 



Diseased Action causing Disuse, with residtant Changes in 

 Skidl-form 



The result of disuse are beautifully illustrated in No. 1104; in this 

 instance not from loss of teeth but from disease of the jaw. The specimen is 

 that of a male, aged about forty years ; the right lower jaw exhibits a large 

 mass of hyperostosis on the free surface of the right condyloid process,* 

 which doubtless interfered with mastication, and notably on the corresponding 

 side, as shown in the great amount of wear of the molars and premolars. 

 Notwithstanding that the disease had presumably appeared after the skull had 

 become mature, the affected side shows a number of characters due to disuse 

 which are not noted upon the other. The infraorbital margin has a minute 

 exostosis on ectomaxillary element at the suture ; the outer pterygoid plate is 

 perforate in the centre ; the parietotemporal line is more remote from the 

 lambda than on the opposite side ; the lower border of the malar bone is 

 thin. 



The great contrast between the external pterygoid plates in the above 

 specimen is also a feature in a skull of the Princeton series (No. 6), forty 

 years of age. The teeth on the right side are lost or worn down to stumps ; 

 in other respects the series is intact. The left zygomatic arch showed the 

 effects of fracture with displacement of the fragments. Correlated with these 



* Several examples of hyperostosis of the condyles are described by J. B. Davis s 



