OBLITERATION OF SUTURES IN SKULL 517 



TABLE 5 



Premature synostosis in one suture only 

 Number of skulls 1820 



THE PREMATURE OBLITERATION OF TWO SUTURES AND MORE 



We will begin with the discussion of the more simple cases in 

 which only two sutures were prematurely closed. It is quite 

 natural that amongst this group the coincidence of a synostosis 

 in the sagittal and masto-occipital suture appears most fre- 

 quently. One will remember that the obliteration of the masto- 

 occipital suture, either unilateral or bilateral, has been found 

 in no less than 10 per cent of the infantile skulls. The proba- 

 bility therefore that such an instance can be complicated with 

 an obliteration of the sagittal suture is not small. Now, the 

 same possibilities may occur in these cases, as in the non-com- 

 plicated synostosis of the masto-occipital suture. Together 

 with the sagittal suture the masto-occipital can be obliterated 

 bilaterally or unilaterally, totally or partially. It does not 

 seem necessary for me to describe all these cases in detail, as 

 no principle is involved. I will restrict the communication to 

 those cases in which the premature obliteration appeared in 

 both sutures. A summary of this is seen in table 6. 



As this table shows, we find among 1820 skulls 19 in which 

 at the same time the sagittal and masto-occipital sutures were 

 no longer intact, this making 1 per cent. The absolute numbers 

 are too small to decide whether the frequency increases accord- 

 ing to the age of the individuals. One can demonstrate how- 

 ever that a predisposition of these two sutures toward a pre- 

 mature closure is revealed by the relative large number of cases 



THE AMERICAN JOURNAL OF ANATOMY, VOL. 17, NO. 4 a 



