482 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1957 



(upper left) shows the skull of a child, whose permanent first molars 

 were just beginning to erupt, in which two trephine openings are 

 visible, but no sign of fracture, unless it be the little crack in the tem- 

 poral squama extending down from the smaller opening. This is 

 an example of how difficult it is sometimes to find the surgical 

 motivation. 



SURGICAL TECHNIQUES 



The striking feature about Squier's Cuzco skull, as mentioned in 

 the beginning, is the rectangular pattern of canoe-shaped cuts (fig. 1) . 

 Only three skulls with cuts of this type are known outside of Peru — 

 one from France and two from Palestine. In Peru such skulls have 

 been found mainly in the Central Highlands. By their nature these 

 cuts are deeper at the middle than at either end and hence when they 

 penetrate the skull in a rectangular pattern the piece of bone that is 

 freed is much smaller than the total area involved in the cutting. 

 This means that the primitive surgeon who used this technique had to 

 cut the scalp in such a way as to expose much more of the skull vault 

 than he intended to open. One of the dangers here was that the large 

 area of exposed bone would lose the blood supply normally received 

 through the scalp and that the ischemic bone would become infected. 

 Obviously, then, the ancient surgeons in Peru and elsewhere who 

 operated in this way were using a technically unsound procedure. 



Just as obviously the technique used in cutting the seven holes in 

 the skull shown in plate 1 must have been efficient ; it enabled the indi- 

 vidual to survive each successive operation with a minimum of post- 

 operative bone scarring. When circular holes were to be made, ap- 

 parently very little more scalp was removed or turned back than was 

 needed for the opening in the bone. Other examples show that the 

 bone was cut and/or scraped in a circular fashion so as to produce 

 a beveled edge. It is not clear how often a button of bone was re- 

 moved or how often the bone simply was scraped away over the whole 

 area of the opening. In general, this technique, with one or other of 

 its variants, was favored wherever trephining was practiced in an- 

 cient times. 



Trephining by drilling small holes in a circular pattern and then 

 cutting the slender connections between them, as illustrated in plate 2, 

 probably was not practiced outside of Peru and only occasionally in 

 Peru. Failure to use this technique more often may have been due 

 to fear that the tip of the drill would damage the brain. 



In making their incisions through the scalp and in effecting an 

 opening in the skull, without the use of general anesthetics, primitive 

 surgeons relied on the sharp edges of flaked stones, especially flint and 

 obsidian. In Melanesia the shark's tooth also was used as a cutting 

 instrument. When metals became available they were made into 



