On a previous occasion1 I described a modification of the Lichtwitz antrum trocar. Further experience with this type of straight needle employed in irrigations of the antrum for diagnostic and therapeutic purposes has convinced me of its advantages.
There seems to be some misconception as to the anatomic position of a straight needle when inserted into the antrum. This can be easily dispelled by the following considerations:
1. Actual examination of the instrument in situ on a cadaver, after removal of the canine fossa, will bear out the fact that the straight needle is satisfactory.
2. Reproductions of roentgenograms showing the invasion of the antrum of a cadaver, first, by a curved Coakley trocar (fig. 1 A) and, second, by a straight needle (fig. 1 B) prove conclusively that there is very little difference, if any, in the position assumed by the two instruments.
3. As the space between the inferior