副鼻窦后前位投照方法一般采用瓦氏位,即鼻尖离开暗盒0.5～1.5cm距离或听眦线与胶片成37°角。如果掌握角度准确,标准位置岩骨嵴应对称地投影于两侧上颌窦底下缘,但因人而异,头型不一,以鼻尖距离较难掌握,听眦线37°角不易目测,用角度尺测量较繁锁。我们试图在听眦线为37°角的原有基础上找一条垂线,这条垂线与听眦线夹角为53°。 Parasolus posterior projection method is generally used Valsalva, that is, nose tip away from the cassette 0.5 ~ 1.5cm distance or listen to the line and the film into a 37 ° angle. If the grasp angle is accurate, the standard position rockbone crest should be symmetrically projected on both sides of the lower edge of the maxillary sinus, but varies from head to head, to the nose tip distance is more difficult to grasp, Angle foot measurement more complicated. We tried to find a vertical line on the basis of a 37 ° angle, which is 53 ° to the hearing line.