ABSTRACT
Objective:To measure the safe range from the foramen rotundum to the siphon of internal carotid artery using three-dimensional reconstruction technique, and to provide guidance for operation through pterygopalatine fossa.Methods:The skulls of 121 volunteers were scanned to get the final results with thin-section computed tomographic images.The position of the siphon of internal carotid artery (point A)and foramen rotundum (pointB)were ascertained.Three-dimensional reconstruction technique was used to build a coordinate system paralleled to the frankfort horizontal plane and the nasal septum plane.The coordinate system took point A as the coordinate origin.Point C and point D were the projections of point A in two planes parallel with frankfort horizontal plane and nasal septum plane which included point B.The distances of AC,AB,and BC were measured. The angles of the line went through A and B to the three planes were also measured.Results:The distance of AC was measured as 13.22 (3.79)mm (range,8.33 - 105.67 mm;95%CI:8.55 - 21.39 mm).The angle to the sagittal plane was measured as 33.54 (9.23)° (range,5.38- 66.58°;95%CI:30.88 - 34.20°). The angle to the coronal plane was measured as 53.17 (10.48)°(range,5.60-75.02°;95%CI:51.29-55.06°).The angle to the horizontal plane was measured as 9.43 (12.91 ) mm (range,- 28.44 - 82.22;95% CI:7.11 - 11.76 ). Conclusion:The safety distance from foramen rotundum to the siphon of internal carotid artery in the operation through pterygopalatine fossa (PPF) under nasoendoscope is obtained by thin-section computed tomographic images.