Abstract: Objective　To investigate the anatomic characteristics of the needle entry path of the modified percutaneous approach, providing morphological basis for the clinical puncture.　Methods　Eighty dried cadaveric adult skulls (160 sides) were collected and stimulated by using a curved needle (with a front end of 10mm bending 30°) according to the modified puncture approach. The following parameters were measured: the depth of the first arrival with the needle from the lower margin of the zygomatic arch to the maxillary surface (L1), the depth (L2) that the needle reached the maxillary margin of pterygomaxillary fissure, and gliding distance (L3), the fissure width that the needle reached the maxillary margin of pterygomaxillary fissure (L4), the distance from the external opening of foramen rotundus to the infraorbital fissure (L5), the maximum length of the fissura pterygomaxillaris (L6) and the maximum width (L7), the maximum length (LA) and width (LB) of the skull. Thirty-six sagittal head specimens with intact soft tissue were taken for simulated puncture to verify the feasibility of bone measurement results in the head.　Results　On the left side, the measured values of L1, L2, L3, L4, L5, L6, L7 were (23.04±3.42)mm, (38.14±3.63)mm, (20.67±3.93)mm, (5.85±1.27)mm, (19.66±2.61)mm, (23.38±2.49)mm, (6.66±1.24)mm, respectively. And on the right side, these measured values were (22.96±3.34) mm, (38.40±3.49) mm, (20.82±3.93) mm, (5.86±1.33) mm, (19.29±2.61) mm, (23.85±2.38) mm, (6.76±1.21) mm, respectively. There was no statistical difference between the left side and the right side (P>0.05). Bilateral L1 and L2 were positively correlated with LA, but not with LB. Bilateral L1 was positively correlated with L2 but negatively correlated with L3, and L2 was positively correlated with L3. Confirmatory experiments showed that the correlation of skull specimen measurements was still applicable in cranial biopsy.　Conclusions 　There is no significant difference in the trajectory of the puncture when the paracentesis is performed on either side of the skull. The puncture depth is related to the length of skull and gliding distance, but irrelevant to the width and the sides of the skull.

Key words:  , Foramen rotundum, 　Modified lateral approach, 　Anatomy, 　Primary maxillary neuralgia