Quantitative anatomic study on transmaxillary approach to the lateral skull base with Dextroscope system

Abstract

Objective To quantitatively measure the anatomic structures of transmaxillary approach to the lateral skull base with Dextroscope system in order to provide quantitative datum for the operation on this area.Methods The experiment was divided into two groups,cadaver group and VR group.The cadaver group included 15 freshly embalmed cadaveric specimens.The VR group included the images created by the Dextroscope system from the CT scans.In the cadaver group,actual anatomy of transmaxillary approach to the lateral skull base was examined under microscope. In the VR group,the anatomy was simulated and the distances between important landmarks were measured.It was identified A as the inflexion of the anterior,median and interior wall,B as the inflexion of posterior,median and interior wall,C as the virtual point that line between A and Foramen Rotundun perforated the posterior wall of maxillary sinus,D as the virtual point that line between A and front root of lateral pterygoid plate perforated the posterior wall of maxillary sinus.The distance between A and B was compared between cadaver and VR groups in order to confirm the reliability.Then the distances between A and C,A and D,the angle of AC and AD,and other related data were measured.Results The distance between A and B was ( 25.53 ± 6.55 ) mm in the cadaver group and(25.97 ±7.23) mm in the VR group respectively (P ＞0.05).The distance between A and C was (32.81 ±9.06) mm,A and D (33.43 ±9.16) mm.The angle of AC and AD was 41.20° ± 8.76°.The vertical distance between D and the median wall of maxillary sinus was (5.65 ± 2.33 ) mm.The data measured in virtual group was highly coincided with the data in cadaver group verified by statistics.Conclusions The virtual reality technique could actualize the measurements thal could not be finished in the cadaver,provide quantitatively anatomic data for the transmaxillary approach to the lateral skull base.It has clinical significance. Key words: Virtual reality technique; Lateral skull base; Maxillay sinus; Pterygopalatine fossa