Objective: To make 3-D reconstruction of frontal recess by high speed spiral CT, which can be helpful to nasal endoscopic frontal sinus operation.
Method: Fifty-one cases (102 laterals) of frontal recess 3-D reconstruction by 16 line high speed spiral CT were enrolled in the research, which included 58 laterals with chronic frontal sinusitis and 44 laterals of normal nasal sinus. The structure of frontal recess, the agger nasi and the adhere style of uncinate process were recognized. The parameter of frontal recess was measured. Finally the data of two groups were compared and analyzed.
Result: CT 3-D reconstruction of frontal recess could display the frontal sinus, frontal endosome and frontal recess. The shape of frontal recess varied greatly in different cases, which depended on the near structure especially agger nasi and uncinate process. The difference of average Y axes inner diameter between agger nasi and frontal endosome was significant. The difference of average Y axes inner diameter between frontal endosome and anterior nasal spine, between the line of frontal endosome to anterior nasal spine and the line of Aeby's plane and between bhullar cell and anterior nasal spine were not significant in two groups.
Conclusion: The drainage flow of frontal recess depends on the near structures especially on the agger nasi and uncinate process. The prevalence of agger nasi is high, and the position of it is constancy, as far agger nasi can be an anatomic landmark of frontal sinus operation. The position of frontal endosome is constancy. The scalloped area from anterior nasal spine 50-60 degrees to the line of Aeby's plane and within 100 mm radius is safety section to nasal endoscopic frontal sinus operation. CT 3-D reconstruction of this area is helpful to avoid insult.