Abstract:

Objective　To review microsurgical anatomic features of the olfactory nerve and suggest operative nuances that may contribute to reducing the rate of postoperative olfactory dysfunction.　Methods　Region of ethmoidal plate of 15 dry skulls (30 sides) were observed and measurements among the ethmoidal plate and those related structures were carried out. Microsurgical dissection was carried out in 15 cadaveric heads filled with colored latex to obtain the anatomic features of the olfactory bulb, olfactory tract and olfactory trigone.　Results　Cribroethmoid foramen with butterfly-like shape were distributed in an area with a length (19.77±1.23) mm, and the transverse diameter in the midpoint was (3.15±0.45) mm. The number of cribroethmoid foramen in nasal concha were denser than in septum（t＝8.179，P＜0.01）.The olfactory tract enveloped by olfactory cistern was situated in the shallow part of the olfactory sulcus,  being interposed between the gyrus rectus and the medial orbital gyri. The olfactory trigone is divided into medial and lateral olfactory strains in front of the anterior perforated substance. The arterial supply in most cases of the olfactory nerve was relatively independent. And the blood supply was segmental in a few cases.   Conclusions   The olfactory never is located in the anterior skull base in the shape of triangle cone. The arterial supply in most cases of the olfactory nerve was relatively independent. Knowledge of the microsurgical features would help to preserve the olfactary nerve and avoid postoperative complications.

Key words: Olfactory nerve, Olfactory bulb, Olfactory tract, Microsurgical anatomy