Surgical Anatomy of the Anterior Ethmoidal Canal in Ethmoid Roof: Anatomical and Computed Tomographic Analysis / 대한이비인후과학회지

ABSTRACT

BACKGROUNDS AND OBJECTIVES: This study was undertaken to examine three main relationships. First, the distance and angle from the anterior ethmoid canal to the limen nasi and the sill were measured. Second, The location of the anterior ethmoid canal was examined in relation to the lamellas and the skull base. Third, the existence of bony defects in the canal and the course through the anterior cranial fossa were studied. MATERIALS AND METHODS: This study employed both sagittal computed tomography and cadaver dissection. Seventy sagittally divided heads from randomly chosen Korean adult cadavers were used. Sagittal computed tomography was performed on all specimens. Then they were meticulously dissected under a surgical microscope. RESULTS: The mean distance and angle between the limen nasi and the anterior ethmoid canal was 49.0 mm and 54.5, respectively. The anterior ethmoid canal was located between the 2nd and 3rd lamella in 61 of 70 cases. In 60 of 70 cases, it was attached to the base of the skull, and in the remaining 10 cases, it ran 2 to 3 mm below the skull base. When viewed from the superior side, the course of the anterior ethmoid canal formed a diagonal line from the lateral to the medial side. Partial bony defects of the anterior ethmoid canal were observed in eight cases and complete bony defects in none. CONCLUSION: This study provides surgeons with a better understanding of the anatomy of the anterior ethmoid canal.