Computed tomographic assessment of lateral lamella of cribriform plate and comparison of depth of olfactory fossa.

INTRODUCTION

Endoscopic sinus surgery is an upcoming branch in rhinological practice but with some major risks since it has to play around the skull base area. Lateral lamella of cribriform plate is the thinnest area of the skull base. Thus this study is undertaken to evaluate the height of lateral lamella of cribriform plate and the depth of olfactory fossae by the help of computed tomographic images.

METHODS

Computed tomographic study of 50 patients was done in Advanced Imaging and Diagnostic center, Kathmandu Medical College. Coronal sections at the centre of infra-orbital foramina were taken as reference slide. The height of cribriform plate point was subtracted from the height of medial ethmoidal roof point to measure the length of lateral lamella of cribriform plates on both sides.

RESULTS

The median height of LLCP in 100 slides was 2.8 mm. LLCP height was 0 to 3.9 mm in 86 slides, 4 to 7 mm in 12 slides and greater than 7mm in 2 slides. The LLCP length was greater in right side in 28 (56%) patients and was greater in left side in 19 (38%) patients. It was equal in both sides in only three patients (6%).

CONCLUSIONS

As regards the length of LLCP; 0 to 3.9 mm length was most common. The olfactory fossa depth was more in the right side compared to the left side. Thus, right side is more vulnerable to injury during surgery. Thus adequate caution has to be exercised by the rhinological surgeon during endoscopic sinus surgery.