2. Anatomic Variations in paranasal sinus region and their clinical importance Reviewed articles by Jahanbakhsh Hashemi MD Associate prof of radiology (MUMS)

4. With the advent of functional endoscopic sinus surgery (FESS) and coronal CT imaging, considerable attention has been directed toward paranasal region anatomy. Detailed knowledge of anatomic variations in paranasal sius region is critical for surgeons performing

5. (FESS) as well as for the radiologist involved in the preoperative work – up. To be in the known anatomical variants with some accompanying pathologies, directly influence the success of diagnostic and therapeutic management of paranasal sinus diseases.

6. It was suggested that remarkable anatomic variations of paranasal sinus and their pathologic consequences should be well defined in order for improve success of management strategies. To avoid potential complications of sinus surgery. The radiologist must pay close attention to anatomical variations in preoperative evaluation.

7. Variations were classified as: 1. Bony abnormalities 2. Extentios of sinus air cells

8. Bony abnormalities A- septum B- ethmoid structures That project into the nasal cavities primary turbinate including superior, middle, and inferior. And secondary turbinate. Including the uncinate process and Ethmoid bulla.

9. Extentions of sinus air cells 2- sinus air cell Extentions External Extensions of air cells from the bone of origin, Twenty – seven extensions related to the Four major groups of paranasal sinuses, Five of these were midline and the remainder were unilateral or bilateral.

11. Septal deviation

12. Septal deviation

13. Septal deviation

14. Deformity of the chondrovomeral junction

15. Septal spur

16. Paradoxical middle turbinate

18. Hypoplasia of the middle turbinate

19. Ostiomeatal complex

20. Ostiomeatal complex