Surreptitious Area of Middle Ear - the Sinus Tympani.

Sinus tympani is one of the hidden space in the retrotympanic area of middle ear which is commonly invaded by cholesteatoma and known for recidivism. Conventional surgical approaches sometimes fail to access deep sinuses and eradicate the disease. The aim of our study was to measure endoscopic depth of Sinus tympani in Indian Population. Total of 30 patients underwent mastoid exploration and intraoperatively depth of Sinus Tympani was measured using a 0.5 mm calibrated probe with 30 degree rigid Hopkins endoscope. Endoscopic depth in the present study ranges between 2.5 and 5.5 mm. It was higher in right ear in case of females however no significant difference were seen in males and females on left side. It is difficult to clear disease from Sinus Tympani because of its inaccessible location. Sinus Tympani can also show variations in terms of its depth further making difficult to clear disease.