C shaped curve on tympanometry is seen in: (A) Serous otitis media, (B) Otosclerosis, (C) TM perforation, (D) Retracted tympanic membrane
Answer is D. Type C tympanometry Maximum compliance occurs with negative pressure in excess of 100mm H2O Seen in retracted tympanic membrane and may show some fluid in middle ear. Ref: Dhingra 7e pg 27.