On tympanometry, a Type Ad (very high compliance) curve is most characteristically associated with which middle ear condition?

• A Ossicular chain disruption (discontinuity) at the incudostapedial joint ✓
• B Otosclerosis (fixation of footplate)
• C Eustachian tube dysfunction with negative middle ear pressure
• D Acute otitis media with effusion

Explanation

A Type Ad tympanogram shows abnormally high peak compliance (high peak, steeply rising curve), indicating a highly mobile, floppy middle ear system. This is characteristically seen in ossicular discontinuity (most commonly incudostapedial joint disruption), where the ossicular chain no longer constrains tympanic membrane movement. Otosclerosis produces Type As (low compliance, stiff system). Eustachian tube dysfunction produces Type C (negative peak pressure). Acute otitis media with effusion produces Type B (flat tympanogram).

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.