Role of Eustachian Dysfunction and Primary Sclerotic Mastoid Pneumatisation Pattern in Aetiology of Squamous Chronic Otitis Media: A Correlative Study

Squamous chronic otitis media (COM) implies formation of a retraction pocket (inactive form) or frank cholesteatoma (active form) in pars tensa or pars flaccida of tympanic membrane. A retraction pocket or frank cholesteatoma are believed to occur due to tubal dysfunction. The present study was undertaken to investigate the pattern of mastoid pneumatisation and Eustachian dysfunction by dynamic slow motion videoendoscopy (DSVE) in cases of both, active and inactive type of squamous chronic otitis media (COM). 52 patients (65 ears) comprising of twenty-six ears with pars flaccida squamous disease and 39 ears with Pars Tensa squamous disease were enrolled for the study. DSVE findings, in terms of grade and type of Eustachian dysfunction were noted. Mastoid pneumatization pattern on CT-scans, and peroperative status of mastoid pneumatisation, especially contracted mastoid with anteriorly placed sigmoid sinus or low lying dura were also recorded for every case while performing tympano-mastoidectomy. Primary sclerotic/diploic type of mastoid pneumatisation pattern and Eustachian dysfunction were found to have inverse relationship in the cases of squamous otitis media. Eustachian dysfunction, diagnosed on DSVE, had significant association with both pars flaccida ( P  = 0.0001) and pars tensa disease ( P  = 0.0007). Primary sclerotic or diploic mastoid were found to be more common in ears with pars flaccida squamous disease than pars tensa COM (46.15% vs. 38.46%, P  < 0.05).