Axial computerized tomography scans from 14 patients with adhesive OM and 19 cases (control group) with normal middle ear-tympanic membrane were retrospectively examined in terms of petroclival angle and eustachian tube-tympanic cavity ventilation angle. Measurements of these two angles were compared between the two groups. A correlation was also investigated between these two angles.
The petroclival angle (54.5° vs 62.3°) and the eustachian tube-tympanic cavity ventilation angle (156° vs 162.6°) in the adhesive OM group were narrower than those of controls (p < 0.01). The correlation analysis showed that there was a strong association between two angles (r, 0.803; p < 0.01).
More medially positioning of the petrous bone and acutely angled-eustachian tube-tympanic cavity ventilation axis were observed in this study. It would be reasonable to conclude that these findings might take part in development of adhesive OM. We should also admit that these results do not decline the previous theories that account for development of the adhesive otitis media.