Association of chronic otitis media with rhinologic and otologic variations: a high-resolution computed tomography study

<ns3:p>Background Unilateral chronic otitis media (COM) offers a unique opportunity to investigate anatomical variations that may predispose one side to disease while sparing the other. This study aimed to compare the anatomical variations between the diseased and healthy sides of the skull of patients with unilateral COM. Methods This within-subject case-control study, conducted at the Department of ENT of Khyber Teaching Hospital, Peshawar, Pakistan, included 100 temporal bones (50 adult patients) with unilateral COM. Utilizing high-resolution computed tomography scans, COM sides (50 temporal bones) were compared with the healthy sides (50 temporal bones) in terms of anatomical variations in the nose, paranasal sinuses, temporal bone, and eustachian tube (ET). Results Among the rhinologic variants, a deviated nasal septum was more frequent on the COM side than on the healthy side (19 vs. 8; p=0.05, OR=2.37), and the angle of septal deviation was significantly larger on the COM side (1.89±2.66 vs 0.46±1.13; p=0.003, Cohen’s d=0.44). Concha bullosa was more common on the COM side (18vs 9; p=0.04, OR=3.25). Sinus opacification and turbinate hypertrophy showed no statistically significant difference between the two sides (p&gt;0.05). Among the otologic variants, the mastoid was less pneumatized (4vs 20) and more frequently sclerotic on the COM side (39vs 12; p&lt;0.01, Cramér’s V=0.54). The prevalence and thickness of Korner septa were similar on both sides (p&gt;0.05). ET lengths were comparable between sides, but the ET angle was narrower on the COM side (22.09±1.80 vs 22.90±1.76; p=0.01, Cohen’s d=0.34). The tubotympanic angle was wider (148.86±3.57 vs 144.76±2.15°; p&lt;0.001, Cohen’s d=0.96), and the pretympanic diameter was smaller on the COM side (3.03±0.77 vs 3.91±0.56, p&lt;0.001, Cohen’s d=1.01). Conclusion Significant anatomical differences were observed between the diseased and healthy sides of the skull in patients with unilateral chronic otitis media, particularly in the nasal septum, concha bullosa, mastoid pneumatization, and ET anatomies.</ns3:p>