Anatomical Anomalies of Eustachean Tube and Its Role in the Development of Otitis Media with Effusion

Although many years have passed from the recognition of otitis media with effusion (OME), there is much controversy on its etiology, pathogenesis, and treatment strategies. This condition occurs more frequently in infants and children. Moreover, it is more common in Eskimo and Native American than White American and Blacks. In addition, socioeconomic and cultural factors can affect its prevalence. In this regard, racial differences for length, width, and angle of eustachean tube and skull base dimensions should also be considered. In this study, lateral cephalography was used. In this research, 30 patients with bilateral OME referred to otolaryngology clinic of Loghman Hakim hospital as case and 30 children at an age range of 4-9 years as control were chosen. Then, for evaluation of mastoid system, middle ear, and eustachean tube, the reference points were determined as follows: posterior nasal spine (PNS), pterygoid (PTT), Mastoid apex (MA), middle ear point (MEP), posterior mastoidal point (PMP), and tuberculum articulare (TA). Thereafter, the variables MEP­PMP, MEP-MA, MEP-PT, MEP-TA, TA-PT, TA-PNS, PT-PNS in mm, and MEP-PT­PNS in degree were measured. The data was obtained for control and case groups and the average values were determined. For statistical analysis, student's t-test was used. The averaged age for control and case groups was 73 ± 16 and 78 ± 18.6 months respectively and there was no significant difference between them. The results showed that there was only a significant difference between the two groups regarding MEP-PMP, MEP-PT, MEP-TA, TA-PNS, and PT-PNS (P<0.001). Therefore, it can be concluded that in patients, there exist a shortened tensor veli palatini in both horizontal and vertical portions and a less mastoid pneumatization. These results showed that there is an anatomical (craniofacial) difference between affected patients and normal persons and it should be considered as an important ethiopathogenetic factor.