Clinical Relevance Between The Abnormal Gasification Of Epitympanum And Aditus Of Antrum And The Pathological Mechanism Of Chronic Otitis Media

Objective:To study the anatomic characteristics of anterior epitympanum recess(AER)and aditus of antrum(AA)in otitis media,exploring the clinical relevance between the morphological changes of AER and AA and otitis media.Materials and methods:32 patients with chronic suppurative otitis media(CSOM)and 9 patients with cholesteatoma of middle ear(CME)from September 2016 to August 2018 were enrolled in the study.In Zhongshan Affiliated Hospital of Dalian University from September 2017 to August 2019,23 patients with CSOM and 9 patients with CME were selected for the study.The basic information(sex,age and course of disease)of all patients were collected,and the CT imaging data of temporal bone were collected in patients with CSOM and CME.All patients suffered from monaural disease.The anatomic structure of both ears was measured and the measured data of healthy ears were used as control.CT axial examination of temporal bone was performed in patients with CSOM and CME,and the coronal image was reconstructed by post processing with iconography.The AER of both ears was measured on the axial and coronal CT of the temporal bone,and AA of both ears was measured on axial CT.Measurement method of AER:Selecting the axial CT of temporal bone in both ears of patients,taking the direction consistent with the long axis of malleanvil joint as the benchmark,measuring the distance between the front boundary of AER and the anterior attic bony plate,and taking the maximum value as the length of AER,that is,the anterior to posterior distance distance(AP).On the axis perpendicular to the long axis of malleanvil joint,measuring the maximum distance between the inner and outer walls of AER,which was taken as the width of AER,that is,the transverse distance(T).Obtaining the coronal CT image of temporal bone through image post-processing,and measuring the distance from tensor tympanic semicanal to tegmen tympani as the superior-to-inferior distance of AER.Measurement method of AA:on the axial position of temporal bone CT,measuring the maximum internal and external distance of AA,that is,the width distance(W).The structure of AER and AA was measured by two radiologists and one otologist through AGFA HealthCare.SPSS 24.0 software was used for data analysis.All data were tested by independent samples test and paired samples test.The statistical difference was analyzed,and P<0.05 was regarded as the statistical difference.The size of the above-mentioned anatomical structures of the healthy ear and the affected ear of CSOM and CME patients were compared respectively,and the data of the healthy ear on the left and right sides of all patients were compared.Through the measurement and observation of its structure on temporal bone CT,the clinical relevance between abnormal gasification and otitis media diseases of AER and AA was analyzed.Results:1.The AP value,T value,SI value and W value of AER in healthy ears of CSOM patients were 2.40±0.84mm,2.87±0.98mm,3.37±0.97mm and 3.28 ± 1.03mm respectively.The AP value of AER was 2.60±1.04mm,T value was 3.44±1.14mm,SI value was 4.04±1.33mm,and W value of AA was 2.86±1.03mm.The results showed that there were significant difference in T value,SI value and W value of AA between the affected ears and the healthy ears(P<0.05).The T and SI values of AER in affected ears were higher than those in healthy ears.The W value of AA in the affected ears was lower than in healthy ears.2.The AP value,T value,SI value and W value of AER in healthy ears were 2.36±1.12mm,2.77 ±0.98mm,3,76 ± 1.24mm and 3.23±0.65mm respectively.The AP value of AER in affected cars was 2.53±1.23mm,T value was 3.34±1.06mm,SI value was 3.54±1.38mm,and W value of AA in affected ears was 2.70±0.88mm.The results showed that there was significant difference in the W value of AA between the affected ear and the healthy ear(P<0.05).The W value of the affected ear was lower than that of the healthy ear.3.The AP value,T value,SI value and W value of AER of left healthy ear in all patients were 2.07±0.89mm,2.99 ±1.01mm,3.14±0.81mm and 3.31±1.28mm respectively.The AP value,T value,SI value and W value of AER of right healthy ear were 2.70 ±0.85mm,2.68± 0.92mm,3.82 ± 1.17mm and 3.03 ± 0.64mm respectively.There were no significant difference in AP,T,SI and W values of AA between the right and left healthy ears(P>0.05).Conclusion:1.The abnormality of middle ear bone structures is the main cause of CSOM and CME.2.A A stenosis plays an important role in the pathogenesis of CSOM and CME.