岡山大学BETTER HEARING CLINICの調査成績（昭和27, 8年度） 第2編 学童耳管咽頭口の型体的分類並に夫と難聴及びアデノイド肥大との関係に就て

It is understandable that lips of the Eustachian-tube orifice in children show the various shapes, as they are in the course of growing of the tubal cartilage, and their lymphatic tissue are so susceptible to the inflammation due to their physiologically excessive development; and therefore, it is thought abnormal forms of these lips are found more often in children than in adults. In order to explore this point still further, the author examined the lips of the Estachian-tube orifice in 550 sides of the third year in elementary school with the nasopharyngoscope, and classified them into six groups according to the shapes of the lips: group Ⅰ, standard form (basic form); group Ⅱ, swollen form; group Ⅲ, overlapped form; group Ⅳ. intermediate form; group Ⅴ, unobservable form (obstructed from view by adenoid hypertrophy); and group Ⅵ. underdeveloped form. Of these, groups Ⅱ, Ⅲ and Ⅳ are caused by one of the three factors; namely, (A) edema, (B) granule, and (C) node. There is a very little relationship among the so-called adenoid hypertrophy, groups Ⅰ, Ⅱ, Ⅲ, Ⅳ, Ⅴ, and the factors A, B, C. The incidence of hard of hearing is more frequent starting with group Ⅲ, followed by groups Ⅳ, Ⅱ, Ⅴ, Ⅵ, and Ⅰ in that order, while it likewise increases in the order of the factors A, B, and C. Looking the degree of hard of hearing from the standpoint of adenoid hypertrophy, deafness due to the changes of the Eustachian-tube orifice in form and factor tends to increase with complication with the adenoid hypertrophy.