Abstract
The statistical observations of congenital malformation of the external ear was recorded here. The prevent material consisted of 651 subjects having 773 malde veloped ears, which were found in 29000 outpatients examined at the Department of Otorhinolaryngology of Kyushu University Hospital from 1960 to 1965.
The frequency of each kind of maldeveloped ear was: fistula auris congenita 196 patients (251 ears), microtia 174 (192), atresia auris congenita 161 (184), accessory auricle 66 (78), pocket ear 30 (38) and the others 24 (30)(Table 2). The sex distribution of the subjects was: 410 males and 241 females. There was distinct male preponderance, especially in microtia and atresia auris congenita (Table 3). The sides affected were: 340 right-sided, 189 left-sided and 122 bilateral. Unilateral defect was preponderent mainly in microtia and atresia auris congenita (Table 3). The frequency of the patients who had malformed ear visit ing our Department for one year made no difference.
(1) fistula auris congenita: 113 male and 83 female cases; 91 right-side, 50 left-side and 55 bilaterally affected. Locations of fistula: crural, 166 patients; preauricular, 19; helicine, 9; and the others, 2 (Table 3, 7).
(2) microtia: the total number of patients observed was 174 (192 ears) ; males 122, and females 52. 105 right-side, 51 left-side, and 18 bilaterally affected. The preponderances in male and unilateral cases were distinct.
We divided our subjects into five groups. In determining the degree, the gradation of Marx was followed. Degree I cases, consisting of 5 ears, included subjects with auricles which are normal in all the characteristic features except in their extraordinarily small size. In Degree II, to which 46 subjects belonged, part of the characteristic features of an auricle was lost. Degree III included 132 subjects with distinctly malformed auricles. The cavum conchae did not exist and most of the cases were lacking the auditory canal. Degree IV consisted of 9 subjects. At this stage the auricle was very defective, showing only its trace, often a malformed lobule. Degree V was anot i a (Table 8).
(3) atresia auris congenita: the total number of patients was 161 (184 ears) ; male 116, female 45. 91 right-side, 47 left-side and 23 bilaterally affected. As in microtia, distinct male and unilateral preponderances were observed. Atresia mostly accompanied microtia. The patients were divided into three groups. Degree I: high grade stenosis. Degree II: the canal was almost lost, only a hol low. Degree III: complete atresia which was the commonest (Table 3, 10, 11).
(4) accessory auricle: the patients were composed of 34 males and 32 fema les. 27 right-side, 27 left-side and 12 bilaterally affected. It was very interest ing that an accessory auricle (over-development) and microtia (arrested develop ment) appeared in the same patient both and on the same side or each on the respective side (Table 3, 9).
Malformed ear was often accompanied with cleft palate, hare lip, facial hemiatrophia and facial paralysis (Table 5). There was no relationship discover ed between the month of birth and the congenital malformation of an external ear (Table 4, 6). In the course of reporting the statistical studies, hereditary factors and phenocopy were taken into account.
