Functional volume of the middle ear after a tympanostomy tube insertion was measured and the correlation between the middle ear volume and acute otitis media or upper respiratory diseases was investigated. Thirty-eight patients (fifty-one ears) with secretory otitis media were studied and divided into three groups according to the middle ear volume at three months postoperatively. The middle ear volume in group A (n=5) was less than 1cc, and the mastoid cavity was opacified on CT scan. In group B (n=27) it was 1-3cc, and in group C (n=19) was more than 3cc.
The average incipient ages of acute otitis media in group A, B and C were 1.6±0.5, 3.1±1.5 and 4.9±2.2 years old, respectively. The onset of acute otitis media in group A was significantly earlier than that of groups B and C (p<0.005). The mean ages of secretory otitis media in each group were 2.8±1.2 years old in group A, 4.7±1.3 in group B and 4.2±1.4 in group C. This differences between group A and the other two groups were statistically significant. The complications such as chronic sinusitis, nasal allergy and cleft palate seem to be more frequent in patients with smaller functinal volumes.
In conclusion, small functional volume of the middle ear was correlated with the early onset of acute and secretory otitis media.

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The histopathologic findings of temporal bone in thanatophoric dysplasia were reported. There were two types (type 1, classic form. type 2, clover leaf form) in thanatophoric dysplasia regarding to clinical and X ray findings. In these temporal bones specific histopathologic findings were distinguished from each other. In type 1 temporal bone, poor formation of the modiolus, the foot of stapes and oval window were found. In type 2, endolymphatic collaps and the loss of organ of Corti were observed. The inner auditory meatus was very deep and abnormal formation of periosteal layer was shown, Regarding to above mentioned findings, a conductive hearing impairment was suspected in type 1 and sensory hearing impairment in type 2.

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There are two kinds classification of cholesteatoma: congenital cholesteatoma and acquired cholesteatoma. According to these classifications, acquired cholesteatoma is classified to a primary cholesteatoma wihtout a perforation of the tympanic membrane, and secondary cholesteatoma with a perforation of the tympanic membrane. But it is believed that all acquired cholesteatomas are caused by retraction pocket in the pars flaccida and the posterior superior quadrant (P. S. Q) of parse tensa of the tympanic membrane. Seventy-two patients of cholesteatomas and 159 patients of otitis media with effusion (O. M. E), under the ages of 15 years, were studied, and the findings of the tympanic membrane under a microscope, particularly the findings of the retraction pocket were analysed and the temporal bone pneumatization on X-ray film was evaluated.
According to the findings of the tympanic membrane, all O. M. E. cases were classified into four types: tensa type with retraction of the pars tensa alone: tensa + flaccida type with retraction of the pars tensa and pars flaccida; adhesion type with adhesion of the pars tensa; and P. S. Q. type with adhesion of the pars tensa and retraction pocket in the posterior superior quadrant. In the tensa + flaccida type, adhesion type and P. S. Q. type, the size of the pneumatized cells were more suppressed and the histological findings of radial fiber of the. lamina propria were more extensively damaged than those of the tensa type with retraction of the pars tensa alone. Consequently the findings of retraction pocket in the pars flaccida and P. S. Q. and adhesion of the pars tensa resembled to the advanced stage of O. M. E.. On the contrary, in 14 cases of cholesteatoma it was clear that the findings of retraction pockets in the very early stage of cholesteatoma, or pre-cholesteatoma, were almost the same findings as observed in the advanced cases of O. M. E.. From these findings it was belived that some of the advanced cases of O. M. E would change to primary acquired cholesteatoma.

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Labyrinthine fistula is often encountered in surgery of chronic otitis media and cholesteatoma. The usefulness of CT scanning for preoperative identification of fistula is evaluated in 8 cases in cholesteatoma surgery. Fistula symptom was observed in 3 but 5 cases. Labyrinthine fistula was recognized on CT scanning in 6 cases. In 5 cases without fistula symptom, CT scanning revealed fistula in 3 but 2 cases. These results imply that CT scanning is very useful but not completely reliable for detection of labyrinthine fistula, and that a great care should always be taken in surgery of cholesteatoma even if CT scanning could not demonstrate labyrinthine fistula.

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Tympanometric screening was performed in children in a primary school and in a nursery school. Four consecutive screenings were performed in a nursery school during a 16-month period to investigate spontaneous change of tympano-gram. The children who had never been treated were selected as subjects. In 4-year-old children incidence of type C and type B was very high, but these were very low in primary school student. The spontaneous improvement of tympanogram was observed in many ears. Type C improved to type A in 79.2% of ears and type B improved to type A in 66.7%, although in some ears the type of tympano-gram was deteriorated. The incidence of rhinitis and sinusitis in children who showed deteriorated or unchanged tympano-gram was higher than in those who showed improved tympano-gram.

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The pure-tone thresholds of air conduction, airbone gaps and gains with prosthesis were investigated in 116 ears with chronic otitis media with perforation in order to clarify the indication and the diagnostic basis of the prosthesis test. The pure-tone thresholds of 65 ears were within 40dB. Sixty-one (95%) among them had no ossicular chain abnormality, and received type I tympanoplasty. In 44 of the 116 ears. the air-bone gaps were within 20dB. Ninty-eight percent of these ears had no ossicular chain abnormality and also received type I tympanoplasty. Thus, in these ears. the prosthesis test was not always necessary. Among 72 ears those air-bone gaps were beyond 20dB, 33 ears showed more than 10dB gains with prosthesis and 27 of these 33 ears received typy I tympanoplasty. Thus it can be said that a 10dB gain with prosthesis was a good indecation for the prospect of the middle ear pathology and the surgical method.

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In the present study the air volume of the middle ear space in 77 ears with chronic otitis media (COM) was measured by tympanometry, and the correlation between the volume (compliance value) and the duration or the age of onset of COM was analysed.
This study showed that the air volume in the middle ear was significantly less in the early onset group (15 years of age or younger) compared to the later onset group. It was also shown that in the group with longer duration of the disease (20 years or longer) the air volume was less than that of the group with shorter duration of the disease.

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The purpose of this study was to investigate the relationship between age and pathological conditions of chronic otitis media. One hundred thirty five operated cases with chronic suppurative otitis media with central perforation of the tympanic membrane were analysed in the present study. These cases were divided into 6 age groups, 10-19, 20-29, 30-39, 40-49, 50-59 and more than 60 years of age. In each age group, middle ear pathologies and pre-and post-operative hearing level were examined.
The air and bone conduction thresholds in speech frequencies before tympanoplasty became higher in accordance with age. The pathological conditions of the epitympanum, the mesotympanum, the mastoid cavity and the ossicular chain were significant in the higher age group. The air conduction threshold after tympanoplasty was better in the younger age group.

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Five cases of congenital cholesteatoma, including one bilateral case associated with bilateral middle ear anomaly, were reported. Review of the Japanese literatures showed that, including our case, there were seven ears of congenital cholesteatoma associated with anomalies of ossicles. In all the seven ears, anomalies of ossicles were found to be hypoplasia of the long process of the incus and/or superstructure of the stapes. Most of reported cases of congenital cholesteatomas occupying in the posterior portion of the mesotympanum without apparent middle ear anomaly, had a loss of the long process of incus and/or superstructure of the stapes.
From these observations it is assumed that although there are a considerable number of cases of congenital cholesteatomas associated with anomalies of the ossicles, the number of reports is limited, because the association of cholesteatoma and ossiculur anomaly is obscure after cholesteatoma becomes larger.

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