Bone mineral density and morphology of the three auditory ossicles, malleus, incus, and stapes, are maintained by osteoclasts and osteoblasts. However, correlation between bone resorptive changes in the ossicles and hearing loss has not been established. In this review, we discuss osteoporotic changes of the auditory ossicles and pathology of middle ear diseases through the study of mice lacking osteoprotegerin (Opg^-/-mice), a soluble decoy receptor for the osteoclastogenic cytokine RANKL. All three ossicles in Opg^-/-mice showed thinning and shortening compared to wild-type controls. Most notably, the junction between the stapes and the otic capsule was fused in Opg^-/-mice unlike in wild-type mice. Furthermore, progressive hearing loss was detected in Opg^-/-mice starting at 6 to 15 weeks of age. These data suggest that OPG plays a crucial role as “audioprotegerin” in hearing by protecting the auditory ossicles and otic capsule from osteoclastic bone resorption. We also discuss clinical implications of resorption of the ossicles for middle ear diseases including otosclerosis and cholesteatoma.

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Several authors reported the effect of steroid administration for inner ear barotrauma as clinical results, however, there is no experimental study to prove its effect. The purpose of this study is to investigate the effect of steroid administration for inner ear barotrauma in the experimental study. Guinea pigs were subjected to rapid compression and decompression between 1 absolute pressure (ATA) and 2 ATA in a chamber within 5 seconds. The guinea pigs that had hearing threshold shift were randomly divided into steroid administrated group (treatment group)(19 ears) and control group (16 ears). In the treatment group, guinea pigs were administrated with dexamethasone at a dose of 2.0mg/kg/day intraperitoneally once a day for 5days after the pressure loading. Before, just after pressure loading, 2, 3, 5, and 7 weeks after pressure loading, auditory brainstem response (ABR) testing was performed, and the healing threshold shift was evaluated. The time course change of the healing threshold shift was compared between the two groups. The time course change of the healing threshold shift was significantly different between the two groups (repeated measured ANOVA, p<0.05), and the healing threshold shift was more remarkable in the treatment group. When compared two groups in the moderately to severely damaged ears, the hearing threshold shift of the treatment group was significantly lower than that of the control group at 2 and 7 weeks after pressure loading (non paired t-test, p<0.01 and p<0.05). In conclusion, we suggested that steroid administration would be effective for the treatment of inner ear barotraumas.

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Introduction and methods: The severity of patulous eustachian tube (PET) and insufficient closure of the eustachian tube (ICET) varies in individuals. However, there are no definitions, diagnostic standards, or treatment guidelines for PET and ICET at present. To establish diagnostic standards and treatment guidelines for future use, preliminary research was conducted using a questionnaire sent to otorhinolaryngologists at 1198 clinics and hospitals nationwide.
Results: The number of completed questionnaires recovery was 437, a response rate of 36.5%. 238 hospitals reported less than one new patient with PET or ICET per month. Moreover, 208 hospitals reported no regular outpatients. Only 17 hospitals reported 11 or more outpatients treated for PET or ICET. About 90% of the hospitals listed three symptoms as suggesting PET and ICET: autophony, aural fullness, and tympanophonia. In addition, about 15% listed hearing loss and tinnitus. The most common facts confirmed by physicians when PET or ICET is suspected were: past history of rapid weight loss, symptom changes with changes in posture, and synchronized movement of the eardrum with respiration as shown by microscopic examination. Most physicians made diagnosis on movement of the eardrum synchronized with respiration, and the results of the eustachian tube function test or the SR mode of impedance audiometry. There was no consensus about effective treatment and therapeutic gain in cases of PET. Prognosis of PET was thought to vary depending on each case. Most respondents replied that patients with obstruction of the eustachian tube were examined more often than those with PET or ICET.
Conclusion: Although PET and ICET may be initially identified in many hospitals, treatment tends to be concentrated at certain hospitals due to referral to specialists. And then the eustachian tube function test is carried out at a limited number of hospitals, though symptoms indicating PET or ICET are commonly recognized by otorhinolaryngologists. Therefore, necessities of common diagnostic criteria, and a treatment guideline were highlighted from this questionnaire survey.

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We evaluated the effectiveness of short-term tympanostomy tube in children with intractable recurrent otitis media. The subjects were 370 children (682 ears) who were diagnosed as having intractable recurrent otitis media. These children underwent insertion of a grommet-type tympanostomy tube, and were followed until the removal of the tube at our clinic between July 2002 and June 2006. The following results were obtained.
1. The patients developed acute otitis media in a mean of 3.6 times/year preoperatively. Postoperatively, the mean number of episodes after removal of the tube per year decreased to 0.47. More than 69.0% of the patients had no further episodes of acute otitis media, and they were classified as a good result.
2. The mean number of days of antimicrobial administration /month was 18.3 preoperatively but markedly decreased to 2.1 in patients with a satisfactory course and to 7.2 in those with a unsatisfactory course. In particular, in patients showing a satisfactory course, the number of antimicrobial administration/month days significantly decreased because of a decreased risk of acute otitis media in the presence of purulent otorrhea.
3. Concerning complications, there were no cases showing perforation of the tympanic membrane. Tympanic sclerotic lesions were observed in 1. 2% of all patients.
4. A tympanostomy tube was re-inserted in 1.3% of all patients and all of these had persistent otorrhea postoperatively. All cases of re-insertion of the tube showed a good course in the first tympanostomy tube insertion.
5. The biggest problem of the short-term tympanostomy tubes was that the tube could be dislodged easily if the otorrhea was mucoid. In this study, we recognized the dislodged grommet-type tube in 68 cases and after all we needed the long- term tympanostomy tube insertion in 55 cases. Therefore, we should make the incision as small as possible when we inserted a grommet-type tympanostomy tube.

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Cleft palate is frequently associated with intractable otitis media with effusion. We investigated chronological changes in the mastoid cell in 108 cleft palate patients (216 ears) during preoperative examinations at Showa University Hospital. Twenty-five patients (50 ears) without cleft palate were also reviewed. We obtained Schi ller's view of x-rays in these patients serially at the ages of 1, 3, and 5 years. After these films were scanned into the computer, the area of each mastoid cell was measured using image analysis software, then the findings were analyzed. The mastoid cell area in the cleft palate patients without otitis media was significantly smaller than that in the cases without cleft palate at each of the ages examined. Although growth of the mastoid cell area with age was found in a cleft palate patient with otitis media, no significant growth of the mastoid cells occurred after insertion of a ventilation tube.

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It has become possible to use circum-aural earphone in clinical pure-tone audiometry because its reference equivalent threshold sound pressure levels were standardized recently. In this study, test-retest intra-subject variability in pure-tone audiometric threshold at seven frequencies with circum-aural (HDA-200) and traditional supra-aural (AD-02) earphones was investigated.
After the first test, each earphone was removed and replaced for the second test. Equivalence of thresholds with the above two earphones was also investigated.
At 12 Hz and 250 Hz, test-retest variability with circumaural earphone was significantly smaller than that with supra-aural earphone. From this result, it was expected that the use of circum-aural earphone could improve accuracy of hearing tests like glycerol test in which the presence of small threshold change must be evaluated at low frequencies.
The mean hearing threshold levels of otologically normal subjects aged between 18 and 25 years were within 2.1 dB at every frequency with circum-aural earphone, whereas they were more than 5 dB at 125 Hz and 250 Hz with supra-aural earphone, as previously reported. There were significant threshold differences at low frequencies of the same ear between two earphones. This result indicates that current calibration method of supra-aural earphone neglecting the influence of sound leakage from the gap between earphone and pinna should be modified.

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We encountered a patient treated for bilateral sudden deafness, whose hearing level became progressively worse. She showed high alkaline phosphatase activity, high urinary hydroxyproline excretion, and typical temporal bone X-ray findings. Her hearing loss (HL) was a high frequency sensorineural HL and a low frequency air-bone gap. Paget's disease of the bone or fibrous dysplasia was suspected, and a temporal bone biopsy was performed and Paget's disease was diagnosed. Oral alendronate effectively improved her condition.

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Idiopathic hemotympanum with facial paralysis and inner ear damages is quite rare. A 45-year-old man presented with idiopathic hemotympanum with moderate hearing loss, equilibrium disorder and facial paralysis. CT findings revealed no fracture in his temporal bone. High-intensity areas on unenhaced T1 weighted MR images were observed at the middle ear, mastoid and a part of the vestibule. Blood coagulation studies showed normal prothrombin time and activated partial thromboplastin time. Any significant increase in the anti-Varicell-zoster virus IgG titer and anti-Herpes simplex virus IgG titer was not observed during first two weeks. After conservative treatments' of administration of corticosteroids and valaciclovir, his hearing and facial paralysis were recovered.

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