Provision of binaural hearing should be considered the standard of care for hearing impaired patients whenever it can be provided without significant risks. In the case of patients with severe to profound hearing loss effective binaural hearing may require bilateral cochlear implantation. The combined experience of many centers around the world has provided substantial insight into the benefits of bilateral cochlear implantation. At the Dallas Otolaryngology Cochlear Implant Program, over 40 children and 40 adults have been implanted bilaterally. Although there are some benefits that require further detailed study to quantify, there are many benefits that have become both objectively and subjectively apparent. Our experience, combined with published results of other centers, has allowed us to define guidelines for which the benefits of bilateral cochlear implantation significantly outweigh the risks. For these patients, bilateral implantation should be considered the standard of care, even as we continue to define the increasing benefits and expand the criteria to more patients over the long term.
This article will review the data available in the scientific literature as well as presentations at respected scientific meetings and will discuss our center's experience and rationale for providing binaural hearing to cochlear implant recipients of all age groups.

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Five small asymptomatic vestibular schwannoma were discovered on routine examination of 973 serially sectioned temporal bones of 521 individuals. One of 5 cases was diagnosed as neurofibromatosis II. The incidence of the tumor including neurofibromatosis II was 0.96%, and that of the tumor excluded the case of neurofibromatosis II was 0.77% of individuals in this series. The mean age of the four individuals except neurofibromatosis II was 70 years, the specific ages being 63, 67, 73, and 77 years. The small size of the vestibular schwannomas and the advanced ages of 4 individuals in this study suggest that schwannomas can either remain inactive for a long period or cease to grow at times. The finding of asymptomatic vestibular schwannoma indicates the high incidence of this tumor in the general population in Japanese as well as in Caucasian. The much lower incidence of symptomatic tumors can only be explained by the conclusion that this tumor exhibits considerable variation in growth characteristics, and usually the tumor enlarges so slowly as to be of no clinical symptoms, but occasionally it grows more rapidly to become symptomatic and require surgical removal. The high incidence of asymptomatic vestibular schwannoma and low incidence of symptomatic one suggest that watchful waiting is a realistic and justifiable alternative to treatment, particularly in patients who have small vestibular schwannoma.
The tumor in 3 cases arose from the inferior division of vestibular nerve, in one from the superior division. Another case of neurofibromatosis II had a multicentric origin from the cochlear nerve and the inferior division of vestibular nerve in unilateral ear. Many vestibular schwannomas originate on the inferior division of vestibular nerve, and this fact suggests that the earlier estimate by caloric test in the evaluation of suspected vestibular schwannomas would be inaccurate.

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In the present study, we investigated the distribution of patients with sudden deafness in Japan using the data obtained by the fourth nationwide epidemiological survey on sudden deafness conducted by the Research Committee of the Ministry of Health Labour and Welfare in 2001. We investigated the distribution of patients by dividing the whole country into 9 districts and 47 prefectures. The annual number of patients with sudden deafness per 100, 000 was from 17 (Shikoku) to 42 (Chugoku) and from 3 (Yamanashi, Nagasaki) to 48 (Osaka), respectively. More patients tend to be reported in densely-populated areas judging from the data concerning the distribution of patients per 100, 000 in each prefecture.

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I investigated 146 S. pneumoniae strains and 257 H. influenzae strains isolated from the epipharynx of 319 pediatric patients with severe acute otitis media from January 2006 to August 2007, and the detection frequency of drug resistant bacteria, the patients' age and use of day care facilities were analysed. And also the annual change in the detection frequency of drug resistant bacteria in these patients with that reported in 2004 was compared.
1. The risk factors for infection with drug resistant bacteria in these patients included their age, use of day care facilities, administration of antibiotics within the previous month and recurrent otitis media. In this study, the patients received antibiotics within a month before visiting our clinic and those who developed 5 or more recurrent acute otitis media in the preceding 6 months were excluded.
2. The relation between the detection frequency of drug resistant bacteria and their age showed that the drug resistant S. pneumoniae (DRSP) was detected in significantly higher rate in the patients under 3 years of age compared to the patients aged 3 or older, while the detection frequency of ampicillin (ABPC)-resistant H. influenzae showed no differences between these two age groups.
3. The relation between the detection frequency of drug-resistant bacteria and the use of day care facilities in the patients under 3 years of age showed that DRSP and ABPC-resistant H. influenzae were detected with significantly higher frequency in the patients attending a day care facility than in those who did not.
4. Among the patients with infections with drug-resistant bacteria, a special attension should be paid to those with S. pneumoniae infection under 3 years and attending to a day care facility. Amoxicillin/clavulanic acid (AMPC/CVA)(14: 1) was apparently effective in these patients. However, AMPC/CVA (14: 1) was ineffective in some patients under 3 and ABPC-resistant H influenzae was isolated from the majority of them. As the sensitivity of cefditoren (CDTR) to ABPC-resistant H influenzae was favorable, high dose CDTR proved effective in patients with ABPC-resistant H influenzae infections refractory to AMPC/CVA (14: 1).
5. The detection frequency of DRSP was approximately 40% in 2001, 2003 and 2006-2007. Moreover, it was maintained low throughout the country. On the other hand, the detection frequency of ABPC-resistant H influenzae significantly increased in 2006-2007 compared with that in 2001.
These findings indicated that the detection frequency of DRSP could be maintained low by adopting a penicillin-based strategy for the treatment of upper respiratory tract infections in the pediatric patients, while there might be an increase in the detection frequency of ABPC-resistant H influenzae.

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The tympanic perforation closure technique using Terdermis^® was studied in 30 cases: 18 males and 12 females.
Their ages ranged from 7 to 79, with the average age of 45.7.
During operation, the perforation edge was removed circumferentially to make the eardrum fresh.
Terdermis^® with a silicon membrane was inserted under the perforation.
Tissue adhesive (fibrin glue) was not used.
Postoperatively, no oral antimicrobial agents nor ear drops were administered.
At the initial operation, successful closure of perforation was achieved in 19 out of 30 cases (63%), while 11 cases were unsuccessful.
Perforation closure rate was 86% including successful cases of the second operation.
This technique can be effective for a comparatively small perforated eardrum.

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Endoscope is very useful for otosurgery of congenital cholesteatoma in children, because endoscopic observation can give a full view to find residual cholesteatoma in the tympanic sinus or behind the ossicles or to avoid any injury of the important structures.
In the middle ear, there is a region where microscopic observation is very difficult due to the anatomical feature. It is very dangerous to perform otosurgery without adequate observation of these structures.
We experienced 7 children with congenital cholesteatoma in the past 6 years and obtained good results. We reported a case of the youngest one that was the most difficult to inspect througout the middle ear cavity.
Disadvantage of endoscope was that otosurgeon has to hold an endoscope with the left hand and handle forceps or suction tube with the right. It might be difficult to handle endoscope and surgical tools together in the narrow external canal. We think that otosurgeon needs some experience for endoscopic operation.
Our conclusion was that endoscope should be used in otosurgery of cholsteatoma in children to perform safe operation with a full view of the middle ear cavity and to avoid to overlook the residual lesions.

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In 2000, a new classification system of ossicular reconstruction was proposed by the Terminology Committee of Otological Society of Japan. We have often used this new classification to evaluate postoperative hearing after treatment by different surgical techiniques. In the present study, we assessed the postoperative outcome of Type III or IV tympanoplasty by measuring the hearing levels at various frequencies.
A total of 357 ears (189 right ears and 168 left ears) in 160 male and 197 female patients aged from 6 to 74 years who were followed up for at least six months were studied. The surgical technique was Type III-cin 125 ears, III-i in 117 ears, IV-c in 63 ears, and IV-i in 52 ears. The success rate of these techniques was 75%, 83%, 43%, and 58%, respectively. Overall, tympanoplasty was successful in 69%(248/357) of the patients. In these 248 successful cases, the improvement of hearing was examined at various frequencies. Comparison of the techniques with respect to the improvement of average hearing after surgery showed no significant differences between any pair of techniques. Then the improvement of hearing at each frequency was compared. The results showed that there were no statistical differences at 250, 500, or 1, 000 Hz, but the Type IV-i technique tended to achieve better hearing at 2, 000 Hz or higher frequencies and there was significantly better improvement than with the Type III-i technique. At 4, 000 Hz, the Type IV-i technique provided significantly better hearing than both the Type III-c and II-i techniques.

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Between 1980 and 2006, 20 patients with malignant tumors of the external auditory canal and middle ear were treated at the Department of Otolaryngology, Shiga University of Medical science. Eleven patients with tumors of the external auditory canal and nine patients with tumors of the middle ear were registered. Lymph nodes metastasis and distant metastasis were not observed in all cases. In the external auditory canal tumors, partial resection of the external auditory canal was performed in one case, total resection of the external auditory canal in 4 cases, and partial temporal bone resection in 6 cases. No recurrence was noted in all cases with external auditory canal tumor by the en bloc resection. Surgical treatments were performed in five of nine patients in the middle ear tumors, radical mastoidectomy in three cases, partial temporal bone resection in one case, curettage of the tympanic tumor in one case. The prognosis of the middle ear tumors was very poor. Only the case that enforced curettage in tympanic tumor was alive. For the treatment of malignant temporal bone tumor, the precise diagnosis of the tumor involvement and en bloc surgical resection is important.

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Congenital cholesteatoma is classified into the closed type (characterized by cystic epithelium) and the open type (characterized by membranous epithelium). It has been reported that the closed type is common, while the open type is relatively rare. Since conductive hearing impairment is a presenting symptom in most of the patients with an open type of congenital cholesteatoma, this condition is often detected during exploratory tympanotomy. Although open type cholesteatoma is said to be associated with a high incidence of auditory ossicular malformations, there is still controversy on this issue. We treated 3 patients with the open type of cholesteatoma. The present report described their clinical findings and discussed the characteristics of this disease.
Case 1
A 7-year-old girl with left-sided conductive hearing impairment was referred to our clinic for detailed examination. Since CT scans revealed a defect of the incudo-stapedial joint, exploratory tympanotomy was performed. As a result, a very small open-type cholesteatoma was found, which extended from the region corresponding to the long process of the incus to the facial nerve canal. After dissecting the cholesteatoma, conductive hearing was restored by tympanoplasty (III-i). The patient has had no recurrence 10 years after surgery.
Case 2
A 34-year-old woman presented to her local clinic with left-sided tinnitus. She was referred to our clinic because left-sided conductive hearing impairment was detected, although the tympanic membrane was normal. Since CT scans revealed a defect in the long process of the incus and a slight soft tissue shadow around the defect, exploratory tympanotomy was performed. This revealed an open-type cholesteatoma spreading from the facial nerve canal to the foot plate of the stapes. After resection of the cholesteatoma, conductive hearing was restored by tympanoplasty (IV-i).
Case 3
A 6-year-old boy was referred to our clinic after hearing impairment was detected at a school medical check-up. CT scans revealed a defect in the process of the incus, so exploratory tympanotomy was performed. Membranous tissue was detected near the incudo-stapedial joint, and the head of the stapes was adherent to this tissue. After the membranous tissue was removed, an open type cholesteatoma was found on the facial nerve canal. There were absence of curura of the stapes. His conductive hearing was restored by tympanoplasty (IV-i).
The tympanic membrane is normal in most patients with the open type cholesteatoma, and it is difficult to make an accurate diagnosis of this disease preoperatively based on imaging alone. When patients with conductive hearing impairment and a normal tympanic membrane are seen, it is important to take this type cholesteatoma into consideration along with auditory ossicular malformations and otosclerosis.

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Glomus tumors are highly vascular neoplasms of neural crest origin. Preoperative embolization provides certain advantages during surgery, including decreased blood loss and improved resection. However, the role that preoperative embolization should play is still a matter of controversy due to the risk of potential complications, such as cranial nerve deficits.
The first case was resected without preoperative embolization, since it was a small tumor on the promontory. The surgery was completed successfully with little blood loss.
The second case had preoperative embolization since the tumor was larger and extended to the hypotympanum. On preoperative angiography, the petrous branch of the middle meningeal artery and the stylomastoid artery contributed to the tumor's blood supply. Both of these arteries were occluded using PVA embolization material. Since both arteries are responsible for blood flow to the facial nerve, there was a risk of facial palsy, but, fortunately, no neurological abnormality occurred after embolization. Surgery was subsequently performed 24 hours after embolization.
In the paper, the blood supply of glomus tympanicum tumors and variations in the blood supply to the facial nerve are discussed.
Small Glasscock type 1 tumors do not require embolization.

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Wegener's granulomatosis (WG) was first described as a disease independent of polyarteritis nodosa by Dr. Wegener in 1939. Its main pathological features are necrotizing granuloma and vasculitis of the upper airway, lower airway, and kidney. However WG can also involve the temporal bone because it is a systemic autoimmune disease. There were few reports showing the temporal bone pathological findings, and the mechanism of sensorineural hearing loss has not yet been elucidated. We described the mechanism of hearing loss on the basis of temporal bone pathological findings.
The patient was a 74-year-old woman whose first symptom was nasal discharge with blood. She was diagnosed of WG and administered with cyclophosphamide and steroid, and subjected to radiation therapy. However her hearing loss deteriorated, and finally she died of pneumonia. Temporal bone pathological findings revealed almost total loss of osteoblasts in the both cochlear and vestibular labyrinthine capsules, resolution of the vestibular bony labyrinth, and infiltration of inflammatory cells into the vestibular labyrinth. We speculated the following mechanism. Deposition of autoimmune complexes in the vessel walls of the labyrinthine capsule caused thickening of the vessel walls, and blood flow was disturbed. This led the labyrinthine capsule to necrosis with osteoblast defluxion. Finally, the bony labyrinth was resolved, and inflammation occured in the inner ear. This was thought to be one of the mechanisms of sensorineural hearing loss associated with WG.

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We report a case of the temporal encephalocele with severe middle ear infection.
A 35-year-old woman was diagnosed with chronic otitis media (CT scan in 2000 showed no specific findings), and had a history of purulent otorrhea and the appearance of severe granulation in 2004.A bony defect of the tegmen tympani was demonstrated on 3D-CT scan of the temporal bone, and the signal from the region extruded through the bony defect was continuous with that of intracranial tissue on sagittal plane MRI. On pathogenic examinations, cortical neural tissue surrounded by granulation was diagnosed.
As the middle ear infection was intractable to all preoperative treatment, the patient underwent a 2-staged and combined approach in order to minimize the surgical risk. In the first stage of surgery via the middle fossa, the herniated brain tissue was amputated without opening the middle ear cavity. The bone defect was repaired using a three-layer graft (periosteum-free bone-periosteum) and a temporalis fascia flap extradurally.In the second stage via a transmastoidal approach, amputated brain tissue with granulation that filled the mastoid cavity was removed and the bone defect was covered with a periosteal flap at the side of the mastoid cavity. There was no further otorrhea or CSF leakage postoperatively.
Each of the three surgical approaches has a specific advantage, and generally, the preferred surgical approach is determined by the position, size and presence of infection. When infection in the middle ear cannot be controlled as in the present case, 2-staged and combined surgery is one of the surgical options for reducing the intra cranial infection.

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Objective pulsatile tinnitus (PT) is caused by various diseases, including glomus tumors, atherosclerotic carotid artery disease, and arteriovenous shunts. Of these above mentioned diseases, both aquired arteriovenous fistulas (AVF) and aneurysms of the superficial temporal artery (STA) have generally occurred after trauma. To the best of our knowledge, only two cases with nontraumatic AVF of the STA have been described
A 70-year-old woman presented with PT of the left ear without a past history of head trauma. The continuous PT was synchronous with her heartbeat. The vascular bruit at the left preauricular region was audible with otoscope and stethoscope.
A palpable thrill at the same region disappeared by compressing the proximal STA. Ultrasound, CT, MRI and selective angiography were performed and a fistula from aneurysm of the STA through the unknown vein into the internal jugular was demonstrated. The patient underwent surgery to remove the lesion. The thrill pulsated deep behind the parotid gland was disappeared, when temporary clips was placed on the external carotid artery. So the external carotid artery was ligated, and there has been no sign of recurrence 11 months after the surgery.
The patients with a complaint of PT are not so common, but life-threatening diseases could be present. And the treatment for PT could be possible in some cases. Therefore, it is important to make a correct diagnosis in these patients by meticulous history taking as well as physical examinations. Examinations by otoscope and stethoscope are essential in all patients. Furthermore, ultrasound and selective angiography were helpful for diagnosis in the present case.

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We report a case of hereditary conductive hearing impairment, which was diagnosed by subsequent examinations, although it was considered as pseudohypacusis at the first visit. Since the patient had hyperopia and broad thumbs, Teunissen-Cremers syndrome was suspected. Since her hearing was fluctuated, determining of a true threshold of her hearing was difficult. CT, tympanometry, stapedials muscle reflex, and other tests were performed. Finally, we diagnosed of conductive hearing impairment based on auditory brainstem response (ABR). Exploratory tympanotomy was performed and ossicular anomaly and stapes fixation were detected. Her hearing was improved by stapedotomy. When pseudohypacusis was suspected, a careful examination is necessary. It was considered that the diagnosis of conductive hearing impairment is very important in this case, because hearing improvement can be expected following an appropriate surgical procedure.

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Perception deafness caused by the mitochondrial 1555 A>G mutation has been observed frequently in Japan. Recent studies indicate that patient having this 1555 mutation is more likely to be suseptaible to aminoglycoside antibiotics. Therefore, if the presence of 1555 mutation can be detected, administration of aminoglycoside antibiotics can be prevented. This genetic examination to detect 1555 mutation could be one of the most significant items in personalized medicine. We have developed a qualitative assay to detect 1555 mutation using Invader system.
While 1555 mutations were assumed to be all homoplasmic, recent studies have indicated that heteroplasmy exist among 1555 mutation. Using PCR-RFLP, Abe et al reported that two out of 341 congenital deafness patients examined were heteroplasmic. In order to examine the heteroplasmy in detail, we have modified the current qualitative Invader Assay system for detection of 1555 mutation to be a more quantitative system to detect heteroplasmy.
Standard curve was generated from serial dilutions of wild and mutant type plasmids by measuring the fluorescence signal for conversion to quantitative coefficient.The copy number of mutant and wild type plasmids were determined by substitution of quantitative coefficient to the standard curve. The amount of mutant type was expressed as % heteroplasmy against total mitochondrial DNA
While results from PCR-RFLP were 5% and 95% heteroplasmy, the quantitative Invader Assay presented 2% and 91% heteroplasmy. Accuracy and reproducibility has been verified. This quantitative Invader Assay may become useful tool in determining the relationship between the amount of heteroplasmy and clinical manifestation.

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