Histologic Serial Changes of Obliterating Materials in the Rat Temporal Dorsal Bullae / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Mastoid obliteration surgery is a modern trend for otitis media either with or without cholesteatoma. The aim of our study is to evaluate histologic changes and effectiveness over time resulting from different obliterating materials and the existence of mucosa in the temporal dorsal bullae in rats. MATERIALS AND METHOD: Rats were divided into two groups. One group had the mucosa removed and was treated with trichloroacetic acid (TCA). The other group with mucosa remaining was untreated. The temporal dorsal bullae of the two groups of rats were obliterated with Mimix(R) (hydroxyapatite cement), Regenafil(R) (demineralized bone matrix), cartilage chip, and bone chip. Three months and again six months after the implantation, 5 animals in each group were examined. A histological study was performed to evaluate inflammation, new bone formation, and mucocele formation within the bullae. RESULTS: The group that had Mimix(R) implanted had a high inflammatory reaction, low implanted material resorption and cyst formation. The group with Regenafil(R) implanted had high cyst formation and more cyst formation with the passage of time. The group with bone chip implanted had high new bone formation, but also high cyst formation. The group that had cartilage chip implanted had high new bone formation, low implanted material resorption and low cyst formation. CONCLUSION: Cartilage chip is the only material that should be used in the air cell with mucosa remaining. Demineralized bone matrix and bone chip should not be used in the air cell with mucosa remaining. Hydroxyapatite cement should not be used due to severe inflammation.

Histopathologic Study on the Obliteration of the Temporal Dorsal Bullae in Rat Using Hydroxyapatite Cement and Demineralized Bone Matrix / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Mastoid obliteration surgery is a useful technique for otitis media either with or without cholesteatoma. Obliterating materials have to satisfy low antigenecity, less inflammation, little tissue resorption, high regeneration power and good integration into the host tissue. The aim of our study is to evaluate histopathological changes and effectiveness resulting from the different obliterating materials in the temporal dorsal bullae in rats. MATERIALS AND METHOD: We divided the rats into two groups. Group A was untreated, but group B underwent removal of mastoid mucosa with 2% trichloroacetic acid (TCA). Both groups had mastoid obliteration by the implantation of hydroxyapatite cement (Mimix(R)) and demineralized bone matrix (Regenafil(R)). Twelve weeks after the implantation, a histological study was performed to evaluate remaining implanted material, new bone formation and the formation of cysts within the bullae. RESULTS: There was no or minimal inflammation or foreign body reactions in the mastoid obliteration groups with Mimix(R) and Regenafil(R). In the obliterated group that was not treated with 2% TCA, the remaining implanted material with Mimix(R) group was more than in the Regenafil(R) group (p<0.05). The obliterated groups of Mimix(R) and Regenafil(R) were similar with respect to new bone formation. The mucocele formation in the obliterated groups treated with 2% TCA was less than in the obliterated groups not treated with 2% TCA (p<0.05). CONCLUSION: We suggest that Mimix(R) and Regenafil(R) could be valuable resources as graft materials for mastoid obliteration procedures. The research continues for evaluation of long term results of these materials and their potential as graft materials.

Results of Bone Mineral Density Measurement in Woman Patients with Idiopathic Benign Paroxysmal Positional Vertigo / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: It has been proposed that displaced particles arising from otoconial degeneration are the leading cause of idiopathic BPPV (iBPPV). Otoconial degeneration might be linked with skeletal decalcification due to both conditions being related to a disturbance in calcium metabolism. The aim of this study was to evaluate the results of bone mineral density (BMD) measurement in women with iBPPV. SUBJECTS AND METHOD: Fifty-four women with iBPPV underwent BMD test and the results were given as a T-score. We compared the T-scores of the patients with those of 173 healthy women by age and by the presence of menopause, and we also compared the T-scores by type of iBPPV among the premenopausal patients. RESULTS: In all age groups, the mean T-score was significantly lower in the patients group than in the control group (p<.001). Regardless of the presence of menopause, the mean T-score in the patients was significantly lower than that in the control group (p<.001). By type of iBPPV, there was no significant difference in the T-scores among the groups. CONCLUSION: This study demonstrates that the values of BMD measurement in women with iBPPV were significantly lower than in the control group regardless of age or the presence of menopause. The results of this study suggest that iBPPV is linked with calcium metabolism. Future study will elucidate the utility of the therapy for disturbed calcium metabolism to decrease the recurrence of iBPPV.

Bilateral Cochlear Implantation in Four Children / 대한이비인후과학회지

The benefits of bilateral cochlear implants (CIs) include better understanding of speech in noise and localization of sound sources. Following the improvement observed in adults, children were also included in the bilateral CIs program. The aim of this study was to investigate the impact of bilateral CIs use on speech perception in quiet and in noise. Four children underwent testing from 9 to 18 months after activation of bilateral hearing. Speech perception tests in quiet and in noise (signal to noise ratio of +10 dB) were performed in all children with the first CI alone and bilaterally. Subjects showed varying degrees of improved performance on speech perception tests in quiet and in noise according to bilateral auditory experience. Bilateral CIs can offer a substantial benefit in speech perception in quiet and in noise. The extent of the advantage, however, may require a more prolonged period of adjustment and learning.

Clinical Features of the Dizzy Patients with Vertebrobasilar Insufficiency / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Dizziness is the most common symptom of vertebrobasilar insufficiency (VBI), occurring in at least two-thirds of patients. The aim of our study is to document the clinical features and the treatment outcomes in the dizzy patients with VBI. SUBJECTS AND METHOD: A retrospective review of 36 patients suffering dizziness associated with VBI was performed at a tertiary referral center. RESULTS: The most frequent type and duration of dizziness were rotational (52.8%) and minute (55.6%). Sixteen patients (44.4%) reported that their episodes of dizziness occurred several times per a month. Half of the patients had at least one isolated episode of dizziness and in 25% VBI began with an isolated episode of vertigo. Twenty-three patients (63.9%) had risk factors for cerebrovascular diseases. Benign paroxysmal positional vertigo occurred in 27.8%, and 38.9% had a significantly decreased or absent response to caloric stimulation. On the dynamic posturography, visual dysfunction (33.4%) and vestibular dysfunction (19.4%) were observed. Thirty-two patients (88.9%) had abnormal finding on the pure tone audiometry. Nineteen (61.3%) of 31 patients experienced resolution or significant reduction of their episodes of dizziness with treatment. But one patient progressed to acute infarction. CONCLUSION: VBI-associated dizziness cause various clinical manifestations and there should be relevant differential diagnosis for episodic vertigo that last only minutes. We should pay special attention to the VBI in patients with isolated, transient dizziness and the risk factor of the cerebrovascular disease.

Vestibular Evoked Myogenic Potentials Produced by Stimulation with 500 Hz-tone Burst / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Vestibular evoked myogenic potential (VEMP) is muscle reflex caused by surface electrodes following repeated high-intensity auditory stimulation. The current study attempted to determine whether VEMP can be consistently evoked from the sternocleidomastoid muscle (SCM) by the 100 dB air-conducted and 50 dB bone-conducted 500 Hz-tone burst. SUBJECTS AND METHOD: Air-conducted and bone-conducted VEMPs in response to 500 Hz-tone burst were recorded from the SCM of 13 normal volunteers. Subjects were seated on their chairs and made to hold their heads turned up as far as possible towards the side, contralateral to the stimulated ear voluntarily. Two different sound durations (rise/fall time=2 msec, plateau time=2 msec[2/2] and rise/fall time=5 msec, plateau time=5 msec[5/5]) were presented through a insertphone or bone vibrators. Latencies and amplitudes of p13 and n23 responses were measured. RESULTS: All normal volunteers showed p13-n23 responses to 50 dB bone-conducted tone burst as well as to 100 dB air-conducted tone burst. The values of latency of p13 and n23 were the most reliable at 5/5 air-conducted in evaluation by coefficiency of variance. Mean p13 and N23 latencies by airconducted tone burst were significantly longer than those of bone-conducted. Mean p13-n23 amplitudes by air-conducted tone burst were significantly larger than those by bone-conducted at 2/2 sound duration. CONCLUSION: VEMP could be consis-tently evoked by the 100 dB air-conducted and 50 dB bone-conducted 500 Hz-tone burst, especially at 5/5 air-conducted.

Aging Effect on the Morphology of the Otoconia Using Scanning Electron Microscopy / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Displaced otoconia in the semicircular canal from senile otoconial degeneration have been believed as a major cause of benign paroxysmal positional vertigo (BPPV). The otoconia are mainly composed of calcium carbonate, and thus they are susceptible to chemical deformation during the usual process of scanning electron microscopy (SEM). The aims of this study were to present an optimal protocol of otoconial preparation for SEM and to investigate the change of otoconial morphology due to aging. SUBJECTS AND METHOD: The macula in mice were dissected free from the temporal bone and were divided into three groups using different fixatives and buffers: 2.5% glutaraldehyde in phosphate buffer, 2.5% glutaraldehyde in cacodylate buffer and 70% acetone. The duration of storage in buffer differed for each group, and SEM was used to examine the morphology. After the optimal processing protocol was made, we analysed the difference in the otoconial morphology in younger and older rats. RESULTS: The otoconia with shorter storage duration in phosphate buffer had more clear surface, while longer exposures resulted in coarse surface and fused otoconia. The otoconia stored in cacodylate buffer had smooth surface and showed grossly normal morphology regardless of exposure time. The otoconia fixed in acetone had irregular surface and was easily displaced. In older rats, the bodies of many otoconia were pitted, fissured, penetrated and eventually broken into several fragments. The size variation of utricular otoconia was greater in older rats. The giant otoconia were discovered frequently on the outer margin of utricular macula in older rats. The weakened or linked filaments that were cut in the older group were frequently observed. CONCLUSION: The appropriate processing for SEM is needed to observe the intact otoconial morphology. Older rats showed more degeneration of otoconia and linked filaments. This study for morphologic changes of senile otoconia is expected to be helpful in understanding the etiology of BPPV and aging effect.

Epitympanoplasty with Mastoid Obliteration Technique: 38 Months Follow-Up Results of 283 Cases / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: There have been heated controversies over the choice of the canal wall down mastoidectomy and canal wall up mastoidectomy, which are operational methods used to eliminate the lesion of chronic otitis media including cholesteatoma. Combining the advantages of both methods, we devised a new operational method in 1994. This study reports the surgical results of the epitympanoplasty employing the mastoid obliteration technique after a follow-up 38 months in 283 cases. SUBJECTS AND METHOD: A retrospective review was made of 283 cases (273 patients) on which this technique was performed by the first author between Dec. of 1994 to Mar. of 2004. The follow-up period varied from 8 to 104 months, with the average period of 38 months. We analyzed postoperative complications including cavity problems, the recurrent cholesteatoma, residual cholesteatoma cases in the mastoid cavity, residual cholesteatoma in the tympanic cavity and postoperative otorrhea and hearing results. RESULTS: The overall incidence of postoperative complications was 21.9%. The results of postoperative complications in the above listed order were 0%, 0%, 1.0%, 4.3% and 5.7%, respectively. Air-bone gap (ABG) closure was 4.73 dB HL and the statistical analysis revealed that the postoperative ABG was significantly lower than the preoperative ABG (p=0.0023). CONCLUSION: The present study suggests that this procedure prevents the cavity problem, helps reduce recurrence and effectively manages the residual cholesteatoma. Also, this procedure achieves good audiologic results.