MEG Analysis of Auditory Response and Clinical Epidemiology on Relationship between Occlusal and Chewing Ability and Hearing

本研究的目的是（1）检查临床病例中咬合条件改善后听力变化的机制，（2）检查单侧咀嚼与听力水平之间是否存在关系，（3）检查听力计绘制的听力图分析是否可用于评估患者的咀嚼部位。研究：用脑磁图（MEG）分析了被试者咬棉花卷时听觉诱发磁场（AEFs）的变化。与对照组相比，三种咬合条件下的所有ECD均定位在± 1 mm以内。所有咬合条件下的AEF的N100 m峰潜伏期（ms）与对照组无显著差异。在所有受试者中，AEF的反应根据咬合压力的强度而降低。在实验条件下，右半球的反应高于左半球。反应明显较小， ...更多信息 我们需要进行进一步的研究来证实：1）由于颞下颌关节（TMJ）的移位，中耳和内耳的解剖结构发生变化，2）支配中耳和内耳的神经结构，3）门控理论，这是声音感觉的抑制现象。研究II-1：参与这项研究的受试者是262人，他们访问了东京的牙科诊所。本门诊绝大多数患者的听力恢复水平均采用听力计测量。我们使用患者在牙科治疗和咀嚼指导前后的听力图。我们试图将所有波长（Hz）的听力水平模式分类，并总结为五组。分析各组的性别、年龄分布，并对治疗前后听力图及咀嚼指导进行配对t检验。8.2.结果表明：1）单侧咀嚼对听力有明显影响; 2）我们的分类有助于诊断患者咀嚼部位，也有助于评价牙科治疗; 3）牙科治疗有可能改善患者的听力。在实验前获得了对本研究的个人书面知情同意书，并得到了TDC伦理委员会的批准。我们进行了问卷调查，口腔检查，咬合检查用咬合器（GC FPD-707），和Sirognathograph分析系统（东京志和产业）。我们还在第一次访问时为受试者的牙齿做了石膏模型。结果表明，模式分析与传统的评估方法相结合，可以对动态咬合和咀嚼功能进行更详细的评估。少

The purposes of this study were (1)to examine the mechanism responsible for changes in hearing with the improved occlusal conditions seen in clinical cases, (2)to examine whether there was a relationship between unilateral chewing and hearing level, (3)to examine whether analysis of audiogram plotted by an audiometer could be use to evaluate patient's chewing-sites.Study : Changes in auditory evoked magnetic fields (AEFs) were analyzed when subjects bite a cotton roll by magnetoencephalography (MEG). All ECDs for the three occlusal conditions localized in less than ±1mm compared with the control group. There were no significant differences in peak latency (ms) for the N100m of the AEF among all occlusal conditions and the control group. The response of AEFs decreased according to the strength of biting pressure in all subjects. The response in the right hemisphere was higher than for the left hemisphere under the experimental conditions. The response was significantly smaller in the ri … More ght hemisphere as biting on the same side.We need to conduct further studies to confirm the role of : 1)changes in the anatomical structure of the auris media and auris interna due to shifting in the temporomandibular joint (TMJ), 2)innervating neurarchy in the auris media and auris interna, and 3)gate control theory which is the suppression phenomenon in sonic sensation.Study II-1 : Subjects participated in this study was 262, who visited the dental office in Tokyo. In this clinic, healing levels of the most of patients were measured by audiometer. We used the patient's audiogram before and after dental treatment and chewing instruction. We attempt to classify the patterns of hearing levels at all wavelengths (Hz) and summarized as five groups. Sex and age distribution in each class was analyzed and also comparison of audiogram before and after dental treatment and chewing instructions was performed by paired t-test using SAS software Ver. 8.2.Data suggest that 1)Unilateral chewing had clearly affected hearing ability, 2)Our classification is useful to make diagnosis chewing site of the patient and also it can be useful to evaluate dental treatments, and 3)Dental treatment have possibility to improve hearing ability of patients.StudyII-2 : There were 20 subjects (3 females, 17 males, aged 27- 58) who visited a dental clinic. Individual written informed consent to this study was obtained before the experiment, which was approved by the Ethics Committee of the TDC. We conducted a questionnaire, oral examination, occlusal examination with an Occluzer (GC FPD-707), and the Sirognathograph Analyzing System (Tokyo Shika Sangyo). We also made a plaster cast of the subjects' teeth on their first visit. We evaluated each subject's dynamic function with a combination of these five techniques and pattern analysis.The results revealed that a more detailed evaluation of dynamic occlusal and chewing functions can be undertaken by combining pattern analysis with conventional evaluations. Less