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The purpose of this study was to use functional magnetic resonance imaging (fMRI) to quantify changes in brain activity during experimental occlusal interference. Fourteen healthy volunteers performed a rhythmical tapping occlusion task with experimental occlusal interference of the right molar tooth at 0 mm (no occlusion), 0.5 mm, and 0.75 mm. The blood-oxygen-level dependent (BOLD) signal was quantified using statistical parametric mapping and compared between rest periods and task periods. In tapping tasks with experimental occlusal interference of 0.75 mm or 0.5 mm, there was clear activation of the contralateral teeth-related primary sensory cortex and Brodmann’s area 46. At 0 and 30 minutes after removal of the experimental occlusal interference, the activation clearly appeared in the bilateral teeth-related primary sensory cortices and Brodmann’s area 46. At 60 minutes after the removal of the experimental occlusal interference, the activation of Brodmann’s area 46 had disappeared, and only the bilateral teeth-related primary sensory cortices were active. The present results suggest that adjustments for experimental occlusal interference can be objectively evaluated using fMRI. We expect that this method of evaluating adjustments in occlusal interference, combined with fMRI and the tapping task, could be applied clinically in the future.

Background: An oral appliance (OA) can alleviate upper airway obstruction by pulling the mandible forward during sleep. While a large mandibular advancement with an OA decreases the number of apnea and hypopnea events, long‐term use may cause side effects, such as toothache, stiffness, and pain in the temporomandibular joint.Objetives: This study aimed to evaluate the effectiveness of different mandibular positions for obstructive sleep apnea (OSA) and determine the optimal therapeutic mandibular position.Methods: Thirty‐two patients (17 males and 15 females) with mild to moderate OSA participated in this prospective study. All patients were randomly allocated to receive a 50% mandibular advancement or a 75% mandibular advancement with an OA. The pre‐ and posttreatment apnea‐hypopnea index (AHI), apnea index (AI), and Epworth Sleepiness Scale (ESS) were compared. Treatment effectiveness and treatment success were compared between groups.Results: AHI improved significantly in both groups, and AI improved significantly in the group with 50% mandibular advancement. No significant improvements in the ESS were observed in either group. There was no significant difference in treatment effectiveness between groups. In the proportion of females and males whose treatment was effective in the two groups, females were significantly greater than males.Conclusions: For patients with mild to moderate OSA, 50% mandibular advancement is recommended as the initial therapeutic mandibular position. It was suggested that gender differences also affect treatment effectiveness.

Although oral appliances (OAs) have become widely used for the management of obstructive sleep apnea (OSA), side effects of OAs are generally related to poor utilization. The purpose of the present study was to evaluate relationship between utilization and treatment efficacy of a boil-and-bite appliance for OSA patients. A total of 135 patients with OSA who had used an OAs were mailed a questionnaire to determine whether they were currently using the OA. If so, they were asked about OA use, improvement of signs and subjective symptoms, and utilization. Otherwise, they were asked to indicate why and when they quit using the OA. Results of overnight polysomnography (PSG) before and after treatment were reviewed. Of the 48 responding patients, 33 patients were currently using the OA. The most common complication was excessive salivation (n = 11). All indices from PSG excluding arousal index were significantly improved after treatment (p < 0.05). Thirty patients showed improved signs and subjective symptoms. Eight out of 12 subjects (66.7%) were successfully treated, achieving an apnea-hypopnea index (AHI) < 10/h and >50% reduction in apnea-hypopnea index. Of the 15 patients no longer using the OA, the primary reason for quitting was “no treatment effect” (n = 5). No indices from PSG recording differed between before and after treatment in the not-using group. These results suggest that both subjective and objective signs and symptoms improved with use of the OA in the using group. However, no signs and subjective symptoms or indices of sleep quality differed between before and after treatment in the not-using group. Device improvements are needed to achieve better treatment efficacy, and thus improve compliance. The present study evaluated relationship between utilization and treatment efficacy of a boil -and bite appliance for OSA patients. Device improvements are needed to achieve better treatment efficacy, thus improve compliance.

補綴治療の難易度は，開口障害，残存歯の有無，周囲軟組織の状態に大きく作用される．上顎欠損では，欠損腔の大きさや口腔外との交通の有無，皮膚移植の有無，下顎欠損では，下顎の連続性，下顎偏位なども大きな因子となる． 腫瘍摘出後に生じた上顎顎欠損に対する補綴的対応の主な目的は欠損腔の封鎖であるが，顎補綴装置の製作に際して，欠損腔以外の領域は精度の高い印象採得が必要であり，欠損腔部位は，印象材硬化後に安全に撤去できるよう配慮しなければならない．さらに，可動性皮弁による口蓋閉鎖が行われている場合には，皮弁部に支持を求めることは難しく，筋圧維持などを考慮した義歯研磨面形態を決定する必要がある． 一方，下顎の場合は咬合の確保が大きな目的であるため，下顎骨欠損部は金属プレートや自家骨などを用いて下顎骨の連続性を修復し，その上部は皮弁を用いた外科的顎堤再建が積極的に行われているが，術前と同様の顎運動や咀嚼運動を再現することは非常に困難である．また，皮弁のボリュームや被圧縮性が過大な場合は義歯の装着に大きな障害となり，口腔周囲組織の力学的動態にも大きな変化が生じていることが多い． 我々は，部位により異なる印象材を用いた印象採得を行うとともに，フレンジテクニックを利用してこれらの動態に調和した顎義歯床縁形態，床研磨面形態を付与した顎義歯製作を心がけている．このような処置を行うことで比較的良好な術後経過をたどることもあるが，術後管理を適切に行わなければ，経時的に残存歯の移動，顎堤形態や咬合の変化が起こり，支台装置の破損などにより補綴装置を再製する場合が少なくない．したがって顎顔面補綴治療においては，補綴科医，口腔外科医だけでなく，歯科衛生士，歯科技工士，言語聴覚士などのチームアプローチにより，術前カンファレンスで治療方針を決定するとともに徹底した患者の術後管理を行うことが必要である．

This case report describes a patient with obstructive sleep apnea (OSA) who could not receive oral appliance therapy because of temporomandibular disorders and was instructed to perform tongue rotation exercises. The patient’s maximum tongue pressure, lip-seal strength, and subjective sleep quality improved post-intervention. Furthermore, apnea-hypopnea index and sleep architecture were improved after exercise compared with the baseline. These results suggest that tongue rotation exercises can improve not only oral function but also respiratory function during sleep and, thus, may be meaningful to introduce as an adjunctive therapy for OSA with impaired oral function or intolerance to conventional therapies.