総義歯によるリハビリテーションが咬合力および顎頸部筋電図に及ぼす影響と咬合面垂直方向寸法との相関性

Effects of rehabilitation with complete dentures on bite force and electromyography of jaw and neck muscles and the correlation with occlusal vertical dimension.

抄録

研究目的:

本研究の目的は，総義歯による口腔リハビリテーションが咬合力および上顎筋と胸鎖乳突筋の筋電図に及ぼす影響，ならびに咬合面垂直寸法（OVD）との相関を評価することである．研究課題は、"総入れ歯によるリハビリテーションが咬合力および舌骨上筋と胸鎖乳突筋の筋電図に及ぼす影響、およびOVDとの相関は何か？"であった。

OBJECTIVES: The purpose of this study was to assess the effects of oral rehabilitation with complete dentures on bite force and electromyography of the suprahyoid and sternocleidomastoid muscles, and their correlation with occlusal vertical dimension (OVD). The research questions were "What are the effects of rehabilitation with complete dentures on bite force and electromyography of suprahyoid and sternocleidomastoid muscles, and how are they correlated with OVD?"

材料と方法:

不満足な可撤式総義歯を装着している患者を3セッション（T0、T1、T2）に分けて参加させた。T0では、まだ古い義歯を装着したまま、咬合力検査と上顎洞筋と胸鎖乳突筋の表面筋電図検査を実施した。新義歯装着30日後（T1）、新旧義歯を装着したまま、これらの検査を繰り返し、OVDを測定した。また、新しい人工関節を挿入して100日後（T2）にも検査を繰り返した。データはShapiro-Wilk正規性検定、分散分析（ANOVA）、Pearson相関および線形回帰に供した（すべて5％有意水準）。

MATERIALS AND METHODS: Patients who are wearers of unsatisfactory removable complete dentures were attended in three sessions (T0, T1, and T2). At T0, while the patients still wore the old dentures, they were submitted to bite force and surface electromyographic exams of the suprahyoid and sternocleidomastoid muscles. These exams were repeated, and the OVD was measured while the patients wore their old and new prostheses, 30 days after insertion of the new prosthesis (T1). The exams were repeated 100 days after the insertion of the new prosthesis (T2). The data were submitted to the Shapiro-Wilk normality test, analysis of variance (ANOVA), and Pearson correlation and linear regression, all with 5% significance.

結果:

15名の患者が研究に参加した。T0，T1，T2において，咬合力や筋電図に統計的有意差は認められなかった．しかし、相関検定および回帰検定により、OVDと最大随意咬合力、およびOVDと嚥下時の筋電図との間に、上顎筋に対する重要な相互作用が認められた。

RESULTS: Fifteen patients participated in the study. No statistically significant difference was observed for bite force or electromyography in T0, T1, or T2. However, the correlation and regression tests showed important interactions between the OVD and maximum voluntary occlusal bite force, as well as the OVD and electromyography during deglutition for the suprahyoid muscles.

結論:

リハビリテーションは咬合力や評価筋の活動（筋電図）に影響を与えなかった。一方、OVDは咬合力、およびリハビリテーション後の水の嚥下に対して重要な因子であることが示された。

CONCLUSION: Rehabilitation did not impact bite force nor the activity of the assessed muscles (electromyography). On the other hand, OVD was shown to be an important factor for bite force, and deglutition of water after rehabilitation.

臨床的意義:

本研究は、リハビリテーションが口腔機能に及ぼす影響を明らかにするとともに、咬合力や嚥下時の筋電図に重要な因子であることが判明したことから、OVDを正しく再確立することの重要性を再確認するものです。

CLINICAL RELEVANCE: This study shows what are the influences of rehabilitation on oral functions and reinforces the importance of corrected reestablishment of OVD because it has been found to be an important factor for bite force and electromyography during deglutition.