咀嚼機能障害と無歯顎患者の口腔衛生関連QOLの関係．介入研究

Relationship Between Masticatory Function Impairment and Oral Health-Related Quality of Life of Edentulous Patients: An Interventional Study.

抄録

目的:

インプラント固定式下顎骨オーバーデンチャーへの移行前後に、咀嚼機能障害が従来型総義歯装着者の口腔保健関連QOLに及ぼす影響を検討する。

PURPOSE: To investigate the influence of impaired masticatory function on the oral health-related quality of life of conventional complete denture wearers before and after the transition to implant-retained mandibular overdentures.

材料および方法:

40名の無歯顎患者を対象に，総義歯装着3ヵ月後およびインプラント固定式下顎骨オーバーデンチャーへの移行後に咀嚼機能と口腔保健関連QOLを評価した．咀嚼機能は，標準化した人工試験食（Optocal）を用いた嚥下閾値試験により，中央粒径（×50）および均質化係数（B）を測定した．試験後、咀嚼機能の結果をもとに、患者を咀嚼能力に応じて2群に分類した（i）満足、（ii）不満足。また，×50 のカットオフ値は 3.68mm とし，B index は中央値で分類した．口腔衛生関連の QOL は，OHIP-EDENT（Oral Health Impact Profile for Edentulous Adults）質問票を用いて分析した．咀嚼機能の結果と OHIP-EDENT スコアの比較には Mann-Whitney 検定を用い，関連性の確認には Spearman 相関検定と重回帰を用いた．

MATERIALS AND METHODS: Masticatory function and oral health-related quality of life were evaluated in 40 edentulous patients after 3 months of adaptation to complete dentures and after transition to implant-retained mandibular overdentures. Masticatory function was evaluated through the swallowing threshold test with a standardized portion of an artificial test food (Optocal) to determine median particle size (×50) and homogenization index (B). After the test, the masticatory function outcomes were used to categorize patients in 2 groups according to chewing performance: (i) satisfactory or (ii) unsatisfactory. The cutoff value for ×50 was based on a preestablished value of 3.68 mm, whereas for the B index, median values were adopted for categorization. The oral health-related quality of life was analyzed via the Oral Health Impact Profile for Edentulous Adults (OHIP-EDENT) questionnaire. The Mann-Whitney test was used to compare masticatory function outcomes and OHIP-EDENT scores, and associations were checked using the Spearman correlation test and multiple linear regression.

結果:

咀嚼機能が不十分な総義歯装着者では，機能制限（p＝0.02）および身体障害（p＝0.04）と有意な相関が認められた．インプラント義歯への移行後は，心理的不快感領域（p＝0.02）のみが咀嚼機能カテゴリーに影響された．重回帰分析では，総義歯装着者の機能制限領域（p＜0.001）のみが咀嚼機能アウトカムと関連していることが明らかとなった．

RESULTS: Masticatory function was significantly correlated with functional limitation (p = 0.02) and physical disability (p = 0.04) for complete denture wearers with unsatisfactory masticatory function. After the transition to implant-retained mandibular overdentures, only the psychological discomfort domain (p = 0.02) was influenced by the masticatory function category. Multiple linear regression analysis revealed that only the functional limitation domain (p < 0.001) of the complete denture wearers was associated with masticatory function outcomes.

結論:

インプラント固定式下顎骨オーバーデンチャーは，機能制限につながる問題を解消し，結果として咀嚼機能および口腔保健関連QOLを改善する．

CONCLUSIONS: Implant-retained mandibular overdentures eliminate the problems that lead to functional limitations, consequently improving masticatory function and oral health-related quality of life of these individuals; however, patients with unsatisfactory masticatory function after transition to implant-retained mandibular overdentures still experience more psychological discomfort.