咀嚼効率に影響する咬合パターン因子

[Occlusal pattern factors influencing masticatory efficiency].

抄録

本研究の目的は、咬合パターン因子と咀嚼効率との関係を検討することである。正常歯列の被験者50名を対象とし、咬合パターン標準値を求めた。咀嚼能率の測定には、今岡らによって報告された簡易粒子計数法を用いた。測定項目は、各被験者の犬歯を含む習慣的咀嚼側の咬合パターンについて、咬合接触面積数、各面積の大きさ、投影面積の咬合面数、投影面積の因子の大きさ、咬合面の傾斜の5因子とした。咬合パターン5因子と咀嚼効率との相関を分析し、咬合パターン修復の基準を得た。その結果は以下の通りであった：1.1.咬合接触数，咬合小窩角の数および傾斜が咀嚼効率に影響を及ぼす主な因子であった．2.標準的な咬合接触数は15、咬合面数は25であった。3.3.小臼歯の咬合面傾斜角は大臼歯の咬合面傾斜角よりやや大きかったが、標準的な咬合面傾斜角は25〜30度であった。4.咀嚼能率と咬合接触面および咬合小面部の投影面積との間には有意な相関は認められなかった。5.5.カスプポイント、窩洞、辺縁隆起の同一部位に出現する咬合小面の傾斜角度は10～15度であり、その他の部位の咬合小面の傾斜角度は大きいので、咬合小面の分類を考慮する必要がある。

The purpose of this study was to investigate the relationship between occlusal pattern factors and masticatory efficiency. 50 subjects with normal dentition were tested to obtain the occlusal pattern standard. The simplified particle counting method, which was previously reported by Imaoka et al., was used to determine the masticatory efficiency. Measurements included 5 factors of the occlusal pattern of the habitual chewing side, including the canine of each subject: the number of occlusal contact areas, the size of each area, the number of occlusal facets of the projected area, the size of the factors of the projected area and the inclination of the occlusal facets. The correlation between the 5 factors of the occlusal pattern and the masticatory efficiency were analyzed to obtain a standard for the restoration of occlusal patterns. The results were as follows: 1. The number of occlusal contacts and the number and inclination of occlusal facet were the main factors which to influenced the masticatory efficiency. 2. The standard number of occlusal contacts and occlusal facets were 15 and 25 respectively. 3. Although the inclination of the occlusal facets of premolars was slightly bigger than those of molars, the standard inclination of the occlusal facets was 25-30 degrees. 4. There was no significant correlation between the masticatory efficiency and the projected area of the occlusal contacts and facets. 5. The classification of occlusal facets should be considered, because of the inclination of the occlusal facets which appear at the same areas of the cusp point, the fossa and the marginal ridge was 10-15 degrees, and the inclination of the other areas of occlusal pattern was bigger.