5～7歳児の乳歯列における歯の摩耗：危険因子

Tooth wear in the deciduous dentition of 5-7-year-old children: risk factors.

抄録

本研究は、乳歯列における歯の摩耗の分布と重症度、および考えられる危険因子との関係を調査するために行われた。5～7歳児243名の層別クラスター標本をSmith and Knightの歯牙摩耗指標を用いて調査し、構造化質問票により内在的および外在的リスク因子への曝露を後方視的に調査した。摩耗の重症度は、影響を受けた歯質の表面数と、基本的侵食摩耗検査スコアリング・システムに基づく六分儀の累積スコアによって定量的に推定した。歯牙摩耗のない小児はわずか1.6%であったが、45.6%は象牙質を含む中等度から重度の摩耗が認められた。最も影響を受けた歯は上顎犬歯（83.2％）であり、最も影響を受けた表面は咬合面/切歯（52.7％）であった。象牙質を含む歯の摩耗の可能性は、女児よりも男児で高く（OR = 1.72）、ギリシャ人よりも移民で高く（OR = 1.93）、5歳児よりも6歳児および7歳児で高かった（OR = 2.78～2.93）。年齢、性別、国籍で調整した後、いくつかの食事要因、特に清涼飲料水への暴露は、歯の摩耗の有病率（OR = 1.27）と重症度に有意に影響することがわかった。清涼飲料水の摂取が1食/週増えるごとに、象牙質が侵された面の数は年間0.03面増加し（p＜0.05）、六分儀の累積スコアは0.04点増加した（p＜0.05）。歯牙摩耗の有病率および重症度が高い小児のクラスターは、4年間にわたり平均10食/週の清涼飲料水にさらされていた。六分儀の累積スコアは、罹患歯質の表面数と比較して、評価されたリスク因子によってよりよく予測された。歯の磨耗は小児によくみられる症状であり、歯列の老化という生理的過程と食事要因による侵食作用の両方が関係している。小児の清涼飲料水摂取を減らす戦略は、小児期やその後の人生における歯の摩耗を防ぐだけでなく、他の多くの一般的な疾患や口腔の健康疾患を防ぐなど、様々な効果が期待される。

This study was conducted to investigate the distribution and severity of tooth wear in deciduous dentition and its relationship with possible risk factors. A stratified cluster sample of 243 5-7-year-old children was examined using the tooth wear index of Smith and Knight, and their exposure to intrinsic and extrinsic risk factors was retrospectively investigated through a structured questionnaire. The severity of wear was quantitatively estimated by the number of surfaces with affected dentine and by the cumulative score of the sextants, based on the Basic Erosive Wear Examination scoring system. Only 1.6% of the children were tooth wear free, whereas 45.6% had moderate to severe wear involving dentine. Maxillary canines were the most affected teeth (83.2%), and occlusal/incisal the most affected surfaces (52.7%). The likelihood of tooth wear involving dentine was greater in boys than girls (OR = 1.72), in immigrants than in Greeks (OR = 1.93), and in 6- and 7-year olds than in 5-year olds (OR = 2.78 to 2.93). After adjustment for age, gender, and nationality, exposure to several dietary factors and especially to soft drinks was found to significantly affect the prevalence (OR = 1.27) and the severity of tooth wear. Every additional serving/week of consumption of soft drinks increases the number of surfaces with dentine affected by 0.03 per year (p < 0.05) and the cumulative score of sextants by 0.04 (p < 0.05). The cluster of children with the higher prevalence and severity of tooth wear had an average exposure to soft drinks of 10 servings/week for a duration of 4 years. The cumulative score of sextants was better predicted by the assessed risk factors, in comparison with the number of surfaces with affected dentine. Tooth wear is a common condition in children, related both to the physiological process of aging of dentition and to the erosive effect of dietary factors. Strategies to reduce the intake of soft drinks in children are expected to have multiple benefits preventing tooth wear in childhood and in later life, as well as many other general and oral health diseases.