母親のう蝕リスクが子どものう蝕感受性に与える影響

[Impact of maternal caries risk on children's caries susceptibility].

抄録

目的:

幼児期のう蝕の発生・発達を効果的に抑制・予防するための基礎資料とするため、妊娠中の母親のう蝕リスクが乳児のう蝕感受性に与える影響を評価する。

PURPOSE: To evaluate the impact of caries risk of pregnant mothers on caries susceptibility of infants in order to provide a basis for effective control and prevention of the occurrence and development of early childhood caries.

方法:

西城・美雲母子衛生病院の妊娠4ヶ月から9ヶ月の妊婦と乳児140名を研究対象として選択した。WHO2013年う蝕診断基準に従い、妊婦の口腔内検査、アンケート調査、刺激性唾液サンプルの採取を行った。う蝕活動性は、デントカルトSM、デントクルLB、デントバフストリップの標準キットを用いて測定した。6ヶ月、1年、2年の時点で、う蝕の記録と安静時唾液サンプルの採取を行った。6ヶ月、1歳、2歳の乳児のS.mutansのコロニー形成を検出するために、Nested PCRを使用した。統計分析は、SPSS 21.0ソフトウェアパッケージで行われた。

METHODS: A total of 140 pregnant women and infants from 4 to 9 months of gestation in Xicheng and Miyun Maternal and Child Health Hospital were selected as the study subjects. According to WHO 2013 caries diagnosis standard, oral examination, questionnaire survey and stimulating saliva samples of pregnant mothers were collected. Caries activity was determined using the Dentocult SM, Dentocule LB and Dentobuff Strip standard kit. At 6 months, 1 year, and 2 years, caries was recorded and resting saliva samples were collected. Nested PCR was used to detect the colonization of S.mutans in infants at 6 months, 1 year, and 2 years of age. Statistical analysis was concluded with SPSS 21.0 software package.

結果:

2年間の観察後、追跡調査不能率は11.43％、母子124組が追跡調査された。母親のオープンカリエス（未治療の虫歯）の数、デントカルトSMによるStreptococcus mutansの検出、デントクルLBによるLactobacillusの検出、デントバフストリップによる唾液緩衝能、アンケート結果に基づいて、中等度カリエスリスク（LCR）グループと高カリエスリスク（HCR）グループに分けられた。その結果，1歳児では，HCR群の白斑有病率（18.33％）およびdmft（0.3±0.087）がLCR群（3.13％，0.06±0.044）より有意に高い（P＜0.05）ことが明らかになった．2歳児では，HCR群の白斑（21.67％）およびdmft（0.33±0.088）がLCR群（6.25％, 0.09±0.048）（P＜0.05） に比べ有意に高かった．2歳児では，HCR群のう蝕（20.00％）およびdmft（0.33±0.10）がLCR群（6.25％, 0.11±0.055）（P＜0.05） に比べ有意に高かった．S.mutansの検出率は，6ヵ月児，1歳児，2歳児において，HCR群がLCR群より有意に高かった（P＜0.05）．また，6ヵ月後のS.mutans検出児のう蝕有病率（29.62％）およびdmft（0.67±0.22）は，検出しない児（13.40％）およびdmft（0.30±0.082）より有意に高い（p＜0.05）．

RESULTS: After 2 years of observation, the rate of lost follow-up was 11.43%, 124 pairs of mother-child were followed up. The study was divided into moderate and low caries risk (LCR) group and high caries risk (HCR) group based on the number of open caries (untreated cavities) in mothers, detection of Streptococcus mutans by Dentocult SM, Lactobacillus by Dentocule LB, saliva buffering capacity by Dentbuff Strip, and questionnaire results. The results showed that the prevalence of white spot(18.33%) and dmft (0.3±0.087) in HCR group were significantly higher than those in LCR group (3.13%, 0.06±0.044) (P＜0.05) at one-year old children. The prevalence of white spot (21.67%) and dmft (0.33±0.088) in HCR group were significantly higher than those in LCR group (6.25%, 0.09±0.048) (P＜0.05) at two-year old children. The prevalence of caries (20.00%) and dmft (0.33±0.10) in HCR group were significantly higher than those in LCR group (6.25%, 0.11±0.055)(P＜0.05) at two-year old children. The detection rate of S.mutans in HCR group was significantly higher than that in LCR group at 6 months, 1-year old and 2-year old children(P＜0.05). The prevalence of dental caries (29.62%) and dmft (0.67±0.22) in children with S.mutans detected at 6 months were significantly higher than those in children without S.mutans detected (13.40%) and dmft (0.30±0.082) (P＜0.05).

結論:

2年間の観察後、う蝕リスクの高い母親は、子どものう蝕感受性も高いことがわかった。同時に、母親のう蝕リスクの高さは、子どもの口腔内のS.mutansのコロニー形成に一定の影響を与え、S.mutansのコロニー形成が早いほど、2歳児におけるう蝕リスクが高くなることが示された。したがって、妊娠初期にう蝕リスクの高い母親の口腔保健行動に介入することは、S.mutansの垂直感染を阻止または遅延させることにより、ECCの発生と発症をある程度効果的に予防または低減することができる。

CONCLUSIONS: After 2 years of observation, mothers with high caries risk also had higher caries susceptibility in their children. At the same time, the high risk of dental caries in mothers affected the colonization of S.mutans in children's oral cavity to a certain extent; and the earlier colonization of S.mutans, the higher risk of dental caries at 2-year old children. Therefore, intervention of oral health behaviors of mothers with high caries risk in early pregnancy can effectively prevent or reduce the occurrence and development of ECC to some extent by blocking or delaying the vertical transmission of S.mutans.