低出生体重儿和早产儿乳牙釉质发育缺陷与龋齿易感性的研究

目的从临床和实验研究两方面探讨乳牙釉质发育缺陷与龋齿易感性的关系。方法选择１７６例３～８岁的低出生体重儿和早产儿，分析乳牙釉质发育缺陷与龋齿的相关性；将４颗自然脱落的釉质发育不全乳前牙用于釉质溶解度的研究，比较发育不全部位和正常部位釉粉的溶解度。结果临床研究发现乳牙釉质发育缺陷与龋齿的发生显著相关；乳牙釉质混浊和釉质发育不全分别与龋齿的发生显著相关。溶解度研究发现发育不全的釉质溶解度大，且达到平衡的时间短。结论釉质发育缺陷（釉质发育不全和釉质混浊）增加了牙齿对龋的易感性     

Cariogenic microbiome and microbiota of the early primary dentition: A contemporary overview

Recent advances in the field of molecular microbiology provide an unprecedented opportunity to decipher the vast diversity of the oral microbiome in health and disease. Here, we provide a contemporary overview of the oral microbiome and the microbiota of early childhood caries (ECC) with particular reference to newer analytical techniques. A MEDLINE search revealed a total of 20 metagenomic studies describing cariogenic microbiomes of ECC, 10 of which also detailed the healthy microbiomes. In addition, seven studies on site‐specific microbiomes, focusing on acidogenic and aciduric microbiota of deep‐dentinal lesions, were also reviewed. These studies evaluated plaque and saliva of children aged 1.5–11 years, in cohorts of 12–485 individuals. These studies reveal a very rich and diverse microbial communities, with hundreds of different phylotypes and microbial species, including novel species and phyla such as Scardovia wiggsiae, Slackia exigua, Granulicatella elegans, Firmicutes in the plaque biofilms of children with ECC. On the contrary, bacteria such as Streptococcus cristatus, S. gordonii, S. sanguinis, Corynebacterium matruchotii, and Neisseria flavescens were common in plaque biofilm of noncarious, healthy, tooth surfaces in subjects with caries. The review illustrates the immense complexity and the diversity of the human oral microbiota of the cariogenic plaque microbiome in ECC, and the daunting prospect of its demystification.     

早产儿乳牙釉质发育缺陷及患龋状况的临床研究

目的研究早产儿乳牙釉质发育缺陷及龋病的发病率,并探讨两者的相关关系。方法选取3～7岁早产儿及足月出生儿两组各173名,进行乳牙釉质发育缺陷及患龋情况的调查统计和数据对比分析。结果早产儿组釉质发育缺陷(DDE)的患病率(63.58%)明显高于正常出生组DDE的患病率(34.10%),其患病率男女性别间无明显差异。DDE好发于上颌切牙。早产儿组的患龋率(69.36%)与正常出生组的患龋率(71.68%)无明显差异。结论早产儿的乳牙釉质发育缺陷率较高,做好早产儿的口腔保健及父母的口腔健康知识教育是非常重要的。     

Prenatal and neonatal risk factors for the development of enamel defects in low birth weight children

Oral Diseases (2010) 16 , 257–262 Objective: To analyse the influence of several prenatal and neonatal risk factors in the development of enamel defects in low birth weight children. Subjects and methods: Children between 4 and 5 years of age (n = 102) were classified into: Group 1) 52 low birth weight (<2500 g); Group 2) 50 normal birth weight (≥2500 g). Medical history, prenatal and neonatal variables were collected. Enamel defects were evaluated with the modified Developmental Defects of Enamel Index. Results: The prevalence of hypoplasia and average number of affected teeth were significantly higher in group 1 than in group 2 (59.6%vs 16% and 1.6 vs 0.3 respectively). Low gestational age was linked to a higher prevalence of hypoplastic (P = 0.027) and combined defects (P = 0.001). Children with neonatal risk factors (low Apgar scores, parenteral nutrition, orotracheal intubation, mechanical ventilation and acidosis) developed defects more frequently (P < 0.05). Defects were symmetrically distributed in children who were not intubated; in those who required intubation they concentrated on the left maxillary teeth (P < 0.05). Smoking during pregnancy, young maternal age and multiple birth were significantly associated to developmental defects. Conclusions: The prevalence of enamel defects in primary dentition is significantly influenced by birth weight, gestational age and several systemic factors. Orotracheal intubation probably plays an important role as a result of laryngoscope trauma on the maxilla.     

Genetic influences on dental enamel that impact caries differ between the primary and permanent dentitions

Clinically, primary and permanent teeth are distinct anatomically and the presentation of caries lesions differs between the two dentitions. Hence, the possibility exists that genetic contributions to tooth formation of the two dentitions are different. The purpose of this study was to test the hypothesis that genetic associations with an artificial caries model will not be the same between primary and permanent dentitions. Enamel samples from primary and permanent teeth were tested for microhardness at baseline, after carious lesion creation, and after fluoride application to verify association with genetic variants of selected genes. Associations were found between genetic variants of ameloblastin, amelogenin, enamelin, tuftelin, tuftelin interactive protein 11, and matrix metallopeptidase 20 and enamel from permanent teeth but not with enamel from primary teeth. In conclusion, our data continue to support that genetic variation may impact enamel development and consequently individual caries susceptibility. These effects may be distinct between primary and permanent dentitions.     

乳牙釉质发育不全的组织学研究

本研究运用偏光显微镜和显微放射照相技术对发育不全乳牙的组织学特征进行分析,发现釉质发育不全乳牙的新生线表现为低矿化的窄带状,病损发生于生后釉质,病损底多与新生线相吻合,病损内可见不同程度的矿化不良区域。得出:釉质发育不全不仅有釉质量的减少,而且有质的改变。后者可能增加了釉质发育不全牙齿对龋的易感性。     

Research issues in early childhood caries

Research 3 needed to establish what nomenclature and case definition for early childhood caries (ECC) are most relevant to health care professionals and to the public. Profiles or indexes for predicting the prevalence of ECC in communities should be developed on the basis of the socioeconomic factors, immigrant status and ethnic/racial backgrounds of populations. Future research should target risk factors of ECC, particularly prenatal and perinatal histories, nutritional status and microbiologic factors. Determining the relation of malnutrition of infants and young children, low birthweight, complicated pregnancies and traumatic births with the development of enamel linear hypoplasia deserves research attention. Factors that affect how and when infants and young children are colonized by mutans streptococci also need further study. The evaluation of chemotherapeutic preventive agents will likely yield more fruitful interventions for prevention than trying to change behaviors. Research in young children to prevent ECC, however, has particular ethical considerations. Withholding treatments or administering placebos to vulnerable subjects is not acceptable. Consequently, future clinical research likely will determine the relative rather than the absolute effectiveness of preventive regimens; the former requires large sample sizes and may necessitate multi-center studies. Human studies may be hampered by problems of recruitment, compliance and transiency of subjects. Because federal support for research on dental caries has declined in recent years, a special initiative that focuses specifically on ECC may be necessary to obtain adequate funding for research on the disease.     

Dental caries in the primary dentition: assessing prevalence of cavitated and noncavitated lesions

BACKGROUND: Dental caries in the primary dentition has received renewed attention in recent years because caries in the primary dentition is predictive of later caries experience, and because of efforts to address early childhood caries. More detailed caries diagnostic criteria have been developed and used for the permanent teeth; however, such criteria have not been widely adopted for caries diagnosis in the primary dentition. METHODS: As part of the Iowa Fluoride Study, caries diagnostic criteria were developed specifically for the primary teeth. The criteria included noncavitated (d1) lesions and cavitated (d2-3) lesions. Examinations were conducted on 698 children in the primary dentition by two trained examiners who did duplicate examinations on 11 percent (n = 67) of these children. RESULTS: Interexaminer agreement for any d1 and any d2-3 lesions at the person level was 100 percent. At the tooth level for d1d2-3f, there was 98.5 percent agreement and kappa was .91. For d1 at the tooth level, agreement was 97.0 percent agreement and kappa = .24. For d2-3 it was 99.4 percent agreement and kappa = .81. Prevalence of untreated d2-3 was 16.5 percent, while that of d1 was 24.1 percent. Nearly 73 percent had no d2-3 or filled surfaces, while over 63 percent had no d1, d2-3, or filled surfaces. Decay experience was most common on the primary second molars. About 56 percent of untreated d2-3 decay was located in the pits and fissures, while 58 percent of d1 decay was located on smooth surfaces. CONCLUSION: Despite some concern with reliability of diagnosing d1 lesions, it appears that the d1d2-3 criteria are informative and useful in assessing the primary dentition.     

Prevalence and distribution of developmental enamel defects in primary dentition of Chinese children 3–5 years old

Abstract A total of 1344 children, 3–5 yr old, from two rural counties, Haidian and Miyun, close to Beijing, China, were examined in 1992. A modified DDE Index was employed in this study, and a pre-designed formula was used to calculate an enamel detect score (EDS) for each individual in the study. Oral examination was performed by one dentist under natural light using a standard mouth mirror and dental probe. Developmental enamel lesions were diagnosed without drying or cleaning the teeth prior to examination. Results from this study showed that primary teeth with defective enamel were seen in 23.9% of the children examined, opacity in 1.6%, and hypoplasia in 22.2%. Among the teeth, maxillary central and lateral incisors were affected by enamel hypoplasia most often (40.8% and 39.2%), followed by maxillary canines (25.7%), maxillary 1st molars (22.1%), and mandibular 1st molars (18.5%). The enamel defects occurred more frequently on the buccal surfaces of teeth than on any other surface. The study did not find a significant association of the children's age, family socioeconomic status, and anthropometric measurements with the distribution of enamel defects. However, there was a significantly higher prevalence of teeth with defects in males compared to females (P < 0.001), as well as mean tooth surfaces with defects (P < 0.05), and mean EDS (P < 0.05). Children born prematurely were shown to have four times more enamel lesions than children who were full term (P < 0.01). Children with low birth weight also showed a statistically significant higher prevalence of enamel defects (P < 0.05) and a greater severity of hypoplastic lesions measured by EDS (P < 0.05) than those with normal birth weight. The results indicate that nutrition during fetal development is important in determining normal development of enamel in primary teeth. Nutritional status (diagnosed by anthropometric measurements) after the critical period was not associated with enamel defects induced earlier in life. The study suggested, therefore, that nutrition is important for maintaining proper development of the teeth only during the critical period when teeth are susceptible to the formation of defects.     

Mineralization defects of primary teeth in children born pre-term

abstract — Investigation of 82 2- to 3-year-old children born pre-term and 39 healthy full-term controls showed that enamel mineralization defects were significantly more common in the pre-term group than among the controls. Pre-term delivery per se does not seem to be the direct cause of enamel mineralization defects, but rather it seems that common complications such as asphyxia and/or hyperbilirubinemia explain the increased incidence in children born pre-term.     

Caries experience in the primary dentition of Tanzanian and Finnish 3–7-year-old children

Caries experience of primary teeth in relation to age, sex, ethnic group, socioeconomic status and frequency of consuming sweet snacks and drinks was studied among groups of Tanzanian and Finnish 3-7-yr-olds, a total of 1118 children. In all age groups the Tanzanian children had higher mean dmft scores than Finnish children did. In the Finnish group the mean dmft score was higher at age 7 than at age 3, while in the Tanzanian group no statistically significant difference in dmft scores was found between age groups. In both groups maxillary incisors and molars were the main teeth affected by caries. Frequent consumption of sweet snacks and drinks increased the risk for caries in Tanzanian but not in Finnish children. High socioeconomic status decreased the risk for caries in Finnish children but among Tanzanian children high SES was not associated significantly with the risk of developing caries. According to these results, caries experience in Tanzanian urban nursery school children was significantly higher than in Finnish children of the same age, the differences being especially high among the youngest age groups.     

Risk indicators for early childhood caries in Taiwan

OBJECTIVES: The purpose of this study was to investigate the prevalence, patterns, and etiological factors for caries in children. METHODS: A total of 981 children less than 6 years of age were examined using a dental mirror and explorer. A parent or a caregiver was asked to complete a questionnaire regarding information about the child, the household, and oral hygiene. The prevalence and patterns of dental caries including pit and fissure caries, facial/lingual caries, molar proximal caries, and facial/lingual molar proximal lesions, were analyzed. Each child was classified as caries free or as having one of these four caries patterns. RESULTS: Weighted mean deft was 0.14 at age 2, 2.58 at age 3, 4.41 at age 4, 6.94 at age 5, and 7.31 at age 6. Weighted mean defs was 4.71, 8.44, 16.45 and 18.64 at ages 3, 4, 5, and 6, respectively. By age 2, 5.09% of children had caries. By age 6, 89.38% of children had caries. By age 3, 30.02% of children fitted the facial and lingual pattern of caries and by age 6, 52.90% of children fit the 'facial-lingual and molar-proximal' pattern, indicating extensive smooth surface decay. The total prevalence of early childhood caries was 56%. Multivariate-adjusted odds ratios identified factors associated with the high caries experience of the young children and found caries was strongly associated with the lack of proper tooth brushing and high consumption of sweets. Higher caries scores were also associated with areas of low urbanization. CONCLUSIONS: The findings of this survey indicated a high level of untreated caries among children in Taiwan.     

Assessing risk indicators for dental caries in the primary dentition

The aim of the present study was to assess indicators shown to be associated with the prevalence of caries in the primary dentition of 7-year-old Flemish schoolchildren. Cross-sectional first year data of the longitudinal Signal-Tandmobiel survey were analysed (n=4468). Gender, age, oral hygiene habits, use of fluorides, dietary habits, geographical factors and parental modelling were the considered predictors. From the multiple logistic regression analysis, including schools as a random effect, and after adjusting for the confounding variables-educational system and province (stratification variables), gender and age-it became clear that the following risk indicators remained significant (at 5% level) for the presence of caries: frequency of toothbrushing (P=0.05) with an OR 1.24 for brushing less than once a day, age at start of brushing (P<0.001) with an OR=1.22 for a delay of 1 year, regular use of fluoride supplements (P<0.001) with an OR=1.54 for no use, daily use of sugar-containing drinks between meals (P<0.001) with an OR=1.38, and number of between-meals snacks (P=0.012) with an OR=1.22 for using more than 2 between-meal snacks. There was a significant difference (P<0.05) in caries experience determined by the geographical spread, with an explicit trend of caries declining from the east to the west. In a model with an ordinal response outcome, the daily use of sugar-containing drinks between meals had a more pronounced effect when caries levels were high. From this study it became obvious that, in Flemish children, an early start of brushing and a brushing frequency of at least once a day need to be encouraged, while the use of sugar-containing drinks and snacks between meals needs to be restricted to a maximum of 2 per day. Geographical differences need to be investigated in more detail.     

Longitudinal study of non-cavitated carious lesion progression in the primary dentition

OBJECTIVES: This study reports changes in non-cavitated tooth surface diagnoses after a 4-year period. METHODS: Dental examinations were conducted for Iowa Fluoride Study cohort children who had non-cavitated lesions in the primary dentition and were also examined an average of 4 years later in the mixed dentition. Comparison of fluoride exposures, socioeconomic factors, and beverage consumption patterns were made between children who had lesions progress and those who did not. RESULTS: Of 129 non-cavitated pit and fissure lesions in the first exams, 40 (31%) progressed to either frank decay or filled status, while among 132 noncavitated smooth surface lesions, 7 (5%) were filled and none had frank decay in the second exam. No fluoride, socioeconomic status or beverage variables were significantly associated with lesion progression. CONCLUSIONS: Non-cavitated smooth surface lesions rarely progressed in this age group, but nearly one-third of pit and fissure lesions progressed.     

Dental enamel defects in celiac disease

The teeth of 40 adults aged 19 to 67 yr with celiac disease (CD) were examined for dental enamel defects (ED). A total of 33 of the 40 adults with CD (83%) had systematic ED in contrast to only 5 of the 112 clinical controls (4%). Unspecific enamel lesions were found in both groups, but they were more common in the control group (80% vs. 18%). Altogether 69% of the permanent teeth in adults with CD were found to be defected, in clinical controls only 19%. In adults with CD the ED were in contrast to those in controls symmetrically and chronologically distributed in all four sections of dentition. The present study clearly shows that symmetrically and chronologically distributed enamel defects are strongly associated with CD. Therefore in the absence of symptoms and signs of malabsorption dentists could easily select the right patients possibly suffering from CD for gastroenterologic consultations.     

Developmental enamel defects in children born preterm: a systematic review

The purpose of this review was to evaluate the association between developmental enamel defects and children born preterm. An identical search was performed in PubMed and Embase and was limited to human studies and studies written in English, German, Danish, Swedish, or Norwegian. Reviews, case studies, and case series were excluded. A total of 283 articles were identified. Twenty‐three publications, of which 19 were follow‐up studies, two were case–control studies, and two were cross‐sectional surveys, were enrolled in the review. The majority of the studies (n = 17) dealt with enamel hypoplasia of the primary teeth. Thirteen studies reported an association between preterm birth and enamel hypoplasia, and, in addition, few studies reported an increased risk of enamel opacities in the primary teeth, in children with a birth weight <1500 g. Seven studies dealt with enamel disturbances of the permanent teeth, four of which suggested an increased risk of enamel opacities. This systematic review suggests an increased risk of enamel hypoplasia in primary teeth of children born preterm and enamel opacities in very‐low birth‐weight children. A larger number of well‐designed studies are, however, needed in order to increase the validity of the studies.     

儿童乳牙龋和乳牙黑色素沉着关系研究

目的　评价学龄前儿童乳牙色素沉着患病率以及色素沉着与乳牙龋之间的关系。方法　选取上海市5个公立幼儿园的1 012名学龄前儿童进行调查,1名口腔医师采用WHO推荐的方法进行龋齿的检查,另1名口腔医师检查颊舌面色素沉着。采用SPSS软件对数据进行统计分析。结果　乳牙色素沉着的患病率为12.7%,色素沉着最常见的部位是下颌前牙的舌侧。乳牙色素沉着与年龄和性别无关。城区幼儿园儿童乳牙色素沉着患病率为16%,明显高于郊区儿童6.4%的患病率（P<0.001）。有色素沉着的儿童患龋率和龋失补牙数、龋失补牙面数分别为56.6%、2.94和4.41,明显低于无色素沉着儿童（72.1%,dmft:4.25; dmfs:7.06,P<0.001）。但两组龋齿的牙面分布比例无明显区别。结论　乳牙色素沉着和乳牙龋之间存在负相关关系。