Profile of subgingival microbiota in children with primary dentition

Eruption of primary teeth has a great influence on the oral environment by providing suitable niches for bacterial colonization. The aim of the study was to investigate the composition of the subgingival microbiota of primary incisors, canines and molars in 40 systemically healthy children aged 4-5 yr, chosen randomly. Subgingival plaque samples were taken from the mesiobuccal sites of primary incisors (61, 81), canines (53, 73) and molars (64, 84). The samples were cultured for bacterial isolation anaerobically and in 10% CO2 plus air using selective and non-selective media. Forty-one different microbial species were isolated. Gemella morbillorum and Peptostreptococcus magnus were statistically significantly more frequently detected in incisors while P. micros, Streptococcus intermedius, Bacteroides forsythus, Fusobacterium nucleatum, Prevotella loeschei, P. melaninogenica and Selenomonas sputigena were more frequently detected in molars. The bacterial species S. constellatus, G. morbillorum and P. magnus were isolated in greater numbers in incisors and P. micros, S. intermedius, Campylobacter concisus, Bacteroides egertheii, B. forsythus, P. oralis and S. sputigena were isolated in greater numbers in molars, respectively. Cluster analysis revealed 4 clusters in which 6-7 bacterial species were elevated above mean levels. Cluster I was predominated by S. constellatus, S. mitis, S. sanguis, G. morbillorum, P. melaninogenica and P. oralis; cluster II was predominated by S. sanguis, Actinomyces naeslundii, Capnocytophaga gingivalis, C. ochracea and P. intermedia; cluster III was predominated by S. mitis, C. ochracea, F. nucleatum, P. loeschei, P. melaninogenica and P. oralis; and finally cluster IV was predominated by S. sanguis, C. gingivalis, Veillonella parvula, Campylobacter gracilis, F. nucleatum and P. intermedia. The bacterial species S. constellatus, P. micros, Pseudoramibacter alactolyticus, Eikenella corrodens and F. nucleatum were associated with non-bleeding sites while S. intermedius, C. concisus, P. intermedia and P. loescheii were found more frequently in bleeding sites.     

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.     

Marginal bone loss in the primary dentition of patients with juvenile periodontitis

Abstract 118 patients with juvenile periodontitis (JP), diagnosed when the patients were 13–19 years old, were studied retrospectively with respect to radio-graphic marginal bone loss in the primary dentition, experienced when the patients were 5–12 years old. 168 other 13–19 year old patients without any signs of bone Joss in the permanent teeth were used as a reference group. The JP patients were classified into 2 groups according to the number of sites with bone loss in the permanent dentition: JP group I having 1 site with bone loss (n=45) and JP group II having 2 sites with bone loss (n=73). It was found that 35 patients (52%) of JP group II displayed 1 or more sites with bone loss in the primary dentition during the age of 5–12 years. The corresponding numbers for JP group I and the reference group were 9 (20%) and 8 (5%) respectively. These findings indicate that juvenile periodontitis, at least in some individuals, may have its onset already in the primary dentition.     

Characteristics of the gum chewing occlusal phase in children with primary dentition

Understanding of the growth and development of mandibular function is indispensable to the diagnosis of functional disturbances during childhood. The purpose of this study was to clarify the characteristics of the occlusal phase during gum chewing in children with primary dentition. Chewing motion at the working molar of 14 children with primary dentition and 28 female adults was recorded optoelectrically, and the frontal and sagittal angles of their closing and following opening strokes were measured and compared. In children the closing strokes were entered more vertically and anteriorly than in adults, and the opening strokes shifted to the non-working side in adults but moved to the working side in children. The degree of variance also differed between the two groups; the variance of the frontal angle was larger than that of sagittal angle in adults, but the opposite was true in children. These results suggested that the chewing pattern in children during the occlusal phase is distinctly different from adults and the chewing movement in children is not always less stable than in adults.     

Root exposure in the primary dentition studied in human skulls

The aims of the present study were to examine, on the primary dentition of 75 human dried skulls, the distance from the cemento-enamel junction (CEJ) to the alveolar bone crest, and to evaluate its relation to developmental age, bone morphology and attrition. The measurements from the CEJ to the alveolar crest were longer for the maxillary teeth, the second molars showed the shortest measurements, while the cuspids showed the longest. Significant positive partial correlations were found between age and the distance from the CEJ to the alveolar crest when controlling for attrition (r = 0.64), and between age and attrition when controlling for the distance from the CEJ to the alveolar bone crest (r = 0.54). The partial correlation between migration and attrition when controlling for age proved to be not significant (r = 0.13). Significant correlations were found between age and the distances from the mental foramen to: the alveolar crest (r = 0.90), and to the lower border of the mandible (r = 0.97). These findings suggest that root exposure takes place in the primary dentition, as the result of continuous eruption at a faster rate than formation of alveolar bone, presumably to compensate for facial growth.     

Plaque and gingivitis in the deciduous and permanent dentition

Abstract The aim of the present investigation was to monitor de novo plaque formation and associated alterations of the gingival conditions in the deciduous, mixed and permanent dentition in man. 31 volunteers, divided into 3 study groups participated in the trial. Group 1 was made up of 11 subjects, 4–6 years of age (deciduous dentition), group 2 comprised of 10 subjects, 8–9 years of age (mixed dentition) and group 3 included 10 subjects, 14–16 years of age (permanent dentition). After a screening examination, each participant received detailed instruction in a proper oral hygiene technique and was subjected to professional tooth cleaning. The professional debridement and the oral hygiene instruction were repeated after 1 week. After another week, a given day was termed Day 0 and a baseline examination was performed. This examination included assessments of plaque and gingivitis. Each subject received an additional, comprehensive professional tooth cleaning and was asked to abstain from all mechanical oral hygiene measures. Re-examinations were performed after 3 and 7 days. The findings demonstrated that: (i) during a 7-day period of no active oral hygiene, subjects with a mixed or a permanent dentition formed visible amounts of plaque and developed modest signs of gingivitis; (ii) during the 7 days of the trial, young subjects with a fully erupted deciduous dentition formed less plaque than the older subjects, and failed to respond to de novo plaque formation with enhanced signs of gingivitis; (iii) in subjects with a mixed dentition, the amount of plaque formed during the 7 days of experiment and the matching gingivitis development were similar in the deciduous and permanent tooth segments of the dentition.     

The relationship between alveolar bone height and age in the primary dentition

Abstract The natural history of changes in attachment level in the primary dentition should be determined before considering diagnostic criteria for periodontal diseases in children. The present study was designed to describe longitudinal changes in the distance between the alveolar bone crest and the cementoenamel junction (ABC-CEJ) determined radiographically. Bite-wing radiographs were obtained from 33 children as part of a routine annual dental examination in a rural community. The ABC-CEJ distance of 1500 sites located at the mesial and distal aspects of primary molars and distal aspect of primary cuspids were measured. An analysis of variance model was used to assess the effect of age, sex, tooth, side of the mouth, jaw, site and patient on the ABC-CEJ measurements. The side of the mouth (left, right) and the site (mesial, distal) had no significant effect on the ABC-CEJ distance. ABC-CEJ distances in the upper jaw were greater than in the lower jaw, and different teeth exhibited different ABC-CEJ distances. Canines had the greatest distance and second molars the smallest. The most interesting relationship was between alveolar bone height and age. The overall ABC-CEJ distance seemed to increase with age; however, this was not a linear relationship but followed the pattern of facial growth, with two spurts separated by a period of minimal increase. The results indicate that different levels of ABC-CEJ distance might be considered as a cut-off value for radiographic diagnosis of alveolar bone loss at different ages, for different primary teeth and for different jaws.     

Correlation between caries experience in primary and permanent dentition in birth-cohorts 1950–70

Abstract – Caries experience in the primary molars and canines at 8 yr of age and in the permanent dentition at 16 was correlated in every fourth birth-cohort between 1950 and 1970 in a Danish community. Correlations between 0.44 and 0.56 were found. Cross-tabulation of the data also revealed close association, but prediction of individual high caries risk children based solely on screening for caries experience in the primary dentition is hardly cost-effective.     

Prevalence of dental fluorosis in the primary dentition

OBJECTIVES: This paper presents data on the prevalence of primary tooth fluorosis among children residing in Iowa, and the relationships between fluorosis prevalence and selected measures of fluoride exposures. METHODS: Children in the study cohort were followed prospectively during the first year of life. This study assessed their home water fluoride concentrations and use of fluoride dentifrice or dietary fluoride supplements. A total of 637 children (320 females and 317 males) were examined for fluorosis using a modification of the TSIF index at age 4 1/2 to 5 years, with 90.4 percent having intact primary dentitions. RESULTS: 74 children (11.6%) had fluorosis present on one or more of their primary teeth, and 71 children (11.1%) had two or more teeth affected. Nearly all fluorosis was mild, with the primary second molar teeth most commonly affected. Fluorosis was significantly associated with higher water fluoride concentration, but not with the use of dentifrice or fluoride supplements. CONCLUSIONS: The results of this study show that primary tooth fluorosis is relatively uncommon, but is most frequently seen on the posterior teeth, particularly the primary second molars, which form at later stages of development. This finding suggests that primary tooth fluorosis is mostly a postnatal phenomenon, and is associated with higher water fluoride levels.     

昆明市乳牙列错畸形发病率的调查研究

目的 了解云南省昆明市市区乳牙列错情况,为乳牙期错畸形的预防性和阻断性矫治提供依据.方法 对昆明市市区3所幼儿园的乳牙全萌出且达到接触的2 116名乳牙列儿童进行调查,计算其错畸形发病率.结果 在2116名乳牙列儿童中,错1 516名,错率72％.排列在错前6位的依次是:深覆、牙列拥挤、前牙反、切、乳牙早失、开.结论 昆明市市区乳牙列错率的数据报告显示其发病率较高,需加强乳牙列错畸形的防治.     

不完全性腭裂患者腭裂修复术后乳牙期与替牙期颅面形态变化的对比研究

目的研究不完全性腭裂患者修复术后乳牙期与替牙期的颅面形态差异。方法选择21例乳牙期和20例替牙期不完全性腭裂患者作为两个实验组，两组的性别比例匹配，进行X线头影测量对比分析。结果替牙期相比乳牙期颅底大小、上颌长、下颌大小及各面高均显著增长。上颌矢状向位置、下颌矢状向位置、颅底角下颌角、下颌平面角、上下颌垂直向关系以及面高之比均无显著变化。面突度显著减小。结论随年龄增长腭裂患者颅面部增大，但各部分之间的相互位置关系基本保持不变。     

上海地区儿童乳牙列错牙合畸形流行病学调查分析

目的了解上海地区儿童乳牙列错牙合畸形流行情况,为儿童口腔卫生保健措施的制定提供理论依据。方法按照分层随机抽样的原则抽取上海市10个区20所幼儿园的2 744名3~6岁乳牙列儿童,对乳牙牙合发育情况进行检查。结果上海地区儿童乳牙牙合错牙合畸形患病率高达69.64%,男女无统计学差异;各类错牙合畸形患病率排序依次为:深覆牙合最高为55.39%,其次是深覆盖24.31%、牙列拥挤21.25%、反牙合12.03%和开牙合7.22%,其中35%的受检者同时患有两种及以上的错牙合畸形。结论上海地区乳牙牙合错牙合畸形无论是患病率还是临床类型排序较以往调查结果都发生了明显变化,需制定相应的预防保健措施,预防其发生、发展,提高儿童口腔健康水平。     

Traumatic injuries in the primary dentition

Abstract  – As a support for the guidelines published in 2001, a review of the literature was carried out using the evidence-based approach in order to update the state of the art regarding epidemiology and treatment of traumatic dental injuries in the primary dentition. An online search in Medline, and a review of expert literature, lead to the conclusion that most luxation injuries heal spontaneously, and unless more conclusive evidence is available, conservative treatment of acute dental trauma for preschool children is suggested. Pain control, the dentist's ability to cope with the child's anxiety, and follow-up instructions in oral hygiene techniques will allow many primary teeth that are currently lost at the time of injury to be saved.     

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.     

Severe sequelae of acute dental trauma in the primary dentition – a case report

Abstract –  The incidence of traumatic injuries to primary teeth is high. Previous studies report frequencies ranging from 4% to 33% of all children. The damage limitation and the prevention of sequelae are goals that shall direct the treatment for dental trauma. Inappropriate approachs to dental trauma can cause more damage than the trauma itself. This article describes the diagnosis, management and follow-up of a 5-year-old boy who presented with uncommon sequelae of an inappropriate approach following a severe luxation of the primary maxillary right central incisors 2 years ago.     

Bite force determination in children with primary dentition

The aim of this study was to determine the bite force with primary dentition in 30 children with normal occlusion (group I), cross bite (group II) and open bite (group III). The magnitude of the bite force was determined through a pressurized transmitter tube (pressure sensor MPX 5700 Motorola), which was connected to a converse analog/digital electronic circuit. The children bit the tube with maximum force three times successively for 5 s, with a 10 s interval among each bite, and the sign was sent directly to the computer. The highest value of the three, for each patient, was considered. Analysis of variance evaluated difference among the three groups. The means of maximum bite force were 213 17, 249 63 and 241 19 N for the groups, respectively, and there were no significant statistical differences among them (P > 0.05). The analysis of correlation showed that the weight, height and bite force presented weak positive correlation (r=0.24 and 0.23). It was concluded that in the studied groups the type of occlusion did not affect the maximum values of the bite force and body variables had a small influence in this magnitude.