Noninvasive cross‐sectional imaging of proximal caries using swept‐source optical coherence tomography (SS‐OCT) in vivo

The aim of this study was to determine the diagnostic accuracy of swept‐source optical coherent tomography (SS‐OCT) in detecting and estimating the depth of proximal caries in posterior teeth in vivo. SS‐OCT images and bitewing radiographs were obtained from 86 proximal surfaces of 53 patients. Six examiners scored the locations according to a caries lesion depth scale (0–4) using SS‐OCT and the radiographs. The results were compared with clinical observations obtained after the treatment. SS‐OCT could detect the presence of proximal caries in tomograms that were synthesized based on the backscatter signal obtained from the proximal carious lesion through occlusal enamel. SS‐OCT showed significantly higher sensitivity and larger area under the receiver operating characteristic curve than radiographs for the detection of cavitated enamel lesions and dentin caries (Student's t ‐test, p < 0.05). SS‐OCT appears to be a more reliable and accurate method than bitewing radiographs for the detection and estimation of the depth of proximal lesions in the clinical environment. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

运用CT三维重建测量重度先天性脊柱侧凸Cobb角的临床应用

目的:评价在CT三维重建上测量重度先天性脊柱侧凸Cobb角度的可重复性和可靠性。方法:收集在我院诊治的重度先天性脊柱侧凸病人的CT三维重建和脊柱全长X线片,共计67例。由五名不同测量者对CT三维重建脊柱畸形冠状面主弯Cobb角测量两次,两次间隔在三周以上,并测量脊柱全长X线片脊柱畸形冠状面主弯Cobb角一次,运用组内相关系数分析测量结果之间的可重复性和可靠性。结果:同一测量者两次测量结果之间的差值平均为4.5°。同一测量者两次测量结果之间的组内相关系数为0.969,不同测量者之间测量结果的组内相关系数为0.913。取五名测量者在CT三维重建上第一次测量的Cobb角度,其平均值为(110.5±23.5)°,五名测量者在X线片上测量结果的平均值为(103.1±22.0)°,对两组数据进行Mann-Whitney非参数检验差异有统计学意义(Z=-2.86,P=0.004)。结论:在CT三维重建上测量重度先天性脊柱侧凸的Cobb角,可以减小测量的误差,提高测量的可重复性和可靠性,是一种相对准确的测量方法。     

Natural dental caries in molars of osteogenic disorder Shionogi rats

Osteogenic disorder Shionogi (ODS) rats are genetically defective in ascorbic acid biosynthesis. They exhibit a gait abnormality due to dysfunctional bone formation and display various dental abnormalities. Conditions of the oral cavity and tooth quality both influence the development of dental caries. This study was designed to determine the characteristics of dental caries in ODS/ ShiJclod/od rats. Caries were scored and compared among ODS/ShiJclod/od, ODS/ShiJcl+/+, and Jcl:Wistar retired breeders. Among male rats, the caries scores of the ODS/ShiJclod/od and ODS/ShiJcl+/+ groups were similar to each other but greater than those in Jcl:Wistar rats, whereas among female rats, caries scores in ODS/ShiJclod/od animals were equivalent to or somewhat greater than those in ODS/ShiJcl+/+ rats, whose scores were markedly greater than those of Jcl:Wistar rats. The results suggest that ODS/ShiJcl rats were more susceptible to dental caries than were Jcl:Wistar rats. Under the conditions of the study, caries scores between ODS/ ShiJclod/od and ODS/ShiJcl+/+ rats differed only among parous females.     

Oral health status in elders from South Brazil: a population-based study

doi: 10.1111/j.1741‐2358.2011.00617.x Oral health status in elders from South Brazil: a population‐based study Objective: To assess the oral health status of community‐dwelling adults aged 60 years and older from southern Brazil and to determine demographics, socioeconomic, behavioural and dental risk indicators. Materials and methods: This cross‐sectional study used a multistage, probability sampling method to draw a representative sample of the metropolitan area of Porto Alegre, Brazil. A subsample of 217 subjects was included in this analysis. Oral mucosal lesions, dental caries, tooth loss and periodontal status (full‐mouth, six sites per tooth exam) were assessed by calibrated examiners. Results: Prevalence of edentulism was 39.5%, and mean tooth loss was 20.2 (SE = 0.6). Older individuals [Odds Ratio (OR) = 2.2], women (OR = 2.3), white people (OR = 5.9), individuals of lower socioeconomic status (OR = 5.6) and smokers (OR = 3.5) had higher likelihood of being edentulous. Approximately 36% of dentate individuals had caries and/or restoration affecting, in average, 5.0 teeth. Periodontitis affected 79% of subjects, and it was associated with older age (OR = 4.0), men (OR = 3.4) and large amounts of supragingival plaque (OR = 3.0). Conclusion: Poor oral health was observed in this elderly population from South Brazil. Sociodemographic disparities accounted for most of the burden of disease and treatment needs.     

An Interobserver Reproducibility Analysis of Ki67 Visual Assessment in Breast Cancer

Background

Ki67 labeling index (LI) is used as a predictive marker and is associated with prognosis in breast cancer. However, standardised methodologies for measurement are lacking which has limited its application in clinical practice. In this study, we evaluated the interobserver concordance of visual assessment of Ki67 LI in breast cancer.

Methods

Ki67- immunostained slides of 160 cases of primary invasive breast cancer were visual assessed by five breast pathologists with two different methods to choose the scoring fields: (1) hot-spot score, (2) average score. Proportions of positive invasive tumor cells at 10 % intervals were scored. The intra-class correlation coefficient (ICC) was used to assess the interobserver reproducibility.

Results

(1) A perfect concordance of Ki67 LI was demonstrated according to both score methods (P<0.0001). Average score method (ICC, 0.904) demonstrated a better correlation than hot-spot score method (ICC, 0.894). (2) By respective means according to two score methods, all cases were classified into three groups (≤10%, 11%-30% and >30% Ki-67 LI). The concordance was relatively low in intermediate Ki67 LI group compared with low and high Ki67 LI groups. (3) All cases were classified into three groups by paired-difference (d) between means of hot-spot score and average score (d<5, 5≤d<10, d≥10). The consistency was observed to decrease with increasing paired-difference according to both methods.

Conclusions

Visual assessment of Ki67 LI at 10 % intervals is a candidate for a standard method in breast cancer clinical practice. Average score and hot-spot score of visual assessment both demonstrated a perfect concordance, and an overall average assessment across the whole section including hot spots may be a better method. Interobserver concordance of intermediate Ki67 LI in which most cutoffs are located for making clinical decisions was relatively low.     

Introducing Computer-Based Testing in High-Stakes Exams in Higher Education: Results of a Field Experiment

The introduction of computer-based testing in high-stakes examining in higher education is developing rather slowly due to institutional barriers (the need of extra facilities, ensuring test security) and teacher and student acceptance. From the existing literature it is unclear whether computer-based exams will result in similar results as paper-based exams and whether student acceptance can change as a result of administering computer-based exams. In this study, we compared results from a computer-based and paper-based exam in a sample of psychology students and found no differences in total scores across the two modes. Furthermore, we investigated student acceptance and change in acceptance of computer-based examining. After taking the computer-based exam, fifty percent of the students preferred paper-and-pencil exams over computer-based exams and about a quarter preferred a computer-based exam. We conclude that computer-based exam total scores are similar as paper-based exam scores, but that for the acceptance of high-stakes computer-based exams it is important that students practice and get familiar with this new mode of test administration.     

Xerostomic medications and oral health: the Veterans Dental Study (part I)

Objectives: To quantify the adverse effects of the number of xerostomic medications on dental caries, oral mucosa, andperiodontal disease. Design: Secondary analysis of across‐sectional study of the Veterans Dental Study. Setting: Four New England area VA outpatient clinics. Subjects: The sample consists of 345 male veterans participating in The Veteran's Dental Study who also had pharmacy records. Main outcome measures: Oral health data included total surfaces of coronal caries, a modification of the root caries index, mean oral mucosa scores, and Community Periodontal Index of Treatment Need (CPITN). Oral health parameters were measured and recorded in clinical dental examinations. Exposures: Intake of xerostomic medications 14‐385 days prior to the dental examination. Statistical Analyses: The relationships between exposure and outcome were analyzed via linear and logistic regression methods adjusting for possible confounding factors such as disease burden index, alcohol consumption, dental care, and smoking status. Results: Veterans who were taking at least one xerostomic medication were almost three times more likely to have mean mucosa scores in the worst 25 percentile than veterans taking no xerostomic medications, OR= 2.63 (confidence interval [CI] 1.34,5.16, p=0.03) after adjusting for age, number of teeth, disease burden index, income, smoking and alcohol use. Participants who were taking at least one xerostomic medication experienced higher but non‐significant increases in coronal (OR =1.21; CI. 0.66, 2.25) and root caries (OR =1.10 CI. 0.54, 2.24) measured by numbers of total decayed surfaces. Conclusion: There were significant deleterious effects of xerostomic medications on oral mucosa. However, xerostomic medications do not appear to increase coronal caries, or periodontal index measured by CPITN among ambulatory, community dwelling participants who were able to perform routine preventive oral care.     

Reliability of the Radiographic Sagittal and Frontal Tibiotalar Alignment after Ankle Arthrodesis

BackgroundAccurate measurement of the tibiotalar alignment is important in radiographic outcome assessment of ankle arthrodesis (AA). In studies, various radiological methods have been used to measure the tibiotalar alignment leading to facultative misinterpretation of results. However, to our knowledge, no previous study has investigated the reliability of tibiotalar alignment measurement in AA. We aimed to investigate the reliability of four different methods of measurement of the frontal and sagittal tibiotalar alignment after AA, and to further clarify the most reliable method for determining the longitudinal axis of the tibia.MethodsThirty-eight weight bearing anterior to posterior and lateral ankle radiographs of thirty-seven patients who had undergone AA with a two screw fixation technique were selected. Three observers measured the frontal tibiotalar angle (FTTA) and the sagittal tibiotalar angle (STTA) using four different methods. The methods differed by the definition of the longitudinal tibial axis. Method A was defined by a line drawn along the lateral tibial border in anterior to posterior radiographs and along the posterior tibial border in lateral radiographs. Method B was defined by a line connecting two points in the middle of the proximal and the distal tibial shaft. Method C was drawn „freestyle”along the longitudinal axis of the tibia, and method D was defined by a line connecting the center of the tibial articular surface and a point in the middle of the proximal tibial shaft. Intra- and interobserver correlation coefficients (ICC) and repeated measurement ANOVA were calculated to assess measurement reliability and accuracy.ResultsAll four methods showed excellent inter- and intraobserver reliability for the FTTA and the STTA. When the longitudinal tibial axis is defined by connecting two points in the middle of the proximal and the distal tibial shaft, the highest interobserver reliability for the FTTA (ICC: 0.980; CI 95%: 0.966–0.989) and for the STTA (ICC: 0.997; CI 95%: 0.996–0.999) is provided. Intergroup analysis for FTTA measurements revealed a statistically significant difference between the method in which the lateral border of the tibia was used to determine the longitudinal axis of the tibia, and the other methods in which the longitudinal axis was defined by bisecting the tibia.ConclusionsWhen the longitudinal axis of the tibia is defined by connecting two points in the middle of the proximal and the distal tibial shaft for measuring the FTTA and STTA, the most favorable interobserver reliability is provided. Therefore, this method can be recommended for evaluating the frontal and the sagittal alignment on anterior to posterior and lateral radiographs after ankle arthrodesis.     

The effect of geochemical factors on prevalences of dental diseases for prehistoric inhabitants of the state of Missouri

In previous epidemiological studies, it has been suggested that geochemical factors besides fluoride may affect the prevalences of dental diseases. Our objective in this study was to determine whether the prevalences of periodontal diseases, coronal caries, and root caries for prehistoric inhabitants vary between geochemical regions of the state of Missouri. Burial sites were located on unique maps that depict geochemical variation among regions of the state. Data on dental caries and alveolar bone loss were gathered from 179 of the best preserved skeletal remains of the Late Woodland (A.D. 400-900) and Mississippian (A.D. 900-1700) periods. Mean caries scores and proportions of individuals with caries were calculated for these geochemical regions. Average alveolar bone loss was regressed on age for the individuals of these regions. Significant differences in caries and bone loss were found between several regions. These differences cannot be adequately explained by fluoride concentrations or by diet. It is suggested that geochemical factors, in addition to fluoride, may have affected the prevalences of dental diseases.     

Quantitative detection of Streptococcus mutans in the dental plaque of Japanese preschool children by real-time PCR

AIMS: To detect quantitatively the total bacteria and Streptococcus mutans in dental plaque by real-time PCR with prbac, Sm and GTF-B primers, and to compare their presence with the prevalence of dental caries in Japanese preschool children. METHODS AND RESULTS: Human dental plaque samples were collected from the labial surfaces of the upper primary central incisors of 107 children. The dental status was recorded as dft by WHO caries diagnostic criteria. Positive dt and dft scores by the Sm or GTF-B primer were significantly higher than negative scores (P < 0.01). The proportions of Strep. mutans to the total bacteria from sound, and sound and/or filled upper primary incisors were significantly lower than those from decayed or filled, and decayed incisors, respectively (P < 0.01). CONCLUSIONS: The ratios of Strep. mutans to total bacteria in plaque detected by real-time PCR with Sm and GTF-B primers were closely associated with the prevalence of dental caries in Japanese preschool children. SIGNIFICANCE AND IMPACT OF THE STUDY: These assays may be useful for the assessment of an individual's risk of dental caries.     

Study of dental caries and periapical lesions in a mediaeval population of the southwest France: Differences in visual and radiographic inspections

Dental caries and periapical lesions have often been studied in archaeological samples. The majority of these studies concern lesions detected clinically and, in some cases, radiography is used to improve the scoring results. The purpose of the present study was to compare and combine the two methods for recording caries and cysts. The studied dental material derived from a mediaeval sample from the south of France. The study included sixty mandibles (788 teeth). Each tooth was observed clinically and radiographically. Absence of teeth was noted and unerupted teeth, which could be viewed on radiographs were also noted. The location and degree of development of each lesion were recorded. Occlusal lesions of degree 1 were mostly detected clinically (5.1% vs.1.4% detected radiographically). Radiographic detection increased the score of approximal lesions of degree 2 (1.4% vs. 0.7%) and the detection of intraosseous lesions. This research has shown that the combination of radiographic and clinical examinations improves the caries detection and thus, increases the caries score in a studied dental sample.     

Accuracy of dental age estimation charts: Schour and Massler,Ubelaker and the London Atlas

Dental age estimation charts are frequently used to assess maturity and estimate age. The aim of this study was to assess the accuracy of estimating age of three dental development charts (Schour and Massler, Ubelaker, and the London Atlas). The test sample was skeletal remains and dental radiographs of known‐age individuals (N = 1,506, prenatal to 23.94 years). Dental age was estimated using charts of Schour and Massler, Ubelaker, and The London Atlas. Dental and chronological ages were compared using a paired t‐test for the three methods. The absolute mean difference between dental and chronological age was calculated. Results show that all three methods under‐estimated age but the London Atlas performed better than Schour and Massler and Ubelaker in all measures. The mean difference for Schour and Massler and Ubelaker was ?0.76 and ?0.80 years (SD 1.27 year, N = 1,227) respectively and for the London Atlas was ?0.10 year (SD 0.97 year, N = 1,429). Further analysis by age category showed similar accuracy for all three methods for individuals younger than 1 year. For ages 1–18, the mean difference between dental and chronological ages was significant (P < 0.05) for Schour and Massler and Ubelaker and not significant (P > 0.05) for the London Atlas for most age categories. These findings show that the London Atlas performs better than Schour and Massler and Ubelaker and represents a substantial improvement in accuracy of dental age estimation from developing teeth. Am J Phys Anthropol 154:70–78, 2014. © 2014 Wiley Periodicals, Inc.     

The Effect of Therapy Dogs on Exam Stress and Memory

Therapy dogs have been shown in many different situations to reduce stress and improve outcomes, but their effects on academic performance are unknown. I hypothesized that interaction with therapy dogs prior to exams would reduce stress in students and improve exam scores. In study 1, participants who chose to interact with the therapy dogs showed a significantly larger stress decrease and scored 5.5 points higher on their final exam than those who did not interact. In study 2, investigating memory retrieval, participants assigned to interact with therapy dogs immediately prior to their final exam showed a marginally larger stress reduction, but no difference in exam score, compared with those who watched a movie about dogs. To investigate memory consolidation, in study 3, participants were assigned to interact with therapy dogs or watch a movie immediately after learning some material. A significant interaction between condition and exam question type suggests that, compared with those who watched a movie about dogs, interacting with therapy dogs impaired memory for material learned just prior to the manipulation, but enhanced memory for material encountered at other times. Overall, interaction with therapy dogs appears to reduce stress, but had no effect on memory retrieval in study 2, and differentially affected memory consolidation of associated material in study 3.     

Intra and Interobserver Reliability and Agreement of Semiquantitative Vertebral Fracture Assessment on Chest Computed Tomography

Objectives

To evaluate the reliability of semiquantitative Vertebral Fracture Assessment (VFA) on chest Computed Tomography (CT).

Methods

Four observers performed VFA twice upon sagittal reconstructions of 50 routine clinical chest CTs. Intra- and interobserver agreement (absolute agreement or 95% Limits of Agreement) and reliability (Cohen''s kappa or intraclass correlation coefficient(ICC)) were calculated for the visual VFA measures (fracture present, worst fracture grade, cumulative fracture grade on patient level) and for percentage height loss of each fractured vertebra compared to the adjacent vertebrae.

Results

Observers classified 24–38% patients as having at least one vertebral fracture, giving rise to kappa''s of 0.73–0.84 (intraobserver) and 0.56–0.81 (interobserver). For worst fracture grade we found good intraobserver (76–88%) and interobserver (74–88%) agreement, and excellent reliability with square-weighted kappa''s of 0.84–0.90 (intraobserver) and 0.84–0.94 (interobserver). For cumulative fracture grade the 95% Limits of Agreement were maximally ±1,99 (intraobserver) and ±2,69 (interobserver) and the reliability (ICC) varied from 0.84–0.94 (intraobserver) and 0.74–0.94 (interobserver). For percentage height-loss on a vertebral level the 95% Limits of Agreement were maximally ±11,75% (intraobserver) and ±12,53% (interobserver). The ICC was 0.59–0.90 (intraobserver) and 0.53–0–82 (interobserver). Further investigation is needed to evaluate the prognostic value of this approach.

Conclusion

In conclusion, these results demonstrate acceptable reproducibility of VFA on CT.     

郑州孙庄遗址仰韶文化人群的龋病

孙庄遗址位于河南省郑州市中原区孙庄村,是分布在黄河中游的一处仰韶文化晚期遗址,该遗址出土的54例仰韶时期的人骨保存状况良好,为我们了解仰韶文化人群的龋患情况提供了珍贵的资料。本文以肉眼观察为主并结合超景深显微镜对遗址出土的846枚牙齿进行鉴定、统计与分析,得出以下结论：孙庄遗址古代人群的龋病患病率70.37%,龋齿率22.93%,龋均3.59;壮年组患龋率最高,为88.89%,不同年龄组之间的龋齿率差异性显著;龋齿率女性为30.55%,男性为16.16%,女性龋齿率显著高于男性,P(0.000)<0.05,两性之间的龋齿率有显著差异;浅龋率为6.70%,中龋率为21.65%,深龋率为27.32%,深龋已穿髓率为19.07%,残冠残根率为25.26%,随着年龄的增长,龋病的病变程度呈加重趋势;龋损范围小于1/2牙冠累龋最常见,占总患龋齿数的42.27%;上颌龋齿率为26.91%,下颌龋齿率为19.70%,上下颌龋齿率差异显著（P<0.05）。龋病在不同牙位上的发生率依次为M3>M2>P2>M1>P1>C>I1>I2;邻面和 面是主要的龋患分布处,分别占患龋牙齿数的46.40%和39.18%。孙庄人群门齿较高的患龋率表明该遗址人群患龋情况已经非常严重,患龋率与龋齿率明显高于其他古代组,较高的龋病罹患率可能与孙庄人群复杂的农业经济模式有关。     

Comparison of a Novel Computerized Analysis Program and Visual Interpretation of Cardiotocography

Objective

To compare a novel computerized analysis program with visual cardiotocography (CTG) interpretation results.

Methods

Sixty-two intrapartum CTG tracings with 20- to 30-minute sections were independently interpreted using a novel computerized analysis program, as well as the visual interpretations of eight obstetricians, to evaluate the baseline fetal heart rate (FHR), baseline FHR variability, number of accelerations, number/type of decelerations, uterine contraction (UC) frequency, and the National Institute of Child Health and Human Development (NICHD) 3-Tier FHR classification system.

Results

There was no significant difference in interobserver variation after adding the components of computerized analysis to results from the obstetricians'' visual interpretations, with excellent agreement for the baseline FHR (ICC 0.91), the number of accelerations (ICC 0.85), UC frequency (ICC 0.97), and NICHD category I (kappa statistic 0.91); good agreement for baseline variability (kappa statistic 0.68), the numbers of early decelerations (ICC 0.78) and late decelerations (ICC 0.67), category II (kappa statistic 0.78), and overall categories (kappa statistic 0.80); and moderate agreement for the number of variable decelerations (ICC 0.60), and category III (kappa statistic 0.50).

Conclusions

This computerized analysis program is not inferior to visual interpretation, may improve interobserver variations, and could play a vital role in prenatal telemedicine.     

Evidence that the apolipoprotein E-genotype effects on lipid levels can change with age in males: a longitudinal analysis.

We previously reported that change, with age, in plasma levels of total cholesterol (TC) and LDL cholesterol (LDL-C) differed between apolipoprotein E (APOE) genotypes epsilon 3 epsilon 3 and epsilon 3 epsilon 4, in a sample of 77 older, unrelated males. By use of a larger sample from that cohort, followed longitudinally during 1969-87, the change in TC and in LDL-C, between the epsilon 3 epsilon 3 and epsilon 3 epsilon 4 APOE genotypes, over three exams, was reanalyzed. Additionally, the change in triglycerides (TG) and in HDL-cholesterol (HDL-C), between the epsilon 3 epsilon 3 and epsilon 3 epsilon 4 APOE genotypes-as well as the differences between the epsilon 3 epsilon 3 and epsilon 3 epsilon 2 genotypes, for TC, LDL-C, TG, and HDL-C-were contrasted over the three exams. At exam 1 TG was higher in the epsilon 3 epsilon 4 group than in the epsilon 3 epsilon 3 group (mean age 48 years), and at exams 2 and exam 3 (mean ages 58 and 63 years, respectively) it was similar (P = .009 for the exam-by-genotype-interaction effect in the repeated-measures analysis). A similar trend was seen for TC (P = .03), yet previously detected LDL-C effects were not apparent (P = .46). Those with the epsilon 3 epsilon 2 genotype had higher TG and lower LDL-C and TC at each exam than were seen in those with the epsilon 3 epsilon 3 genotype, although the differences in the values were not always statistically significant. Differences in TC, LDL-C, and TG, between the epsilon 3 epsilon 2-genotype and epsilon 3 epsilon 3-genotype groups, did not significantly change over the three exams. HDL-C levels were relatively stable over the exams; however, the exam-by-genotype interaction was significant for the epsilon 3 epsilon 2 genotype versus the epsilon 3 epsilon 3 genotype (P = .02). The epsilon 4 allele effects on TG and TC changed between longitudinal exams and may be age dependent. Changes, with age, in the effect of the epsilon 3 epsilon 4 genotype on lipids may impact the risk of developing atherosclerotic disease.     

Home or away? Differences between home‐ and clinic‐based dental examinations for older people

Objective: To determine whether home‐based and clinic‐based dental examinations of older people are comparable. Background: Despite a number of studies which have examined the concordance between different examiners or examination circumstances, none has directly compared an oral examination conducted at home with one conducted in an appropriate clinical setting. Materials and methods: Dentate participants (n = 61) aged between 65 and 74 years underwent two clinical examinations, one in a conventional dental clinic and the other in the person’s home. Kappa statistics, intra‐class correlation coefficients and ‘Difference against mean’ plots were used to determine the nature and extent of any bias. Results: The summary estimates for missing teeth and dental caries were close, although the home‐based examinations resulted in a lower estimate of the mean number of decayed teeth and of untreated coronal decay. The lowest reliability statistics were observed with respect to the prevalence of untreated coronal caries, filled root surfaces and root surface (Decayed or Filled Surfaces) DFS. The periodontitis prevalence estimates were closer, but the reliability statistics were relatively low. The extent of bleeding on probing was relatively under‐estimated in the home‐based examinations. ‘Difference against mean’ plots indicated that, overall, the clinic‐based examinations detected more disease (although this was not observed for all clinical parameters which were measured). Conclusion: While clinic‐based examinations will remain the preferred option, the potential loss of information associated with home‐based examinations is unlikely to be great enough to preclude using them where required, although surveys with larger samples (and therefore more accurate estimates) should restrict their proportion of home‐based examinations to no more than 10%. As they are less precise, surveys with samples of 300 or fewer can safely accommodate up to about one‐third of their examinations being conducted in participants’ homes.     

Caries prevalence in skeletal series--is it possible to compare?

Because of the relationship with subsistence, dental caries is a central issue in paleopathological research. Usually, comparisons between caries prevalence exhibited in different skeletal series are made. Dietary variation is the most common explanation for cavities prevalence. The aim of this paper is to verify if it is possible to compare caries prevalence reported on papers for archaeological skeletal series. Another goal is to determine if other factors besides diet are implicated in dental cavity prevalence explanation. Twenty six papers about dental health with caries prevalences published from 1999 to 2004 were analyzed for completeness. This assessment includes carious lesion diagnosis and characteristics, age, sex and size characteristics of samples, and prevalence calculation method. The majority of the analyzed papers do not provide adequate information in the topics listed above. Only very few implicated factors other than diet as a contributor to caries lesions development.     

Bacteriological Studies of the Effects of Cow's Milk on Dental Plaque and Dental Caries in Rats

The effects of liquid milk and skim milk powder on the bacterial composition of rat dental plaque and dental caries were examined in two separate experiments. First, groups of rats fed a cariogenic diet plus one or other of three types of liquid milk had. after 28 d. similar plaque flora. Those rats receiving reconstituted spray-dried skim milk had a significantly higher incidence of dental caries than those receiving either pasteurized and homogenized milk or ultra-heat treated milk. The differences in caries scores may be related to differences in inorganic phosphate and calcium levels of the milks. Secondly, rats fed a diet containing 65% phosphate-free sucrose plus 32% spray-dried skim milk in powder form had a significantly lower dental caries score than did rats receiving a diet containing 65% sucrose plus 32% autoclaved roller-dried skim milk powder. At the end of this experiment, the plaque flora had changed significantly and the difference in caries incidence was related to the reduction in the percentage of potentially cariogenic bacteria.
These results indicate that the mechanism by which milk reduces dental caries incidence may be (a) by remineralizing incipient carious lesions or (b) by mediating changes in the bacterial composition of dental plaque.