bluuebunny/crossref_metadata_2025 huggingface dataset:
First-Cousin Matings and Congenital Heart Disease in Saudi Arabia
Authors: Becker Susan , Al Halees Zohair
Published: April 2003

Background: Consanguinity may be a risk factor that contributes to congenital heart disease in an inbred population, particularly among first cousins; with high rates of intermarriage between relatives, consanguinity is associated with congenital heart disease particularly among first cousins. Patients and Methods: This study examines a group of 1,028 consecutive congenital heart disease (CHD) patients identified through the Congenital Heart Disease Registry at King Faisal Specialist Hospital in Riyadh, Saudi Arabia. Families were interviewed by an Arabic-speaking data collector for information on consanguinity and demographic data. After exclusions for nonavailability, data were collected on 949 cases and the proportions of first-cousin consanguinity in the study sample were compared to national population data. A z test of proportions was utilized to test the hypothesis that there are higher proportions of first-cousin consanguinity in the study sample of congenital heart patients than in the general population. Findings: Data indicate that the proportion of first-cousin matings among CHD patients is significantly higher than that of first-cousin intermarriages reported in the general population (p < 0.001). Regional breakdowns of the data substantiate significant differences (p < 0.001) in the proportions of first-cousin consanguinity in the study sample compared to the general population. Interpretation: In a population with a high degree of inbreeding, consanguinity may exacerbate underlying genetic risk factors, particularly for offspring of first-cousin matings. This finding has public health implications for genetic counseling and prevention of some cardiac malformations.
Etiological Characterization of 512 Severely Mentally Retarded Institutionalized Patients in Havana
Authors: Lantigua-Cruz Aracely , Mora Fidel , Arechaederra Miriam , Rojas Iris , Morales Estela , Rodríguez Haydée , Viñas Carlos , Noa Carlos E. , Barrios Barbara
Published: April 2003

Objective: To investigate etiological factors in severe mental retardation (SMR). Methods: An etiological study is presented of 512 SMR patients in five specialized institutions in Havana. Results: Prenatal, perinatal and postnatal causes were apparent in 58.0, 24.8 and 11.1% of the patients, respectively; infantile psychosis was determined in only 0.4%. The remaining 5.6% were classified as having SMR of undeterminable origin, i.e. patients with apparently normal pre-, peri- and postnatal histories who had neither dysmorphism nor affected first-degree relatives, and had a normal karyotype and metabolic screen. Among prenatal causes, genetic factors were the most frequent (82.8%), while environmental factors were apparent in only 5.3% of these cases. Of the cases with prenatal genetic etiology, chromosomal aberrations were present in 86.5% (Down syndrome 96.2% and 3.7% other chromosomal aberrations), monogenic disorders in 11.3% [neurocutaneous diseases (32.1%) and fragile X syndrome (25%) were the most frequent], and multifactorial disorders in 2.0%. Thirty-five patients (11.7%) presented multiple congenital anomalies of ‘prenatal unknown’ causes. The latter group may include unidentifiable chromosomal aberrations, uniparental disomy, de novo mutations and multifactorial or teratogenic factors. Conclusion: Accurate determination of the etiology of SMR is important not only for genetic counseling purposes, but also in identifying prenatal events which make infants more vulnerable to perinatal risk factors.
Development of an Antenatal Screening Programme for Congenital Abnormalities in a South Wales District: Lessons Learnt for Clinical Governance
Authors: Al-Jader Layla N. , Hopkins Sharon
Published: April 2003

An earlier report on antenatal screening for Down syndrome in a South Wales district identified sub-standard and variable practices. A multidisciplinary Professional Advisory Group was set up in 1996 to review the service and recommend a model of care, as well as quality outcome measures to form the standards for audit and evaluation. The programme drew heavily on evidence-based practice and the opinion and aspirations of the pregnant women. This was the first organised attempt at standardisation of the screening practices for congenital abnormalities in Wales. A year later, several goals had been achieved. Each obstetric unit now has a named Screening Midwife Specialist. The first genetic course in the UK specifically tailored for midwifes has been established. Lack of leadership in fetal medicine and ultrasound scanning was identified in one maternity unit, resulting in the appointment of two additional sonographers and a consultant obstetrician. The Professional Advisory Group produced a new, district-wide, annually updated information booklet for expectant mothers. A new information system was installed in each maternity unit to facilitate audit of outcome. Several clinical, biochemical and cytogenetic indicators were specified as quality outcome indicators and were collated and compared with the recommended standards. The uptake of serum screening has declined from around 95 to 75% in two units (to 62.9% overall, closely resembling the percentage expected based on the findings of a local survey of pregnant women). The rate of amniocentesis was significantly reduced by 28.7%, as women thought more clearly about their options and the limitations of tests. This suggests that women have a better understanding and more autonomy in making decisions regarding tests. An enthusiastic public health lead was essential in initiating and maintaining the changed programme.
Caries Development from 11 to 22 Years of Age: A Prospective Radiographic StudyPrevalence and Distribution
Authors: Mejàre I. , Källestål C. , Stenlund H. , Johansson H.
Published: April 2003

The aim was to assess the distribution and pattern of caries development longitudinally in teenagers and adolescents whose treatment had been based on remineralizing rather than restorative strategies. A baseline cohort of 536 children was studied, using bite-wing radiographs, from 11 to 22 years of age. The results showed a slow but continuous increase in both enamel and dentin caries of approximal surfaces. At 21, 29% of all posterior approximal surfaces had enamel caries according to the radiographic diagnoses, 14% had dentin caries and another 5% were restored. At the age of 20–21, the skewed distribution of DMFSappr apparent at 12 and 15 had given way to a more uniform picture and the percentage of individuals with no decayed approximal surfaces (DMFSappr = 0) decreased from 71 at 12–13 to 28 at 20–21 years of age. The proportion of DFSoccl in relation to all DFS decreased from 83% at 12 to 52% at 21. The occlusal, mesial and distal surfaces of the first molar accounted for 60% of all restored surfaces at 21.
Accuracy of Radiographic Detection of Residual Caries in Connection with Tunnel Restorations
Authors: Wenzel A. , Hintze H. , Hörsted-Bindslev P.
Published: April 2003

The aim of this study was to evaluate the diagnostic accuracy of radiographic examination for the detection of residual caries after tunnel preparation and filling with glass ionomer cement. Further, two different radiographic modalities were compared. Forty-five extracted human promolars and molars with clinical signs of approximal caries were selected for the study. The teeth were radiographed in order to identify surfaces with dentinal lesions suitable for tunnel preparation. Seventeen of the teeth had lesions that were as a minimum through the enamel and as a maximum into the outer half of the dentin (14 teeth = 1 lesion, 3 teeth = 2 lesions). Seventeen surgically removed third molars were thereafter included. These teeth were sound with respect to caries. The teeth were arranged in blocks with approximal contacts and radiographed using two image receptors: Ektaspeed Plus film (E) and the Digora (D) digital storage phosphor plate system. The 20 carious surfaces and 20 surfaces of the impacted teeth were prepared following the guidelines for the class II tunnel technique and filled with glass ionomer cement. The radiographic examination was repeated with both modalities after filling, and the approximal surfaces scored on the radiographs by 5 observers using the criteria: 0 = no filling, 1 = filling with residual caries, 2 = filling with no adjacent caries. All teeth except the unerupted third molars were sectioned, and the sections examined under the microscope. Residual caries was observed in 8 surfaces. On average, sensitivity was 0.25 for E and 0.32 for D, specificity 0.83 for E and 0.76 for D, positive predictive value 0.38 for E and 0.32 for D, and negative predictive value 0.75 for E and 0.77 for D. The differences between the two modalities were not statistically significant (p > 0.3). Based on the relatively small number of lesions in this study, it is suggested that radiography immediately after tunnel restoration cannot be recommended, as the diagnostic benefit from this examination seems to be minuscule.
Autofluorescence and Mineral Content of Carious Dentine: Scanning Optical and Backscattered Electron Microscopic Studies
Authors: Banerjee Avijit , Boyde Alan
Published: April 2003

The aim of this study was to investigate the extent of natural intrinsic fluorescence in carious human dentine and any correspondence of such autofluorescence (AF) to the mineral distribution within the lesion. Two investigative techniques were used, both employing the same sample set and fields in diamond-polished block surfaces of polymethylmethacrylate-embedded carious teeth. AF at emission wavelengths > 515 nm, excited by 488-nm laser light, was assessed using a confocal laser scanning optical microscope (CLSM), the recordings made under standard operating conditions. The relative mineral content was assessed using digital backscattered scanning electron microscopy (20 kV BSE-SEM). The AF intensity correlated with the level of demineralisation as seen by BSE, but the depth of the lesion as seen by CLSM was significantly greater implying that the AF is not directly related to the mineral component.
An in vitro System for the Analysis of Changes in Depth Distribution of Diffusates in Bacterial Films
Authors: Assinder S.J. , Dibdin G.H. , Marshall M. , Shellis R.P.
Published: April 2003

No suitable technique exists which allows simultaneous analysis of time- and depth-dependent concentrations of all components of interest in single samples of intercellular fluid from dental plaque biofilms. We have developed an in vitro model which allows detailed study of these interactions by analysis of intercellular fluid and pH measurement at the film base. Compact, defined-depth films of Streptococcus mutans were formed in a micrometer-controlled, variable-depth well and bathed in synthetic saliva. Films exposed to synthetic saliva containing glucose for 2 min followed by clearance with glucose-free synthetic saliva gave typical ‘Stephan-type’ pH profiles. Intercellular fluid isolated from successive 200-μm-thick sections of 600-μm-deep films was analysed by ion chromatography. A concentration gradient of lactate, falling with depth, was measured. The experimental system described here, the first of its type to be described, can easily be used to analyse pH changes and the depth-dependent distribution of diffusates in a model bacterial film. Although this bacterial film is far removed from a natural biofilm, the apparatus has potential for the study of grown biofilms and is an important advance towards position-dependence analysis of diffusates in biofilms.
Comparison of Erosion of Dental Enamel by Four Drinks Using an Intra-Oral Applicance
Authors: Rugg-Gunn A.J. , Maguire A. , Gordon P.H. , McCabe J.F. , Stephenson G.
Published: April 2003

There are several causes of erosion – acidic foods and drinks have been implicated and reducing their erosive potential would seem an important area of research. Calcium-citrate-malate (CCM) appeared to have potentially useful properties as an anti-erosion additive. The study aims were to test the ability of an intra-oral enamel slab system to measure erosion and to compare the erosive potential of a citric acid-based orange juice drink either with or without added CCM and a positive and negative control. Eleven adults wore an upper removable appliance for four periods each of 6 days. Each appliance held two enamel slabs which were inserted into the test drinks for 15 min 4 times a day for 6 days. Loss of enamel was quantified by profiling casts of the enamel slabs taken before and after the test period. Loss of enamal was greatest during exposure to a diet phosphoric acid-based cola drink (p < 0.001) but was similar during exposure to the two citric acid-based orange drinks, with or without CCM, and distilled water. The loss of surface enamel measured from a scanning electron micrograph agreed well with the measurement obtained by profilometry. It can be concluded that (a) the intra-oral enamel slab system was able to discriminate between drinks in their erosive potential, and (b) it was not possible to determine if CCM had any potential for reduction in erosion in an acid beverage as the level of erosion observed for both the critic acid-based orange drinks was not statistically significantly different from that observed with distilled water.
Cells for the Study of Acidic Dissolution in Packed Apatite Powders as Model Systems for Dental Caries
Authors: Morgan H. , Wilson R.M. , Elliott J.C. , Dowker S.E.P. , Anderson P.
Published: April 2003

A number of different designs of cells have been developed for the study of dissolution processes in packed apatite powders. Basic design requirements were that no deleterious processes, such as high temperature sintering or binding agents, were involved, and that there was maximum opportunity for experimental study. One design used alternating filter paper discs and apatite layers (typically 42 mg). At the end of an experiment, the cell could be disassembled and infrared spectra and X–ray powder diffraction patterns made of individual layers. Cells without filter paper discs were also made, but terminal sampling at well–defined depths was more difficult or impossible. The cells were constructed from poly(methylmethacrylate) so the course of dissolution could be monitored by radiography. Subsurface loss of apatite was almost always seen after from 2 weeks to 8 months exposure to buffer solutions at pH 3.0–5.5. The greatest loss of apatite was typically 0.4–2 mm below the surface, which is at a larger distance than usually seen for dental enamel. This may be attributable to the low packing density (typically 35–60 vol%) found in the present systems compared with enamel.
Analysis of pH–Driven Disruption of Oral Microbial Communities in vitro
Authors: Bradshaw D.J. , Marsh P.D.
Published: April 2003

Previously, a mixed culture chemostat system was used to demonstrate that the pH generated from carbohydrate metabolism, rather than carbohydrate availability per se, was responsible for the shifts observed in the oral microflora which are associated with high carbohydrate diets and the development of dental caries. The aim of this study was to determine more accurately the microbially generated pH at which such shifts occurred. Nine oral bacteria were grown in three independent chemostats, and pulsed with glucose on 10 consecutive days. In one chemostat, pH control was discontinued for 6 h, and the pH fall was restricted to a minimum value of pH 5.5; the pH fall was arrested in the other two chemostats at either pH 5.0, or at pH 4.5. When the pH was allowed to fall, the numbers and proportions of Streptococcus mutans and Lactobacillus rhamnosus increased; this increase was directly related to the magnitude of the pH fall. Veillonella dispar was the most numerous organism following all glucose pulsing regimes, especially at low pH. The increase in proportions of acidogenic bacteria was accompanied by a fall in the proportions of acid–sensitive species (Fusobacterium nucleatum, Prevotella nigrescens, Streptococcus gordonii and Streptococcus oralis). The counts of these species were relatively stable between pH 5.5 and 4.5, but were markedly reduced when the pH fell below pH 4.5; Neisseria subflava could not persist in the culture at pH 4.5 or below. The data suggest that the disruption of communities associated with glucose metabolism and low pH can be explained in terms of a two–stage process. A fall in pH to a value between pH 5.5 and 4.5 may allow the enrichment of potentially cariogenic species, whilst permitting species associated with health to remain relatively unaffected. A further reduction in pH (<pH 4.5) may not only enhance the competitiveness of odontopathogens, but inhibit the growth and metabolism of non–caries–associated species. The results also indicate that species other that mutans streptococci or lactobacilli are competitive at pH values low enough to demineralise enamel, and thus suggest that a broader range of micro–organisms may be associated with caries initiation.
Secretory Immunity in Defense against Cariogenic Mutans Streptococci
Authors: Russell M.W. , Hajishengallis G. , Childers N.K. , Michalek S.M.
Published: April 2003

Specific immune defense against cariogenic mutans streptococci is provided largely by salivary secretory IgA antibodies, which are generated by the common mucosal immune system. This system is functional in newborn infants, who develop salivary IgA antibodies as they become colonized by oral microorganisms. The mechanisms of action of salivary IgA antibodies include interference with sucrose–independent and sucrose– dependent attachment of mutans streptococci to tooth surfaces, as well as possible inhibition of metabolic activities. The goal of protecting infants against colonization by mutans streptococci might be accomplished by applying new strategies of mucosal immunization that would induce salivary IgA antibodies without the complications of parenteral immunization. Strategies of mucosal immunization against mutans streptococci currently under development include the use of surface adhesins and glucosyltransferase as key antigens, which are being incorporated into novel mucosal vaccine delivery systems and adjuvants. The oral application of preformed, genetically engineered antibodies to mutans streptococcal antigens also offers new prospects for passive immunization against dental caries.
Caries and Fluorosis Prevalence in Communities with Different Concentrations of Fluoride in the Water
Authors: Angelillo I.F. , Torre I. , Nobile C.G.A. , Villari P.
Published: April 2003

The need to defluoridate and fluoridate the water supplies in areas with drinking water naturally containing above–optimal (≥2.5 mg/l) and suboptimal (≤0.3 mg/l) fluoride concentration and caries and fluorosis prevalence of 12–year–old schoolchildren were assessed in Italy. In the low–fluoride area, 48.4% children were caries–free (DMFT = 0) and the DMFT and DMFS were 1.5 and 2.6; in the high–fluoride area, 46.8% had a DMFT = 0 and the values of the indices were 1.4 and 1.6, respectively. Multiple logistic regression analysis showed a significant association in the caries–free status according to parents' employment status (OR = 1.2, 95% CI = 1.1–1.3) and children's sweets consumption, since children who consumed sweets at least once a day had an adjusted odds ratio of 1.8 (95% CI = 1.4–2.3) compared to those with a lower consumption. Multiple linear regression analysis showed that DMFT and DMFS were significantly higher in children with a lower socioeconomic status and in those who consumed sweets at least once a day, with the DMFS significantly associated also with the area of residence. DT and FT scores were higher in the high– and low–fluoride areas, respectively. No evidence of fluorosis was reported in 94.5 and 55.3% of children in the low– and high–fluoride areas, respectively. The Community Fluorosis Index (CFI) for all permanent teeth was significantly higher in the high–fluoride area, 0.8, than the value, 0.1, found in the low–fluoride community. Our results substantiate the difficulties in defining universal guidelines for the fluoridation or defluoridation of drinking water and the need for an epidemiological approach to the decision as to fluoridate and defluoridate the water supply.
Fluoride Augments the Mitogenic and Antigenic Response of Human Blood Lymphocytes in vitro
Authors: Loftenius A. , Andersson B. , Butler J.E. , Ekstrand J.
Published: April 2003

It has been shown that fluoride, the agent responsible for reduction of dental caries worldwide and a recognized proliferative agent, is an adjuvant when given intragastrically to rats. Furthermore, plasma fluoride levels increase in humans after various fluoride treatments. The studies presented here show that fluoride also has the ability to affect the cells of the human immune system. This was tested by measuring the effect of sodium fluoride (NaF) on cytokine production by human whole blood cells stimulated in vitro. These studies revealed that NaF augments the human lymphocyte response from human blood to a mitogen (phytohemagglutinin, PHA) or a specific antigen (morbilli antigen from infected cells, MorbAg). The cytokine interferon–γ (IFN–γ), released from activated T and/or NK cells, was significantly (p<0.01) increased when whole blood cells were simultaneously incubated with 0.62 mmol/l NaF and PHA compared to PHA alone. This tendency was also true for NaF and MorbAg. The lymphocyte activation marker interleukin–2 receptor (measured in soluble form) increased after simultaneous stimulation of the cells with PHA and 0.62 mmol/l NaF compared to stimulation with PHA only. However, 0.62 mmol/l NaF did not enhance interleukin–6 release, in blood mainly produced by monocytes. The ability to influence the IFN–γ release during an immune response could be one of the primary means by which the fluoride ion influences the immune system.
The Validity and Repeatability of Three Light–Induced Fluorescence Systems: An in vitro Study
Authors: Lagerweij M.D. , van der Veen M.H. , Ando M. , Lukantsova L. , Stookey G.K.
Published: April 2003

New optical systems are being developed that aim to determine the extent of demineralization in enamel. In our laboratory we have compared three such systems: a ring illuminator equipped with a laser, a beam splitter also equipped with a laser and an intra–oral camera equipped with a white–light arc lamp. The aim of the study was to compare the ability of the different optical systems to detect small enamel lesions with microradiographic analysis and to determine the repeatability of these systems. Forty human enamel specimens (3mm in diameter) were mounted in acrylic and polished. The specimens were kept moist throughout the study. Each specimen of the four groups was individually exposed to 14 ml of Carbopol demineralizing solution for 24, 48, 72 and 96 h, respectively. The mineral loss of the 40 specimens was assessed with blue–violet light– induced fluorescence. Each image was captured with a video camera and analysed with dedicated software. The measurements were repeated 3 times with complete shut–down of the system in between the measurements. The same measurements were performed with the ring illuminator, the beam splitter and the arc lamp. The specimens were then cut into thin sections and analysed with microradiography. Similar high correlations between microradiography and the light–based analysis systems were found for the beam splitter and the clinical caries camera set–up. The repeatability was best for the beam splitter set–up. This indicates that the light–induced fluorescence measurement technique can be used in different configurations and that the repeatability of the measurements is influenced by the physical stability of the set–up.
Performance and Reproducibility of a Laser Fluorescence System for Detection of Occlusal Caries in vitro
Authors: Lussi A. , Imwinkelried S. , Pitts N.B. , Longbottom C. , Reich E.
Published: April 2003

The diagnosis of occlusal caries at non–cavitated sites remains problematic, especially since clinical visual detection has limited sensitivity. Electrical methods of detection show considerable promise, but specificity is reduced. The aims of this in vitro study were: (1) to assess the validity of a new laser fluorescence device – the DIAGNOdent – (and compare the values with those of a fixed–frequency electrical device); (2) to determine the optimum cut–off points of the new device for different stages of the caries process, and (3) to assess the reproducibility of the new laser device. For validity and determination of optimum cut–off points, 105 extracted teeth with macroscopically intact occlusal surfaces were measured by a single examiner, using both the laser fluorescence device (on both moist and dried teeth) and an Electronic Caries Monitor. The teeth were subsequently examined histologically to determine the specificity, sensitivity and likelihood ratio at the D2 (caries extending through more than half of the enamel thickness) and D3 (caries involving dentin) levels. The values obtained for the laser device ranged from 0.72 to 0.87 (specificity), 0.76 to 0.87 (sensitivity) and 3.0 to 5.6 (likelihood ratio). Those for the ECM ranged from 0.64 to 0.78 (specificity), 0.87 to 0.92 (sensitivity) and 2.4 to 4.1 (likelihood ratio). To determine intra– and interexaminer reproducibility of the DIAGNOdent, 11 dentists recorded two different measurements at the same site on a separate set of 83 extracted molar teeth, and these were compared using Cohen’s kappa (at D2 and D3 levels) and Spearman’s correlation coefficient. The average intra–examiner kappa scores were 0.88 (D2) and 0.90 (D3), with a Spearman correlation of 0.97. For interexaminer reproducibility, the average kappa values were 0.65 (D2) and 0.73 (D3), with a Spearman correlation of 0.84. It is concluded that for occlusal caries (1) the new laser device has a higher diagnostic validity than the ECM, and (2) in vitro, measurements using the device are highly reproducible. Thus, the laser device could be a valuable tool for the longitudinal monitoring of caries and for assessing the outcome of preventive interventions.
Distribution of Three Cariogenic Bacteria in Secondary Carious Lesions around Amalgam Restorations
Authors: González-Cabezas C. , Li Y. , Gregory R.L. , Stookey G.K.
Published: April 2003

Secondary dental caries remains an unresolved problem in dentistry and little is known of its microbial etiology. The purpose of this study was to compare the distribution of the three most suspected cariogenic groups of bacteria, mutans streptococci. Actinomyces naeslundii genospecies 2 and lactobacilli, in natural secondary caries around amalgam restorations. Extracted teeth with secondary caries were sectioned to obtain three samples that were randomly distributed to three different groups. Each group was immunolabeled with antibodies to either Streptococcus mutans, A. naeslundii genospecies 2 or Lactobacillus casei and subsequently labeled with secondary fluorescent antibodies. All samples were analyzed three–dimensionally using confocal microscopy. The results indicated that the three different bacteria were widely present and could have an important role in the development of secondary caries around amalgam restorations.
A Two–Film versus a Four–Film Bite–Wing Examination for Caries Diagnosis in Adults
Authors: Hintze H. , Wenzel A.
Published: April 2003

The aim of this study was to compare the caries diagnostic outcome of a two–film and a four–film routine bite–wing examination undertaken in an adult population. A digital bite–wing examination using two and four films, respectively, was performed in 174 patients. The radiographs from the two examinations were assessed jointly by 2 observers for the number of imaged surfaces in the area from the distal surface of the canine to the distal surface of the third molar and for the detection of carious lesions. Significantly more surfaces were available for examination by the four–film than by the two–film examination. Overlapping surfaces were recorded in 14 and 10%, respectively, of the surfaces imaged by the two–film and four–film set. The prevalence of primary enamel and dentinal caries was 6.8% with the two–film and 5.6% with the four–film method. In 1,684 surfaces only imaged by the four–film method caries was detected in 20 surfaces. If these extra lesions were added to the number of lesions found by the two–film method the total disease prevalence using the last–mentioned method would increase by 2‰. The majority (92–99%) of all recorded lesions were detected in surfaces located between the occlusal surface of the first premolar and the mesial surface of the third molar. The little additional diagnostic outcome obtained by the use of four instead of two films did not seem to match the extra resources (double patient charge and radiation dose, and extended scan/developing and recording time for the dentist) connected to the four–film method. Thus, it may be recommended that a routine bite–wing examination undertaken in young adults should be performed with only two films: one in each side of the mouth, placed behind the premolars and the first and second molars.
Caries Prevalence after Cessation of Water Fluoridation in La Salud, Cuba
Authors: Künzel W. , Fischer T.
Published: April 2003

In the past, caries has usually increased after cessation of water fluoridation. More recently an opposite trend could be observed: DMFT remaining stable or even decreasing further. The aim of the present study conducted in La Salud (Province of Habana) in March 1997 was to analyse the current caries trend under the special climatic and nutritional conditions of the subtropical sugar island Cuba, following the cessation, in 1990, of water fluoridation (0.8 ppm F). Diagnostic evaluations were carried out using the same methods as in 1973 and 1982. Boys and girls aged 6–13 years (N = 414), lifelong residents in La Salud, were examined. Between 1973 and 1982 the mean DMFT had decreased by 71.4%, the mean DMFS by 73.3% and the percentage of caries–free children had increased from 26.3 to 61.6%. In 1997, following the cessation of drinking water fluoridation, in contrast to an expected rise in caries prevalence, DMFT and DMFS values remained at a low level for the 6– to 9–year–olds and appeared to decrease for the 10/11–year–olds (from 1.1 to 0.8) and DMFS (from 1.5 to 1.2). In the 12/13–year–olds, there was a significant decrease (DMFT from 2.1 to 1.1; DMFS from 3.1 to 1.5), while the percentage of caries–free children of this age group had increased from 4.8 (1973) and 33.3 (1982) up to 55.2%. A possible explanation for this unexpected finding and for the good oral health status of the children in La Salud is the effect of the school mouthrinsing programme, which has involved fortnightly mouthrinses with 0.2% NaF solutions (i.e. 15 times/year) since 1990.
Salivary Factors Affecting Dental Erosion in Children
Authors: O’Sullivan E.A. , Curzon M.E.J.
Published: April 2003

Dental erosion is becoming a major dental problem in both children and adults. The aim of this study was to measure the salivary flow rates, buffering capacity and mutans streptococci counts in children with erosion, and compare them to age– and sex–matched caries–free and caries–active individuals to establish which factors may be important in erosion. The study was conducted as a case–control study with standard methods of salivary and mutans streptococci measurement. The results showed significant differences for mutans streptococci counts (p = 0.05), unstimulated and stimulated salivary pH and buffering capacity (p = 0.001). These results suggest that although individuals with erosion have caries experience similar to a caries–free individual, their salivary characteristics more closely match those of a caries–active subject. The tests described are simple to carry out and may be useful in explaining individual patient susceptibility.
Genotypes of Mutans Streptococci Tend to Persist in Their Host for Several Years
Authors: Emanuelsson I. Redmo , Thornqvist E.
Published: April 2003

The aim of this study was to evaluate the consistency of the prevalence of mutans streptococci in a group of Swedish families. Eleven families, which had previously been examined for genotypes of mutans streptococci, were re–examined after 2–5 years. The families consisted of mother, father and a child (mean age 7.2 years at the follow–up examination). One father did not participate. Pooled plaque samples were obtained from buccal and occlusal surfaces. Isolates of mutans streptococci were genotyped using chromosomal DNA digested with restriction endonuclease HaeIII, separated by gel electrophoresis and visualised through UV illumination after ethidium bromid staining. Comparing the DNA fingerprints of mutans streptococci found at baseline and follow–up, 9 children harboured one or two genotypes which were similar on the two sampling occasions. Two of these children had also gained a genotype. The remaining 2 children had lost a genotype each and 1 of them had gained two new genotyes. All 21 adults showed one or two genotypes identical to those found at baseline. Nine of these 21 adults had also lost one genotype. Four of these 9 and additionally 4 of the remaining adults showed one or two new genotypes. Six mother–child pairs shared a genotype at baseline and this pattern remained for five pairs at the end of the study. The results suggest that genotypes of mutans streptococci have a fairly high degree of consistency in children between 3 and 8 years of age as well as in adults, indicating persistence of the strains. However, the results also indicate that some subjects may gain and/or lose genotypes.
Comparative Reduction of Enamel Demineralization by Calcium and Phosphate in vitro
Authors: Tanaka M. , Kadoma Y.
Published: April 2003

In theory, calcium and phosphate in the plaque fluid exert a large influence on the demineralization of enamel surface. In order to know the effect of increasing the concentration of either of these factors, the following in vitro experiment was conducted. Three thin sections, about 150 Ìm thick, were cut out from each of 13 human premolars. All surfaces of the sections, except for the original enamel surface, were coated with nail varnish. These sections were immersed into one of two sets of demineralizing solutions for 1 week at 25°C. Each set, the ‘calcium set’ and the ‘phosphate set’, contained three solutions. The composition of these solutions differed mainly in calcium or phosphate concentrations. After 1 week, the degree of demineralization was determined by image analysis of contact microradiograms from each section. The subsurface demineralization in enamel was reduced by 95% by increasing the calcium concentration of the demineralizing solution from 7 to 21 mmol/l. A similar reduction (87%) was observed by increasing the phosphate concentration. However, the amount of phosphate needed was approximately 20 times more than that of calcium. The larger inhibitory effect that calcium has on enamel demineralization was related to the larger effect it has on the degree of saturation of the solution. Even though no statistically significant difference was found between the effect of calcium and phosphate on the demineralization of enamel (when the solutions had the same degree of saturation), the difference in the standard deviation of demineralization suggests the existence of some other factors which have an influence on the demineralization reaction.
Effect of Tooth–Bound Fluoride on Enamel Demineralization/ Remineralization in vitro
Authors: Takagi S. , Liao H. , Chow L.C.
Published: April 2003

The effect of tooth–bound fluoride (F) on enamel caries formation was investigated under the condition that loosely bound F was essentially absent. Eighteen thin enamel sections, prepared from the lingual or buccal surfaces of extracted human molars, were embedded in acrylic resin with the enamel surfaces exposed. The sections were placed in a pH 7 remineralizing solution (RS; 1.2 mmol/l Ca, 0.72 mmol/l P, 30 mmol/l KCl, 50 mmol/l HEPES) for 5 days, and were randomly divided into 3 groups: (1) control group that received no treatment, (2) acidulated phosphate fluoride (APF) group that received 5 cycles of a 4 min treatment with APF gel followed by immersion in the RS for 2 days (RS changed daily) and (3) dicalcium phosphate dihydrate (DCPD) – APF group that received 5 cycles of a 4–min pH 2.1 DCPD–forming solution followed by 4 min APF gel and then placed in the RS for 2 days. After the treatment cycles, the sections were washed in a constant composition F titration system to remove loosely bound F. An in vitro model, which consisted of cycles of de– (6 h) and remineralization (18 h) each day for 5 days, was used to produce caries–like lesions in the specimens. The ΔZ (mineral loss) values, measured by quantitative microradiography, of the lesions formed in the three groups were (mean ± standard deviation; n = 6) 91.2±12.3 Ìm for the control group, 41.3±10.1 Ìm for the APF group and 21.2±4.8 Ìm for the DCPD–APF group. The same system produced lesions in untreated shark enamel with a mean ΔZ of 4.4±0.3 Ìm (n = 12). One–way fixed–effects ANOVA indicated that mineral loss was significantly different among the different groups (p<0.05). The results showed that enamel resistance to lesion formation increased with increasing tooth–bound F content. Shark enamel was much more resistant to demineralization than human enamel.
Changes in Dental Caries Prevalence in 12–Year–Old Students in the State of Mexico after 9 Years of Salt Fluoridation
Authors: Irigoyen M.E. , Sánchez-Hinojosa G.
Published: April 2003

The purpose of this study was to describe the dental caries experience in 12–year–old students in the State of Mexico and to detect changes after 9 years of salt fluoridation (1988–1997). The 1987 WHO dental caries criteria were used in both surveys. The population studied encompassed 2,275 12–year–old students in 1988, and 1,138 in 1997. The proportion of ‘caries–free’ children was 10.3% in the first survey and 27.7% in the second one. The mean DMFT index was 4.39 (SD 2.9) in 1988 and 2.47 (SD 2.4) in 1997, the confidence interval of the differences between DMFT means was [95% CI 1.73, 2.11]; the caries reduction detected was 43.7%. The Unmet Restorative Index was 82.3% in 1988 and 72.8% in 1997. The results of the present study indicate that the oral health status of State of Mexico students has improved during the last decade; however, there is still a need for further caries reduction and an increment in access to dental treatment.
Socio–Economic and Behavioural Risk Factors for Tooth Loss from Age 18 to 26 among Participants in the Dunedin Multidisciplinary Health and Development Study
Authors: Thomson W.M. , Poulton R. , Kruger E. , Boyd D.
Published: April 2003

Objective: To determine the risk factors associated with tooth loss between the ages of 18 and 26. Methods: Dental examinations at ages 18 and 26 were conducted on Study members in the Dunedin Multidisciplinary Health and Development Study, and sociodemographic and dental service use data were collected using a self–report questionnaire. At age 15, an estimate of socio–economic status (SES) for each Study member had been obtained by classifying the occupation of the male parent. A case of tooth loss was defined as an individual who had lost one or more teeth (excluding third molars) due to caries between ages 18 and 26. Logistic regression and Poisson analysis were used to model the occurrence of tooth loss. Results: Among the 821 study members who were examined at both ages, one or more teeth were lost because of caries by 85 (10.3%). After controlling for sex, SES and visiting pattern, baseline caries experience predicted subsequent tooth loss, with the odds increasing by 2.8 for every increase by 1 in the number of decayed surfaces present at age 18. Episodic dental visitors had 3.1 times the odds of their routine visiting counterparts of losing a tooth over the observation period. The number of teeth lost was, on average, 2.3 times higher among episodic dental visitors. Conclusions: Socio–economic inequalities in tooth loss appear to begin early in the life course, and are modified by individuals’ SES and dental visiting patterns.
Approximal Caries Depth Assessment with Storage Phosphor versus Film Radiography
Authors: Svanæs D.B. , Møystad A. , Larheim T.A.
Published: April 2003

Objectives: To study whether caries–specific enhancement of storage phosphor images might improve the observer performance of approximal caries depth assessments compared with film radiography. Materials and Methods: 120 exposures were made of 120 extracted human teeth. To obtain geometrically identical images, Ektaspeed Plus films and storage phosphor plates were exposed simultaneously. The imaging plates were scanned in a Digora® scanner and the files transferred to a different platform for image enhancement. Nine observers viewed films and storage phosphor images without provisions for adjustment of image intensity and contrast. For each imaging modality, 240 approximal surfaces were rated for caries on a 5–point confidence scale. Definite and probable caries lesions were also rated for lesion depth, and all ratings were compared with the histological state. Diagnostic accuracy was expressed as the area under the ROC curve (Az value). Paired t tests were used to compare the imaging modalities for diagnostic accuracy and F tests to compare observer variances. Results: Enhanced storage phosphor images demonstrated significantly higher mean Az values than film (p = 0.0066). Significantly higher mean Az values were demonstrated in the outer half of enamel (p = 0.01), but no significant differences were found between the modalities for caries lesions penetrating beyond the outer half of the enamel. The number of correctly diagnosed true–positive surfaces with caries in outer enamel was significantly higher with storage phosphor images than with film (p = 0.00014). False–positive surfaces were most frequently registered in the outer enamel with both modalities, but in this region the number of false–positive surfaces was significantly higher with storage phosphor images than with film (p = 0.0038). Pooled sensitivity and specificity values were 0.48/0.94 and 0.61/0.86 for film and storage phosphor images, respectively. The interobserver variability was significantly lower for storage phosphor images than for film. Conclusion: Enhancement of storage phosphor images with a caries–specific procedure significantly improved the accuracy of caries depth assessments in the outer half of the enamel compared with film radiography and reduced observer variability.
Fetomaternal Attachment and Anchorage inthe Early Diffuse Epithel iochorial Placenta of the Camel (Camelus dromedarius)
Authors: Abd-Elnaeim M.M. , Pfarrer C. , Saber A.S. , Abou-Elmagd A. , Jones C.J.P. , Leiser R.
Published: April 2003

Placentae of 22 one-humped camel concepti with crown-rump lengths (CRL) ranging from 2.5 to 26 cm were studied. The placentae were processed for light, transmission and scanning electron microscopy of exposed surfaces and microvascular corrosion casts. In very early stages of pregnancy (2.5–4.5 cm CRL) three froms of fetomaternal interrelationship are described. (1) Precontact, where the mononuclear trophoblast cells are still separated from the uterine epithelium by a gap containing interareolar histotroph. Both fetal and maternal epithelia develop apical ectoplasmic pads in this location. (2) Apposition, where microvilli of the apical cell membrane of the trophoblast contact the uterine epithelium focally. Multinuclear trophoblast giant cells develop beside the population of already present mononuclear trophoblast cells. Uterine ectoplasmic pads can be observed. (3) Adhesion occurs when apical cell membranes of fetal and maternal epithelia adhere to each other closely, thus forming a ‘normal’ intercellular space of 20 nm width, without any intervening uterine luminal space. Microvillous interdigitation in this location varies from a non-microvillous ‘smooth adhesion’, to a distinctly villiform ‘rough adhesion’, and a ‘semismooth adhesion’ is achieved when trophoblastic microvilli make intimate contact with the non-microvillous uterine apical cell membranes of ectoplasmic pads. This fetomaternal attachment process is sufficient until the conceptus reaches approximately 9 cm CRL. Then, from 10 to 13 cm CRL, additional anchorage of the placenta to the endometrium is accomplished by the growth of temporary grooves and ridges of the allantochorion and the endometrium, which indent each other in a complementary fashion. The height of these groove-ridge structures increases gradually in 14 to 18 cm CRL fetuses, and they also widen at about 25 cm CRL, thus forming globular fetal troughs and irregular, thick maternal ridges. These together create units responsible for improved fetomaternal anchorage and metabolic exchange for the increasing needs of the growing fetus.
Structure and Function of the Proteins of the Mammalian Zona pellucida
Authors: Prasad S.V. , Skinner S.M. , Carino C. , Wang N. , Cartwright J. , Dunbar B.S.
Published: April 2003

The zona pellucida (ZP) is the extracellular matrix that plays important roles in sperm-egg interaction. The ZP is composed of three major glycoproteins that exhibit heterogeneity due to extensive post-translational modifications including glycosylation and sulfation. Because of these modifications the nomenclature of ZP proteins from different species based on electrophoretic mobilities has been confusing. As the cDNAs and genes encoding the different ZP proteins have been isolated and sequenced, it is now possible to relate these ZP proteins according to gene families. Using the mouse ZP nomenclature, the ZP proteins from different mammalian species can be classified into three protein families: ZP1, ZP2, and ZP3. Although some of the structural domains of the ZP proteins of different species are conserved within each family, they exhibit distinct biological properties. In the mouse it has been established that ZP3 is the primary sperm receptor while ZP2 has secondary sperm receptor properties. In the pig, however, ZP1 has been shown to have sperm receptor activity similar to that observed in the rabbit and nonhuman primates. It is of interest that the human ZP2 and ZP3 gene families are 60–70% conserved with respect to the mouse ZP amino acid sequence, while the mouse ZP1 is only 39% conserved with respect to human ZP1. Such differences in protein structure and glysosylation may explain the marked species differences in the biochemical, physicochemical and immunochemical properties of the ZP. Studies have now shown that the proteins of the ZP are expressed in a stage specific manner and that there is increasing evidence that ZP proteins are expressed by both granulosa cells and the oocyte and may play a role in granulosa cell differentiation.
Clinical Value of Esophageal Motility Testing
Authors: DiMarino Jr. Anthony J. , Allen Melvin L. , Lynn Richard B. , Zamani Saeed
Published: April 2003

Esophageal motility testing is the method of choice in evaluating esophageal motor disorders. Some physicians, however, question the clinical utility of esophageal motility testing, since the results are often normal in symptomatic patients. The clinical utility of esophageal motility testing is reviewed for patients with a complaint of noncardiac chest pain, dysphagia or symptoms of gastroesophageal reflux disease. Esophageal motility testing is particularly useful for evaluating patients with dysphagia, but less so for gastroesophageal reflux disease patients, and has little clinical utility in patients with noncardiac chest pain.