Caries prevalence in the deciduous dentition of a mediaeval population from the south-west of Scotland

The prevalence, distribution and location of dental caries were studied in the deciduous dentition of 185 skeletons aged between 6 months and 13 years from a large, mostly mediaeval, cemetery, where successive phases of use could be distinguished. The main phases dated from 1240 to 1440 AD. During this period, no consistent trend or pattern of caries was identified, but there was a significantly higher caries prevalence in the age band 6-12.9 years than in the age band 0.1-5.9 years. The caries prevalence in the juveniles from the earlier Northumbrian, or Anglo-Saxon, phase of the cemetery was higher than in any mediaeval phase group, with mostly approximal surfaces affected. In the mediaeval population, first deciduous molars generally showed lower caries prevalence than second deciduous molars, significantly lower for the older age band, and maxillary molars consistently showed lower levels than mandibular molars. The highest caries rate, shown by mandibular second molars in the older age band, was 7.9%. In deciduous molars, the occlusal surface was most frequently affected by caries, whereas in the permanent molars of the same population the approximal surfaces had shown the highest level of attack. The overall caries prevalence in deciduous teeth in the mediaeval population of Whithorn was 2.3% of the teeth present, lower than the levels found in previous Scottish and English population groups, including a small assemblage of children from the Scottish sites of Elcho, Southwick and Kirkhill.     

The Zurich Study. XXIV. Structural and emotional aspects of childhood and later psychopathology

This study investigated the effect of different etching times on the retention of fissure sealants in second primary and first permanent molars. Eighty-four children with a total of 144 second primary molars and 264 first molars were included in the study. Etching times of 15, 30, 45 and 60 seconds were used. The fissure sealants were evaluated at 6 and 12 months. The results showed that the overall retention rate of fissure sealants in second primary molars was 73.0% at 6 months and 64.7% at 12 months, whereas in first permanent molars the retention rates were 60.7% at 6 months and 44.1% at 12 months respectively. There was no significant difference in the retention of fissure sealants either on second primary molars or on first permanent molars at a 6- and 12-month follow-up with the different etching times. It was concluded that the different etching times did not appear to affect the retention of fissure sealants on the first permanent molars or second primary molars. It might therefore be prudent to etch the teeth for a much shorter period than conventionally recommended.     

Hypodontia of primary and permanent teeth in a sample of Saudi children

Hypodontia, congenitally missing teeth is more common in permanent than primary dentition. The present investigation reports the prevalence and pattern of hypodontia in the primary and permanent dentitions, excluding third molars in a sample of Saudi children. The sample consists of 1,300 children, aged 5 to 10 years of age. Clinical and radiographic examinations were performed. The prevalence of children with hypodontia was found to be 2.6 percent. The mandibular second premolar was the tooth most frequently absent and account for 45 percent of the total missing teeth. In primary dentition, the maxillary lateral incisor was the tooth most frequently absent (9%). A peg-shaped permanent maxillary lateral incisor was present in 0.7 percent of the sample. Congenitally missing teeth were almost equally distributed between maxillary (52%) and mandibular (48%) arches.     

Molar polymorphisms and the timing of dentition mineralization

The chronological age, skeletal age, and morphological age at the time of mineralization of 14 stages of the permanent teeth of 121 boys and 111 girls of the serial experimental sample of the Burlington Growth Centre were contrasted according to whether or not the children had 4- or 5-cusped mandibular permanent first molars, and whether or not they had agenesis of one or more third molars. In the boys with 4-cusped mandibular first molars, the mineralization of the teeth occurred at significantly earlier chronological and skeletal ages when they were significantly shorter in stature. Tooth mineralization was not consistently earlier in the girls with 4-cusped molars, but these girls tended to be taller and heavier than those with 5-cusped molars. In contrast, in both sexes with agenesis of third molars, the mineralization of the teeth was significantly delayed according to chronological, skeletal and morphological evaluation. The change in timing of mineralization was greatest for the second premolars and second molars, and least for the first molars.     

Effect of heterochronic parabiosis on liver microsomal enzyme oxidation

Third molars have been associated with a host of pathologies and there are risks involved with their surgical removal. They also have the highest incidence of congenital absence of all the permanent teeth. The aim of this study was to determine the prevalence and distribution of congenitally missing third molars in local Chinese patients. The orthopantomographic radiographs of 786 Singaporean Chinese patients aged 12 to 16 years were examined. It was found that 562 (71.5%) of the children had all 4 third molars. Varying degrees of third molar agenesis were noted in the other 224 (28.5%) children. Of these, 43 (5.5%) showed total absence of third molars. There was no significant difference in agenesis between the right and left sides and no sexual predilection was noted. However, more third molars were missing from the maxilla compared to the mandible, the ratio being 3:2.     

Surgical repair for supravalvular aortic stenosis: intermediate to long-term follow-up

The prevalence of different malocclusion features was investigated in 396 6-year-old Icelandic children, using the epidemiologic registration method described by Bj?rk et al. in 1964. Girls were ahead of boys with regard to dental stage (P < 0.01). One or more permanent teeth were congenitally missing in 5% of the children. Postnormal occlusion was found in 27% of the boys and in 31% of the girls, and prenormal occlusion was found in 6% and 5%, respectively. Straight terminal plane at the second deciduous molars was found in individuals with either normal or postnormal occlusion. Thus, it can be misleading to use the relation of the terminal planes as a measurement of the sagittal relation between the jaws. The prevalence of hypodontia was much lower than has been reported previously for Icelandic children.     

Night-to-night variability in CPAP use over the first three months of treatment

Caries of the pits and fissures of permanent teeth continues to be a problem for children, newly erupted permanent molars being particularly at risk. Oral hygiene measures have been shown to be able to reduce the incidence of caries. The aim of this study was to compare the caries-preventive effects on newly erupted first permanent molars of a professional tooth cleaning and oral health education program (test) with a standard preventive program (control), comprising selective fissure sealing and application of topical fluorides. School Dental Service clinics of the Health Department of Western Australia, in Perth, were assigned to four test or four control clinics. Schoolchildren, mean age 6.3 +/- 0.3 (s) years with sound, newly erupted first permanent molars were included in the study (207 test, 197 control). After 12 months, 186 test and 163 control children were examined by an examiner who was 'blind' to the test or control status of the children. Caries of the first permanent molars developed in 34 test and 35 control children; the estimated risk ratio was 0.86 (95% CI 0.56, 1.30). Children in the test group had an average DFT score of 0.26 +/- 0.62 compared with 0.29 +/- 0.64 DFT in the control group (t-test, P = 0.67). The 12-month results suggest that there was no statistically significant difference between the caries-preventive effects of a professional tooth cleaning and oral health education program and a program based on selective fissure sealing and application of topical fluorides.     

Insulin effects on ouabain binding in A6 renal cells

OBJECTIVES: This study sought to identify risk markers associated with the provision of new restorations in children and to investigate whether the carious status of a tooth surface is associated with the restorative decisions of dentists. METHODS: A total of 911 schoolchildren in grades one, two, and three were randomly selected from the island of Montreal, Quebec, Canada. Dental examinations were carried out in 1990, 1991, and 1992. Tooth surfaces of first permanent molars were classified as sound, noncavitated, and cavitated. The carious status of a tooth was matched with restorative decisions reported to the insurance board. RESULTS: The presence of a carious cavity was a strong risk marker for placement of new restorations (odds rations > or = 4.11). After one year, less than 2 percent of sound tooth surfaces of first permanent molars were restored and about 21 percent of noncavitated tooth surfaces were restored. When new class I restorations placed in maxillary first permanent molars within 3-6 months after the baseline examination were evaluated, we found that between 73 percent and 86 percent of these new restorations were placed in sound or noncavitated tooth surfaces. A similar trend also was observed in mandibular first permanent molars. Poor agreement between epidemiologic diagnosis and restorative decisions was found. The restorative profile of dentists was a significant risk marker for placement of new restorations. CONCLUSION: The majority of new restorations in first permanent molars were placed in sound and noncavitated tooth surfaces because of the ubiquitous prevalence of these tooth surfaces and the validity problems of current caries diagnosis methods.     

Mal de Meleda: a report of four cases from the United Arab Emirates

Scanning electron microscopy was used to study the effect of cyclophosphamide (Cy) on molar development in 18 Sprague-Dawley rats from 15 to 48 days of age after birth. Doses of 30 mg/kg body weight of Cy dissolved in 1 ml 0.9% NaCl were given to the rats at 10 and 13 days of age. Eighteen control rats had injections of 1 ml 0.9% NaCl at the same ages. The most obvious changes in the experimental teeth were found in the developing roots of the first and second molars and in both the crown and roots of the third molar. The roots of the first and second molars were short and showed apical closure in the experimental rats. In addition to the disturbances in crown and root formation, the third molars were also significantly reduced in total size as compared with the third molars in the control rats.     

Novel LQT-3 mutation affects Na+ channel activity through interactions between alpha- and beta1-subunits

This study describes mesial and distal enamel thickness of the permanent posterior mandibular dentition. The sample comprised 98 Caucasian adults (59 males, 39 females) 20 to 35 years old. Bitewing radiographs of the right permanent mandibular premolars and first and second molars were illuminated and transferred to a computer at a fixed magnification via a video camera. Enamel and dentin thicknesses were identified and digitized on the plane representing the maximum mesiodistal diameter of each tooth. The results showed that there were no significant sex differences in either mesial or distal enamel thickness. Enamel on the second molars was significantly thicker (0.3 to 0.4 mm) than enamel on the premolars. Distal enamel was significantly thicker than mesial enamel. There was approximately 10 mm of total enamel on the four teeth combined. Assuming 50% enamel reduction, the premolars and molars should provide 9.8 mm of additional space for realignment of mandibular teeth.     

Survival characteristics of periodontally-involved teeth: a 40-year study

Four hundred and fifty-five teeth that were judged clinically to have a questionable prognosis were observed over a 40-year span in 166 patients in a private practice. Therapy initially was debridement with oral hygiene instruction, followed by flap curettage procedures and preventive maintenance recall therapy. An assessment of compliance based on oral hygiene and recall attendance was also performed. A total of 55 (12%) teeth were lost with an average survival rate of 8.8 years prior to extraction. No teeth were lost during the first 2 years of observation. The majority of extracted teeth were maxillary second molars (38.2%), followed by maxillary first molars (25.5%), and mandibular second molars (16.4%). Tooth loss patterns appeared to be bilaterally symmetrical, with 51% of teeth lost in the right quadrants and 49% lost in the left quadrants. Indications for extraction were primarily periodontal abscesses. Teeth that were considered to have a very questionable prognosis have been retained for many years after therapy, supportive treatment, and patient compliance with recall attendance.     

Split-mouth study of sealant retention with carbon dioxide laser versus acid etch conditioning

A survey was carried out to determine the reasons for tooth extractions of permanent teeth in Singapore. Data were obtained from 52 dentists practising general dentistry over a period of 12 months. At the end of the 12-month period, data were collected from 1276 patients, from whom a total 272 teeth were extracted. In this population group, the results showed that the percentage of teeth extracted due to periodontal reasons and caries were about the same, that is 35.8% and 35.4%, respectively. There was an increase in teeth extracted due to periodontal reasons with age. In patients above 40 yr, an average of 76% of teeth were lost due to periodontal reasons. An average of 26.7% of teeth were lost due to periodontal reasons in patients under 40 yr old. However, the trend for loss of teeth due to caries is reversed. Posterior teeth were more frequently extract compared to anterior teeth. Third molars accounted for 24.7% of all extractions carried out, whilst central incisors were 8.0% of all extractions. Molars were often lost due to caries and lower anterior teeth were most frequently lost due to periodontal reasons. The results of this study did not demonstrate one predominant reason for extraction. Both caries and periodontal reasons were equally common causes of tooth extraction.     

Dietary amino acids as new and novel agents to enhance allograft survival

Little is known about the long-term effects of fluoride-releasing materials on carious dentine in vivo. The aim was to investigate the 2-year influence of a resin-modified glass ionomer cement (RM-GIC) and amalgam on the bacteriological counts of carious dentine that remained under class I restorations. To enable a split-mouth design, 33 molar pairs in 33 patients (mean age 15.1 years, SD 1.4) were selected, based on clinically and radiographically diagnosed occlusal dentine caries. The enamel of the carious molars was removed, and the carious dentine was sampled under aseptic conditions just beneath the dentinoenamel junction. The molars were alternately restored with RM-GIC or amalgam without further removal of carious dentine. The samples were processed for microbiological determination of total viable counts (TVC), mutans streptococci (MS), and lactobacilli (LB). The molar pairs of 25 patients were reevaluated after 2 years using the same clinical techniques and were permanently restored after complete caries removal. Both materials showed a substantial decrease in numbers of TVC and LB of the carious dentine after the 2-year period. Compared to amalgam, the decrease in the numbers of LB was significantly more pronounced for RM-GIC. No microorganisms were detected in only 11 molars (6 RM-GIC and 5 amalgam) after the 2-year period. Based on this study, we suggest that complete removal of carious dentine is still the best conservative treatment, irrespective of the restorative material used.     

Progress in the pathology of uterine smooth muscle neoplasms

To investigate the factors that influence the probability of clinical cavitation at radiolucent areas of proximal surfaces of posterior teeth, 108 molars and premolars with varying depths of proximal radiolucency were examined clinically, after cavity preparation on the carious contiguous tooth surfaces. The data obtained were subjected to logistic regression analysis with cavitation as the dependent variable, while age, tooth type and past caries experience (DMFT and DFS) were independent variables. When proximal radiolucency was confined to the outer half of enamel, there was no cavitation, but when it extended to the amelodentinal junction and the outer and inner half of dentine, there was cavitation in 19.3, 79.1 and 100% of cases, respectively. Moreover, there was a statistically significant relationship between the probability of cavitation, depth of radiolucency and age, suggesting that these should be among the main factors considered when restorative management of a radiolucent proximal surface of a posterior tooth is contemplated.     

Detection of Streptococcus mutans by PCR amplification of the spaP gene in teeth rendered caries free

OBJECTIVES: To investigate the degree of association between tactile and optical criteria as used to assess the carious status of the enamel-dentine junction (EDJ) during cavity preparation, assessment with a caries detector dye and detection of Streptococcus mutans using culture and polymerase chain reaction (PCR) techniques. METHODS: Twenty-nine teeth, extracted within the previous 30 min, and 15 teeth prepared under rubber dam in vivo, were clinically assessed at the EDJ after the removal of evident carious tissue. Demineralisation was then assessed using a caries detector dye (1% acid red in propylene glycol; Cavex). A rosehead bur was used to remove tissue at the EDJ for culture and PCR analysis. Culture was carried out on a tryptone yeast cystine sucrose bacitracin selective medium, and PCR used to amplify a sequence (192 bp) of the spaP gene, which encodes the surface protein antigen I/II of S. mutans. RESULTS: Demineralised tissue at the EDJ, as shown using the dye, was found in 52% of teeth. Removed tissue was culture and PCR positive for S. mutans in 2 and 47% of teeth, respectively. A highly significant association (77% of cases; P < 0.001) was shown between dye and PCR assessment methods. No association was found between any other combination of assessment methods. CONCLUSIONS: Culture methods may underestimate the presence of S. mutans. Removal of sufficient dye-stained tissue is therefore recommended to prevent further carious assault from residual S. mutans.     

Selective quasispecies transmission after systemic or mucosal exposure of macaques to simian immunodeficiency virus

OBJECTIVES: Mutans streptococci (MS) are the primary pathogens involved in the development of early childhood caries. However, factors that may affect their acquisition in the mouths of young children are not well understood, and the period of initial colonization remains controversial. This study investigated the relationship of age, number of teeth, and bottle usage/content with regard to the isolation of MS in 6-24-month-old children. METHODS: A total of 122 children from low-income families attending a nutritional supplement program, and their mothers, participated in this study. Children were examined for dental caries and number of erupted teeth and were sampled for MS. Mothers were administered a questionnaire to obtain details of baby bottle use, including what food items were put in the bottle during the last week. RESULTS: MS was detected in more than one-third of the 6-24-month-olds. Unlike some studies that suggest a later period of infectivity, approximately 20% of children under 14 months of age, including 4 of 22 infants aged 6-9 months, were colonized with MS. When examined separately, age, number of teeth, and bottle usage/content were each found to be related to the presence of MS. Mutans streptococci colonization was more likely with increasing age and number of teeth, and children whose bottles contained sweetened beverages were more likely to be colonized than children whose bottles contained milk. Logistic regression models that controlled for both age and number of teeth indicated that children who consumed sweetened beverages in their baby bottle had a statistically significant, four-fold increase in the odds of colonization by MS relative to children who consumed milk. CONCLUSIONS: The finding that approximately 20% of the children under 14 months of age were infected with MS indicates that colonization in this sample of low-income preschool children may begin earlier than suggested by some investigations. Additionally, the risk of MS colonization appears lower among infants who consume milk rather than sweetened beverages in the bottle.     

"Carious" and "noncarious" lesions of the hard dental tissues. Ultrastructural (SEM) and microanalytical (EDS) analyses of teeth from the 3rd century B.C

The study was carried out on 80 teeth (70 of permanent dentition and 10 of primary one) of mandibular and maxillary bones. The teeth owned to subjects lived in the III c.b.C. in Sicily, and they were found in Naxos necropolis. The teeth were examined as far as carious and non carious lesions, then they were prepared for instrumental analyses by Scanning Electron Microscopy (SEM) and Energy dispersed X ray spectrometry (EDS). To an objective examination of the sample no caries were detected in the teeth sample apart one tooth, on the other hand there was an extensive occlusal abrasion, from a macroscopic point of view there were no difference as far teeth morphology. SEM examination pointed out all around dentinal tubules a circle of sclerotic dentin as reaction to occlusal wear. The amelocemental junction showed from a ultramicroscopic point of view an overlap of cementum onto enamel. EDS analysis pointed out a higher P concentration on the crown versus the root in all the teeth of the sample.     

Factors affecting smoking of elementary and high school children from Chile

The outcome of orthodontic treatment involving early extraction of 4 second molars was evaluated in 52 patients (29 girls, 23 boys). Computer-assisted analysis of cephalograms, casts and panoramic X-rays was performed at the start (T1, mean age 11.5 years) and at the end (T2, mean age 14.4 years) of treatment. Following treatment, mesial migration of upper and lower first molars was counteracted; however, treatment only moderately influenced normal development of the position of the incisors and the profile. At the end of treatment, the third molars had erupted in only 3 patients. Nevertheless, on average a significant mesial movement of these teeth was observed. In addition, there was a significant improvement in the axial inclination of the third molars, especially in the upper arch. This improvement was correlated with the original position of the teeth. All patients needed a longer follow-up period and it seems reasonable that some of them might require a second treatment phase to adjust the position of the third molars.     

Risk of renal cell carcinoma after kidney transplantation

Dental trauma occurs very often in children and its consequences vary from tiny fractures to the complete avulsion of the tooth. According to Andreasen, 86.5% of incidents of dental trauma suffered by preschool children cause injury to maxillary primary incisors, whereas only 0.5% cause injury to primary molars. This case report is of a male patient aged 7 years who had fallen down a month before, struck his chin against a step, and fractured the maxillary and mandibular left primary second molars (65 and 75) and the mandibular right primary second molar (85). The 65 required only smoothing of sharp edges, 75 received endodontic treatment and a stainless steel crown, and 85 was extracted and a space maintainer fitted. The early diagnosis of fractures of posterior teeth is very important; a thorough examination of all posterior teeth should be made, especially when child suffers trauma to the chin region.