Prevalence of microorganisms in root canals of human deciduous teeth with necrotic pulp and chronic periapical lesions.
(33/431)
The objective of this study was to evaluate bacterial prevalence in 31 root canals of human deciduous teeth with necrotic pulp and periapical lesions using bacterial culture. After crown access, the material was collected using absorbent paper points for microbiological evaluation and determination of colony forming units (CFU). Anaerobic microorganisms were found in 96.7% of the samples, black-pigmented bacilli in 35.5%, aerobic microorganisms in 93.5%, streptococci in 96.7%, and S. mutans in 48.4%. We concluded that in human deciduous teeth root canals with necrotic pulp and periapical lesions the infection is polymicrobial, with a large number of microorganisms and a predominance of streptococci and anaerobic microorganisms. (+info)
Are severe occlusal problems more frequent in permanent than deciduous dentition?
(34/431)
OBJECTIVE: To determine the prevalence and severity of occlusal problems in populations at the ages of deciduous and permanent dentition and to carry out a meta-analysis to estimate the weighted odds ratio for occlusal problems comparing both groups. METHODS: Data of a probabilistic sample (n=985) of schoolchildren aged 5 and 12 from an epidemiological study in the municipality of Sao Paulo, Brazil, were analyzed using univariate logistic regression (MLR). Results of cross-sectional study data published in the last 70 years were examined in the meta-analysis. RESULTS: The prevalence of occlusal problems increased from 49.0% (95% CI =47.4%-50.6%) in the deciduous dentition to 71.3% (95% CI =70.3%-72.3%) in the permanent dentition (p<0.001). Dentition was the only variable significantly associated to the severity of malocclusion (OR=1.87; 95% CI =1.43-2.45; p<0.001). The variables sex, type of school and ethnic group were not significant. The meta-analysis showed that a weighted OR of 1.95 (1.91; 1.98) when compared the second dentition period with deciduous and mixed dentition. CONCLUSIONS: In planning oral health services, some activities are indicated to reduce the proportion of moderate/severe malocclusion to levels that are socially more acceptable and economically sustainable. (+info)
Extractions as a form of interception in the developing dentition: a randomized controlled trial.
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OBJECTIVE: To determine if the extractions of lower primary canines are an effective procedure to relieve crowding of the labial segment. STUDY DESIGN: randomized controlled trial. Subject sample: 83 cases were collected in clinics in Italy, Germany and Wales. The groups were followed over a 2-year period. METHODS: Subjects were randomly allocated to a primary canine non-extraction or extraction group. Dental casts of the patients were collected at the start and at the recall period of the trial. The outcome measures recorded were lower incisor crowding, arch length, intermolar width, overbite, overjet, lower clinical crown heights and lower incisor inclinations. STATISTICS: The Mann-Whitney test was used to compare the differences between the extraction and non-extraction groups. RESULTS: In both groups, crowding reduced 1.27 mm in the non-extraction group and 6.03 mm in the extraction group. The difference between the 2 groups was 4.76 mm (P<0.05). The arch perimeter decreased more in the extraction group by 2.73 mm (P<0.05). As the incisor inclination stayed essentially the same, the loss in arch length was attributed to the molars moving forward. The net gain from extracting deciduous canines was 2.03 mm. CONCLUSIONS: There was a reduction in lower incisor crowding as a result of lower primary canine extraction. However, arch perimeter decreased more in the extraction group leaving less space for the eruption of the lower secondary canines. (+info)
Temporomandibular disorders in Turkish children with mixed and primary dentition: prevalence of signs and symptoms.
(36/431)
The prevalence of signs and symptoms related to TM (temporomandibular) disorders was examined in 40 children with primary dentition and in 40 children with mixed dentition. The purpose of this study was to evaluate the relationship between dentition and TM disorders in the examined population. Maximum mouth opening was also evaluated. Clinical examination was done by one investigator. A questionnaire was used in combination with the clinical examination. The results showed that there was an increase in signs and symptoms from the primary to the mixed dentition group, but only the joint sounds were found significantly different between the two groups. There was no statistically significant difference in maximum mouth opening capacity between the groups. (+info)
Older age becomes common late in human evolution.
(37/431)
Increased longevity, expressed as number of individuals surviving to older adulthood, represents one of the ways the human life history pattern differs from other primates. We believe it is a critical demographic factor in the development of human culture. Here, we examine when changes in longevity occurred by assessing the ratio of older to younger adults in four hominid dental samples from successive time periods, and by determining the significance of differences in these ratios. Younger and older adult status is assessed by wear seriation of each sample. Whereas there is significant increased longevity between all groups, indicating a trend of increased adult survivorship over the course of human evolution, there is a dramatic increase in longevity in the modern humans of the Early Upper Paleolithic. We believe that this great increase contributed to population expansions and cultural innovations associated with modernity. (+info)
Cementum-like tissue deposition on the resorbed enamel surface of human deciduous teeth prior to shedding.
(38/431)
Prior to the shedding of human deciduous teeth, odontoclastic resorption takes place at the pulpal surface of the coronal dentin, and this resorption occasionally extends coronally from the dentinoenamel junction into the enamel. After the end of resorption, however, the resorbed enamel surface is repaired by the deposition of a cementum-like tissue. Using this phenomenon as an observation model, in this study we examined the sequence of cellular and extracellular/matrix events involved in the enamel resorption repair by light and electron microscopy. As the odontoclast terminated its resorption activity, it detached from the resorbed enamel surface; thereafter, numerous mononuclear cells were observed along the resorbed enamel surface. Most of these mononuclear cells made close contact with the resorbed enamel surface, and coated pits or patches were observed on their plasma membrane facing this surface. Furthermore, they frequently contained thin needle- or plate-like enamel crystals in their cytoplasmic vacuoles as well as secondary lysozomes. Following the disappearance of these monononuclear cells, the resorbed enamel surface now displayed a thin coat of organic matrix. Ultrastructurally, this organic layer was composed of a reticular and/or granular organic matrix, but contained no collagen fibrils. Energy-dispersive X-ray microanalysis of this thin organic layer in undecalcified sections revealed small spectral peaks of Ca and P. Cementum-like tissue initially formed along this thin organic layer, increased in width, and appeared to undergo mineralization as time progressed. The results of our observations demonstrate that regardless of type of matrix of dental hard tissues, tooth repair may be coupled to tooth resorption, and suggest that mononuclear cells and an organic thin layer found on the previously resorbed enamel surface may play an important role in the repair process initiated after resorption of the enamel. (+info)
Assessment of treatment for functional posterior cross-bites in patients at the deciduous dentition phase.
(39/431)
The aim of this study was to clinically assess the results of treatment for functional posterior cross-bites by means of selective grinding in individuals at the deciduous dentition phase over a period of 12 months. From a total of 1,011 children examined in the 2-to-6-year age bracket, 26 with functional posterior cross-bites were selected. The sample was divided into 2 groups of 13 children each, group 1 receiving the treatment proposed and group 2 serving as the control group. Treatment was followed up by exercises designed to alter the children's muscular memory. The results showed that correction of functional posterior cross-bite was achieved for all the children treated, the correction remaining stable 12 months later. No self-correction of malocclusion occurred among the control group. (+info)
Breast feeding, bottle feeding, and non-nutritive sucking; effects on occlusion in deciduous dentition.
(40/431)
AIMS: To assess the effect of the type of feeding and non-nutritive sucking activity on occlusion in deciduous dentition. METHODS: Retrospective study of 1130 preschool children (3-5 years of age) who had detailed infant feeding and non-nutritive sucking activity history collected by a structured questionnaire. They all had an oral examination by a dentist, blinded to different variables evaluated. RESULTS: Non-nutritive sucking activity has a substantial effect on altered occlusion, while the effect of bottle feeding is less marked. The type of feeding did not have an effect on open bite, which was associated (89% of children with open bite) with non-nutritive sucking. Posterior cross-bite was more frequent in bottle fed children and in those with non-nutritive sucking activity. The percentage of cross-bite was lower in breast fed children with non-nutritive sucking activity (5%) than in bottle fed children with non-nutritive sucking activity (13%). CONCLUSIONS: Data show that non-nutritive sucking activity rather than the type of feeding in the first months of life is the main risk factor for development of altered occlusion and open bite in deciduous dentition. Children with non-nutritive sucking activity and being bottle fed had more than double the risk of posterior cross-bite. Breast feeding seems to have a protective effect on development of posterior cross-bite in deciduous dentition. (+info)