Influence of irradiation on collagen content during wound healing in diabetic rats

O objetivo desta pesquisa experimental foi estudar os efeitos da irradiação por elétrons sobre o conteúdo de colágeno e a organização macromolecular do tecido de granulação, na pele de ratos diabéticos. Para tanto, 48 ratos da linhagem Wistar foram separados em 4 grupos: controle; irradiado; diabético e diabético irradiado. Inicialmente, a diabetes melito foi induzida, nos dois últimos grupos, por meio da administração intravenosa de estreptozotocina. Após quinze dias da indução, todos os animais foram submetidos a uma cirurgia para a produção de uma ferida excisional, na região dorsal anterior. No terceiro dia pós-operatório, aplicou-se uma dose única de 1 Gy, de feixes de elétrons com 6 MeV de energia, em uma área externa que compreendia cerca de 1 cm lateralmente às bordas das feridas. Amostras teciduais dos 4 grupos foram examinadas por microscopia de luz polarizada aos 4, 7, 13 e 21 dias pós-operatórios. Por meio de uma avaliação essencialmente qualitativa, foi possível concluir que a irradiação local por elétrons e as disfunções associadas à diabetes determinaram um decréscimo no conteúdo de colágeno do tecido neoformado, que foi mais pronunciado nos animais diabéticos irradiados. A organização macromolecular do tecido de granulação apresentou-se retardada nos animais irradiados, diabéticos e diabéticos irradiados, em comparação com os animais do grupo controle.The aim of the present experimental research was to investigate the effects of electron irradiation on the collagen content and on the organization of the granulation tissue of skin, in diabetic rats. In this study, 48 Wistar rats were assigned to 4 groups: control, irradiated, diabetic and irradiated diabetic. First, diabetes mellitus was induced in the last two groups, by means of a single intravenous injection of streptozotocin. Fifteen days later, all animals underwent a surgery in order to create an excisional wound on their anterior dorsal skin. On the third post-operative day, only an approximately 1-cm-wide area around the wounds was exposed to 1 Gy of 6 MeV electron beam radiation, which was delivered in a single dose. Wound healing was examined by means of polarized light microscopy at 4-, 7-, 13- and 21-day time intervals after wounding. Based upon an essentially qualitative evaluation, it was possible to conclude that local electron irradiation and diabetes' associated dysfunctions caused a decrease in the collagen content of newly-formed tissue, which was more pronounced in irradiated diabetic animals. The macromolecular organization of granulation tissue was delayed in irradiated, diabetic and irradiated diabetic animals, in relation to what was observed in control animals

Breastfeeding and non-nutritive sucking patterns related to the prevalence of anterior open bite in primary dentition

OBJECTIVE: Nutritional, immunological and psychological benefts of exclusive breastfeeding for the frst 6 months of life are unequivocally recognized. However, mothers should also be aware of the importance of breastfeeding for promoting adequate oral development. This study evaluated the association between breastfeeding and non-nutritive sucking patterns and the prevalence of anterior open bite in primary dentition. MATERIAL AND METHODS: Infant feeding and non-nutritive sucking were investigated in a 3-6 year-old sample of 1,377 children, from São Paulo city, Brazil. Children were grouped according to breastfeeding duration: G1 - non-breastfed, G2 - shorter than 6 months, G3 - interruption between 6 and 12 months, and G4 - longer than 12 months. Three calibrated dentists performed clinical examinations and classifed overbite into 3 categories: normal, anterior open bite and deep bite. Chi-square tests (p<0.05) with odds ratio (OR) calculation were used for intergroup comparisons. The impact of breastfeeding and non-nutritive sucking on the prevalence of anterior open bite was analyzed using binary logistic regression. RESULTS: The prevalence estimates of anterior open bite were: 31.9% (G1), 26.1% (G2), 22.1% (G3), and 6.2% (G4). G1 would have signifcantly more chances of having anterior open bite compared with G4; in the total sample (OR=7.1) and in the subgroup without history of non-nutritive sucking (OR=9.3). Prolonging breastfeeding for 12 months was associated with a 3.7 times lower chance of having anterior open bite. In each year of persistence with non-nutritive sucking habits, the chance of developing this malocclusion increased in 2.38 times. CONCLUSIONS: Breastfeeding and non-nutritive sucking durations demonstrated opposite effects on the prediction of anterior open bite. Non-breastfed children presented signifcantly greater chances of having anterior open bite compared with those who were breastfed for periods longer than 12 months, demonstrating the benefcial infuence of breastfeeding on dental occlusion

In vitro induction of enamel subsurface demineralization for evaluation of diagnostic imaging methods

The aim of this study was to investigate a model of inducing enamel subsurface demineralization for evaluating diagnostic imaging methods. Fifty sound teeth had their crowns coated with acid-resistant varnish, leaving a 7 mm² circular window of exposed enamel in one of the proximal surfaces. The specimens were assigned to 5 groups (4 experimental and the control) and were kept immersed in a buffer solution at pH 4.8, 50% saturated in relation to enamel, for 60, 75, 90 and 120 days, or were not exposed to the solution. Digital radiographs were taken, prior to and after each immersion period, and interpreted by a radiologist. For validation, the enamel was submitted to microhardness profiling. In addition, the solutions were analyzed for phosphorus (Pi) and calcium (Ca) concentrations. Microhardness data were evaluated using two-way ANOVA (

Unveiling an oral hemangiolymphangioma

Hemangiolymphangioma is a very rare vascular malformation that develops as a combination of dilated venous and lymphatic vessels. We describe an unusual case of hemangiolymphangioma of the tongue affecting an adult man who complained of an uncomfortable, slowly progressing exophytic irregular dark red-violaceous nodular mass on his tongue that impaired speech and swallowing for two weeks. The clinical differential diagnoses were Kaposi’s sarcoma and a COVID-19-related lesion. A complete blood count and serology for HIV-1 and 2 and RT-PCR for COVID-19 were requested and results were negative. An incisional biopsy was performed. Microscopically, the lesion exhibited several dilated vessels lined by normal-appearing endothelial cells, some filled with prominent intravascular erythrocytes and others containing proteinaceous eosinophilic material resembling lymphatic vessels, in close association with hyperkeratosis, papillomatosis, and acanthosis. From immunohistochemical analysis, most vessels were found to be CD34 positive, some highlighted by α-SMA, whereas D2-40 was focal. Positive staining for some lymphatic and blood vessel markers, i.e., D2-40 and CD34, respectively, indicates a mixed derivation of the lesion. HHV-8 was negative. Clinical features, the congested blood vessels with ectasia in intimate association with hyperplastic epithelium, and the immunohistochemical profile supported the final diagnosis of oral hemangiolymphangioma. The patient underwent minimally invasive surgical excision with no intercurrences. After 18 months of follow-up, there were no signs of relapse

Prevalência de características da oclusão normal na dentição decídua

The aim of this research was to study the normal occlusal patterns of deciduous dentition in Brazilian preschool children. The sample consisted of 356 preschool children, of both genders, aged 3-5 ½ years from the urban zone of Salvador, Bahia. The occlusion exam was carried out by two examiners, in the classroom, utilizing a wooden spatula. The data were analyzed by the statistical program EPI-INFO 6.02 using the Chi-squared test. The frequency of the type I arch was 43.3% for the upper and 46.3% for the lower arch. The frequency of the type II arch was 56.7% for the upper and 53.75 for the lower arch, however, no difference between genders was noticed. The distribution of primate spaces was: 89.9% for the upper and 67.1% for the lower arch. This prevalence decreased significantly as age increased (p < 0.01). Normal canine relationship was found in almost 60% of the children for the right and left sides. Out of 712 evaluated terminal planes, 55.9% presented mesial terminal step for the primary second molars, 37.9% straight terminal plane and 6.2% distal step. The results permitted to conclude that the presence of generalized spacing between incisors, commonly described by other authors, was not the most prevailing condition for both arches in this sample. On the other hand, primate spaces were the most common ones. The most frequent normal occlusal patterns for canine and molar relationships were found to be the Class I patterns.O objetivo deste estudo foi verificar os padrões oclusais normais da dentição decídua em crianças pré-escolares brasileiras. A amostra foi constituída por 356 crianças, de ambos os sexos, na faixa etária de 3-5 ½ anos e residentes na cidade de Salvador. O exame de oclusão foi realizado na sala de aula, por duas examinadoras, utilizando-se uma espátula de madeira. Os dados foram analisados pelo EPI-INFO 6.02, aplicando-se o teste chi². A freqüência do arco tipo I foi de 43,3% para a arcada superior e 46,3% para a inferior. O arco tipo II esteve presente em 56,7% das arcadas superiores e em 53,7% das inferiores, entretanto, sem diferença entre os sexos. A distribuição dos espaços primatas foi de 89,9% para o arco superior e 67,1% no arco inferior, diminuindo significativamente tal prevalência com o aumento das idades (p < 0,01). A relação canina normal foi encontrada em quase 60% das crianças, para ambos os lados. Dos 712 planos terminais distais avaliados, 55,9% apresentaram plano terminal mesial para os segundos molares decíduos; 37,9% plano terminal reto e 6,2% degrau distal. Os resultados permitem concluir que a presença dos espaços interincisais generalizados, comumente relatados por outros autores, não foi o mais freqüente para ambos os arcos nesta amostra, contudo, os espaços primatas foram os mais prevalentes. Os freqüentes padrões normais de oclusão para as relações canino e molar foram os de Classe I

Bottle feeding, increased overjet and Class 2 primary canine relationship: is there any association?

The aim of this study was to investigate the association between bottle feeding and prevalence rates of increased overjet and Class 2 primary canine relationship. The sample consisted of 911 children (461 boys, 450 girls) aged 3 (13.9%), 4 (40.8%), 5 (34%) and 6 (11.3%) years, with complete primary dentition. Information about nutritive and nonnutritive (pacifier and/or digit) sucking habits was collected through questionnaires. Three calibrated dentists (&#954;: 0.9-1.0 and Rs &gt; 0.90) performed the clinical assessments. The children were divided into four groups: G1 - not bottle-fed; G2 - exclusively bottle-fed; G3 - breast- and bottle-fed, bottle feeding ceased before 3 years of age; and G4 - breast- and bottle-fed, bottle feeding ceased between 3 and 4 years of age. Associations between nutritive and nonnutritive sucking behaviors and the malocclusions studied were analyzed by multiple binary logistic regression (&#945;= 0.05). The frequencies of increased overjet were: 25.3% (G1), 38.8% (G2), 39.2% (G3) and 47.8% (G4). The percentages of Class 2 canine relationship were: 27.9% (G1), 48.8% (G2), 43.4% (G3) and 43% (G4). No significant effect of bottle feeding was found. The chances of diagnosing increased overjet (O.R. = 4.42, p < 0.001) and Class 2 canine relationship (O.R. = 4.02, p < 0.001) were greater for children with pacifier and/or digit-sucking habits, compared to those without a history of nonnutritive sucking behavior. It may be suggested that bottle feeding alone is not directly associated with higher prevalence rates of increased overjet and Class 2 canine relationship in the primary dentition

Association between nonnutritive sucking habits and anterior open bite in the deciduous dentition of Japanese-Brazilians

OBJECTIVE: Assess the association between nonnutritive sucking habits and anterior open bite in the deciduous dentition of Japanese-Brazilian children. METHODS: 410 children of Japanese origin were assessed, 206 boys and 204 girls, between 2 and 6 years of age, in schools in São Paulo State, Brazil. Questionnaires concerning their nonnutritive sucking habits were sent to their legal guardians. Chi-square tests (p<0.05) were applied to assess the association between nonnutritive sucking habits and anterior open bite, and the logistic regression test to obtain the relative risk. RESULTS: The prevalence of sucking habits found in the sample was of 44.6% and for the anterior open bite, 4.4%. There was a statistically significant association between anterior open bite and sucking habits (O.R.=10.77), persistence of sucking habits from 2 to 4 years old (O.R.=22.06), and the persistence of sucking habits from 4 to 6 years old (O.R.=17.31). As for the interruption period of the habit, the group that had interrupted the habit for a period equal or inferior to six months showed an increased prevalence of open bite compared to the group without this habit or in which the habit was interrupted for more than six months. CONCLUSION: Japanese-Brazilian children that had sucking habits have greater chance of acquiring anterior open bite in the deciduous dentition

Evaluation of proximal enamel thickness and crown measurements in maxillary first premolars

Estimating enamel thickness and planning the resultant optimal morphology of premolars are substantial steps before interproximal stripping. Aim: To analyze proximal enamel thickness and crown measurements in maxillary premolars. Methods: The mesiodistal, buccolingual and cervico-occlusal measurements of 40 human maxillary first premolars (20 right, 20 left) were registered with a digital caliper. The teeth were embedded in acrylic resin and sectioned mesiodistally at the level of the contact areas to obtain 1 mm-thick central sections. Enamel thickness on the proximal surfaces was measured using a perfilometer. Measurements were compared by the Student’s t-test (α = 0.05). Results: The mean enamel thickness on the mesial surface was 1.22 mm for the right (± 0.17) and left (± 0.18) sides. On the distal surface, the corresponding values were 1.28 mm (± 0.19) on the right side and 1.39 mm (± 0.17) on the left side. Mean values, in millimeters, for the mesiodistal, buccolingual and cervico-occlusal measurements on both sides ranged from 7.03 (± 0.43) to 7.07 (± 0.48), 9.59 (± 0.48) to 9.65 (± 0.58) and 8.65 (± 0.66) to 8.85 (± 0.65), respectively. There were no significant differences between right and left teeth. However, enamel thickness was significantly greater (p<0.05) on the distal surface. Conclusions: In maxillary first premolars, considering the greater thickness of distal enamel, interproximal stripping during orthodontic treatment may be more pronounced on this surface. The greatest mean value was observed for the buccolingual crown measurement, followed by the cervicoocclusal and mesiodistal dimensions