Treatment effects produced by the Bionator appliance. Comparison with an untreated Class II sample

The purpose of this retrospective investigation was to evaluate the dentoalveolar and skeletal cephalometric changes of the Bionator appliance on individuals with a Class II division 1 malocclusion. Lateral cephalograms of 44 patients were divided into two equal groups. The control group comprised 22 untreated Class II children (11 males, 11 females), with an initial mean age of 8 years 7 months who were followed without treatment for a period of 13 months. The Bionator group (111 males, 11 females) had an initial mean age of 10 years 8 months, and were treated for a mean period of 16 months. Lateral cephalometric headfilms were obtained of each patient and control at the beginning and end of treatment.The results showed that there were no changes in forward growth of the maxilla in the experimental group compared with the control group. However, the Bionator treatment produced a statistically significant increase in mandibular protrusion, and in total mandibular and body lengths. There were no statistically significant differences in craniofacial growth direction between the Bionator group and the control group, although the treated patients demonstrated a greater increase in posterior face height. The Bionator appliance produced labial tipping of the lower incisors and lingual inclination of the upper incisors, as well as a significant increase (P < 0.01) in mandibular posterior dentoalveolar height. The major effects of the Bionator appliance were dentoalveolar, with a smaller significant skeletal effect. The results indicate that the correction of a Class II division 1 malocclusion with the Bionator appliance is achieved not only by a combination of mandibular skeletal effects, but also by significant dentoalveolar changes.

Structure of magnetic poly(oxyethylene)-siloxane nanohybrids doped with Fe-II and Fe-III

Hybrid organic - inorganic nanocomposites doped with Fe-II and Fe-III ions and exhibiting interesting magnetic properties have been obtained by the sol - gel process. The hybrid matrix of these ormosils ( organically modified silicates), classed as di-ureasils and termed U( 2000), is composed of poly( oxyethylene) chains of variable length grafted to siloxane groups by means of urea crosslinkages. Iron perchlorate and iron nitrate were incorporated in the diureasil matrices, leading to compositions within the range 80 greater than or equal to n greater than or equal to 10, n being the molar ratio of ether-type O atoms per cation. The structure of the doped diureasils was investigated by small-angle X-ray scattering (SAXS). For Fe-II-doped samples, SAXS results suggest the existence of a two-level hierarchical structure. The primary level is composed of spatially correlated siloxane clusters embedded in the polymeric matrix and the secondary, coarser level consists of domains where the siloxane clusters are segregated. The structure of Fe-III-doped hybrids is different, revealing the existence of iron oxide based nanoclusters, identified as ferrihydrite by wide-angle X-ray diffraction, dispersed in the hybrid matrix. The magnetic susceptibility of these materials was determined by zero-field-cooling and field-cooling procedures as functions of both temperature and field. The different magnetic features between Fe-II- and Fe-III-doped samples are consistent with the structural differences revealed by SAXS. While Fe-II-doped composites exhibit a paramagnetic Curie-type behaviour, hybrids containing Fe-III ions show thermal and field irreversibilities.

Structure and luminescence of Eu3+-doped class I siloxane-poly(ethylene glycol) hybrids

Transparent, flexible, and luminescent EU3+-doped siloxane-poly(ethylene glycol) (PEG) nanocomposites have been obtained by the sol-gel process. The inorganic (siloxane) and organic PEG phases are usually linked by weak bonds (hydrogen bonds or van der Waals forces), and small-angle X-ray scattering (SAXS) measurements suggest that the structure of these materials consists of fractal siloxane aggregates embedded in the PEG matrix. For low Eu3+ contents, n = 300 and n = 80, the aggregates are small and isolated and their fractal dimensions are 2.1 and 1.7, respectively. These values are close to those expected for gelation mechanisms consisting of reaction-limited cluster-cluster aggregation (RLCCA) and diffusion-limited cluster-cluster aggregation (DLCCA). For high Eu3+ content, SAYS results are consistent with a two-level structure: a primary level of siloxane aggregates and a second level, much larger, formed by the coalescence of the primary ones. The observed increase in the glass transition temperature for increasing Eu3+ content is consistent with the structural model derived from SAXS measurements. Extended X-ray absorption fine structure (EXAFS) and luminescence spectroscopy measurements indicate that under the experimental conditions utilized here Eu3+ ions do not strongly interact with the polymeric phase.

Small-angle X-ray scattering and X-ray absorption near-edge structure study of iron-doped siloxane-polyoxyethylene nanocomposites

The local and medium-range structures of siloxane-POE hybrids doped with Fe(III) ions and prepared by the sol-gel process were investigated by X-ray absorption near-edge structure (XANES)/extended X-ray absorption fine structure (EXAFS) and small-angle X-ray scattering (SAXS), respectively. The experimental results show that the structure of these composites depends on the doping level. EXAFS data reveal that, for low doping levels ([O]/[Fe] > 40, oxygens being of the ether-type of the POE chains), Fe(III) ions are surrounded essentially by a shell of chlorine atoms, suggesting the formation of FeCl4- anions. At high doping levels ([O]/[Fe] < 20), Fe(III) ions interacts mainly with oxygen atoms and form FeOx species. The relative proportion of FeOx species increases with iron concentration, this result being consistent with the results of SAXS measurements showing that increasing iron doping induces the formation of iron-rich nanodomains embedded in the polymer matrix.

Serology of paracoccidioidomycosis. II. Correlation between class-specific antibodies and clinical forms of the disease

Untreated and previously treated patients with paracoccidioidomycosis were studied for: (i) serum levels of total IgG, IgM and IgA immunoglobulins, by radial immunodiffusion and Paracoccidioides brasiliensis (Pb) antibodies, by indirect immunofluorescence; (ii) correlation between their levels with the clinical forms of the disease; (iii) correlation between the serum titres obtained by tube precipitin with those of anti-Pb IgG, IgM and IgA. In the untreated group, serum IgG levels were significantly increased in patients with the more systemic forms of the disease, especially the acute progressive form. Serum IgA levels were significantly increased in all patients with no statistical difference between clinical forms. Serum IgM levels were normal in all patients. Anti-Pb IgG, IgA and IgM were detected in 97·5%, 32·5% and 45·0% of all cases, respectively. There was a sharp tendency towards higher levels of anti-Pb IgG among those with the acute progressive form (83·4%) in relation to the chronic, more localized forms, mixed form (68·0%) and isolated organic form (55·5%). In the untreated and previously treated group sera, there was positive correlation between the level of anti-Pb IgG and positivity for the tube precipitin test, suggesting that the precipitin-type antibodies are of the IgG class. Broadly, the present data demonstrate a polyclonal activation of the humoral immune system in paracoccidioidomycosis, with a positive relationship between serological results and severity of the disease. © 1984.

Structural and Phylogenetic Studies with MjTX-I Reveal a Multi-Oligomeric Toxin - a Novel Feature in Lys49-PLA2s Protein Class

The mortality caused by snakebites is more damaging than many tropical diseases, such as dengue haemorrhagic fever, cholera, leishmaniasis, schistosomiasis and Chagas disease. For this reason, snakebite envenoming adversely affects health services of tropical and subtropical countries and is recognized as a neglected disease by the World Health Organization. One of the main components of snake venoms is the Lys49-phospholipases A2, which is catalytically inactive but possesses other toxic and pharmacological activities. Preliminary studies with MjTX-I from Bothrops moojeni snake venom revealed intriguing new structural and functional characteristics compared to other bothropic Lys49-PLA2s. We present in this article a comprehensive study with MjTX-I using several techniques, including crystallography, small angle X-ray scattering, analytical size-exclusion chromatography, dynamic light scattering, myographic studies, bioinformatics and molecular phylogenetic analyses.Based in all these experiments we demonstrated that MjTX-I is probably a unique Lys49-PLA2, which may adopt different oligomeric forms depending on the physical-chemical environment. Furthermore, we showed that its myotoxic activity is dramatically low compared to other Lys49-PLA2s, probably due to the novel oligomeric conformations and important mutations in the C-terminal region of the protein. The phylogenetic analysis also showed that this toxin is clearly distinct from other bothropic Lys49-PLA2s, in conformity with the peculiar oligomeric characteristics of MjTX-I and possible emergence of new functionalities inresponse to environmental changes and adaptation to new preys. © 2013 Salvador et al.

Análise da microestrutura do amálgama dental quando associado a diferentes materiais intermediários

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação tomográfica tridimensional do tratamento da classe II divisão 1 com aparelho de Herbst

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação das estruturas anatômicas para sobreposição cefalométrica maxilar utilizando telerradiografias em norma de 45 graus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Alterações cefalométricas induzidas pelo aparelho de Herbst com dois tipos de ancoragem para maxila

Pós-graduação em Ciências Odontológicas - FOAR

Padrão rotacional das estruturas dentofaciais natural e induzido pelo tratamento com aparelho de Thurow modificado: estudo cefalométrico com implantes metálicos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Prevalência de má oclusão e necessidade de tratamento ortodôntico, comparando a classificação de Angle e o índice de estética dentária, na cidade de Lins-SP

Pós-graduação em Odontologia Preventiva e Social - FOA

Avaliação das alterações dentoalveolares e esqueléticas induzidas pelo Ertty System® no tratamento da má oclusão de classe II subdivisão

Pós-graduação em Ciências Odontológicas - FOAR

Avaliação do tratamento ortodôntico precoce da classe II, 1ª divisão, subdivisão

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influence of the socioeconomic status on the prevalence of malocclusion in the primary dentition

OBJETIVO: avaliar a influência da condição socioeconômica na prevalência de má oclusão na dentição decídua em uma população amazônica. MÉTODOS: esse estudo transversal compreendeu 652 crianças, de ambos os sexos, entre 3 e 6 anos de idade. Os indivíduos estavam matriculados na pré-escola na rede privada de ensino (alto nível socioeconômico; n = 312) ou, rede pública (baixo nível socioeconômico; n = 340), em Belém, no Pará. O teste chi-quadrado e estatística binominal foram usados para avaliar as diferenças entre os grupos socioeconômicos, com nível de significância considerado em p < 0,05. RESULTADOS: foi observada uma alta prevalência de má oclusão (81,44%) na amostra examinada. As meninas das escolas públicas exibiram uma prevalência significativamente menor (72,1%) em comparação às das escolas privadas (84,7%), principalmente com relação à prevalência da má oclusão de Classe II (p < 0,0001), mordida cruzada posterior (p = 0,006), sobremordida (p = 0,005) e sobressaliência (p < 0,0001). De maneira geral, a prevalência de má oclusão foi similar entre as crianças do sexo masculino dos dois grupos (p = 0,36). A perda precoce de dente decíduo foi significativamente mais prevalente no grupo com menor nível socioeconômico (20,9%) quando comparada à de crianças nas escolas privadas (0.9%), em ambos os sexos (p < 0,0001). CONCLUSÃO: a condição socioeconômica influencia a ocorrência de má oclusão na dentição decídua. Na maior metrópole da Amazônia, uma em cada cinco crianças do grupo com baixo nível socioeconômico perdeu, no mínimo, um dente decíduo antes dos sete anos.