Abstract Pain is common in orthodontic treatment, is subject to individual variation, and is associated with anxiety and stress, which can potentially become catastrophizing. The aim of the present study was to determine the variability of pain response after the insertion of orthodontic separators and to assess the association of pain levels with dental anxiety, catastrophizing, tooth sensitivity, and genetic expression of cytokines. To this end, 70 patients of both genders were divided into two equal groups according to the elastomeric separator used: G1 (Dentaurum) and G2 (Orthometric). Two separators were inserted in the mesial and distal sides of the lower right first molar. Participants were instructed to rate the level of pain at T0 (before insertion), T1 (just after insertion), and T2 (24 hours after insertion) on a visual analog scale. The gingival crevicular fluid was collected at T0 and T2. The levels of anxiety, catastrophizing, tooth sensitivity, and cytokine expression were also assessed. Statistical analysis was performed with the Fisher-Freeman-Halton, chi-squared, Spearman’s correlation, and dependent and independent t tests (α=5%). Pain intensity was higher at T2 than at T1, in both groups (P<.05). An association was established (P<.05) between pain intensity at T1 and catastrophizing, and at T2 with anxiety and catastrophizing. Within-group differences in cytokine expression were found between T0 and T2. There was no correlation between cytokine expression and pain levels, anxiety, catastrophizing, and sensitivity at T2. Tooth separation produced variable pain levels, which were influenced by anxiety and catastrophizing, however, pain level was not correlated with increased cytokine expression.

ABSTRACT Objective: This study compared mandibular growth in children, aged 7 to 12 years, with Class II malocclusion and normal occlusion, between the following stages of cervical vertebrae maturation: initiation (I), acceleration (A), transition (T). Material and Methods: A total of 148 lateral cephalograms (78 males, 70 females) of Class II malocclusion patients, and 60 lateral cephalograms (30 males, 30 females) of normal occlusion patients were included. The following linear cephalometric measurements were performed: Co-Gn (effective mandibular length), Co-Go (ramus height), and Go-Gn (length of mandibular body). Mean values of increments between stages (I-A, A-T, I-T) were obtained for each group and gender. Results were compared using the Student t-test, and a significance level of 0.05% was adopted. Results: Females group: A-T interval presented a greater increment in Co-Go in the Class II group, which was not significant for the I-T interval, with numerically smaller increments in Co-Gn and Go-Gn, without statistical significance. Males group: intervals I-A, A-T and I-T showed numerically smaller growth increments in the Class II group, with statistical significance for Co-Gn in I-A (p=0.001) and I-T (p=0.003). Comparing genders of the Class II group, Co-Go was higher in males (p=0.002) and I-T interval (p=0.031). In the Normal Occlusion group, the male gender had the greatest Co-Gn (p=0.038) for the I-A interval. In A-T and I-T, Co-Go in males was higher, with statistical significance (p=0.000 and p=0.002, respectively). Conclusion: Growth phenomenon affects the mandibular dimensions regardless of the character of the malocclusion, with a tendency to be smaller in the presence of Class II malocclusion.

RESUMO Objetivo: Esse estudo comparou o crescimento mandibular em crianças de 7 a 12 anos de idade, com má oclusão de Classe II ou Oclusão Normal, entre os seguintes estágios de maturação das vértebras cervicais: iniciação (I), aceleração (A), transição (T). Material e Métodos: No total, 148 telerradiografias laterais (78 meninos, 70 meninas) de pacientes com má oclusão de Classe II e 60 telerradiografias laterais (30 meninos, 30 meninas) de pacientes com Oclusão Normal foram avaliadas. As medidas cefalométricas lineares Co-Gn (comprimento mandibular efetivo), Co-Go (altura do ramo mandibular) e Go-Gn (comprimento do corpo mandibular) foram analisadas e os valores médios dos incrementos entre os estágios (I-A, A-T e I-T) foram obtidos para cada grupo e sexo. Resultados: Os resultados foram comparados pelo teste t de Student, e o nível de significância adotado foi de 0,05%. Sexo feminino: houve maior incremento na altura do ramo no grupo Classe II em A-T, que diminuiu em I-T, com menores incrementos no comprimento mandibular efetivo e no corpo mandibular, sem significância estatística. Para o sexo masculino, nos intervalos I-A, A-T, I-T, os incrementos de crescimento foram numericamente menores no grupo Classe II, com significância estatística para o comprimento efetivo da mandíbula em I-A (p= 0,001) e em I-T (p= 0,003). No grupo Classe II, a altura do ramo foi maior para o sexo masculino (p= 0,002) e no intervalo I-T (p= 0,031). No grupo Oclusão Normal, o sexo masculino apresentou o maior comprimento mandibular efetivo (p= 0,038) no intervalo I-A. Nos intervalos A-T e I-T, a altura do ramo mandibular no sexo masculino foi maior e com significância estatística de p= 0,000 e p= 0,002, respectivamente. Conclusão: O fenômeno do crescimento afeta as dimensões mandibulares independentemente do característica da má oclusão, com tendência a ser menor na presença da má oclusão de Classe II.

Resumo Os objetivos deste estudo clínico foram avaliar a alteração de cor - ΔE (baseada em espectrofotometria e análise visual) e luminosidade - L* (baseada em espectrofotometria) da superfície do esmalte dentário (após tratamento ortodôntico) ao redor da área onde os braquetes ortodônticos foram fixados, com base em diferentes materiais de cimentação, como resina (grupo R) e cimento de ionômero de vidro modificado por resina (grupo RMGIC). Estudo boca dividida foi inicialmente composto por 14 pacientes. Os braquetes ortodônticos foram fixados nos incisivos centrais superiores com resina ou RMGIC. A cor da superfície vestibular de cada dente foi mensurada por espectrofotometria e avaliada por exame visual antes do processo de fixação dos braquetes. Quatro indivíduos foram excluídos durante o acompanhamento; assim, 10 pacientes foram avaliados (n=10). Os braquetes foram removidos após 12 meses de tratamento ortodôntico, a mensuração da cor do dente e o exame visual foram realizados novamente, e o Índice de Remanescente do Adesivo (IRA) também foi mensurado. Os resultados ΔE e L* foram submetidos ao teste t de Student e à análise de variância para medidas repetidas, respectivamente (α=0.05). Os dados do ARI foram analisados em porcentagens. Houve diferença estatisticamente significativa no ΔE entre os grupos; o grupo R apresentou valores estatisticamente maiores de L* após o tratamento ortodôntico. O IRA 2 e 3 prevaleceu no grupo RMGIC, enquanto o grupo R apresentou 0 e 1. Após o tratamento ortodôntico, o grupo RMGIC apresentou menores alterações no ΔE e o aumento da escala branca foi observado na superfície do esmalte ao redor da área onde os braquetes foram fixados no grupo R. A análise visual não mostrou mudança de cor nos dentes avaliados.

Abstract The aims of this clinical study were to evaluate the Color change - ΔE (based on spectrophotometry and visual analysis) and luminosity - L* (based on spectrophotometry) of dental enamel surface (after orthodontic treatment) around the area where orthodontic brackets were fixed, based on different cementing materials such as a resin (R group) and resin-modified glass ionomer cement (RMGIC group). The split-mouth study initially comprised 14 patients. Orthodontic brackets were fixed to the upper central incisors with resin or RMGIC. The color of the buccal surface of each tooth was measured through spectrophotometry and visual examination before the bracket-fixation process. Four individuals were excluded during the follow-up; thus 10 patients were evaluated (n=10). Brackets were removed after 12 months of orthodontic treatment, tooth color measurement and visual examination were performed again, and Adhesive Remaining Index (ARI) was also measured. ΔE and L* results were subjected to Student's t-test and by repeated-measures analysis of variance, respectively (α=0.05). ARI data were analyzed in percentages. There was statistically significant difference in ΔE between groups; the R group showed statistically higher values of L* after orthodontic treatment. ARI of 2 and 3 prevailed in the RMGIC group, whereas the R group presented 0 and 1. After orthodontic treatment, the RMGIC group presented smaller changes in ΔE, and the increase in the white scale was observed on the enamel surface around the area where brackets were fixed in the R group. The visual analysis did not show color change on the evaluated teeth.

Abstract: The aim of this study was to use microscopic and molecular techniques to evaluate the effects of a single session of antimicrobial photodynamic therapy (aPDT) on the alveolar repair process after tooth extraction in rats. The study sample included 84 rats divided into four groups, as follows: a) Control - untreated socket; b) Laser - socket treated using photobiomodulation; c) TBO - socket treated with topic application of the photosensitizer agent, toluidine blue O (TBO); and d) aPDT - socket treated with TBO and laser irradiation. An additional rat was used for thermal mapping during socket irradiation. The animals were euthanatized at 6, 15, and 28 days after unilateral extraction of the upper incisor. Quantitative and qualitative analyses of the connective and bone tissues, blood clot, blood vessel, and inflammatory infiltrate were performed, and real-time polymerase chain reaction was used to study the expression of genes (collagen type I, osteocalcin, alkaline phosphatase [ALP], runt-related transcription factor 2 [RUNX2], and vascular endothelial growth factor [VEGF]) involved in the bone healing process. No statistically significant differences in microscopic and molecular outcomes were observed between the groups (p > 0.05). A positive correlation was seen to exist between blood clot and VEGF (p = 0.000), and a negative correlation was observed between bone tissue and ALP (p = 0.028) and blood vessel and VEGF (p = 0.018). A single session of aPDT in the dental extraction site did not influence the alveolar repair process in rats.

ABSTRACT Objective: The aim of this study was to test the null hypothesis that there is no difference at the midpalatal suture opening after rapid maxillary expansion (RME) using Expander with Differential Opening (EDO), Hyrax-type and Haas-type expanders. Methods: Occlusal radiographs of 52 patients (19 males and 33 females; average age= 9.46?1.20 years) treated with RME were divided into three groups, according to the expander used: EDO (n=17), Hyrax-type (n=21) and Haas-type (n=14). The evaluated variables were: A) Distance between the maxillary central incisors at the incisal edge; B) Distance between the alveolar ridges at the midpalatal suture; C) Suture opening at 10-mm distance from the crest to posterior, at the midpalatal suture; D) Suture opening at 20-mm distance from the crest to posterior, at the midpalatal suture; and E) Suture opening at 30-mm distance from the crest to posterior, at the midpalatal suture. To assess the normality of variables, the Shapiro-Wilk test was performed. For intergroup comparison, ANOVA with a significance level of 5% was used. Results: At the region A, Hyrax-type (4.66 mm) and EDO (4.87 mm) groups presented larger openings than the Haas-type group (3.43 mm). In regions B and C, EDO showed a statistically significant greater opening than the Haas-type group. In region D, a smaller opening of the midpalatal suture was observed in the Haas-type group, compared to the Hyrax-type and EDO groups. Conclusions: EDO and Hyrax-type produced greater immediate skeletal effects, compared with Haas-type, but these differences were about 1 mm and might not be clinically significant.

RESUMO Objetivo: O objetivo do presente estudo foi testar a hipótese nula de que não existe diferença na abertura da sutura palatina mediana após a expansão rápida da maxila (ERM) usando os expansores Diferencial, tipo Hyrax e tipo Haas. Métodos: Radiografias oclusais de 52 pacientes (19 do sexo masculino e 33 do sexo feminino; idade média: 9,46 ? 1,20 anos) tratados com ERM foram divididas em três grupos, de acordo com o tipo de expansor usado: Diferencial (n = 17), tipo Hyrax (n = 21) e tipo Haas (n = 14). As variáveis avaliadas foram: A) distância entre os incisivos centrais superiores na borda incisal; B) distância entre os rebordos alveolares na sutura palatina mediana; C) abertura da sutura a 10 mm de distância da crista para posterior, na sutura palatina mediana; D) abertura da sutura a 20 mm da crista para posterior, na sutura palatina mediana; e E) abertura da sutura a 30 mm da crista para posterior, na sutura palatina mediana. Para verificar a normalidade das variáveis, utilizou-se o teste de Shapiro-Wilk. Para comparação intergrupos, usou-se a ANOVA com nível de significância de 5%. Resultados: Na região A, os grupos tipo Hyrax (4,66 mm) e Diferencial (4,87 mm) apresentaram uma abertura maior do que o grupo tipo Haas (3,43 mm). Nas regiões B e C, o Diferencial mostrou abertura significativamente maior do que o grupo tipo Haas. Na região D, uma abertura menor da sutura palatina mediana foi observada no grupo tipo Haas, comparado aos grupos tipo Hyrax e Diferencial. Conclusões: Os expansores Diferencial e tipo Hyrax produziram maiores efeitos esqueléticos imediatos, comparados ao tipo Haas, mas essas diferenças foram de aproximadamente 1 mm e podem não ser clinicamente significativas.

Resumo Os objetivos do presente estudo foram comparar e avaliar a estabilidade do tratamento precoce da mordida aberta anterior (MAA) com diferentes dispositivos. A amostra inicial foi composta por 99 pacientes randomizados em quatro grupos experimentais: BS - esporões colados; CC - mentoneira; FPC - grade palatina fixa; RPC - grade palatina removível. Análise cefalométrica foi realizada para avaliar os dados do período inicial (T1), final do tratamento (T2) e 2 anos após tratamento (T3), sendo a variável overbite o desfecho principal. Em T3, após perdas de seguimento, haviam 63 indivíduos, sendo BS (n=15; overbite 0.19 mm; 11.54 anos; 10 Feminino (F)/5 Masculino (M)); CC (n=11; overbite -0.19 mm; 11.41 anos; 8 F/3 M); FPC (n=21; overbite 1.23 mm; 11.44 anos; 15 F/6 M) e; RPC (n=16; overbite 0.73 mm; 11.67 anos; 6 F/10 M). Comparações das alterações nas variáveis dentoesqueléticas e abandono de hábitos bucais deletérios durante o tempo de acompanhamento foram estatisticamente analisados com p<.05. Medidas esqueléticas lineares mandibulares e componentes verticais aumentaram gradualmente com a idade, principalmente com o surto de crescimento puberal e estabelecimento da dentição permanente no pós-tratamento. O overbite foi significantemente melhorado durante o tratamento, permanecendo estável com alterações positivas. A extrusão dos incisivos impactou na correção da MAA e estabilidade nos 4 grupos, que registraram uma melhora de 1.15 mm no pós-tratamento (T3-T2). Com suas limitações, todos dispositivos experimentais foram efetivos e mostraram resultados estáveis no tratamento precoce da MAA, sendo que a FPC apresentou a maior correção da MAA e o menor índice de desistência.

Abstract This 2-year-follow up study compared and evaluated the stability of early anterior open bite (AOB) treatment based on different appliances. Children from 7 to 10 years with Angle Class I, AOB larger than 1.0 mm and fully erupted maxillary and mandibular permanent central incisors were eligible. The initial sample was 99 patients distributed, by simple randomization, into four groups: BS (bonded spurs), CC (chincup), FPC (fixed palatal crib) and RPC (removable palatal crib). Cephalometric analysis was performed at baseline (T1), final (T2) and 2-year post-treatment (T3) by taking the overbite measurements as the main outcome. Blinding was possible to cephalometric analysis. At T3, with dropouts, there were 63 individuals, being BS (n=15; overbite 0.19 mm; 11.54 years; 10 female (F)/5 male (M)); CC (n=11; overbite -0.19 mm; 11.41 years; 8 F/3 M); FPC (n=21; overbite 1.23 mm; 11.44 years; 15 F/6 M) and; RPC (n=16; overbite 0.73 mm; 11.67 years; 6 F/10 M). Changes in dentoskeletal variables and breaking deleterious oral habits during the follow up were statically analyzed with p<.05. Mandibular skeletal linear measurements and vertical dental components have gradually increased with age, manly at pubertal growth spurt and at the establishment of permanent dentition after treatment. Incisor teeth extrusion had impact on AOB correction and stability in 4 groups, which recorded a 1.15 mm-improvement of overbite after treatment (T3-T2). The experimental appliances were effective with stable results, being FPC the device recorded the highest AOB correction and the lowest patient withdrawal rate.

Abstract The object of this study was to compare the clinical complications of 4 different appliances used in the early treatment of anterior open bite (AOB), and to test the null hypothesis that there is no difference in the number of complications among the appliances. Records from 99 Class I malocclusion patients with AOB treated using bonded spurs, BS, n = 25; chin cup, CC, n = 25; fixed palatal crib, FPC, n = 25; and removable palatal crib, RPC, n = 24) were examined. The total number and frequency of clinical complications that occurred over 12 months were described and compared by using chi-square and Kruskal-Wallis tests (Dunn’s post-test) (α = 5%, CI = 95%). The incidence of clinical complications was 66.7%, comprising: breakage, bond failure, maladjustment, allergy, soft-tissue lesion, loss of removable appliance and abandonment. Eighteen patients gave up treatment; this occurred more frequently in the groups with removable appliances. Regarding the total number of complications per patient, Group BS exhibited a significantly higher number than the other groups (p < 0.0001). A low frequency of complications (1 to 3) was found in the groups, except for Group BS, in which 8% of the patients presented moderate frequency (4 to 6). In terms of appliance types (fixed or removable), there was no difference in the incidence of complications (p > 0.094). The null hypothesis was rejected, since the BS group exhibited the highest total number and frequency of complications. There was no difference between fixed and removable appliances in terms of incidence of clinical complications, although more patients using removable appliances abandoned their treatment.

Resumo Levantes de mordida posterior são dispositivos para o tratamento ortodôntico confeccionados com resinas compostas ou materiais ionoméricos. Cuidado com a remoção destes se faz necessário para proteção da superfície dentária; para tanto, materiais pigmentados são preferidos por proporcionar melhor visualização. Este estudo propõe uma técnica de pigmentação experimental de resinas compostas convencionais, avaliando a resistência ao microcisalhamento (µ-SBT) na interface de união da resina experimental e superfície de esmalte dental e comparando-a com materiais comercialmente disponíveis para a confecção de levantes de mordida. Quarenta e oito superfícies de dentes humanos foram selecionadas aleatoriamente e divididos em quatro grupos (n=12), de acordo com o material adesivo utilizado: C (Controle, resina composta convencional); P (pigmentação experimental da resina composta convencional); UBL (Ultra Band Lok®); OB (Ortho Bite®). Microcilindros foram preparados para cada tipo de compósito utilizando uma matriz de silicone. As amostras foram mantidas em água destilada por 24h a 37°C, antes da realização do µ-SBT. Os padrões de fratura foram avaliados através de uma lupa estereoscópica com magnificação de 10x. ANOVA com pós teste de Fisher e teste de Dunnett foram utilizados para avaliar os dados. As médias obtidas do µ-SBT ± desvio padrão (MPa) foram: C (39.98a±13.0), P (40.09a± 14.3); UBL (33.26ab±8.6); OB (28.70b±5.5). O tipo de fratura mais prevalente foi a adesiva (80.4%). Além disso, não foi observada correlação estatisticamente significante entre os valores de resistência de união e os padrões de fratura. A técnica de pigmentação experimental não alterou os resultados de µ-SBT da resina composta convencional e mostrou adesividade semelhante à dos compósitos modificados por poliácidos utilizados neste estudo.

Abstract Posterior build-ups are auxiliary devices to orthodontic treatment which are made with resin-based or glass ionomer composites. Their removal requires care to protect the tooth surface, therefore, pigmented materials are preferred for a better visualization. This study proposed a pigmentation experimental technique of a regular composite resin, evaluating the microshear bond strength test (µ-SBT) of this experimental pigmented resin and comparing with a blue-colored polyacid-modified composite resin, used for posterior buildups. Forty-eight buccal and lingual surfaces of human teeth were used and randomly divided into 4 groups (n=12). The groups were divided into: C (control), regular composite resin; P, regular composite resin pigmented; UBL, Ultra Band Lok™; OB, Ortho Bite™. The composites were bonded using a matrix to obtain microcylinders and prepared for each experimental groups. The samples were then stored in distilled water for 24h at 37°C followed by a µ-SBT. The types of bond failures were evaluated using a stereoscopic magnifying glass (10×). The data were analyzed by ANOVA with Fisher post hoc and Dunnett´s test. Means of µ-SBT± standard deviation (MPa) were: C (39.98a±13.0), P (40.09a± 14.3); UBL (33.26ab±8.6); OB (28.70b±5.5). The most prevalent type of failure was adhesive (80.4%). Further, was not observed a statistically significant correlation between the bond strength values and failure patterns. The pigmentation of a commercially available resin did not alter the µ-SBT and exhibited similar adhesiveness as a polyacid-modified composite resin.

Abstract The objective of this study was to assess the effect of a UV light-based auxiliary illumination on adhesive remnant (AR) removal after orthodontic debonding. Sixty human molars were divided according to the adhesive used for bonding: O-opaque; LF-low fluorescence; and HF-high fluorescence. After debonding, the teeth were subdivided according to the AR removal method: No UV light or With UV light. After AR removal, the teeth were polished. Direct visual analysis, scanning electron microscopy (SEM) and time quantification for AR removal analyses were performed (Fisher-Freeman-Halton, Fisher’s exact, chi-square trend, ANOVA, and independent t-tests; α = 5%). Concerning the adhesives, there was no significant difference among direct visual, SEM and time analyses for AR removal (p ≥ 0.05). Regarding AR removal methods, a similarity among the subgroups was verified for direct visual and SEM analyses (p≥0.05). However, a significant trend was verified for the with UV light method to produce greater marks, and the no UV light method, to produce a greater rate of samples with AR before polishing (p = 0.015). AR removal with light was significantly quicker in comparison with the no UV light method (p < 0.0001). The use of UV light may aid orthodontists in removing AR more thoroughly and in less time. However, they should receive special training to apply this technology, and should never dismiss the final polishing procedure.

Abstract The aim of this study was to evaluate deflection forces of orthodontic wires of different alloys engaged into conventional brackets using several ligation types. Stainless steel, conventional superelastic nickel-titanium and thermally activated nickel-titanium archwires tied into conventional brackets by a ring-shaped elastomeric ligature (RSEL), a 8-shaped elastomeric ligature (8SEL) and a metal ligature (ML) were tested. A clinical simulation device was created especially for this study and forces were measured with an Instron Universal Testing Machine. For the testing procedure, the block representing the maxillary right central incisor was moved 0.5 and 1 mm bucco-lingually at a constant speed of 2 mm/min, and the forces released by the wires were recorded, in accordance with the ISO 15841 guidelines. In general, the RSEL showed lighter forces, while 8SEL and ML showed higher values. At the 0.5 mm deflection, the 8SEL presented the greatest force, but at the 1.0 mm deflection the ML had a statistically similar force. Based on our evaluations, to obtain lighter forces, the thermally activated nickel-titanium wire with the RSEL are recommended, while the steel wire with the 8SEL or the ML are recommended when larger forces are desired. The ML exhibited the highest force increase with increased deflections, compared with the elastomeric ligatures.

Abstract: The aim of this study was to evaluate the health-related quality of life (QOL) of patients with squamous cell carcinoma (SCC) according to tumor location. The sample consisted of 27 patients with primary SCC in the oral cavity (n = 15), pharynx (n = 7), and larynx (n = 5) who were undergoing cancer treatment at the Cancer Hospital of Londrina, regardless of age, sex, clinical stage, and type of antineoplastic treatment. Health-related QOL was evaluated using the 30-item Cancer-Quality of Life Questionnaire (QLQ-C30), the 35-item Head and Neck Cancer-Quality of Life Questionnaire (QLQ-HN35), and the University of Washington Quality of Life Questionnaire (UW-QOL). These questionnaires were administered individually to each patient before ambulatory care. Sociodemographic data (age and sex) and clinical data (T stage, tumor location, and type of antineoplastic treatment) were collected from the patients' medical records. Scores were compared according to tumor location using the chi-squared test and one-way analysis of variance (p < 0.05). No score differed significantly according to tumor location. It can be concluded that the health-related QOL of patients with SCC was not influenced by tumor location.

RESUMO Objetivo: o objetivo deste estudo foi avaliar as forças de deflexão de fios ortodônticos retangulares em braquetes convencionais (MorelliTM) e autoligáveis ativos (In-Ovation RTM ) e passivos (Damon 3MXTM). Material e Métodos: foram utilizadas duas marcas comerciais (MorelliTM e GACTM) de fios de aço inoxidável e de níquel-titânio (NiTi), além do fio de NiTi com adição de cobre (OrmcoTM). Os espécimes foram montados em um dispositivo de simulação clínica especialmente desenhado para esse estudo e testado em uma máquina universal de ensaios Instron. Para o procedimento dos testes, a peça representativa do incisivo central superior direito foi movida no sentido vestibulolingual em ativações de 0 a 1 mm, com leituras da força liberada pela deflexão em 0,5; 0,8 e 1 mm, em uma velocidade constante de 2 mm/min. As forças interbraquetes com os fios de aço, de NiTi e NiTi com adição de cobre foram individualmente comparadas pelo teste de ANOVA a dois critérios, seguido pelo teste de Tukey. Resultados: houve menor liberação de forças nos braquetes convencionais, seguidos pelos braquetes autoligáveis ativos e passivos. Entre as marcas comerciais, somente houve diferença para o fio de NiTi, onde a marca MorelliTM apresentou maiores forças do que a GACTM. Conclusão: os braquetes promovem diferentes graus de forças de deflexão, sendo que os braquetes autoligáveis liberam as maiores forças.

ABSTRACT Introduction: The aim of the study was to evaluate deflection forces of rectangular orthodontic wires in conventional (MorelliTM), active (In-Ovation RTM) and passive (Damon 3MXTM) self-ligating brackets. Material and Methods: Two brands of stainless steel and nickel-titanium (NiTi) wires (MorelliTM and GACTM), in addition to OrmcoTM copper-nickel-titanium wires were used. Specimens were assembled in a clinical simulation device especially designed for this study and tested in an Instron universal testing machine. For the testing procedures, an acrylic structure representative of the maxillary right central incisor was lingually moved in activations of 0 to 1 mm, with readings of the force released by deflection in unloading of 0.5, 0.8 and 1 mm at a constant speed of 2 mm/min. Inter-bracket forces with stainless steel, NiTi and CuNiTi were individually compared by two-way ANOVA, followed by Tukey’s tests. Results: Results showed that there were lower forces in conventional brackets, followed by active and passive self-ligating brackets. Within the brands, only for NiTi wires, the MorelliTM brand presented higher forces than GACTM wires. Conclusions: Bracket systems provide different degrees of deflection force, with self-ligating brackets showing the highest forces.

OBJECTIVE: The purpose of this study was to determine the accuracy and reliability of two methods of measurements of linear distances (multiplanar 2D and tridimensional reconstruction 3D) obtained from cone-beam computed tomography (CBCT) with different voxel sizes. MATERIAL AND METHODS: Ten dry human mandibles were scanned at voxel sizes of 0.2 and 0.4 mm. Craniometric anatomical landmarks were identified twice by two independent operators on the multiplanar reconstructed and on volume rendering images that were generated by the software Dolphin®. Subsequently, physical measurements were performed using a digital caliper. Analysis of variance (ANOVA), intraclass correlation coefficient (ICC) and Bland-Altman were used for evaluating accuracy and reliability (p<0.05). RESULTS: Excellent intraobserver reliability and good to high precision interobserver reliability values were found for linear measurements from CBCT 3D and multiplanar images. Measurements performed on multiplanar reconstructed images were more accurate than measurements in volume rendering compared with the gold standard. No statistically significant difference was found between voxel protocols, independently of the measurement method. CONCLUSIONS: Linear measurements on multiplanar images of 0.2 and 0.4 voxel are reliable and accurate when compared with direct caliper measurements. Caution should be taken in the volume rendering measurements, because the measurements were reliable, but not accurate for all variables. An increased voxel resolution did not result in greater accuracy of mandible measurements and would potentially provide increased patient radiation exposure.

The aim of this study was to evaluate the reproducibility of the gray values and noise of a direct digital radiography system (Visualix eHD) for various exposure times and analyzed regions. To obtain radiographic images in a standardized manner, the digital sensor of the system and a stepwedge were positioned in a phantom at a focus-film distance of 30 cm in a dental device at 70 kV, 7 mA and 2.2 mm filtration. Ten consecutive repetitions of X-ray imaging were performed at each exposure time (0.05, 0.07, 0.09 and 0.13 s). Gray values were analyzed using ImageJ software in five regions of interest (ROIs): alveolar bone (AB), soft tissue (ST) and three steps of the stepwedge (S1, S2 and S3). The results showed that both the variability of the gray values and the noise were statistically greater (p < 0.05) in the most radiolucent region (ST). Only the noise was affected by the exposure time. In conclusion, the reproducibility of the gray values and the noise of the Visualix eHD system can vary in specific areas with different radiolucency.

INTRODUÇÃO: o objetivo desse estudo foi obter os valores médios de normalidade das alturas faciais anterior e posterior de 30 jovens mestiços nipo-brasileiros, descendentes de xantodermas e leucodermas, com oclusão normal, com idade média de 14 anos, e verificar a presença ou ausência de dimorfismo entre os sexos. MÉTODOS: elaborou-se um estudo cefalométrico com as mensurações advindas das análises de Wylie e Johnson, Siriwat e Jarabak, Gebeck, Merrifield e Horn. RESULTADOS: os resultados revelaram a presença de dimorfismo entre os sexos para as variáveis AFAT, AFAI, AFA, AFPT e AFPS. CONCLUSÕES: um padrão cefalométrico específico, das alturas faciais anterior e posterior, para os jovens mestiços nipo-brasileiros com oclusão normal, descendentes de xantodermas e leucodermas, foi apresentado e um dimorfismo entre os sexos para cinco das treze variáveis avaliadas foi verificado nessa faixa etária média.

OBJECTIVE: The aim of this study was to determine the standards of facial height in 30 young (14-year-old) Japanese-Brazilian descendants with normal occlusion, and assess whether sexual dimorphism is evident. METHODS: The cephalometric measurements used followed the analyses by Wylie-Johnson, Siriwat-Jarabak, Gebeck, Merrifield and Horn. RESULTS: Results showed dimorphism for total anterior facial height (TAFH), lower anterior facial height (LAFH), anterior facial height (AFH), total posterior facial height (TPFH) and upper posterior facial height (UPFH) measurements. CONCLUSIONS: The standards of facial heights in young Japanese-Brazilian descendants with normal occlusion were observed. Sexual dimorphism was identified in five out of thirteen evaluated variables at this age range.