Comparative cephalometric study of the airways between different ethnic groups with normal occlusion.

OBJECTIVE: This study aimed to compare the nasopharynx and oropharynx airway dimensions of Caucasians, Blacks, Japanese, Japanese Brazilians, and Black Caucasians. METHODS: A sample of 216 lateral radiographs of untreated young Brazilian subjects (mean age of 12.94 years; SD 0.88) were divided into five groups: Black Caucasian, Black, Caucasian, Japanese, and Japanese Brazilian. Lateral radiographs were used to measure the oropharynx (from the midpoint on the soft palate to the closest point on the anterior pharyngeal wall) and the nasopharynx (from the intersection of the posterior border of the tongue and the inferior border of the mandible to the closest point on the posterior pharyngeal wall). Analyses of variance (ANOVA) and Tukey's test were performed (p< 0.05). RESULTS: The linear dimension of the oropharynx was similar among the different ethnic groups. Caucasian individuals presented a significantly greater linear dimension of the nasopharynx than Black Caucasian and Black individuals. CONCLUSIONS: All the groups had similar buccopharyngeal values. However, Caucasian individuals had significantly higher values when compared to Black Caucasians and Black individuals.

Comparative cephalometric study of the airways between different ethnic groups with normal occlusion

ABSTRACT Objective: This study aimed to compare the nasopharynx and oropharynx airway dimensions of Caucasians, Blacks, Japanese, Japanese Brazilians, and Black Caucasians. Methods: A sample of 216 lateral radiographs of untreated young Brazilian subjects (mean age of 12.94 years; SD 0.88) were divided into five groups: Black Caucasian, Black, Caucasian, Japanese, and Japanese Brazilian. Lateral radiographs were used to measure the oropharynx (from the midpoint on the soft palate to the closest point on the anterior pharyngeal wall) and the nasopharynx (from the intersection of the posterior border of the tongue and the inferior border of the mandible to the closest point on the posterior pharyngeal wall). Analyses of variance (ANOVA) and Tukey's test were performed (p< 0.05). Results: The linear dimension of the oropharynx was similar among the different ethnic groups. Caucasian individuals presented a significantly greater linear dimension of the nasopharynx than Black Caucasian and Black individuals. Conclusions: All the groups had similar buccopharyngeal values. However, Caucasian individuals had significantly higher values when compared to Black Caucasians and Black individuals.

RESUMO Objetivo: Este estudo teve como objetivo comparar as dimensões das vias aéreas da nasofaringe e da bucofaringe de leucodermas, melanodermas, xantodermas, feodermas e nipo-brasileiros. Material e métodos: Uma amostra de 216 telerradiografias laterais de jovens brasileiros não tratados (idade média de 12,94 anos; DP 0,88) foi dividida em cinco grupos: melanodermas, leucodermas, xantodermas, feodermas e nipo-brasileiros. As telerradiografias foram utilizadas para medir a bucofaringe (do ponto médio do palato mole até o ponto mais próximo da parede anterior da faringe) e a nasofaringe (da intersecção da borda posterior da língua e da borda inferior da mandíbula até o ponto mais próximo). Foram realizadas análises de variância (ANOVA) e teste de Tukey (p < 0,05). Resultados: A dimensão linear da bucofaringe foi semelhante entre os diferentes grupos étnicos. Indivíduos leucodermas apresentaram dimensão linear da nasofaringe significativamente maior do que indivíduos feodermas e melanodermas. Conclusões: Todos os grupos apresentaram valores da bucofaringe semelhantes. No entanto, os indivíduos leucodermas apresentaram valores significantemente maiores, quando comparados aos feodermas e melanodermas.

Cephalometric comparison of mandibular growth in Brazilian children with Class II malocclusion and normal occlusion during the growth stages determined by the cervical vertebrae maturation.

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.

Incisors' bone height and inclination changes after orthodontic treatment with a self-ligating passive system.

Background: This study aimed to evaluate changes in the alveolar buccal bone height of maxillary and mandibular incisors after orthodontic treatment with a self-ligating passive system and to assess the correlation between bone height and incisor inclination. Material and Methods: Pre (T1) and post-treatment (T2) cone-beam computed tomography images of patients treated with the Damon 3MX appliance system were measured to quantify the alveolar buccal bone height of the maxillary incisors. The incisor's inclination was measured in digital models. Paired t-test was used to evaluate the changes between T1 and T2, and Pearson's coefficient was used to test the correlation. Results: All teeth presented statistically significant alveolar buccal bone loss at T2. A statistically significant buccal inclination was observed only for the lower left lateral incisors. There was no correlation between bone height changes and incisor inclination. Conclusions: Orthodontic treatment with a self-ligating passive system showed changes in alveolar height, but these changes were not correlated with incisor inclination. Key words:Passive self-ligating brackets, orthodontics, corrective, treatment outcome, alveolar bone loss.

Psychological and financial impact of the COVID-19 pandemic during the first stages of the pandemic: Brazilian orthodontists´ perspective.

INTRODUCTION: Brazil faced a catastrophic situation in the coronavirus pandemic. Due to the high risk of contamination and spread of COVID-19, dentist have been attending only urgency and emergency services in Brazil at the beginning of the pandemic. OBJECTIVE: This research aimed to evaluate the psychological and financial impacts caused by the coronavirus pandemic in Brazilian orthodontists. METHODS: This population-based cross-sectional study collected demographic data and mental health measurements from 404 orthodontists. Depression, anxiety, insomnia, and distress were evaluated through Brazilian versions of the 9-item Patient Health Questionnaire (9-PHQ), the 7-item Generalized Anxiety Disorder scale and Mini-Tracking (GAD), the 7-item Insomnia Severity Index (ISI), and the 22-item Impact of Event Scale-Revised (IES-R), respectively. The demographic data of the sample was described using descriptive statistics. The data was analyzed according to sex, professional status, and economic income. Comparisons were performed using Chi-square tests, Mann-Whitney U tests, and Kruskal-Wallis followed by post-hoc tests. RESULTS: Females, graduate students, and lower incomes subgroups showed higher levels of depression, anxiety, insomnia, and distress. Most orthodontists showed moderate to extreme financial and professional concerns during the pandemic. CONCLUSION: The coronavirus pandemic negatively affected the psychological health and increased the financial concerns of the Brazilian orthodontists, mainly female, graduate students, and with income below 10k participants.

Cephalometric comparison of mandibular growth in Brazilian children with Class II malocclusion and normal occlusion during the growth stages determined by the cervical vertebrae maturation

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.

Psychological and financial impact of the COVID-19 pandemic during the first stages of the pandemic: Brazilian orthodontists´ perspective

ABSTRACT Introduction: Brazil faced a catastrophic situation in the coronavirus pandemic. Due to the high risk of contamination and spread of COVID-19, dentist have been attending only urgency and emergency services in Brazil at the beginning of the pandemic. Objective: This research aimed to evaluate the psychological and financial impacts caused by the coronavirus pandemic in Brazilian orthodontists. Methods: This population-based cross-sectional study collected demographic data and mental health measurements from 404 orthodontists. Depression, anxiety, insomnia, and distress were evaluated through Brazilian versions of the 9-item Patient Health Questionnaire (9-PHQ), the 7-item Generalized Anxiety Disorder scale and Mini-Tracking (GAD), the 7-item Insomnia Severity Index (ISI), and the 22-item Impact of Event Scale-Revised (IES-R), respectively. The demographic data of the sample was described using descriptive statistics. The data was analyzed according to sex, professional status, and economic income. Comparisons were performed using Chi-square tests, Mann-Whitney U tests, and Kruskal-Wallis followed by post-hoc tests. Results: Females, graduate students, and lower incomes subgroups showed higher levels of depression, anxiety, insomnia, and distress. Most orthodontists showed moderate to extreme financial and professional concerns during the pandemic. Conclusion: The coronavirus pandemic negatively affected the psychological health and increased the financial concerns of the Brazilian orthodontists, mainly female, graduate students, and with income below 10k participants.

RESUMO Introdução: O Brasil enfrentou uma situação catastrófica durante a pandemia do coronavírus. Devido ao alto risco de contaminação e disseminação do vírus da COVID-19, os cirurgiões-dentistas passaram a realizar apenas atendimentos de urgência ou emergência no início da pandemia. Objetivo: O presente estudo teve como objetivo avaliar o impacto financeiro e psicológico causado pela pandemia do coronavírus nos ortodontistas brasileiros. Métodos: Este estudo transversal de base populacional coletou os dados demográficos e o impacto da pandemia em 404 ortodontistas. Depressão, ansiedade, insônia e angústia foram avaliadas, respectivamente, por meio da versão em português do Questionário de Saúde do Paciente (PHQ-9), do módulo de transtorno de ansiedade generalizada (GAD) do Mini-Tracking (GAD/Mini-Tracking), do Índice de Severidade de Insônia (ISI) e o do Impact of Events Scale-Revised (IES-R). As características demográficas da amostra foram apresentadas por meio de estatística descritiva. Os dados foram analisados de acordo com o sexo, situação profissional e renda econômica. As comparações foram realizadas utilizando os testes de Qui-quadrado, Mann-Whitney U e Kruskal-Wallis, seguidos de testes post-hoc (p<0,05). Resultados: Mulheres, estudantes de pós-graduação e profissionais com menores rendas apresentaram níveis mais altos de depressão, ansiedade, insônia e angústia. A maioria dos ortodontistas mostrou preocupação financeira e profissional moderada a extrema durante a pandemia. Conclusão: A pandemia do coronavírus afetou negativamente a saúde psicológica dos ortodontistas brasileiros e aumentou as preocupações financeiras desses profissionais. As mulheres, os estudantes de pós-graduação e os participantes com renda mensal menor que R$10 mil foram os grupos mais afetados.

Three-dimensional pharyngeal airway space changes after bimaxillary advancement.

INTRODUCTION: The probability of improvement in the upper airway space (UAS) with orthognathic surgery should be considered during the surgical-orthodontic treatment decision, providing not only an esthetic, but also a functional benefit for the patient. OBJECTIVE: The purpose of this study was to evaluate the 3D changes in the upper airway space after maxillomandibular advancement surgery (MMA). METHODS: A retrospective analysis of 56 patients, 21 male and 35 female, with a mean age of 35.8 ± 10.7 years, who underwent MMA was performed. Pre- and postoperative cone-beam computed tomography scans (CBCT) were obtained for each patient, and the changes in the UAS were compared using Dolphin Imaging 11.7 software. Two parameters of the pharyngeal airway space (PAS) were measured: airway volume (AV) and minimum axial area (MAA). Paired t-test was used to compare the data between T0 and T1, at 5% significance level. RESULTS: There was a statistically significant increase in the UAS. Bimaxillary advancement surgery increased the AV and the MAA, on average, by 73.6 ± 74.75% and 113.5 ± 123.87%, respectively. CONCLUSION: MMA surgery tends to cause significant increase in the UAS; however, this increase is largely variable.

Does the use of face masks during the COVID-19 pandemic impact on oral hygiene habits, oral conditions, reasons to seek dental care and esthetic concerns?

BACKGROUND: To evaluate the impact of the use of face masks on oral hygiene habits; oral conditions self-perception; reasons to seek dental treatment; and esthetic concerns. MATERIAL AND METHODS: 1346 participants answered a web-based survey with questions related to the aims of the study. Descriptive statistic was performed and the responses were analyzed with chi-square test and regression analysis. RESULTS: With the use of masks, toothbrushing frequency decreased significantly, and people are significantly less concerned about oral hygiene. The number of subjects that reported to have halitosis increased significantly and this was associated with a decrease in toothbrushing frequency. The greatest complaints of subjects were teeth color and alignment. The prevalence of bruxism increased significantly. Overall, 94.1% considered that esthetics is important to seek dental care even with the use of masks, and 84.2% are maintaining usual periodic dental care. People are significantly less concerned with their smile and dental esthetics with the use of masks. CONCLUSIONS: With the use of face mask, people must be motivated regarding maintaining oral hygiene habits. Some respondents will seek dental care only when masks were no longer necessary, therefore dentists must be aware of a reduction in the volume of patients. Key words:Dental health surveys, esthetics, oral hygiene, dental care, COVID-19, behavior.

McNamara analysis cephalometric parameters in White-Brazilians, Japanese and Japanese-Brazilians with normal occlusion.

INTRODUCTION: McNamara's Jr. cephalometric analysis is a tool to diagnose dental and skeletal discrepancies and is widely used, guiding diagnosis for surgical procedures to be performed or for the use of functional devices. Few studies have shown that different ethnic groups have different cephalometric patterns. Thus, single characteristics should be respected to support the diagnosis and to help the treatment plan for different ethnic groups and their different patterns of miscegenation. OBJECTIVE: Obtain normal values for McNamara's cephalometric analysis for adolescent Japanese-Brazilian descents with normal occlusion, as well as to compare this sample with similar samples of White-Brazilian and Japanese. METHODS: Lateral headfilms from 40 White-Brazilian, 33 Japanese and 32 Japanese-Brazilian descents were selected. The three groups were composed by individuals with normal occlusion, well-balanced profiles and were separated by sex. The data were statistically analyzed with ANOVA, t-test, ANCOVA and MANCOVA tests. RESULTS: White-Brazilian males had significantly greater nasolabial angle than Japanese males. Japanese-Brazilian displayed an intermediate value between White-Brazilian and Japanese. CONCLUSION: White-Brazilian, Japanese and Japanese-Brazilian present different cephalometric characteristics of McNamara analysis. Japanese males have a significantly more acute nasolabial angle than White-Brazilian subjects.

Three-dimensional pharyngeal airway space changes after bimaxillary advancement

ABSTRACT Introduction: The probability of improvement in the upper airway space (UAS) with orthognathic surgery should be considered during the surgical-orthodontic treatment decision, providing not only an esthetic, but also a functional benefit for the patient. Objective: The purpose of this study was to evaluate the 3D changes in the upper airway space after maxillomandibular advancement surgery (MMA). Methods: A retrospective analysis of 56 patients, 21 male and 35 female, with a mean age of 35.8 ± 10.7 years, who underwent MMA was performed. Pre- and postoperative cone-beam computed tomography scans (CBCT) were obtained for each patient, and the changes in the UAS were compared using Dolphin Imaging 11.7 software. Two parameters of the pharyngeal airway space (PAS) were measured: airway volume (AV) and minimum axial area (MAA). Paired t-test was used to compare the data between T0 and T1, at 5% significance level. Results: There was a statistically significant increase in the UAS. Bimaxillary advancement surgery increased the AV and the MAA, on average, by 73.6 ± 74.75% and 113.5 ± 123.87%, respectively. Conclusion: MMA surgery tends to cause significant increase in the UAS; however, this increase is largely variable.

RESUMO Introdução: A probabilidade de melhoria do espaço aéreo superior (EAS) com cirurgia ortognática deve ser considerada durante a decisão do tratamento ortodôntico-cirúrgico, proporcionando não somente um benefício estético, mas também funcional, para o paciente. Objetivo: O objetivo do presente estudo foi avaliar as alterações 3D no espaço das vias aéreas superiores após a cirurgia de avanço maxilomandibular (AMM). Métodos: Foi realizada uma análise retrospectiva de 56 pacientes, 21 homens e 35 mulheres, com média de idade de 35,8 ± 10,7 anos, submetidos a AMM. Foram obtidas tomografias computadorizadas de feixe cônico (TCFC) pré- e pós-operatórias para cada paciente, e as alterações no EAS foram comparadas usando o software Dolphin Imaging v. 11.7. Foram medidos dois parâmetros do espaço aéreo faríngeo (EAF): volume das vias aéreas (VVA) e área axial mínima (AAM). Foi utilizado o teste t pareado para comparar os dados entre T0 e T1, com nível de significância de 5%. Resultados: Houve um aumento estatisticamente significativo no EAS. A cirurgia de avanço bimaxilar aumentou o volume das vias aéreas (VVA) e a área axial mínima (AAM) em média 73,6 ± 74,75% e 113,5 ± 123,87%, respectivamente. Conclusão: A cirurgia de AMM tende a causar o aumento significativo do EAS; no entanto, esse aumento é altamente variável.

McNamara analysis cephalometric parameters in White-Brazilians, Japanese and Japanese-Brazilians with normal occlusion

ABSTRACT Introduction: McNamara's Jr. cephalometric analysis is a tool to diagnose dental and skeletal discrepancies and is widely used, guiding diagnosis for surgical procedures to be performed or for the use of functional devices. Few studies have shown that different ethnic groups have different cephalometric patterns. Thus, single characteristics should be respected to support the diagnosis and to help the treatment plan for different ethnic groups and their different patterns of miscegenation. Objective: Obtain normal values for McNamara's cephalometric analysis for adolescent Japanese-Brazilian descents with normal occlusion, as well as to compare this sample with similar samples of White-Brazilian and Japanese. Methods: Lateral headfilms from 40 White-Brazilian, 33 Japanese and 32 Japanese-Brazilian descents were selected. The three groups were composed by individuals with normal occlusion, well-balanced profiles and were separated by sex. The data were statistically analyzed with ANOVA, t-test, ANCOVA and MANCOVA tests. Results: White-Brazilian males had significantly greater nasolabial angle than Japanese males. Japanese-Brazilian displayed an intermediate value between White-Brazilian and Japanese. Conclusion: White-Brazilian, Japanese and Japanese-Brazilian present different cephalometric characteristics of McNamara analysis. Japanese males have a significantly more acute nasolabial angle than White-Brazilian subjects.

RESUMO Introdução: A análise cefalométrica de McNamara Jr. é uma ferramenta amplamente utilizada para o diagnóstico das discrepâncias dentárias e esqueléticas, principalmente porque fornece um diagnóstico que orienta os procedimentos cirúrgicos a serem realizados ou a utilização de aparelhos funcionais. Estudos têm demonstrado que diferentes grupos étnicos apresentam padrões cefalométricos distintos. Portanto, as características próprias dos indivíduos devem ser respeitadas, para suportar o diagnóstico e facilitar o plano de tratamento, entre as diferentes etnias e seus diferentes padrões de miscigenação. Objetivo: Determinar os valores médios de normalidade das grandezas cefalométricas relacionadas à análise de McNamara em jovens mestiços nipo-brasileiros, com oclusão normal, descendentes de japoneses e brasileiros, e comparar os resultados das variáveis com amostras de jovens brasileiros leucodermas e xantodermas que apresentem as mesmas características. Métodos: Foram selecionadas 40 telerradiografias de jovens leucodermas, 33 de xantodermas e 32 de nipo-brasileiros. As três amostras foram constituídas de indivíduos com oclusão normal e face bem balanceada, e foram divididas por sexo. Os dados foram estatisticamente analisados utilizando ANOVA, teste t, ANCOVA e MANOVA. Resultados: Os leucodermas apresentaram o ângulo nasolabial significativamente maior, comparados aos japoneses, no sexo masculino; enquanto os nipo-brasileiros apresentaram um valor intermediário entre os leucodermas e xantodermas. Conclusão: Os grupos de leucodermas, xantodermas e nipo-brasileiros apresentaram diferentes características cefalométricas da análise de McNamara. Os xantodermas no sexo masculino tiveram o ângulo nasolabial significativamente mais agudo, quando comparados com os leucodermas.

Coated nickel titanium archwires and their uncoated counterparts: In-vitro contemporary comparison of unloading forces.

OBJECTIVE: To compare the unloading forces between aesthetic nickel titanium (NiTi) wires coated with rhodium and epoxy resin, as well as their uncoated equivalents. Additionally, intragroup comparisons between the different deactivation forces were evaluated, and the inner alloy cores were determined. MATERIAL AND METHODS: Forty-four 0.018" NiTi wire segments were equally divided into 4 groups: E- NiTi coated with epoxy resin, C- NiTi uncoated, R- heat-activated NiTi coated with rhodium, and T- heat-activated NiTi uncoated. The unloading values were recorded at 0.5, 1, 2, and 3mm using a 3-point bending test, according to the method in ISO Standard 15.841. Cross-sectional scanning electron microscopy was used to assess the inner alloy core thickness of the wires. RESULTS: The intergroup comparison was successively: at 0.5mm: E (1.21)>C (0.60)=R (0.63)=T (0.58); at 1mm: E (1.30)=C (1.23)>R (0.91)=T (0.80); at 2mm:C (1.93)>E (1.36)=R (1.20) and R (1.20)=T (1.00) and E (1.36)>T (1.00); at 3mm:C (2.44)>R (2.02)>E (1.62)=T (1.68). The intragroup comparisons showed for all groups that the forces were statistically higher at 3mm than the other deactivations (p<0.01). Group E presented a reduced inner alloy core (.0155). CONCLUSION: The unloading forces demonstrated variability between the wires tested and between the different deactivations. Therefore, depending on the type of movement required and the periodontal conditions, orthodontists should pay attention during archwire selection.

Orthodontic brackets friction changes after clinical use: A systematic review.

BACKGROUND: To evaluate the bracket-wire friction force after clinical use. MATERIAL AND METHODS: A systematic search of several electronic databases (PubMed, Embase, Web of Science, Scopus, The Cochrane Library, Lilacs and Google Scholar) without limitations regarding publication year or language, was performed. In-vitro studies analyzing the changes in friction force of orthodontic brackets before/after their clinical use were considered. Risk of Bias was assessed with Downs and Black checklist. All methodological features that could interfere in the results were specifically described. RESULTS: Seven studies satisfied the inclusion criteria and were included in the review. All 7 studies reported at least two groups (before and after clinical use). Friction force increased after intraoral aging in most of the studies. However, there is lack of good quality evidence in this research area. CONCLUSIONS: Brackets present increased surface roughness after clinical use, and consequently increased coefficient of friction (COF) and Friction Force. Further studies are necessary to obtain more reliable results. Key words:Friction, orthodontic brackets, systematic review.

Prophylaxis protocols and their impact on bracket friction force.

OBJECTIVE: To evaluate the effect of two different prophylaxis protocols on the friction force in sliding mechanics during in vivo leveling and alignment. MATERIALS AND METHODS: The sample comprised 48 hemi-arches divided into three groups according to the prophylactic protocol adopted. Group 1 consisted of patients undergoing prophylaxis with sodium bicarbonate, group 2 consisted of patients submitted to prophylaxis with glycine, and group 3 consisted of patients without prophylaxis, as a control. All patients received hygiene instructions and, with the exception of group 3, prophylaxis was performed monthly. After 10 months, the brackets were removed from the oral cavity and submitted to friction force tests and qualitative analysis by scanning electron microscopy. Analysis of variance followed by Tukey tests was performed for intergroup comparison regarding the friction force. RESULTS: The experimental groups presented significantly smaller friction forces than the group without prophylaxis. Accordingly, qualitative analysis showed greater debris accumulation in the group without the prophylactic procedures. CONCLUSIONS: Prophylactic blasting with sodium bicarbonate or glycine can significantly prevent an increase of the friction force during sliding mechanics.

Maturational changes of the normal occlusion: A 40-year follow-up.

INTRODUCTION: In this study, we aimed to evaluate the changes in dental arch dimensions, tooth size, and incisor crowding in subjects with normal occlusion over a 40-year period. METHODS: A sample of 82 white subjects with normal occlusion evaluated in adolescence and early adulthood was recruited for a third evaluation in their sixth decade of life. The final sample included dental casts of 22 subjects (12 men, 10 women) obtained at mean ages of 13.3, 17.8, and 60.9 years. The following variables were measured on the digital casts: mesiodistal tooth size; clinical crown height; arch length, width, and perimeter; palatal depth; crowding; overjet; overbite; and curve of Spee. Interphase changes were evaluated using repeated measures analysis of variance, followed by Tukey tests (P <0.05). RESULTS: Increases of clinical crown height in the posterior teeth and incisor crowding were found. Decreases of mesiodistal tooth size, mandibular intercanine width, arch length, arch perimeter, overbite, and curve of Spee were observed. Palatal depth increased from 13 to 17 years of age. No changes were observed for overjet. CONCLUSIONS: Subjects with normal occlusion had changes in tooth size and alignment, overbite, and arch dimensions from adolescence to late adulthood.

3D analysis of effects of primary surgeries in cleft lip/palate children during the first two years of life.

This study aimed at monitoring the maxillary growth of children with cleft lip/palate in the first two years of life, and to evaluate the effects of primary surgeries on dental arch dimensions. The sample consisted of the three-dimensional digital models of 25 subjects with unilateral complete cleft lip and palate (UCLP) and 29 subjects with isolated cleft palate (CP). Maxillary arch dimensions were measured at 3 months (before lip repair), 1 year (before palate repair), and at 2 years of age. Student's ttest was used for comparison between the groups. Repeated measures ANOVA followed by Tukey's test was used to compare different treatment phases in the UCLP group. Paired ttest was used to compare different treatment phases in the CP group. P<0.05 was considered statistically significant. Decreased intercanine distance and anterior arch length were observed after lip repair in UCLP. After palate repair, maxillary dimensions increased significantly, except for the intercanine distance in UCLP and the intertuberosity distance in both groups. At the time of palate repair and at two years of age, the maxillary dimensions were very similar in both groups. It can be concluded that the maxillary arches of children with UCLP and CP changed as a result of primary surgery.

3D analysis of effects of primary surgeries in cleft lip/palate children during the first two years of life

Abstract This study aimed at monitoring the maxillary growth of children with cleft lip/palate in the first two years of life, and to evaluate the effects of primary surgeries on dental arch dimensions. The sample consisted of the three-dimensional digital models of 25 subjects with unilateral complete cleft lip and palate (UCLP) and 29 subjects with isolated cleft palate (CP). Maxillary arch dimensions were measured at 3 months (before lip repair), 1 year (before palate repair), and at 2 years of age. Student’s ttest was used for comparison between the groups. Repeated measures ANOVA followed by Tukey’s test was used to compare different treatment phases in the UCLP group. Paired ttest was used to compare different treatment phases in the CP group. P<0.05 was considered statistically significant. Decreased intercanine distance and anterior arch length were observed after lip repair in UCLP. After palate repair, maxillary dimensions increased significantly, except for the intercanine distance in UCLP and the intertuberosity distance in both groups. At the time of palate repair and at two years of age, the maxillary dimensions were very similar in both groups. It can be concluded that the maxillary arches of children with UCLP and CP changed as a result of primary surgery.

Applicability of Bolton's tooth size ratios in Mediterranean, Japanese and Japanese-Brazilian populations

Objective: The aim of this study was to determine if Bolton's tooth size ratios can be applied to Mediterranean, Japanese and Japanese-Brazilian populations. Materials and methods: The sample comprised 90 pairs of dental casts of untreated individuals with normal occlusion, divided into 3 groups according to ethnical characteristics: White (30 Mediterranean descendant subjects, with a mean age of 13.64 years), Japanese (30 subjects with Japanese ancestry, with a mean age of 15.63 years) and Japanese-Brazilian (30 Japanese-Brazilian subjects, with a mean age of 13.96 years). A digital caliper was used to measure the maxillary and mandibular mesiodistal widths from first molar to first molar on each dental cast. The anterior and overall tooth size ratios were calculated. T test was applied for comparisons between Bolton standards and the ethnical groups for anterior and overall ratios. Results: Only the Japanese-Brazilian group showed significantly greater ratios than Bolton standards. Conclusion: It was concluded that Bolton's ratios are not applicable to the Japanese-Brazilian population. Therefore, it is suggested that Bolton's ratios may not be suitable for different populations (AU)

Estudo cefalométrico comparativo da análise de Ricketts para jovens brasileiros leucodermas, melanodermas e mestiços (feodermas) com oclusão normal / Cephalometric patterns comparison of Ricketts cephalometric analysis in white, black and afrocaucasian young Brazilian descents with normal occlusion

Os diferentes grupos étnicos podem apresentar características faciais próprias e específicas que devem ser consideradas durante o tratamento ortodôntico. Sendo assim, o estudo e a padronização de variáveis cefalométricas específicas para cada etnia devem ser estabelecidos para facilitar o diagnóstico e o planejamento de tratamento entre as diferentes etnias. O objetivo do presente trabalho foi obter e comparar os valores médios de normalidade para as variáveis cefalométricas da análise de Ricketts em leucodermas, melanodermas e mestiços (feodermas) brasileiros, e avaliar o dimorfismo entre os sexos. A amostra foi constituída de 146 telerradiografias em norma lateral de indivíduos jovens brasileiros não tratados ortodonticamente, apresentando oclusão normal, divididos em três grupos: grupo 1 – 50 indivíduos leucodermas; grupo 2 – 56 indivíduos melanodermas; e grupo 3 – 40 indivíduos feodermas. A partir das telerradiografias foram obtidos os traçados cefalométricos, utilizando-se o software Dolphin Imaging 11.5 para avaliação das grandezas esqueléticas e dentoalveolares. Foram realizados os testes estatísticos: Anova a dois critérios e Ancova. Os jovens brasileiros melanodermas apresentaram a maior protrusão maxilar, incisivos mais vestibularizados, lábios mais proeminentes e maior convexidade facial em relação aos leucodermas, com diferenças estatisticamente significantes entre os três grupos. O grupo feoderma apresentou valores intermediários entre as amostras estudadas e não foi observado dimorfismo entre os sexos. Dessa maneira, afirma-se que é evidente a importância de se estabelecer padrões cefalométricos específicos para a análise de Ricketts em diferentes etnias, uma vez que os mesmos auxiliam no diagnóstico e na escolha da melhor terapia ortodôntica...

The different ethnic groups can present specific facial characteristics that would be considered during orthodontic treatment. Therefore, the study and padronizing of specific cephalometrics partners to any ethnics should be established to facilitate the diagnosis and the treatment plan between the different ethnics and standards of miscegenation. This study objected obtain and compare the mean normal values for skeletal Cephalometric variables for Ricketts analysis in caucasian, black and afrocaucasian young Brazilian descents with normal occlusion, in addition to verifying ethnic and sexual dimorphism. The sample consisted of 146 lateral cephalograms of untreated young Brazilian subjects, with normal occlusion, that were divided into three groups: group 1 – 50 caucasian subjects (25 of each gender) with an average age of 13.59 years; group 2 – 40 afro caucasian subjects (20 of each gender) with an average age of 13.08 years and group 3 – 56 black subjects (28 of each gender) with an average age of 13.40 years. Cephalometric tracings were performed, using Dolphin Imaging 11.5 program, to obtain the skeletal and dental variables. Statistical test was performed: two-way Anova and Ancova. The present study found a bimaxillary skeletal, dentoalveolar and soft tissue protrusion in black Brazilian subjects compared to white Brazilian subjects. Afrocaucasian showed intermediate values. It was not observed the presence of sexual dimorphism. It becomes evident the importance of establishing specific Cephalometric standards for Ricketts analysis in mixed ethnics, since they help to diagnose and choose the best orthodontic therapy...