In vivo assessment of the corrosion of nickel-titanium orthodontic archwires by using scanning electron microscopy and atomic force microscopy.

This study was undertaken to assess in vivo the corrosion in two commercial nickel-titanium (NiTi) orthodontic archwires removed from the oral cavity of patients using fluoride mouthwashes. Five volunteers took part in this study on the corrosion behavior of two brands of NiTi archwires (3M and AO (brand of archwire)) during use of two mouthwashes with neutral sodium fluoride 1.1%, one with acidulated fluoride 1.1%, and one with placebo and a control group. Each patient used one mouthwash in three different periods of time for 1 min a day for 30 days. The archwires were assessed with scanning electron microscopy and atomic force microscopy for qualitative and quantitative analysis. The values obtained with atomic force microscopy (AFM) were submitted to normality test, two-way analysis of variance, and Tukey's test at a significance level of 5%. The AFM images showed a gradual qualitative increase in the roughness of both types of wire between the treatments: control < placebo < neutral fluoride < acidulated fluoride. The arithmetic average of the roughness and root mean square of the roughness were similar. As for 3M archwires, only the acidulated fluoride group differed statistically from the others. As for AO archwires, the control and placebo groups did not differ from each other, but differed from the other fluoride treatments. The group using neutral fluoride also differed significantly from the acidulated fluoride group. 3M archwires were not affected by daily oral challenges. AO archwires were not affected by daily oral challenges either; their association with fluoride, either neutral or acidulated, increased their roughness.

3D Comparison of Mandibular Response to Functional Appliances: Balters Bionator versus Sander Bite Jumping.

AIM: To assess the three-dimensional (3D) maxillomandibular and dental response to Balters Bionator (BB) and the Sander Bite Jumping Appliance (SBJA) in growing patients. MATERIALS AND METHODS: Twenty-seven Class II division 1 patients (13 males, 14 females), consecutively treated with either the BB (9 females, 7 males; 10.1 ± 1.6 years) or SBJA (5 females, 6 males; 11 ± 1.9 years), were collected from a single orthodontic practice. All patients presented overjet ≥5 mm, full Class II or end-to-end molar relationship, mandibular retrusion. CBCT scans were available at T1 and after removal of the functional appliances (T2) with a mean interval of 18 months. The 3D location and direction of skeletal and dental changes with growth and treatment were quantitatively assessed. Statistical analysis was performed by means of Mann-Whitney U test (p < 0.05). RESULTS: Patients treated with the SBJA and BB orthopedic appliances presented, respectively, 4.7 mm and 4.5 mm of 3D displacement of the chin, with marked ramus growth of, respectively, 3.7 mm and 2.3 mm. While the mandible and maxilla grew downward and forward, no opening of the mandible plane was observed. Both appliances adequately controlled labial inclination of lower incisors (1.3° and 0.3°, for the SBJA and BB groups, resp.). No significant between-group differences were found for the T2-T1 changes for any of the variables, with the exception of molar displacements (significantly greater in the SBJA group than in the BB group, 1.2 mm and 0.9 mm, resp.). CONCLUSIONS: The maxillomandibular and dental growth responses to BB and SBJA therapies are characterized by vertical ramus growth and elongation of mandible that improve the maxillomandibular relationship with adequate control of lower incisor position.

Treatment timing for functional jaw orthopaedics followed by fixed appliances: a controlled long-term study.

Objective: To evaluate the role of treatment timing on long-term dentoskeletal effects of Class II treatment with removable functional appliances followed by full-fixed appliance therapy. Materials and methods: A group of 46 patients (23 females and 23 males) with Class II malocclusion treated consecutively with either Bionator or Activator, followed by fixed appliances was compared with a matched control group of 31 subjects (16 females and 15 males) with untreated Class II malocclusion. The treated sample was evaluated at T1, start of treatment (mean age: 9.9 ± 1.3 years); T2, end of functional treatment and prior to fixed appliances (mean age: 11.9 ± 1.3 years); and T3, long-term observation (mean age: 18.3 ± 2.1 years). The treated and the control samples were divided into pre-pubertal and pubertal groups according to skeletal maturity observed at the start of treatment. Statistical comparisons were performed with independent sample t-tests. Results: When treatment was initiated before puberty, Class II correction was mostly confined to the dentoalveolar changes, with significant improvements of both overjet and molar relationships. On the other hand, treatment with the outset at puberty produced significant long-term improvement of sagittal skeletal relationships, which were mainly sustained by mandibular changes. Conclusions: Treatment with removable functional appliances (Bionator or Activator) followed by full-fixed appliances produced significant skeletal long-term changes when it begins at puberty. Prepubertal Class II treatment results primarily in dentoalveolar changes.

ANKYLOGLOSSIA AND ITS INFLUENCE ON GROWTH AND DEVELOPMENT OF THE STOMATOGNATHIC SYSTEM. / A INFLUÊNCIA DA ANQUILOGLOSSIA NO CRESCIMENTO E DESENVOLVIMENTO DO SISTEMA ESTOMATOGNÁTICO.

OBJECTIVE: To critically examine the existing Brazilian and International scientific literature regarding the influence of short lingual frenulum over growth and development of the stomatognathic system, as well as how it impacts the achievement of the shape-function balance. DATA SOURCES: An electronic literature search was conducted in databases, including MEDLINE/PubMed, Google Scholar, LILACS, SciELO, and ScienceDirect, using the key words "lingual frenum" and "development", as well as their equivalents in Brazilian Portuguese. The literature search yielded 51 papers published between January 1997 and the present date; 14 articles of clinical trials were selected for meeting the inclusion criteria and were read in full. DATA SYNTHESIS: The integrated literature review supported the proposition that some malocclusions are closely related to the presence of ankyloglossia and, although very few clinical trials on this topic have been published so far, there is a consensus among authors concerning the negative effects of functional imbalances over the stomatognathic system's proper growth and development. Half of the studies found state that surgical interventions for releasing the lingual frenum are both safe and effective, concerning improvement in breastfeeding scores. Moreover, 4 out of the 14 studies included in this integrated review, report a negative influence of ankyloglossia over the orofacial muscular system. CONCLUSIONS: There is a consensus among the authors concerning the negative effects of lingual frenulum's anatomic and functional alterations over craniofacial growth and development. The opinion about the early surgical intervention, however, is not unanimous.

OBJETIVO: Avaliar criticamente os artigos existentes na literatura brasileira e estrangeira acerca da influência do frênulo lingual encurtado sobre o crescimento e desenvolvimento do sistema estomatognático, bem como sobre a conquista do equilíbrio forma-função. FONTES DE DADOS: A busca eletrônica nas bases MEDLINE/PubMed, Google Scholar, LILACS, SciELO e ScienceDirect com os descritores "freio lingual" e "desenvolvimento" e seus equivalentes em inglês resultou inicialmente em 51 resultados de trabalhos publicados entre janeiro de 1997 e a presente data. Após aplicados os critérios de exclusão, 14 artigos de estudos clínicos foram selecionados para a leitura completa. SÍNTESE DOS DADOS: A revisão integrativa da literatura ajudou a confirmar a proposição de que algumas maloclusões estão intimamente relacionadas à anquiloglossia. Ainda que a quantidade de estudos clínicos publicados até a atualidade seja pequena, há um consenso entre os autores acerca do efeito negativo de desequilíbrios funcionais sobre o crescimento e o desenvolvimento corretos do sistema estomatognático, tanto que a metade dos estudos pesquisados relata que intervenções cirúrgicas para a liberação do frênulo lingual são seguras e eficazes no que diz respeito à melhora na amamentação. Ainda, dos 14 estudos incluídos nesta revisão, 4 reportam influências negativas da anquiloglossia sobre a musculatura orofacial. CONCLUSÕES: Há um consenso entre os autores acerca dos efeitos negativos das alterações anatômico-funcionais do frênulo lingual sobre o crescimento e o desenvolvimento craniofacial, ainda que a opinião sobre a intervenção cirúrgica precoce não seja unânime.

Thin-plate spline analysis of mandibular shape changes induced by functional appliances in Class II malocclusion : A long-term evaluation.

AIMS: The purpose of this work was to evaluate the long-term morphological mandibular changes induced by functional treatment of Class II malocclusion with mandibular retrusion. METHODS: Forty patients (20 females, 20 males) with Class II malocclusion consecutively treated with either a Bionator or an Activator followed by fixed appliances were compared with a control group of 40 subjects (19 females, 21 males) with untreated Class II malocclusion. Lateral cephalograms were available at the start of treatment (T1, mean age 9.9 years), at the end of treatment with functional appliances (T2, mean age 12.2 years), and for long-term follow-up (T3, mean age 18.3 years). Mandibular shape changes were analyzed on lateral cephalograms of the subjects in both groups via thin-plate spline (TPS) analysis. Shape differences were statistically analyzed by conducting permutation tests on Goodall F statistics. RESULTS: In the long term, both the treated and control groups exhibited significant longitudinal mandibular shape changes characterized by upward and forward dislocation of point Co associated with a vertical extension in the gonial region and backward dislocation of point B. CONCLUSION: Functional appliances induced mandible's significant posterior morphogenetic rotation over the short term. The treated and control groups demonstrated similar mandibular shape over the long term.

Morphometric analysis of long-term dentoskeletal effects induced by treatment with Balters bionator.

OBJECTIVE: To evaluate the long-term effects of the standard (Class II) Balters bionator in growing patients with Class II malocclusion with mandibular retrusion by using morphometrics (thin-plate spline [TPS] analysis). MATERIALS AND METHODS: Twenty-three Class II patients (8 male, 15 female) were treated consecutively with the Balters bionator (bionator group). The sample was evaluated at T0, start of treatment; T1, end of bionator therapy; and T2, long-term observation (including fixed appliances). Mean age at the start of treatment was 10 years 2 months (T0); at posttreatment, 12 years 3 months (T1); and at long-term follow-up, 18 years 2 months (T2). The control group consisted of 22 subjects (11 male, 11 female) with untreated Class II malocclusion. Lateral cephalograms were analyzed at the three time points for all groups. TPS analysis evaluated statistical differences (permutation tests) in the craniofacial shape and size between the bionator and control groups. RESULTS: TPS analysis showed that treatment with the bionator is able to produce favorable mandibular shape changes (forward and downward displacement) that contribute significantly to the correction of the Class II dentoskeletal imbalance. These results are maintained at a long-term observation after completion of growth. The control group showed no statistically significant differences in the correction of Class II malocclusion. CONCLUSIONS: This study suggests that bionator treatment of Class II malocclusion produces favorable results over the long term with a combination of skeletal and dentoalveolar shape changes.

Correlation between transverse and vertical measurements in Brazilian growing patients, evaluated by Ricketts-Faltin frontal analysis.

INTRODUCTION: Currently in orthodontic diagnosis, besides the lateral cephalometric analysis which evaluates the anteroposterior and vertical direction, the frontal analysis may be added, leading us to another important dimension in space: the transverse dimension. OBJECTIVE: Few longitudinal samples with the frontal radiograph were published, so this cephalometric study was designed to correlate the transversal and vertical measures by Ricketts-Faltin frontal analysis into two radiographic times. METHODS: The sample consisted of 45 Brazilian children, 25 girls and 20 boys, all presenting mixed dentition, with balanced facial aesthetics and no previous orthodontic/orthopedic treatment. The initial average age (T1) was 7.7 years and the final (T2) 13.3 years. The measurements evaluated were: FTD, MxTD, NTD, LITD, MdTD (transversal), OVD and TVD (vertical). RESULTS: All transversal measures were positively correlated with a medium or high correlation with each other and the vertical measurements; only LITD presented a low correlation with these measurements. CONCLUSIONS: It was concluded that the face has interdependent regions and that this feature remains with growth.

Long-term skeletal and dental effects and treatment timing for functional appliances in Class II malocclusion.

OBJECTIVE: To analyze the long-term skeletal and dentoalveolar effects and to evaluate treatment timing of Class II treatment with functional appliances followed by fixed appliances. MATERIALS AND METHODS: A group of 40 patients (22 females and 18 males) with Class II malocclusion consecutively treated either with a Bionator or an Activator followed by fixed appliances was compared with a control group of 20 subjects (9 females and 11 males) with untreated Class II malocclusion. Lateral cephalograms were available at the start of treatment (mean age 10 years), end of treatment with functional appliances (mean age 12 years), and long-term observation (mean age 18.6 years). The treated sample also was divided into two groups according to skeletal maturity. The early-treatment group was composed of 20 subjects (12 females and 8 males) treated before puberty, while the late-treatment group included 20 subjects (10 females and 10 males) treated at puberty. Statistical comparisons were performed with analysis of variance followed by Tukey's post hoc tests. RESULTS: Significant long-term mandibular changes (Co-Gn) in the treated group (3.6 mm over the controls) were associated with improvements in the skeletal sagittal intermaxillary relationship, overjet, and molar relationship (∼3.0-3.5 mm). Treatment during the pubertal peak was able to produce significantly greater increases in total mandibular length (4.3 mm) and mandibular ramus height (3.1 mm) associated with a significant advancement of the bony chin (3.9 mm) when compared with treatment before puberty. CONCLUSION: Treatment of Class II malocclusion with functional appliances appears to be more effective at puberty.

Morphometric analysis of treatment effects of the Balters bionator in growing Class II patients.

OBJECTIVE: To investigate the effects of the standard (Class II) Balters bionator in growing patients with Class II malocclusion with mandibular retrusion by using morphometrics (thin-plate spline [TPS] analysis). MATERIALS AND METHODS: Thirty-one Class II patients (17 male and 14 female) were treated with the Balters bionator (bionator group). Mean age at the start of treatment (T0) was 10.3 years, while it was 13 years at the end of treatment (T1). Mean treatment time was 2 years and 2 months. The control group consisted of 22 subjects (14 male and 8 female) with untreated Class II malocclusion. Mean age at T0 was 10.2 years, while it was 12.2 years at T1. The observation period lasted 2 years on average. TPS analysis evaluated statistical (permutation tests) differences in the craniofacial shape and size between the bionator and control groups. RESULTS: Through TPS analysis (deformation grids) the bionator group showed significant shape changes in the mandible that could be described as a mandibular forward and downward displacement. The control group showed no statistically significant differences in the correction of Class II malocclusion. CONCLUSIONS: Bionator appliance is able to induce significant mandibular shape changes that lead to the correction of Class II dentoskeletal disharmony.

Long-term dentoskeletal effects and facial profile changes induced by bionator therapy.

OBJECTIVE: To evaluate the long-term skeletal and soft tissue changes induced by the bionator in Class II subjects. MATERIALS AND METHODS: The treatment sample consisted of 20 Class II patients (6 males and 14 females) treated consecutively with the bionator. The sample was evaluated at T1, start of treatment; T2, end of bionator therapy; and T3, long-term observation (including fixed appliances). Mean age at the start of treatment was 10 years 2 months (T1); at posttreatment, 12 years 4 months (T2); and at long-term follow-up, 18 years 11 months (CS 6). The control group consisted of 20 subjects (8 males and 12 females) with untreated Class II malocclusions. Lateral cephalograms were analyzed at the three time points for all groups. Student's t-tests were used for comparisons of starting forms, and of the T1-T2 and T1-T3 changes between groups. RESULTS: The bionator group showed significant, favorable T1-T2 changes both at the skeletal and dentoalveolar levels. The vertical dimension was increased. Significant modifications were assessed for the soft tissues as well. The treated group showed a final improvement in soft tissue pogonion of about 2.5 mm. Significant mandibular changes were noted in the treated group, with a net average 3.3 mm long-term increase in mandibular length compared with untreated Class II controls. CONCLUSIONS: This study suggests that bionator treatment of Class II malocclusion maintains favorable results over the long-term with a combination of skeletal, dentoalveolar, and soft tissue changes.

Quantification of cranial base growth during pubertal growth.

OBJECTIVE: To quantify longitudinal cranial base growth from prepubertal through postpubertal stages of development, as defined by biological indicators of individual skeletal maturity (cervical vertebral maturation - CVM) method and to determine if there is sexual dimorphism resulting from cranial base growth. DESIGN: A longitudinal cephalometric study. SETTING: The Dental School of Paulista University, Brazil. PARTICIPANTS: 36 subjects (21 females, 15 males) who were part of a longitudinal growth study and exhibited normal facial and normal vertical growth patterns. METHODS: Growth maturation of cervical vertebrae stages was assessed by two examiners independently. Cranial base measurements were carried out by one individual and repeated after one month. The growth increments over time were assessed with the one-way repeated-measures analysis of variance and post hoc Tukey multiple comparisions. RESULTS: There were no significant gender differences. There was a significant increase in all cephalometric measures between the different time points. Ba-Na showed the greatest amount of growth (mean change=2.8 mm). From T2-T3, the greatest amount of growth was found for Se-Na (mean change=3.4 mm) and the lowest for CC-Na (mean change=1.4 mm). Comparing overall changes (T1-T3) all the measurements showed statistically significantly increases (P<0.05). For all comparisons of between-stage changes the cranial base grew more than 2.0 mm during the pubertal growth. CONCLUSIONS: Linear variables of cranial base showed significant growth during pubertal stages (pre-peak, peak and post-peak). No significant differences.

Periodontal ligament hydrostatic pressure with areas of root resorption after application of a continuous torque moment.

OBJECTIVE: To evaluate the risk of root resorption, individual finite element models (FEMs) of extracted human maxillary first premolars were created, and the distribution of the hydrostatic pressure in the periodontal ligament (PDL) of these models was simulated. MATERIALS AND METHODS: A continuous lingual torque of 3 Nmm and 6 Nmm respectively was applied in vivo to the aforementioned teeth. After extraction, FEMs of these double-rooted teeth were created based on high-resolution microcomputed tomographics (micro CT, voxel size: 35 microns). This high volumetric resolution made the recognition of very small resorption lacunae possible. Scanning electron micrographs of the root surfaces were created as well. This enabled the investigation of advantages and disadvantages of the different imaging techniques from the viewpoint of the examination of root resorption. Using the FEMs, the same loading conditions as applied in vivo were simulated. RESULTS: The results of clinical examination and simulations were compared using the identical roots of the teeth. The regions that showed increased hydrostatic pressure (>0.0047 MPa) correlated well with the locations of root resorption for each tooth. Increased torque resulted in increased high-pressure areas and increased magnitudes of hydrostatic pressure, correlating with the experiments. CONCLUSION: If hydrostatic pressure exceeds typical human capillary blood pressure in the PDL, the risk of root resorption increases.

Caninos não irrompidos - alternativas de tratamento / Impacted canine - treatment alternatives

A não irrupção do dente canino permanente maxilar é um sério problema que ocorre com certa freqüência, o que justifica o diagnóstico e a intervenção assim que possível, e pode ser diagnosticada por meio do exame de palpação para sentir-se a saliência do canino em desenvolvimento e por exames radiográficos pelos quais verifica-se o posicionamento do dente. Quando não houve erupção espontânea, deverão ser usados métodos ativos, como cirurgia acompanhada de tração com dispositivos ortodônticos. Freqüentemente o canino não irrompe porque nem sempre encontra um corredor de erupção adequado para alinhar-se ao lateral e primeiro pré-molar; este podendo irromper parcialmente ou ficar mal posicionado - localizando-se ectopicamente na face vestibular ou no palato - ou não irromper e ficar intra-ósseo em posições variadas. Se houver um corredor de erupção adequado, o canino pode irromper naturalmente e, se isso não ocorrer, a exposição cirúrgica e o tracionamento devem ser utilizados para orientar sua direção de erupção. Uma visão tridimensional auxilia no diagnóstico das causas que retardam ou impedem sua erupção. Quando o espaço para o canino no arco é suficiente - e mesmo sendo tracionado ele não erupciona - pode-se estar diante de uma anquilose alveolo-dentária. Nesse último caso uma manobra para trazer o dente à sua posição seria o transplante autógeno ou reimplante antes da exodontia definitiva. O controle pós-operatório e a colaboração do paciente são importantes para o sucesso do tratamento. O paciente e seus pais devem estar cientes do prognóstico do tratamento e dos fatores de risco e conseqüências de um canino não-irrompido

Root resorption on torqued human premolars shown by tartrate-resistant acid phosphatase histochemistry and transmission electron microscopy.

OBJECTIVE: To identify clastic cells on the root surfaces of torqued human premolars. MATERIALS AND METHODS: A continuous force of 600 cNmm was applied to upper first premolars in patients 13-16 years of age by using a precise biomechanical model with superelastic wires (NiTi-SE). The 28 teeth in 14 patients were divided into five groups (control [nonmoved], and moved for either 1, 2, 3, or 4 weeks) and processed for tartrate-resistant acid phosphatase (TRAP) histochemistry and transmission electron microscopy. RESULTS: Mononuclear TRAP-positive cells appeared at 2 weeks, where as large multinucleated TRAP-positive cells were numerous at 3 and 4 weeks. Ultrastructural examination revealed many clastic cells in contact with resorption lacunae. In addition, some cementoblast-like cells appeared secreting new cementum over previously resorbed lacunae. CONCLUSIONS: In general, resorption lacunae and the number of clastic cells, which increased with the duration of the applied force, were found on the cementum surface at the pressure areas. Some signs of cementum repair were also noticed, even with the maintenance of the level of the force.

Long-term effectiveness and treatment timing for Bionator therapy.

The aim of the present investigation was to provide information about the long-term effects and optimal timing for class-II treatment with the Bionator appliance. Lateral cephalograms of 23 class-II patients treated with the Bionator were analyzed at three time periods: T1, start of treatment; T2, end of Bionator therapy; and T3, long-term observation (after completion of growth). T3 includes a phase with fixed appliances. The treated sample was divided into two groups according to their skeletal maturity as evaluated by the cervical vertebral maturation (CVM) method. The early-treated group (13 subjects) initiated treatment before the peak in mandibular growth, which occurred after completion of Bionator therapy. The late-treated group (10 subjects) received Bionator treatment during the peak. The T1-T2, T2-T3, and T1-T3 changes in the treated groups were compared with changes in control groups of untreated class-II subjects by nonparametric statistics (P < .05). The findings of the present study on Bionator therapy followed by fixed appliances indicate that this treatment protocol is more effective and stable when it is performed during the pubertal growth spurt. Optimal timing to start treatment with the Bionator is when a concavity appears at the lower borders of the second and the third cervical vertebrae (CVMS II). In the long-term, the amount of significant supplementary elongation of the mandible in subjects treated during the pubertal peak is 5.1 mm more than in the controls, and it is associated with a backward direction of condylar growth. Significant increments in mandibular ramus height also were recorded.

Correlações entre a base craniana e padrão facial em brasileiros leucodermas em normoclusão / Correlations between the cranial base and facial pattern in Brazilians leucoderms with normocclusion

Considerando-se que a base craniana é composta por estruturas que estabelecem sua deflexão e estabilidade precocemente, avaliou-se a possibilidade de usar o ângulo da Base Craniana como parâmetro de comparação entre ângulos que expressam as dimensões faciais. Método - Foi aplicada a análise de correlação de Pearsons entre o ângulo da Base Graniana, ângulo do Eixo Facial, ângulo Facial e da Dentição, através de radiografias cefalométricas de 47 jovens do sexo masculino e 53 jovens do sexo feminino, com idade média de 13 anos e 5 meses, leucodermas, com harmonia facial, oclusão normal e dentição permanente. Resultados - Aferiu-se que o ângulo da Base Craniana, o ângulo do Eixo Facial e ângulo Facial apresentaram correlação direta e estatisticamente significante, enquanto que a correlação entre o ângulo da Base Graniana e o ângulo da Dentição apresentou-se inversa e estatisticamente significante. Conclusão - Concluiu-se que o ângulo da Base Craniana é um parâmetro confiável, podendo ser utilizado na avaliação do desenvolvimento facial normal do paciente infantil.

Cirugía ortognática mandibular / Mandibular orthognathic surgery

El objetivo de este trabajo retrospectivo fue evaluar los componentes que envuelven a la Clase III, teniendo como objetivo la individualización comparativa de los resultados de la cirugía ortognática solamente de la mandíbula, en una muestra de 52 pacientes (37 de Clase III mandibular, con patrón vertical normal, y 15 de Clase III maxilo-mandibular, con el tercio inferior de la cara aumentado en el sentido vertical) utilizando el análisis cefálometrico de Ricketts, los tipos faciales de Ricketts y la Divina Proporción

Cirugía ortognática mandibular / Mandibular orthognathic surgery

El objetivo de este trabajo retrospectivo fue evaluar los componentes que envuelven a la Clase III, teniendo como objetivo la individualización comparativa de los resultados de la cirugía ortognática solamente de la mandíbula, en una muestra de 52 pacientes (37 de Clase III mandibular, con patrón vertical normal, y 15 de Clase III maxilo-mandibular, con el tercio inferior de la cara aumentado en el sentido vertical) utilizando el análisis cefálometrico de Ricketts, los tipos faciales de Ricketts y la Divina Proporción(AU)