Temporomandibular joint in juvenile idiopathic arthritis: magnetic resonance imaging measurements and their correlation with imaging findings.

OBJECTIVE: The aim of this study was to investigate the TMJ components in patients with juvenile idiopathic arthritis (JIA) and to compare them with a control group based on magnetic resonance imaging (MRI) measurements. METHODS: This study comprised an assessment of MRI measurements of 96 temporomandibular joints (TMJ) following classification criteria set by the International League of Associations for Rheumatology (ILAR). Three measurements were considered for study: condyle excursion angle (CEA), height of articular eminence (HAE) and inclination of articular eminence (IAE). All TMJs were assessed by linear measurements made by using the OnDemand 3D software. The comparison between the groups was performed by using Mann-Whitney's test. RESULTS: Lower measurement values were found for IAE, HAE and CEA in JIA patients (P-values < 0.001, 0.005 and < 0.001, respectively). CONCLUSION: The study showed the differences in MRI measurements between JIA patients and controls, with the former with the lowest indices.

Reference standard thickness for bone plates of upper teeth: an ultra-high-resolution study using tomographic mapping / Padrão de referência de espessura para cristas ósseas de dentes superiores: um estudo de ultra-alta resolução usando mapeamento tomográfico

Objective: it is important to know the thicknesses of the alveolar bone plates (ABPs) based on the current literature for the planning and success of orthodontic treatment. However, studies have scientific limitations regarding ABPs as the image resolution is not adequate and is restricted to a few teeth or buccal face only. This study was aimed at reporting a reference standard for bone plates of upper teeth, in which 15 patients (mean age of 21.79 years) with balanced occlusion and a harmonious facial profile were evaluated using cone-beam computed tomography at a voxel size of 0.1 mm. Material and Methods: bone tissues of the cervical, middle, and apical thirds of the root (buccal and palatal), the distance between cement-enamel junction (CEJ) and alveolar bone crest (ABC), and inclination of the teeth to the palatal plane were evaluated. Paired t-test, Spearman's correlation tests, and linear regression tests were used (P < 0.05). Results: the buccal distance between the CEJ and ABC was greater than the palatal one in all pairs of teeth. Most of the bone tissues had a thickness ≤ 1 mm in the buccal face, whereas in the cervical-apical direction, the thickness was ≥ 2 mm. There is no equivalence between genders in the sample. Conclusion: the reduced buccal bone architecture around the first premolars was indicative of local gingival recessions, and the lack of gender uniformity was suggestive of individual evaluation. References of normal bone tissue determining the orthodontic limits were provided to assist in the treatment planning. (AU)

Objetivo: é importante conhecer as espessuras das cristas ósseas alveolares (COAs) com base na literatura atual para o planejamento e sucesso do tratamento ortodôntico. No entanto, os estudos apresentam limitações científicas em relação às COAs, pois a resolução da imagem não é adequada e está restrita apenas a alguns dentes ou face vestibular. Este estudo teve como objetivo descrever um padrão de referência para corticais ósseas de dentes superiores, no qual 15 pacientes (idade média de 21,79 anos) com oclusão equilibrada e perfil facial harmonioso foram avaliados por meio de tomografia computadorizada de feixe cônico no tamanho de voxel de 0,1 mm. Material e Métodos: os tecidos ósseos dos terços cervical, médio e apical da raiz (vestibular e palatina), a distância entre a junção cemento-esmalte (JCE) e a crista óssea alveolar (COA) e a inclinação dos dentes ao plano palatino foram avaliados. Foram utilizados o teste t pareado, os testes de correlação de Spearman e os testes de regressão linear (P < 0,05). Resultados: a distância vestibular entre a JEC e a COA foi maior que a palatina em todos os pares de dentes. A maioria dos tecidos ósseos apresentou espessura ≤ 1 mm na face vestibular, enquanto no sentido cérvico-apical a espessura foi ≥ 2 mm. Não há equivalência entre os gêneros na amostra. Conclusão: a arquitetura óssea vestibular reduzida ao redor dos primeiros pré-molares foi indicativa de recessões gengivais locais, e a falta de uniformidade de gênero foi sugestiva de avaliação individual. Referências de tecido ósseo normal determinando os limites ortodônticos foram fornecidas para auxiliar no planejamento do tratamento. (AU)

Reproducibility of skeletal and dental maturation parameters / Reprodutibilidade de parâmetros de maturação esqueléticos e dentários

ABSTRACT Objective: Amongst other factors, the effectiveness of orthodontic treatment in children and adolescents depends on the identification of most appropriate intervention timing, which has been traditionally based on the identification of maturational stages. There is a wide variety of radiographic methods to identify these phases, either through skeletal parameters, or dental calcification. Considering that the reliability of any given assessment tool is required to enable its safe clinical use, and aiming an appropriate implementation of these parameters in future researches, this study was performed to assess the reproducibility of radiographic growth evaluation methods. Methods: Lateral teleradiographs, hand-wrist, and panoramic radiographs of sixty-eight orthodontic patients randomly selected from files of the Orthodontics Graduation Course (Guarulhos University, Guarulhos, SP, Brazil) were evaluated by two examiners to access both intra- and inter-examiner reproducibility of the assessment methods conceived by Baccetti et al.; Fishman; Greulich and Pyle; Nolla and Demirjian et al. Results: All methods analyzed showed satisfactory intra- and inter-examiner reliability. Among those that evaluated skeletal maturity, a relatively better performance was observed for Baccetti's method. Fishman's and Greulich's parameters presented similar rates, as did Nolla's and Demirjian's. Conclusion: The assessment tools analyzed presented adequate reproducibility and might potentially be used as assessment tools to evaluate children and adolescent's craniofacial growth. Further researches could evaluate the accuracy of radiographic dental calcification parameters for the identification of craniofacial growth stages.

RESUMO Objetivo: Entre outros fatores, a efetividade do tratamento ortodôntico em crianças e adolescentes depende da identificação do momento de intervenção mais apropriado, que tem sido baseado nos estágios de maturação. Uma variedade de métodos radiográficos identifica essas fases através de parâmetros esqueléticos e da calcificação dentária. Considerando que a confiabilidade de qualquer ferramenta de avaliação é necessária para permitir seu uso clínico e aplicação segura de seus parâmetros em pesquisas futuras, este estudo acessou a reprodutibilidade de métodos radiográficos de avaliação do crescimento. Métodos: Telerradiografias laterais, radiografias carpais e panorâmicas de 68 pacientes ortodônticos randomicamente selecionados dos arquivos do Curso de Graduação em Ortodontia (Universidade de Guarulhos, Guarulhos, SP, Brasil) foram avaliadas por dois examinadores para acessar a reprodutibilidade intra e inter-examinador dos métodos de avaliação concebidos por Baccetti et al.; Fishman; Greulich e Pyle; Nolla e Demirjian et al. Resultados: Todos os métodos analisados mostraram confiabilidade intra e inter-examinador satisfatória. Dentre os que avaliam maturidade esquelética, um desempenho relativamente melhor foi observado para o método de Baccetti e colaboradores. Os parâmetros de Fishman e de Greulich e Pyle apresentaram valores similares, assim como os de Nolla e de Demirjian e colaboradores. Conclusão: As ferramentas de avaliação analisadas apresentaram reprodutibilidade adequada e podem ser utilizadas para avaliação do crescimento craniofacial de crianças e adolescentes. Pesquisas futuras poderiam avaliar a acurácia dos parâmetros radiográficos de calcificação dentária para a identificação dos estágios de crescimento craniofacial.

Effectiveness of Invisalign® aligners in the treatment of severe gingival recession: A case report.

In this report, we demonstrate the effectiveness of the InvisalignⓇ system in the treatment of severe gingival recession and bone dehiscence through torque, translation, and intrusion movements in a young woman. Cone-beam computed tomography was used to assess bone parameters and check the teeth during treatment. The root of the mandibular right central incisor, which was buccally positioned and exhibited bone dehiscence of 9.4 mm, was moved toward the center of the alveolar process by using the InvisalignⓇ system and SmartForceⓇ features. The patient was monitored by a periodontist throughout the orthodontic treatment period. Her gingival recession reduced, while the bone dehiscence reduced from 9.40 mm to 3.14 mm. Thus, movement of the root into the alveolus promoted bone neoformation and treated the gingival recession. The findings from this case suggest that orthodontic treatment using the InvisalignⓇ system, along with periodontal monitoring, can aid in the treatment of gingival recession and alveolar defects.

An in vitro assessment of the influences of different wire materials and bracket systems when correcting dental crowding.

A recently developed orthodontic wire alloy known as GUMMETAL® is claimed to deliver more physiological forces to correct dental mispositioning. However, its mechanical characteristics have not been fully characterized yet. This study aimed to determine and compare the elastic properties of different wire alloys, such as nickel-titanium (NiTi), stainless steel (SS), and GUMMETAL®, and assess their unloading forces when combined with either conventional or self-ligating brackets (CL and SL) when correcting dental crowding. All wires had a 0.016″ cross-section diameter. A three-point bending test was performed to assess the maximum deflection of each wire. Then, a subsequent analysis measured the unloading force for each wire/bracket system in a dental crowding clinical simulation device. The test was carried out in a universal testing machine with a cross-speed displacement of 0.5 mm/min. Data were recorded in different ranges and statistically evaluated using two-way analysis of variance. GUMMETAL® displayed higher unloading mean forces in SL brackets (2228.78 cN) than CL brackets (1967.38 cN) for the 1.6-3.0 deflection interval (p = 0.018). Within this interval, NiTi showed higher forces when used with CL brackets (2683.06 cN) than with SL brackets (1179.66 cN) (p < 0.0001). For the CL bracket systems, SS wires showed higher forces (2125.31 cN) in the 1.0-1.6 deflection interval than the other two wire alloys (NiTi, 1541.52 cN and GUMMETAL®, 852.65 cN) (p < 0.0001). SS wires also displayed lower forces with SL brackets (1844.01 cN) than in CL brackets (2125.31 cN) (p = 0.049). Thus, only GUMMETAL® revealed to be an optimal choice for SL brackets, whereas NiTi for CL brackets.

Análisis de flexión en alambres de níquel-titanio con y sin propiedades de transformación térmica / Bending analysis of nickel-titanium wires with and no thermal transformation properties

Objetivo: Evaluar el comportamiento de los alambres de aleación de níquel-titanio con y sin propiedades de transformación térmica en la relación carga/deflexión. Materiales y método: Para ello, 30 segmentos de alambres de níquel-titanio con calibre .014" y 30 mm de largo fueron cortados, conformando 10 segmentos de alambre Flexy NiTi de Orthometric®, 10 segmentos Flexy Copper NiTi termoactivado y 10 segmentos CuNiTi de OrmcoTM. Se usó una máquina universal de ensayos Instron® para analizar el comportamiento de carga y deflexión de los segmentos en una prueba de tres puntos, registrando las fuerzas alcanzadas en 0,5 mm: 1 mm, 2 mm y 4 mm de deflexión. Resultados: Hubo una diferencia estadísticamente significativa entre todos los alambres y entre todas las deflexiones, ya que el alambre Flexy Cooper NiTi presentó la menor carga entre todas las deflexiones analizadas. Conclusión: Se concluye que los alambres termoactivados alcanzan fuerzas más leves, lo que los hace más apropiados para alineaciones iniciales, las cuales requieren un mayor rango de deflexión(AU)

Analysis of proteoglycan expression in human dental pulp.

Proteoglycans are glycosylated proteins which have covalently attached highly anionic glycosaminoglycans. They can be located on the extracellular matrix, cell membrane or intracellular granules. To date, few studies have reported the presence of proteoglycans in human dental pulp. OBJECTIVE: The aim of this study was, therefore, to analyze the expression of lumican, versican and glypican proteoglycans in deciduous and permanent human dental pulp by real-time polymerase chain reaction (q-PCR) and immunofluorescence. DESIGN: Healthy human dental pulps were used: 13 from permanent teeth (group 1) and eight from deciduous teeth (group 2). Versican, lumican and glypican (glypican-1 to 6) gene expressions were quantitatively evaluated by real-time PCR technique, using the expression of the endogenous gene GAPDH as control. Pulp sections were submitted to immunostaining procedure with fluorescence labelling, the tissues being fixed and incubated with well-characterized monoclonal and polyclonal antibodies against proteoglycan epitopes, including anti-versican and anti-lumican. Comparisons among the groups of the quantitative scores for each proteoglycan were analyzed using the t-test and ANOVA (P < 0.05). RESULTS: The real-time PCR analysis showed expression of versican and lumican proteoglycans in the two groups, with significant predominance of lumican gene (P = 0.03). Considering the glypican genes, glypican-3 was the proteoglycan most significantly expressed in permanent pulps (P < 0.001), while glypican-2 was not expressed in this tissue. The immunofluorescence quantification exhibited no significant differences between lumican and versican among the pulps and groups. CONCLUSIONS: The lumican gene was more expressed than versican and glypican-3 was the isoform more expressed in permanent pulp compared to deciduous.

Evaluation of the skeletal maturation of cervical vertebrae with magnetic resonance imaging: a piloty study

Aims: The objective of the present study was to assess the skeletal maturation by means of three-dimensional models of the cervical vertebrae generated through segmentation of the magnetic resonance (MR) images by using medical software. Methods: Twenty MR images of the skull of male and female individuals aged between 8 and 22 years old were selected. Assessment of the images was performed by using the ITK-SNAP software, consisting of three steps: 1) vertebral segmentation; 2) three-dimensional reconstruction; and 3) classification of skeletal maturation. Two specialists in orthodontics and two specialists in dentomaxillofacial radiology assessed the images. Results: Analysis of reproducibility and repeatability were performed by using the RR method, with paired t-test also being applied to the repeatability factor together with Lin's concordance coefficient. The significance level was set at 5%. It was found that there was no difference in the inter-rater reliability (P-value = 0.625), but without statistical repeatability. Conclusions: New tools, as 3D reconstruction software, enabled us to build an effective and friendly 3D-reconstruction system for classification of the skeletal maturation stages of cervical vertebrae (AU)

Cone beam computed tomography diagnostic imaging of intra-osseous mucoepidermoid carcinoma in the mandible.

Intra-osseous mucoepidermoid carcinoma in the mandible is a rarely reported entity, comprising only 2-3% of all mucoepidermoid carcinomas. Unilocular and/or multilocular radiolucency is characteristic of mucoepidermoid carcinoma, but has a radiographic appearance similar to that of odontogenic benign and malignant tumors and thus cannot be accurately diagnosed on plain films. This article describes a case of a 36-year-old man with intra-osseous mucoepidermoid carcinoma in the left mandible. For a detailed analysis, both panoramic radiograph and cone beam computed tomograph were taken. Important clinico-pathological and imaging features, differential diagnosis and review of the literature are described. Key words:Diagnosis, Cone Beam Computed Tomography, Head and Neck Tumors.

Utilização de softwares livres para visualização e análise de imagens 3D na Odontologia / The use of free softwares for 3D image analysis in Dentistry

Softwares livres são programas computacionais, disponíveis gratuitamente na internet, fornecidos aos usuários com a liberdade de executar e repassar sem custo, ou seja, sem a necessidade de se pagar a licença de direitos autorais. Visando aumentar a percepção de Cirurgiões--Dentistas a respeito de vantagens do uso desses softwares como ferramenta de diagnóstico por meio da geração e análise de reconstruções 3D, procuramos introduzir a metodologia da análise computacional em exames de imagem processadas por softwares livres. Adicionalmente,cinco softwares de segmentação e reconstrução 3D serão apresentados.

Free softwares are computer programs, available for free in the internet, provided to the users to execute without cost, in other words, without the necessity to pay the copyright license. Aiming to enhance the dentists’ perception related to the advantages of using these softwares as diagnostic tool through 3D analysis, we are introducing methodologies of computer analysis in images processed by free softwares. Additionally, five free softwares of segmentation and 3D reconstruction are presented.

Dentoskeletal and Soft Tissue Effects in the Treatment of Class II Malocclusion with Klammt's Elastic Open Activator.

AIM: The purpose of this study was to evaluate the dentoskeletal and soft tissue effects resulting from treatment with Klammt's elastic open activator (EOA) functional orthopedic appliance in patients with Class II malocclusion characterized by mandibular deficiency. MATERIALS AND METHODS: Teleradiographs were evaluated in the lateral aspect of the initial (T1) and final (T2) orthopedic phases for 16 patients with Class II, Division 1 malocclusion. The age range was from 9 to 11.2 years, with a mean age of 9.9 years. The cephalometric points were demarcated, and cephalometric measurements were obtained by the same investigator to avoid interobserver variability. RESULTS: The EOA promoted increased lower anterior facial height (LAFH), increased effective mandibular length, clockwise rotation of the mandible, retrusion and verticalization of the upper incisors, proclination and protrusion of the lower incisors, extrusion of the upper molars, mesial movement of the lower molars and anterior projection of the lower lip. CONCLUSION: Skeletal changes characterized by an increase in mandibular length and dentoalveolar changes with an emphasis on the verticalization and retrusion of the upper incisors, proclination of the lower incisors and mesial positioning of the lower molars were key to improving the occlusal relationship and esthetic facial factors. CLINICAL SIGNIFICANCE: The EOA is well indicated in patients with Class II malocclusion due to mandibular deficiency with increased overbite, proclined upper incisors and verticalized lower incisors.

Avaliação do volume do disco articular da ATM por meio de imagens de ressonância magnética usando um software de análise de imagem / TMJ articular disc volume evaluation from magnetic resonance imaging in patients using an analysis software

O objetivo deste estudo foi verificar a variação do volume do disco articular da ATM em pacientes com DTM e em indivíduos de controle, correlacionando-a com diagnóstico de imagem de RM e com dados clínicos. Foram analisados 29 exames de ressonância magnética entre pacientes e controles, totalizando 58 ATMs, em cortes sagitais sequenciais das imagens de RM. O software livre MRIcro foi utilizado para delineamento manual dos limites anatômicos do disco articular e obtenção o volume do disco. Para analisar a correlação entre os volumes dos discos e as variáveis clínicas e por imagem, empregou-se o teste de Kruskal-Wallis. Para caracterizar e comparar as variáveis entre gênero e idade foi aplicado o Teste t de Student independente. Observou-se uma correlação entre o deslocamento do disco (p-valor = 0.001 para ATM direita e p-valor = 0.002 para ATM esquerda) e o volume do disco, que aumentou significativamente no grupo de pacientes. Não foi encontrada associação significativa entre gênero e volume dos discos direito e esquerdo (respectivamente; p-valor = 0,640 e 0,390). Concluiu-se que o volume do disco articular aumentou com a presença de desarranjo intra-articular.

The objective of this study was to measure the variation in the volume of temporomandibular joint disc in the patients with TMD compared with control individuals, in magnetic resonance images and clinical data. Twenty nine subjects have been analyzed between patients and control, totalizing 58 TMJ's in MR sequential sections. The software MRICro was used to anatomic delineation and to acquire the volume. Statistical analysis was conducted using Kruskal-Wallis test to correlate between disc volumes and clinical imaging variables. To compare the dependence on variables gender and age, Student Independence test was used. A correlation has been detected between disc displacement (p-value = 0.001 for right TMJ and p-value = 0.002 for left TMJ) and disc volume, which exhibited significant increase in patients. No significant correlation has been observed between gender and left and right disc volumes (respectively; p-value = 0,640 e 0,390). It was concluded that joint disc volume increased with the presence of internal derangement.

Bruxism in children and transverse plane of occlusion: Is there a relationship or not?

OBJECTIVE: To assess the occurrence of bruxism in deciduous dentition and a potential association between the habit and the presence or absence of posterior crossbite. METHODS: A total of 940 patient files were assessed. They were gathered from the archives of University of São Paulo City - UNICID; however, 67 patient files were dismissed for not meeting the inclusion criteria. Therefore, 873 children, males and females, comprised the study sample. They were aged between 2-6 years old and came from six different public primary schools from the east of the city of São Paulo. Data were collected through questionnaires answered by parents/guardians and by clinical examinations carried out in the school environment in order to obtain the occlusal characteristics in the transverse direction. First, a descriptive statistical analysis of all variables was performed (age, sex, race, posterior crossbite, bruxism, headache and restless sleep); then, the samples were tested by means of chi-square test with significance level set at 0.05%. A logistic regression model was applied to identify the presence of bruxism. RESULTS: The prevalence of this parafunctional habit was of 28.8%, with 84.5% of patients showing no posterior crossbite. Regarding the association of bruxism with crossbite, significant results were not found. Children with restless sleep have 2.1 times more chances of developing bruxism, whereas children with headache have 1.5 more chances. CONCLUSION: Transverse plane of occlusion was not associated with the habit of bruxism. .

INTRODUÇÃO: avaliar a prevalência de bruxismo na dentadura decídua e a associação existente entre este hábito e a presença ou não de mordida cruzada posterior. MÉTODOS: foram avaliados 940 prontuários do arquivo de documentações da Universidade Cidade de São Paulo (UNICID), sendo que 67 foram excluídos por não atenderem aos critérios de inclusão. Logo, 873 , de ambos os sexos, na faixa etária de 2 a 6 anos, procedentes de seis escolas municipais de educação infantil da zona leste da cidade de São Paulo, compuseram a amostra desse estudo. Os dados foram coletados por meio de questionários respondidos pelos pais/responsáveis e exames clínicos, realizados em ambiente escolar, para obtenção das características oclusais no sentido transversal. Primeiramente, efetuou-se uma análise estatística descritiva de todas as variáveis avaliadas na amostra (idade, sexo, raça, mordida cruzada posterior, bruxismo, dor de cabeça e sono agitado) e, em seguida, utilizou-se o teste qui-quadrado, com grau de significância de 0,05%, e um modelo de regressão logística para a presença do bruxismo. RESULTADOS: a prevalência desse hábito parafuncional foi de 28,8% do total da amostra, e 84,5% não apresentaram mordida cruzada posterior. Quanto à associação de bruxismo com a mordida cruzada posterior, não foram encontrados resultados significativos. Verificou-se, também, que as crianças com sono agitado possuem 2,1 vezes mais chances de desenvolver o bruxismo e, as com dor de cabeça, 1,5 vezes. CONCLUSÃO: o plano transversal de oclusão não apresentou relação com o hábito do bruxismo. .

The association between periodontal disease and seizure severity in refractory epilepsy patients.

PURPOSE: Periodontal diseases are common in most populations and affect people at all socioeconomic levels. Evidence suggests that patients with epilepsy actually have higher risks of dental disease and increased oral health needs, but the frequency and consequences of poor controlled seizures on dental and periodontal health have not been reported before. We aimed to assess the impact of seizure frequency on periodontal status and oral hygiene in a sample of epilepsy patients. METHODS: One hundred and nine consecutive patients treated for epilepsy at the outpatient clinic of our University Hospital were invited to take part in an oral examination to determine their periodontal disease status, together with a control group. In addition, seizure frequency and use of medication were documented. RESULTS: In logistic regression model, patients were significantly more susceptible to bad oral hygiene, gingivitis and periodontitis that controls (p<0.001); seizure frequency was significantly related to bad oral hygiene (p=0.010), gingivitis (p<0.001) and periodontitis (p<0.001). Tooth brushing habits and presence of caries were associated with oral health in patients group. CONCLUSION: Our study found a significant positive correlation between periodontal disease and seizure severity. Epilepsy patients need to focus more on their oral health and quality of oral hygiene.

Bruxism in children and transverse plane of occlusion: is there a relationship or not?

OBJECTIVE: To assess the occurrence of bruxism in deciduous dentition and a potential association between the habit and the presence or absence of posterior crossbite. METHODS: A total of 940 patient files were assessed. They were gathered from the archives of University of São Paulo City--UNICID; however, 67 patient files were dismissed for not meeting the inclusion criteria. Therefore, 873 children, males and females, comprised the study sample. They were aged between 2-6 years old and came from six different public primary schools from the east of the city of São Paulo. Data were collected through questionnaires answered by parents/guardians and by clinical examinations carried out in the school environment in order to obtain the occlusal characteristics in the transverse direction. First, a descriptive statistical analysis of all variables was performed (age, sex, race, posterior crossbite, bruxism, headache and restless sleep); then, the samples were tested by means of chi-square test with significance level set at 0.05%. A logistic regression model was applied to identify the presence of bruxism. RESULTS: The prevalence of this parafunctional habit was of 28.8%, with 84.5% of patients showing no posterior crossbite. Regarding the association of bruxism with crossbite, significant results were not found. Children with restless sleep have 2.1 times more chances of developing bruxism, whereas children with headache have 1.5 more chances. CONCLUSION: Transverse plane of occlusion was not associated with the habit of bruxism.

Bone tissue amount related to upper incisors inclination.

OBJECTIVE: To evaluate the amount of buccal and lingual supporting bone tissue of 60 upper central incisors and the relationship with their inclination. MATERIALS AND METHODS: Thirty healthy adult patients with no previous orthodontic treatment were evaluated using cone-beam computed tomography. Cross-sectional views were analyzed to check the amount of the bone tissue on the cervical (cervical buccal thickness/CBT; lingual/CLT), middle (middle buccal thickness/MBT; lingual/MLT), and apical regions (apical buccal thickness/ABT; lingual/ALT). The Pearson correlation, linear regression, and analysis of variance tests were used (P < .05). RESULTS: The values of ABT of both teeth (11, right upper central incisor; 21, left upper central incisor) were significantly increased with the increase in the angle between the axis of the upper central incisor and the palatal plane (1/PP) (tooth 11 P  =  .034; tooth 21 P  =  .009), yet without a strong linear correlation. At the buccal and lingual surfaces, the mean apical supporting bone tissue was significantly greater than the other areas, and the middle region significantly greater than the cervical (P < .001). CONCLUSIONS: For both surfaces (buccal and lingual), the amount of bone tissue in the apical region was significantly higher than the middle and cervical regions, and the middle region was significantly higher than the cervical region. In relation to the upper central incisor's inclination, the higher the 1/PP the higher was ABT. However, the coefficient values for both teeth were low.

Resin pad thickness in conventional and in plain wire lingual systems: a comparative study.

The purpose was to compare resin pad thickness in conventional and plain wire lingual systems, considering archwire form. Resin pads were smaller in plain wire for all studied teeth, except canines and second premolars; which provide better torque control. Archwire was flat/square in anterior region for plain wire system.

Association of infantile bruxism and the terminal relationships of the primary second molars

The aim of this study was to analyze the association between infantile bruxism and the terminal relationships of the primary second molars. A total of 937 pre-school children (both genders), aged from 2 to 6 years, from municipal schools in São Paulo were evaluated. In this study, a questionnaire considering the bruxism habit and the presence of headaches and/or restless sleep was answered by the parents/guardians. A clinical exam of occlusion in the anteroposterior direction (vertical plane - VP, mesial step - MS and distal step - DS) was performed by the examiners in the school environment. Student's t test, Fisher's test and a logistic regression test were applied for the statistical analysis at a significance level of 5%. The prevalence of the bruxism habit was 29.3% among the total sample. Because there was no significant difference between the sides evaluated, the left side was taken as the standard. Among those children with bruxism, 25.7% presented a mesial step terminal relationship at the primary second molars, 29.1% had DS, and 30.2% had VP. Regarding the association of the parafunctional habit with the type of terminal relationship, no significant results were found. Children who slept restlessly or suffered from headaches were verified to show a higher chance of expressing the habit (OR = 2.4 and 1.6, respectively). The prevalence of bruxism in the studied sample was 29.3%, and its association with the primary second molars' terminal relationship was not statistically significant.