Sagittal changes in lower incisors by the use of lingual arch.

OBJECTIVE: The objective of this study was to evaluate a sagittal variation on the lower incisors with the use of the lingual arch on the transition from mixed to permanent dentition. METHODS: The sample was constituted of 44 Caucasian patients (26 girls and 18 boys), divided in two groups: CG, control group, monitoring the lower arch space with no orthodontic/orthopedic treatment during the rated period (n = 14); EG, experimental group, presenting anterior inferior mild crowding and installation of the lingual arch for space maintenance (n = 30). The position of the lower incisors was analyzed on computerized cephalometric tracings performed at the beginning of the monitoring (T1) and at the end, on the permanent dentition (T2). In order to evaluate the position of the incisors it was used Tweed and Steiner measurements: IMPA, 1.NB and 1-NB. The alterations were analyzed through the "t" test for paired samples, while the differences between the groups were analyzed through the "t" test for independent samples, as for sexual dimorphism. RESULTS: The values in T2 were greater in relation to T1 for all measurements on EG (IMPA, p = 0.038; 1.NB, p = 0.007 and 1-NB, p < 0.0001). On comparing the differences (T2-T1) between CG and EG, it can be gauged differences significantly superior for measure 1.NB (p = 0.002) and 1-NB (p < 0.0001) on EG. There was no statistically significant difference between genres. CONCLUSIONS: It was concluded that the lower incisors were projected after using the lingual arch to control the space on the transition from mixed to permanent dentition, however, within acceptable standards, not having difference between genres.

Sagittal changes in lower incisors by the use of lingual arch

OBJECTIVE: The objective of this study was to evaluate a sagittal variation on the lower incisors with the use of the lingual arch on the transition from mixed to permanent dentition. METHODS: The sample was constituted of 44 Caucasian patients (26 girls and 18 boys), divided in two groups: CG, control group, monitoring the lower arch space with no orthodontic/orthopedic treatment during the rated period (n = 14); EG, experimental group, presenting anterior inferior mild crowding and installation of the lingual arch for space maintenance (n = 30). The position of the lower incisors was analyzed on computerized cephalometric tracings performed at the beginning of the monitoring (T1) and at the end, on the permanent dentition (T2). In order to evaluate the position of the incisors it was used Tweed and Steiner measurements: IMPA, 1.NB and 1-NB. The alterations were analyzed through the "t" test for paired samples, while the differences between the groups were analyzed through the "t" test for independent samples, as for sexual dimorphism. RESULTS: The values in T2 were greater in relation to T1 for all measurements on EG (IMPA, p = 0.038; 1.NB, p = 0.007 and 1-NB, p < 0.0001). On comparing the differences (T2-T1) between CG and EG, it can be gauged differences significantly superior for measure 1.NB (p = 0.002) and 1-NB (p < 0.0001) on EG. There was no statisticaly significant difference between genres. CONCLUSION: It was concluded that the lower incisors were projected after using the lingual arch to control the space on the transition from mixed to permanent dentition, however, within acceptable standards, not having difference between genres.

OBJETIVO: avaliar a alteração sagital ocorrida nos incisivos inferiores com o uso do arco lingual no período de transição da dentição mista para a permanente. MÉTODOS: a amostra foi composta por 44 pacientes leucodermas (26 meninas e 18 meninos), divididos em dois grupos: (GC) grupo controle, no qual foi efetuado monitoramento do espaço da arcada inferior, sem tratamento ortodôntico/ortopédico no período avaliado (n = 14); (GE) grupo experimental, presença de suave apinhamento anteroinferior e instalação do arco lingual para manutenção do espaço (n = 30). A posição dos incisivos inferiores foi analisada em traçados cefalométricos computadorizados realizados ao início (T1) e ao final do acompanhamento, já na dentição permanente (T2). Para avaliar a posição dos incisivos foram utilizadas as medidas das análises cefalométricas de Tweed e de Steiner: IMPA, 1.NB e 1-NB. As alterações ocorridas foram analisadas pelo teste t para amostras pareadas, enquanto as diferenças entre os grupos foram avaliadas pelo teste t para amostras independentes, bem como para o dimorfismo sexual. RESULTADOS: os valores em T2 foram maiores em relação a T1 para todas as medidas no GE (IMPA, p = 0,038; 1.NB, p = 0,007; e 1-NB, p < 0,0001). Na comparação das diferenças (T2-T1) entre o GC e GE pôde-se aferir diferenças significativamente superiores para as medidas 1.NB (p = 0,002) e 1-NB (p < 0,0001) no GE. Não houve diferença significativamente estatística entre os sexos. CONCLUSÃO: concluiu-se que os incisivos inferiores foram projetados após a utilização do arco lingual para o controle do espaço no período de transição da dentição mista para a permanente, porém a projeção esteve dentro dos padrões aceitáveis, não havendo diferença entre sexos.

Class II malocclusion with deep overbite: a sequential approach

OBJECTIVE: The aim of this case report was to evaluate the results of deep overbite correction by the segmented arch technique. METHODS: The first stage of the treatment was performed with this technique to intrude incisors and canines. A maxillary transpalatal bar and a mandibular lingual arch using 0.051-in archwire were employed associated to a facial bow, anchored primarily with occipital pull and, after molar relationship correction, changed to high pull. RESULTS: Upper incisors presented a great amount of intrusion and some palatal root inclination as programmed in the treatment plan. The skeletal mandibular response was favorable to achieve profile balance. Periapical radiograph showed rounded apex of incisor roots, expected in any orthodontic intrusion movement. CONCLUSION: The clinical results present the successful approach to deep overbite malocclusion.

OBJETIVO: o objetivo desse relato de caso clínico foi avaliar os resultados da correção da sobremordida exagerada por meio da técnica do arco segmentado. MÉTODOS: na primeira etapa do tratamento, utilizou-se essa técnica para intrusão dos incisivos e caninos. Em seguida, foram confeccionados e instalados uma barra transpalatina superior e um arco lingual inferior, ambos com fio de 0,051" de espessura, sendo associados ao arco facial ancorado, primeiramente, em tração occipital e, após a correção da chave de oclusão, foi modificada para tração parietal. RESULTADOS: os incisivos superiores apresentaram grande quantidade de intrusão com discreta inclinação palatal das raízes, conforme determinado no plano de tratamento. A resposta mandibular foi favorável, possibilitando o alcance de perfil mais harmonioso. Nas radiografias periapicais, observou-se suave arredondamento apical nas raízes dos incisivos, compatível com movimento de intrusão. CONCLUSÃO: os resultados clínicos conferem sucesso na abordagem da correção da sobremordida exagerada.

How to predict the timing of eruption of mandibular second premolars.

OBJECTIVE: To evaluate the relationship between the stages of dental formation and the timing of eruption of mandibular second premolars. MATERIALS AND METHODS: The sample comprised panoramic radiographs of 25 children, 7 to 12 years old, observed by space supervision during development of dentition. The initial radiograph (T1) was taken in the mixed dentition period and the progress radiograph (T2) close to the eruption of mandibular second premolars. The stages of dental formation were determined by the proportion between crown length and total length (CL/TL) as well by the Simpson and Kunos index. Average values between right and left sides (35, 45) were correlated to the time elapsed until dental eruption (T2-T1). Statistical analysis was performed by Pearson correlation analysis. RESULTS: The proportion CL/TL presented higher correlation index with time to eruption than the Simpson and Kunos index. The linear regression equation for prediction of timing of eruption showed high coefficient of determination, low deviation, and good accuracy. According to survival analysis, mean deviation at 95% confidence level was between 3.6 and 6.4 months. There was no difference in contralateral measurements, with high intraclass correlation coefficient for both CL/TL proportion and Simpson and Kunos index. CONCLUSIONS: More advanced stages of dental formation indicate less time until dental eruption. The strong correlation with crown length/total length proportion (CL/TL) provides a linear regression equation for prediction of the timing of eruption of mandibular second premolars.

Anatomic variability in alveolar sites for skeletal anchorage.

INTRODUCTION: Because alveolar bone is used for skeletal anchorage, the variability and reliability of its dimensions are important. METHODS: Interradicular distances, cortical thicknesses, and buccolingual spaces were measured on computed tomography images of 22 adults (13 maxillary and 9 mandibular). Intra-arch analyses were done with paired t tests; the interarch comparisons were studied with independent t tests. The intraclass correlation coefficient was calculated between corresponding units. RESULTS: Interradicular distances were greater for the molars than for the incisors, and apical distances were greater than cervical. The mandibular lingual cortical thickness was the greatest, and the maxillary buccal cortical thickness was less than the mandibular in the molar apical zones. The widest and narrowest buccolingual spaces were found at the maxillary molars and the mandibular incisors, respectively. The cross values of cortical bone thickness were wider than the axial means and they had low agreement, so they had interradicular distances on the right and left sides. CONCLUSIONS: Although interradicular distances must be carefully assessed, the molars were favorable sites for skeletal anchorage. Placing anchorage in anterior sites requires even more careful planning, including the use of computed tomography records.

Natural changes of the maxillary first molars in adolescents with skeletal Class II malocclusion.

INTRODUCTION: The objective of this study was to evaluate natural changes in maxillary posterior alveolar height (MPAH) and axial inclination of the maxillary first molars (AIMFM) in subjects with Class II malocclusion to determine the validity of predictive equations. METHODS: Longitudinal records of 30 untreated white subjects (13 girls, 17 boys) with skeletal Class II malocclusion were collected at ages 9, 12, 14, and 16 years. They had participated in the Burlington Growth Centre study, and cephalograms were analyzed with Dentofacial Planner Plus software (version 2.0, Dentofacial Planner, Toronto, Ontario, Canada). Serial means were compared with the Bonferroni post-hoc test (P <0.05). Predictive equations were obtained and studied with the analysis of agreement. RESULTS: Gradually, means of MPAH had statistical increments with sexual dimorphism from 14 to 16 years of age. A distal mean of AIMFM was found at 9 years of age that decreased significantly during growth, with sexual dimorphism between the ages of 9 and 12 years. Changes in AIMFM varied among subjects in distinct stages. Values of MPAH were predicted with high validity at intervals of 3 years or longer, whereas estimations for AIMFM were unreliable. CONCLUSIONS: In this study group, there was significant alveolar growth, with a natural tendency to upright the distal inclination at the maxillary first molars.

Soft-tissue changes during facial growth in skeletal Class II individuals.

INTRODUCTION: In orthodontic treatment, a harmonious soft-tissue profile can be difficult to achieve; the thickness of the soft tissues can vary greatly, and changes with growth and treatment can be difficult to predict. The purpose of this study was to investigate changes in the thickness and the length of the soft tissues of the nose, upper and lower lips, and chin due to growth from 6 to 16 years of age. METHODS: Cephalograms of 36 subjects (22 boys, 15 girls) with skeletal Class II malocclusions were analyzed. They participated in the Burlington Growth Study, and longitudinal records had been collected at ages 6, 9, 12, 14, and 16 years. The cephalograms were digitized and analyzed with Dentofacial Planner Plus (version 2.0; Dentofacial Software, Toronto, Ontario, Canada) software. Statistical analysis was performed with the nonparametric Friedman test, and comparisons among means were made with 1-way ANOVA software. RESULTS: All structures showed some growth at all stages. The nose showed the greatest increases in thickness and length in both sexes. There was sexual dimorphism at 16 years, with higher values for boys. Upper lips tended to reduce in the girls. Upper lip length showed slight increases, and base of the upper lip showed small increases for both sexes. The lower lip had moderate increases in all measurements, and its thickness showed sexual dimorphism at almost all ages. The soft tissues of the chin increased in both thickness and length, with no sexual dimorphism.

Three palatal arches used to correct posterior dental crossbites.

OBJECTIVE: To assess the force, resilience, and elasticity modulus produced by the Coffin appliance, "W" arch, and quad-helix made with 0.032-inch and 0.036-inch stainless steel wire. MATERIALS AND METHODS: Two groups of 15 arches were made as Coffin appliances, two groups of 15 arches were made as "W" arches, and two groups of 15 arches were made as quad-helices. One group of each appliance was formed in 0.032-inch and one group in 0.036-inch stainless steel wire. All arches (6 groups of 15 each) were submitted to compression trials in the mechanical testing machine EMIC DL-10000, simulating 5-, 8-, 10-, and 12-mm activation. The force and resilience means received a one-way ANOVA statistical analysis. RESULTS: The results showed that the mechanical properties depended on the shape of the appliance, the diameter of the wire used, and the amount of activation. CONCLUSIONS: The three appliances assessed produce appropriate forces for orthodontic treatment as long as they are correctly planned during clinical application.

Alterações histológicas e de conteúdo mineral na área de correção de fenda alveolar por distração osteogênica - in vivo / Mineral contents and histological changes of the wound healing in the bone defect area corrected with distraction osteogenesis - in vivo

O objetivo deste estudo piloto foi de avaliar as alterações de características histológicas e no conteúdo mineral na área de regeneração entre superfícies ósseas aproximadas por distração osteogênica. Foi criado cirurgicamente defeito alveolar, com 4 mm de largura, 6 mm em comprimento e 10 mm em profundidade, em três suínos jovens Sus scropha. Os distratores foram fixados no palato com a finalidade de transportar o segmento ósseo, delimitado por corticotomia, no sentido do fechamento do defeito criado. A área do defeito foi recoberta subperiostamente com membrana absorvível de colágeno e a ativação do parafuso foi iniciada com 1 mm/dia. Os animais testados foram sacrificados no 27° e 48° de cicatrização e o animal controle, que não passou por procedimento cirúrgico algum, foi sacrificado aos três meses de idade. Análise histológica e de energia dispersiva por raios-X (EDXA) revelaram diferenças das características do reparo em relação ao crescimento, observando-se a formação de pontes ósseas entre as superfícies ósseas e deposição gradativa de elementos minerais até os 48 dias de reparo. Ainda, menor densidade mineral foi observada na área de reparo.

Guideline for planning the multidisciplinary rehabilitation of dental mutilated patients

O presente estudo disponibiliza revisão de literatura concernente a pacientes com mutilações dentßrias severas, necessitando abordagem mutidisciplinar para obtenção de reabilitação oral adequada. Registros iniciais, assim como, a previsão cefalométrica e os modelos de setup, planejando o resultado final de um paciente, foram apresentados. Demonstrou-se também um método prßtico para determinar o vetor de distração osteogênica, com o objetivo de controlar melhor o processo de distração osteogênica alveolar, aumentando a qualidade estética e funcional da reabilitação. O tratamento de pacientes com mutilações dentßrias e perda óssea alveolar severa deve ser abordado por uma equipe mutidisciplinar composta por um ortodontista, um protesista, um cirurgião bucomaxilofacial e um periodontista.