The use of three-dimensional cephalometric references in dentoskeletal symmetry diagnosis

OBJECTIVE: The aim of this study is to assess dentoskeletal symmetry in cone-beam computed tomography (CBCT) scans of Brazilian individuals with Angle Class I malocclusion. MATERIAL: A total of 47 patients (22 females and 25 males) aged between 11 and 16 years old (14 years) seen in a private radiology service (CIRO, Goiânia, GO, Brazil) were assessed. All CBCT scans were obtained from January, 2009 to December, 2010. Cephalometric measurements were taken by multiplanar reconstruction (axial, coronal and sagittal) using Vista Dent3DPro 2.0 (Dentsply GAC, New York, USA). Minimum, maximum, mean and standard deviation values were arranged in tables, and Student t-test was used to determine statistical significance (P < 0.05). RESULTS: Data were homogeneous, and differences between the right and left sides were not significant. CONCLUSIONS: Cephalometric measurements of Brazilian individuals with Angle Class I malocclusion can be used to establish facial symmetry and three-dimensional standard references which might be useful for orthodontic and surgical planning. .

OBJETIVO: o objetivo deste estudo é avaliar a simetria dentoesqueléticas em imagens de tomografia computadorizada de feixe cônico (TCFC) de indivíduos brasileiros com má oclusão Classe I de Angle. MÉTODOS: quarenta e sete pacientes (22 meninas e 25 meninos), com idades entre 11 e 16 anos (14 anos, em média), foram atendidos em um serviço de radiologia privado. Todas as imagens de TCFC foram adquiridas a partir de janeiro de 2009 a dezembro de 2010. Medições cefalométricas foram realizadas por reconstruções multiplanares (axial, coronal e sagital) usando o VistaDent 3D Pro 2.0 ( Dentsply GAC, Nova Iorque, EUA). O desvio-padrão mínimo, máximo e a média foram descritos em tabelas, e o teste t de Student foi utilizado para definir significância estatística (p < 0,05). RESULTADOS: os dados foram homogêneos e as diferenças entre os lados direito e esquerdo não foram significativas. CONCLUSÕES: as medidas cefalométricas de indivíduos brasileiros com má oclusão Classe I de Angle podem ser usadas para definir a simetria facial e referências de padrão tridimensional, que podem ser úteis para o planejamento ortodôntico e cirúrgico. .

Class I malocclusion with severe double rotrusion treated with first premolars extraction

Angle Class I malocclusion with bimaxillary protrusion is characterized by severe buccal tipping of incisors, which causes upper and lower lip protrusion. First premolars extraction is recommended to reduce facial convexity as a result of anterior teeth retraction, which keeps canines and first molars in key to occlusion. In order to yield orthodontic results that are compatible with ideal esthetic and cephalometric outcomes, the space closure phase needs to be carried out with overbite and incisors torque control. The majority of cases also requires maximum anchorage of posterior teeth. This case was presented to the Brazilian Board of Orthodontics and Facial Orthopedics (BBO) as a requirement for the title of certified by the BBO.

A má oclusão de Classe I de Angle com biprotrusão é caracterizada pela inclinação acentuada dos incisivos para vestibular, o que provoca a protrusão dos lábios superior e inferior. As extrações dos primeiros pré-molares têm sido indicadas para reduzir a convexidade facial com a retração dos dentes anteriores, mantendo a relação de chave de oclusão dos caninos e dos primeiros molares. Para a obtenção de resultados compatíveis com as metas estéticas e cefalométricas idealizadas para o tratamento ortodôntico, é necessário que a fase de fechamento de espaços seja realizada com controle da sobremordida e do torque dos incisivos. Na maioria dos casos, também há necessidade de se proporcionar ancoragem máxima aos dentes posteriores. O presente caso clínico foi apresentado à Diretoria do Board Brasileiro de Ortodontia e Ortopedia Facial (BBO) como parte dos requisitos para a obtenção do título de Diplomado pelo BBO.

Dental and skeletal components of Class II open bite treatment with a modified Thurow appliance

INTRODUCTION: Due to the lack of studies that distinguish between dentoalveolar and basal changes caused by the Thurow appliance, this clinical study, carried out by the School of Dentistry - State University of São Paulo/Araraquara, aimed at assessing the dental and skeletal changes induced by modified Thurow appliance. METHODS: The sample included an experimental group comprising 13 subjects aged between 7 and 10 years old, with Class II malocclusion and anterior open bite, and a control group comprising 22 subjects similar in age, sex and mandibular plane angle. Maxillary/mandibular, horizontal/vertical, dental/skeletal movements (ANS, PNS, U1, U6, Co, Go, Pog, L1, L6) were assessed, based on 14 landmarks, 8 angles (S-N-ANS, SNA, PPA, S-N-Pog, SNB, MPA, PP/MPA, ANB) and 3 linear measures (N-Me, ANS-Me, S-Go). RESULTS: Treatment caused significantly greater angle decrease between the palatal and the mandibular plane of the experimental group, primarily due to an increase in the palatal plane angle. ANB, SNA and S-N-ANS angles significantly decreased more in patients from the experimental group. PNS was superiorly remodeled. Lower face height (ANS-Me) decreased in the experimental group and increased in the control group. CONCLUSIONS: The modified Thurow appliance controlled vertical and horizontal displacements of the maxilla, rotated the maxilla and improved open bite malocclusion, decreasing lower facial height. .

INTRODUÇÃO: devido ao número reduzido de estudos que distinguem entre as mudanças dentoalveolares e ósseas produzidas pelo aparelho de Thurow, esse estudo clínico, conduzido pelo departamento de Ortodontia da Faculdade de Odontologia de Araraquara, foi proposto para avaliar as mudanças dentárias e esqueléticas induzidas pelo aparelho de Thurow modificado. MÉTODOS: a amostra incluiu um grupo experimental de 13 indivíduos, entre 7 e 10 anos de idade, com má oclusão Classe II e mordida aberta anterior, e um grupo controle de 22 indivíduos, com idades, plano mandibular e má oclusão similares. Com base em 14 pontos cefalométricos, 8 ângulos (S-N-ANS, SNA, PPA, S-N-Pog, SNB, MPA, PP/MPA, ANB) e 3 medidas lineares (N-Me, ANS-Me, S-Go), foram avaliados movimentos maxilares e mandibulares horizontais e verticais dentários e esqueléticos (ANS, PNS, U1, U6, Co, Go, Pog, L1, L6). RESULTADOS: o tratamento produziu diminuição significativamente maior no ângulo entre o plano palatino e o plano mandibular do grupo controle, devido ao aumento do ângulo do plano palatino. Os ângulos A-N-B, S-N-A e S-N-ANS diminuíram significativamente mais no grupo tratado. A PNS sofreu remodelação superior. A altura facial inferior (ANS-Me) diminuiu no grupo tratado, ao passo que aumentou no grupo controle. CONCLUSÕES: o aparelho controlou deslocamento vertical e horizontal da maxila, rotacionou a maxila para melhorar a mordida aberta e diminuiu a altura facial inferior. .

Dentoskeletal effects of Class II malocclusion treatment with the Twin Block appliance in a Brazilian sample: A prospective study

OBJECTIVE: The aim of this study was to assess the dentoskeletal effects of Class II malocclusion treatment performed with the Twin Block appliance. METHODS: The experimental group comprised 20 individuals with initial mean age of 11.76 years and was treated for a period of 1.13 years. The control group comprised 25 individuals with initial mean age of 11.39 years and a follow-up period of 1.07 years. Lateral cephalograms were taken at treatment onset and completion to assess treatment outcomes. Intergroup comparison was performed by means of the chi-square and independent t tests. RESULTS: The Twin Block appliance did not show significant effects on the maxillary component. The mandibular component showed a statistically significant increase in the effective mandibular length (Co-Gn) and significant improvement in the maxillomandibular relationship. The maxillary and mandibular dentoalveolar components presented a significant inclination of anterior teeth in both arches. The maxillary incisors were lingually tipped and retruded, while the mandibular incisors were labially tipped and protruded. CONCLUSIONS: The Twin Block appliance has great effectiveness for correction of skeletal Class II malocclusion in individuals with growth potential. Most changes are of dentoalveolar nature with a large component of tooth inclination associated with a significant skeletal effect on the mandible. .

OBJETIVO: avaliar os efeitos dentoesqueléticos do tratamento da má oclusão de Classe II com o aparelho Twin Block comparado a um grupo controle. MÉTODOS: o grupo experimental foi composto por 20 pacientes com idade inicial média de 11,76 anos e que foram tratados por um período de 1,13 anos. O grupo controle foi composto por 25 indivíduos com idade inicial média de 11,39 anos e que foram acompanhados por um período de 1,07 anos. Telerradiografias em norma lateral foram obtidas ao início e final do tratamento para avaliar as alterações decorrentes do tratamento. A comparação intergrupos foi realizada por meio do teste qui-quadrado e do teste t independente. RESULTADOS: o aparelho Twin Block não apresentou alterações significativas no componente maxilar. O componente mandibular revelou um aumento estatisticamente significativo do crescimento efetivo da mandíbula (Co-Gn) e uma melhora significativa da relação existente entre as bases ósseas. Os componentes dentoalveolar superior e inferior apresentaram um significativo componente de inclinação dos dentes anteriores em ambas as arcadas. Os incisivos superiores foram inclinados para lingual e retruídos, ao passo que os incisivos inferiores foram inclinados para vestibular e protruídos. CONCLUSÕES: o aparelho Twin Block apresenta grande efetividade na correção da má oclusão de Classe II esquelética em pacientes em fase de crescimento. A maior parte das alterações ocorridas é de natureza dentoalveolar, com um grande componente de inclinação dentária associado a um significativo efeito esquelético na mandíbula. .

Evaluation of craniofacial morphology in patients with obstructive sleep apnea using lateral cephalometry and dynamic MRI.

Context: Obstructive sleep apnea (OSA) is a potentially life-threatening disorder, characterized by repeated collapse of the upper airway during sleep with cessation of breathing. The altered mouth breathing produces morphological changes in craniofacial region. Aim: This study was designed to compare and validate the craniofacial morphological characteristics in patients with OSA using lateral cephalometry and to investigate the dentofacial characteristics of patients with OSA with respect to the obstructive sites determined by dynamic magnetic resonance imaging (MRI) to more accurately clarify the pathophysiological features. Materials and Methods: 10 patients with OSA were divided into two groups of five each according to their obstructive site determined by dynamic MRI. (1) Obstruction at the retropalatal and retroglossal region (Rp + Rg group) and (2) obstruction at the retropalatal region (Rp group). Lateral cephalogram both in upright and supine position was taken for all the subjects. In addition, dynamic MRI was performed to identify the sites of obstruction of the upper airway. Statistical analysis used: Independent t-test was performed to evaluate the significant difference in the upright cephalometric variables between the study and control group and between the two groups. The changes in skeletal and soft tissue parameters with change in posture was assessed within the study and control group by paired t test. P value of ≤0.05 was considered as statistically significant. Results: The study indicated that the first group of patients with both retropalatal and retroglossal obstruction showed signs of skeletal discrepancy that predisposed to obstruction at the retroglossal level and the soft tissue components like the soft palate and tongue that contributed to retropalatal obstruction. However, the second group of patients with only retropalatal obstruction had primarily soft tissue components associated with increased BMI that contributed to retropalatal obstruction. Conclusion: Evaluation of craniofacial morphology in OSA patients is bound to help the concerned specialist in recognizing the morphological changes induced by altered sleep pattern so as to provide the appropriate treatment.

Skeletal alterations associated with the use of bonded rapid maxillary expansion appliance

Bonded maxillary expansion appliances have been suggested to control increases in the vertical dimension of the face after rapid maxillary expansion (RME). However, there is still no consensus in the literature about its real skeletal effects. The purpose of this prospective study was to evaluate, longitudinally, the vertical and sagittal cephalometric alterations after RME performed with bonded maxillary expansion appliance. The sample consisted of 26 children, with a mean age of 8.7 years (range: 6.9-10.9 years), with posterior skeletal crossbite and indication for RME. After maxillary expansion, the bonded appliance was used as a fixed retention for 3.4 months, being replaced by a removable retention subsequently. The cephalometric study was performed onto lateral radiographs, taken before treatment was started, and again 6.3 months after removing the bonded appliance. Intra-group comparison was made using paired t test. The results showed that there were no significant sagittal skeletal changes at the end of treatment. There was a small vertical skeletal increase in five of the eleven evaluated cephalometric measures. The maxilla displaced downward, but it did not modify the facial growth patterns or the direction of the mandible growth. Under the specific conditions of this research, it may be concluded that RME with acrylic bonded maxillary expansion appliance did promote signifciant vertical or sagittal cephalometric alterations. The vertical changes found with the use of the bonded appliance were small and probably transitory, similar to those occurred with the use of banded expansion appliances.

Os aparelhos disjuntores com cobertura oclusal de acrílico têm sido sugeridos para controlar o aumento da dimensão vertical da face após a expansão rápida da maxila (ERM). Entretanto, ainda não há consenso na literatura sobre seu real efeito esquelético. O objetivo desse estudo prospectivo foi avaliar longitudinalmente as alterações esqueléticas verticais e sagitais após a ERM realizada com o aparelho disjuntor com cobertura oclusal. A amostra consistiu de 26 crianças, com idade média de 8,7 anos (variação: 6.9-10,9 anos), apresentando mordida cruzada posterior esquelética e indicação para ERM. Após a expansão maxilar, o aparelho foi utilizado como contenção fixa por 3,4 meses, sendo posteriormente substituído por uma contenção removível. O estudo cefalométrico foi realizado em telerradiografias laterais tomadas antes do início do tratamento e novamente 6,3 meses após a remoção do disjuntor. A comparação intragrupo foi feita utilizando-se o teste t pareado. Os resultados mostraram que não houve alterações esqueléticas sagitais significantes ao fim do tratamento. Houve um pequeno aumento em cinco das onze medidas cefalométricas verticais analisadas. A maxila se moveu inferiormente, porém não modificou o padrão de crescimento facial, a inclinação ou direção de crescimento mandibular. Considerando-se as condições específicas deste trabalho, pode-se concluir que a ERM realizada com o aparelho disjuntor com cobertura oclusal de acrílico não promoveu alterações esqueléticas verticais ou sagitais prejudiciais. As alterações verticais encontradas com o uso do aparelho colado foram pequenas e provavelmente transitórias, similar ao que ocorre com o uso dos aparelhos expansores bandados.

Masseter muscle thickness in different skeletal morphology: An ultrasonographic study.

Background: The thickness of the masseter muscle during relaxation and contraction states was measured by ultrasonography. Subjects were classified according to their sagittal skeletal relationships. The association between muscle thickness and facial morphology was studied. Context: Masseter muscle thickness influences the skeletal patterns. Aim: To measure and compare the thickness of the masseter muscle in individuals with skeletal class I occlusion and skeletal class II malocclusions and to correlate its relationship with craniofacial morphology. Settings and Design: The study was conducted in a hospital setup and was designed to study the thickness of the masseter muscle in different skeletal morphologies. Materials and Methods: Seventy two individuals between the ages of 18 and 25 years were divided into Group I, Group IIA and Group IIB according to their skeletal relationships. Masseter muscle thickness was measured by ultrasonography. Eight linear and six angular cephalometric measurements were assessed. Statistical Analysis Used: Analysis of variance and Pearson's correlation analysis. Results: There was a statistically significant difference in muscle thickness between subjects of different skeletal patterns. Significant positive correlation between masseter muscle thickness and posterior total face height, jarabak ratio, ramus height, mandibular length and significant negative correlations with mandibular plane angle, gonial angle and PP-MP angle were observed. Conclusion: This study indicates the strong association between the masseter muscle and skeletal morphology.

Alteraçöes ósseas da face na hanseníase Virchowiana / Facial bone changes in Virchowian Hansen's disease

Objetivando verificar a ocorrência das alteraçöes que acometem certas estruturas esqueléticas da face, foram analisados clínica e radiograficamente, num estudo longitudinal com intervalo de 3 anos, 70 hansenianos virchowianos do Hospital "Lauro de Souza Lima", com idade média de 45,41 anos e de 48,41 anos, respectivamente para o 1§ e 2§ exames. os resultados encontrados permitiram determinar as prevalências de alteraçöes, considerando o tempo de duraçäo da moléstia