A comparison of skeletal, dentoalveolar and soft tissue characteristics in white and black Brazilian subjects

OBJECTIVE: This study aimed to compare skeletal, dentoalveolar and soft tissue characteristics in white and black Brazilian subjects presenting normal occlusions. MATERIAL AND METHODS: The sample comprised the lateral cephalograms of 106 untreated Brazilian subjects with normal occlusion, divided into two groups: Group 1- 50 white subjects (25 of each gender), at a mean age of 13.17 years (standard deviation 1.07); and Group 2- 56 black subjects (28 of each gender), at a mean age of 13.24 years (standard deviation 0.56). Variables studied were obtained from several cephalometric analyses. Independent t tests were used for intergroup comparison and to determine sexual dimorphism. RESULTS: black subjects presented a more protruded maxilla and mandible, a smaller chin prominence and a greater maxillomandibular discrepancy than white subjects. Blacks presented a more horizontal craniofacial growth pattern than whites. Maxillary and mandibular incisors presented more protruded and proclined in black subjects. The nasolabial angle was larger in whites. Upper and lower lips were more protruded in blacks than in whites. CONCLUSIONS: The present study found a bimaxillary skeletal, dentoalveolar and soft tissue protrusion in black Brazilian subjects compared to white Brazilian subjects, both groups with normal occlusion. Upper and lower lips showed to be more protruded in blacks, but lip thickness was similar in both groups

Dentoalveolar changes in adults promoted by the use of auxiliary expansion arch : a CBCT study

The objective of this study was to evaluate the dentoalveolar effects and the changes of buccal cortical bone in the posterior area after expansion obtained with TMA auxiliary expansion arch in adult patients. A retrospective analysis of CT scans of 13 patients (6 male, 7 female) treated at a private clinic, taken immediately before and after the use of an auxiliary expansion archwire, was performed. Mean age at installation of TMA auxiliary expansion arch was 29.23 years (s.d.=9.13) and the mean age when the auxiliary arch was removed was 29.52 years (s.d.=9.16). Mean time of the use of the TMA auxiliary expansion arch was 0.29 years (s.d.=0.09). The patients used fixed appliances and after leveling and alignment, a TMA auxiliary expansion arch was installed, combined with the primary 0.017x0.025-inch thermoactivated Ni-Ti archwire. CBCT scans were taken at T1 and T2. Linear and angular measurements regarding the positioning of maxillary molar, premolars and canines were performed. Intragroup comparison of the variables at T1 and T2 was performed with dependent t tests. There was statistically significant transverse increase and buccal inclination of all teeth. The cortical bone showed adaptability and displacement in the same direction of tooth movement, but in smaller amounts. The auxiliary expansion arch proved to be effective to correct dentoalveolar constriction in adult patients, by increasing the buccal dental inclination with larger displacements than the bone crest adaptation and with significant transverse gains

Stability of transversal correction with hybrid maxillary expansion appliance in bone and tegumental piriformis opening in relation to bone age and maturation of the midpalatal suture

To evaluate the stability of the transverse correction with a hybrid maxillary expansion appliance in the bone and tegumental piriformis opening in relation to bone age and maturation of the midpalatal suture (MPS). 15 patients with a mean initial age

Caracterização cefalométrica da má oclusão de Classe II, 1ª. divisão, em brasileiros leucodermas

One of the main points in Orthodontic studies is the growth and development of the craniofacial structures. In this study, skeletal cephalometric characteristics of Class II, division 1 malocclusion were assessed in lateral cephalograms. The experimental sample comprised 55 white Brazilian individuals of both genders, with an ANB angle of 4.5 degrees or higher. The mean age of the subjects was 13.5 years. Steiner and McNamara Jr cephalometric analyses were used in order to evaluate the relation between angular and linear positions of the apical bases, the dental and cranial structures, comparing with the values obtained in the control group (available at Bauru Dental School-USP). The results showed that, for the experimental group, the maxilla was well positioned in relation to the cranial base. The maxillomandibular relation showed an increased overjet, which was predictable based on criteria for sample selection. The geometrical proportion of the apical bases presented a small mandible and a normal sized maxilla. The craniofacial growth pattern presented a vertical tendency. The maxillary incisors were buccally inclined and well positioned by the linear evaluation. The mandibular incisors showed marked buccal inclination and protrusion. No statistically significant difference between genders was found.Um dos principais temas em Ortodontia é o estudo do crescimento e desenvolvimento craniofacial. Neste estudo, a caracterização cefalométrica da Classe II, 1ª divisão, esquelética, foi estudada em telerradiografias em norma lateral. O grupo experimental foi composto por 55 indivíduos brasileiros leucodermas, de ambos os gêneros, apresentando um ângulo ANB maior ou igual a 4.5 graus. A idade média foi 13.5 anos. Foram utilizadas grandezas cefalométricas da análise de Steiner e McNamara Jr. para avaliar a relação entre as posições angulares e lineares das bases apicais, estruturas dentárias e destas com as estruturas cranianas, comparando com os valores obtidos de um grupo controle (disponível na Faculdade de Odontologia de Bauru-USP). Os resultados mostraram que, no grupo experimental, a maxila apresentou-se bem posicionada em relação à base craniana. A relação maxilomandibular apresentou uma sobressaliência acentuada, o que já era previsível dado o critério de seleção da amostra experimental. A proporção geométrica entre as bases apicais apresentou a mandíbula de tamanho pequeno e a maxila normal. O padrão de crescimento craniofacial apresentou uma tendência vertical. Os incisivos superiores apresentaram-se inclinados para vestibular e bem posicionados pela avaliação linear. Os incisivos inferiores mostraram-se acentuadamente inclinados para vestibular e protruídos. Não houve diferença estatisticamente significante entre os gêneros

Análise retrospectiva dos resultados dos tratamentos ortodônticos e sua relação com a estabilidade pós-contenção

OBJECTIVE: The present study was designed to retrospectively evaluate Class I malocclusion cases treated with extraction of the four first premolars, aiming to establish the relationship between the quality of orthodontic treatment outcomes and the long-term occlusal stability. MATERIAL AND METHODS: The sample comprised 94 patients of both genders, presenting Class I malocclusion, treated with extractions of the four first premolars and Edgewise mechanics. All the patients selected were whites, being 50 males and 44 females. The mean pretreatment age was 13.46 years (s.d. 1.8). The mean treatment time was 2.09 years (s.d. 0.58), the mean retention time was 1.63 years (s.d. 0.73) and the mean time of postretention evaluation was 5.31 years (s.d. 1.61). The dental casts were measured at pretreatment (T1), posttreatment (T2) and postretention (T3), by the PAR index and by the Little irregularity index, and the correction due to treatment (T1-2) and the change at the postretention period (T3-2) were calculated. The descriptive statistics was performed and the Pearson correlation coefficient was applied for the PAR and the Little indices in the total sample, among the times evaluated. RESULTS: The mean PAR reduction due to treatment was 78.54%, and 66.6%, at the postretention stage related to pretreatment stage. Significant correlations were found for the PAR index at the times evaluated, except between T1 and T2 and between T1-2 and T3. In other words, the higher the treatment correction (T1-2), the lower the posttreatment PAR index (PAR T2) will be, and the higher will be the PAR change at the postretention period (PAR T3-2). Also, the higher the posttreatment PAR score (PAR T2), the higher will be the postretention PAR score (PAR T3). CONCLUSION: It was concluded that the quality of orthodontic treatment outcomes is not related to the long-term occlusal stability.OBJETIVO: O presente estudo objetivou analisar retrospectivamente casos com má oclusão de Classe I tratados com extrações dos quatro primeiros pré-molares, visando estabelecer a relação da qualidade dos resultados dos tratamentos ortodônticos e a estabilidade em longo prazo. MATERIAL E MÉTODOS: A amostra consistiu de 94 pacientes de ambos os gêneros, apresentando má oclusão de Classe I, tratados com extrações dos quatro primeiros pré-molares e mecânica Edgewise. Todos os pacientes selecionados eram leucodermas, sendo 50 do gênero masculino e 44 do feminino. A idade inicial média foi de 13.46 anos (d.p. 1.8). O tempo de tratamento médio foi 2.09 anos (d.p. 0.58), o tempo médio de contenção foi 1.63 anos (d.p. 0.73) e o tempo médio de avaliação pós-contenção, 5.31 anos (d.p.1.61). Foram medidos, nos modelos de estudo, o índice PAR e o índice de irregularidade de Little, nas fases pré (T1), pós-tratamento (T2) e pós-contenção (T3), e calculou-se a quantidade de correção com o tratamento (T1-2) e de alteração no período pós-contenção (T3-2). Realizou-se a estatística descritiva e o coeficiente de correlação de Pearson foi aplicado entre os índices estudados e os tempos avaliados. RESULTADOS: A média de redução do índice PAR da amostra total com o tratamento foi de 78.54%, e na fase pós-contenção, de 66.6%, com relação ao inicial. Houve correlação significante para o índice PAR nos tempos estudados, exceto entre T1 e T2 e entre T1-2 e T3. Ou seja, quanto maior a correção do tratamento (T1-2), menor será o índice PAR final (PAR T2), e maior a alteração no período pós-contenção (PAR T3-2). E quanto maior o índice PAR pós-tratamento (PAR T2), maior o índice PAR pós-contenção (PAR T3). CONCLUSÃO: Concluiu-se que a qualidade dos resultados dos tratamentos ortodônticos não está relacionada à estabilidade oclusal em longo prazo

Postretention stability after orthodontic closure of maxillary interincisor diastemas

Anterior spaces may interfere with smile attractiveness and compromise dentofacial harmony. They are among the most frequent reasons why patients seek orthodontic treatment. However, midline diastema is commonly cited as a malocclusion with high relapse incidence by orthodontists. Objectives: This study aimed to evaluate the stability of maxillary interincisor diastemas closure and the association of their relapse and interincisor width, overjet, overbite and root parallelism. Material and Methods: Sample comprised 30 patients with at least a pretreatment midline diastema of 0.5 mm or greater after eruption of the maxillary permanent canines. Dental casts and panoramic radiographs were taken at pretreatment, posttreatment and postretention. Results: Before treatment, midline diastema width was 1.52 mm (SD=0.88) and right and left lateral diastema widths were 0.55 mm (SD=0.56) and 0.57 mm (SD=0.53), respectively. According to repeated measures analysis of variance, only midline diastema demonstrated significant relapse. In the overall sample the average relapse of midline diastema was 0.49 mm (SD=0.66), whilst the unstable patients showed a mean space reopening of 0.78 mm (SD=0.66). Diastema closure in the area between central and lateral incisors showed great stability. Multivariate correlation tests showed that only initial diastema width (β=0.60) and relapse of overjet (β=0.39) presented association with relapse of midline diastema. Conclusions: Midline diastema relapse was statistically significant and occurred in 60% of the sample, while lateral diastemas closure remained stable after treatment. Only initial diastema width and overjet relapse showed association with relapse of midline diastema. There was no association between relapse of interincisor diastema and root parallelism

Comparison of deflection forces of esthetic archwires combined with ceramic brackets

Coated archwires and ceramic brackets have been developed to improve facial esthetics during orthodontic treatment. However, their mechanical behavior has been shown to be different from metallic archwires and brackets. Therefore, the aim of this study was to compare the deflection forces in coated nickel-titanium (NiTi) and esthetic archwires combined with ceramic brackets. Material and Methods Non-coated NiTi (NC), rhodium coated NiTi (RC), teflon coated NiTi (TC), epoxy coated NiTi (EC), fiber-reinforced polymer (FRP), and the three different conventional brackets metal-insert polycrystalline ceramic (MI-PC), polycrystalline ceramic (PC) and monocrystalline ceramic (MC) were used. The specimens were set up on a clinical simulation device and evaluated in a Universal Testing Machine (Instron). An acrylic device, representative of the right maxillary central incisor was buccolingually activated and the unloading forces generated were recorded at 3, 2, 1 and 0.5 mm. The speed of the testing machine was 2 mm/min. ANOVA and Tukey tests were used to compare the different archwires and brackets. Results The brackets presented the following decreasing force ranking: monocrystalline, polycrystalline and polycrystalline metal-insert. The decreasing force ranking of the archwires was: rhodium coated NiTi (RC), non-coated NiTi (NC), teflon coated NiTi (TC), epoxy coated NiTi (EC) and fiber-reinforced polymer (FRP). At 3 mm of unloading the FRP archwire had a plastic deformation and produced an extremely low force in 2; 1 and 0.5 mm of unloading. Conclusion Combinations of the evaluated archwires and brackets will produce a force ranking proportional to the combination of their individual force rankings

Evaluation of the force generated by gradual deflection of 0.016-inch NiTi and stainless steel orthodontic wires in self-ligating metallic and esthetic brackets

The purpose of this study was to evaluate the deflection forces of 0.016-inch Nitinol and stainless steel orthodontic wires, in association to different self-ligating brackets. Specimens were mounted in a clinical simulation model and evaluated in a Universal Testing Machine (INSTRON 3342), using a 10N load cell and ISO 15,841, as a protocol. Eight of these models were prepared, each one for the bonding of each set of self-ligating accessories to be tested: Damon Q, Damon Clear (Ormco), In-Ovation R, In-Ovation C (GAC), BioQuick, QuickClear (Forestadent), SmartClip and Clarity SL (3M). Data were subjected to One-way ANOVA, followed by Tukey tests (P<0.05). Elastic deflection results showed that the deactivation forces increased with increase in wire deflection in the different brackets evaluated. For the different combinations, Clarity SL generated the greatest force and Damon Clear presented the lowest force when compared to the other brackets in all alloys and deflections. BioQuick and QuicKlear were those with the most similar behavior with each other. Strength values increased with gradual increase in wire deflection in all evaluated brackets. Clarity SL generated the greatest and Damon Clear the lowest force when compared to the other brackets in all alloys and deflections tested

Transition temperature range of thermally activated nickel-titanium archwires

Objectives: The shape memory resulting from the superelasticity and thermoelastic effect is the main characteristic of thermally activated NiTi archwires and is closely related to the transition temperature range (TTR). The aim of this study was to evaluate the TTR of thermally activated NiTi archwires commercially available. Material and Methods: Seven different brands of 0.019"x0.025" thermally activated nickel-titanium archwires were tested as received by differential scanning calorimetry (DSC) over the temperature range from -100°C to 150°C at 10°C/min. Results: All thermally activated NiTi archwires analyzed presented stage transformation during thermal scanning with final austenitic temperature (Af) ranging from 20.39°C to 45.42°C. Three brands of NiTi archwires presented Af close to the room temperature and, this way, do not present properties of shape memory and pseudoelasticity that are desirable in clinical applications. Conclusions: The thermally activated NiTi archwires present great variability in the TTR and the elastic parameters of each NiTi archwire should be provided by the manufacturers, to allow achievement of the best clinical performance possible

Comparison of torque expression in esthetic brackets

The objective of this work is to test the null hypothesis that there is no difference in the torque expression among different esthetic brackets. Five ceramic self-ligating brackets (In-Ovation C ? GAC, Damon Clear?Ormco, QuicKlear-Forestadent, Click-It -TP Orthodontics, Clarity SL-3M Unitek) and 4 ceramic conventional brackets (Inspire Ice?Ormco, InVu Ceramic-TP Orthodontics, Ceramic Roth?Morelli, Clarity Metal-Reinforced Ceramic Bracket-3M Unitek) were selected. Metallic Damon MX self-ligating bracket (Ormco) was used as control. Third-order moments were measured at 12º, 24º and 36º using an archwire torsion device associated with a Universal Testing Machine (EMIC DL2000), with 0.019x0.025-inch stainless steel wire. Anova followed by Tukey tests were used for intergroup comparisons. In all tested angulations the Damon Clear bracket presented the highest torque expression, followed by Clarity, Clarity SL and Damon Mx brackets, with the worst torque expression shown by the InVu Ceramic bracket. The InVu Ceramic demonstrated the largest while the Damon Clear brackets demonstrated the smallest slot height and clearance. The null hypothesis was rejected since torque expression was different among the esthetic brackets evaluated. It was also concluded that the slot height is directly related to torque expression