An orthodontic-surgical approach to Class II subdivision malocclusion treatment

Despite the different orthodontic approaches to Class II subdivision malocclusions one has also to consider the skeletal components before undertaking any treatment protocol. Significant involvement of the skeletal structures may require a combined surgical orthodontic treatment, which has remained stable for more than four years, as illustrated in this case report

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

Cephalometric changes during aging in subjects with normal occlusion

Objective: To assess craniofacial changes from early adulthood to the seventh decade of life in individuals with normal occlusion. Methodology:  The sample comprised lateral cephalograms of 21 subjects with normal occlusion (11 male, 10 female), taken at 17 (T1) and 61 years of age (T2). Anteroposterior and vertical maxillomandibular relationships, and dentoalveolar and soft tissue changes were analyzed. Interphase comparisons were performed using paired t-tests. Differences between sexes, and subgroups with and without tooth loss were evaluated using t-tests (p<0.05). Results: Maxillary and mandibular anterior displacement, and facial and ramus height increased from T1 to T2. Maxillary molars showed significant mesial angulation. Maxillary and mandibular molars, and mandibular incisors developed vertically during the evaluation period. Soft tissue changes included a decrease of the nasolabial angle, upper and lower lip retrusion, decrease of upper lip thickness and increase of the lower lip and soft chin thickness. Maxillary incisor exposure by the upper lip decreased 3.6 mm in 40 years. Males presented counterclockwise rotation of the mandible, whereas females showed mandibular clockwise rotation and backward displacement of the chin. The group with tooth loss showed a greater increase of the posterior facial height and ramus height. Conclusion: We observed aging changes in dentoskeletal structures and soft tissue, as well as sexual differences for craniofacial changes during the maturational process. Subjects with multiple tooth losses showed a greater increase in mandibular ramus height

Craniofacial characteristics of Caucasian and Afro-Caucasian Brazilian subjects with normal occlusion

OBJECTIVE: The objective of this study was to compare the skeletal, dental and soft tissue characteristics of Caucasian and Afro-Caucasian Brazilian subjects with normal occlusion and to evaluate sexual dimorphism within the groups. MATERIAL AND METHODS: The sample comprised lateral cephalograms of untreated normal occlusion subjects, divided into 2 groups. Group 1 included 40 Caucasian subjects (20 of each sex), with a mean age of 13.02 years; group 2 included 40 Afro-Caucasian subjects (20 of each sex), with a mean age of 13.02 years. Groups 1 and 2 and males and females within each group were compared with t tests. RESULTS: Afro-Caucasian subjects presented greater maxillary protrusion, smaller upper anterior face height and lower posterior face height, larger upper posterior face height, greater maxillary and mandibular dentoalveolar protrusion as well as soft tissue protrusion than Caucasian subjects. The Afro-Caucasian female subjects had less mandibular protrusion and smaller total posterior facial height and upper posterior facial height than males. CONCLUSIONS: Brazilian Afro-Caucasian subjects have greater dentoalveolar and soft tissue protrusion than Brazilian Caucasian subjects, with slight sexual dimorphism in some variables

Occlusal changes secondary to temporomandibular joint conditions: a critical review and implications for clinical practice

The relationship between Temporomandibular Disorders (TMD) and malocclusion is an extremely critical issue in dentistry. Contrary to the old concept that malocclusion causes TMD, occlusal changes, especially those observed as sudden, may be secondary and reflect joint or muscle disorders due to the obvious connection between these structures and the dental occlusion. Objectives The aim of this article is to present the most commonly occlusal changes secondary to TMD. Methods The clinical presentation of these conditions is discussed. Details regarding diagnosis, treatment, and follow-up of patients presenting TMD prior or during treatment are also presented. Conclusions All plans for irreversible therapy should be preceded by a meticulous analysis of TMD signs and symptoms in such a way that patients are not submitted to irreversible treatment, based on an untrue occlusal relationship, secondary to articular and/or muscular disorders. When present, TMD symptoms must always be controlled to reestablish a “normal” occlusion and allow proper treatment strategy

Angle class II correction with MARA appliance

Objective: To assess the effects produced by the MARA appliance in the treatment of Angle’s Class II, division 1 malocclusion. Methods: The sample consisted of 44 young patients divided into two groups: The MARA Group, with initial mean age of 11.99 years, treated with the MARA appliance for an average period of 1.11 years, and the Control Group, with initial mean age of 11.63 years, monitored for a mean period of 1.18 years with no treatment. Lateral cephalograms were used to compare the groups using cephalometric variables in the initial and final phases. For these comparisons, Student’s t test was employed. Results: MARA appliance produced the following effects: Maxillary growth restriction, no change in mandibular development, improvement in maxillomandibular relationship, increased lower anterior facial height and counterclockwise rotation of the functional occlusal plane. In the upper arch, the incisors moved lingually and retruded, while the molars moved distally and tipped distally. In the lower arch, the incisors proclined and protruded, whereas the molars mesialized and tipped mesially. Finally, there was a significant reduction in overbite and overjet, with an obvious improvement in molar relationship. Conclusions: It was concluded that the MARA appliance proved effective in correcting Angle’s Class II, division 1 malocclusion while inducing skeletal changes and particularly dental changes.Objetivo: avaliar os efeitos proporcionados pelo aparelho MARA no tratamento da má oclusão de Classe II, 1ª divisão. \ud Métodos: utilizou-se uma amostra de 44 jovens, divididos em dois grupos — Grupo MARA, com idade inicial média de \ud 11,99 anos e tratado com o aparelho MARA por um período médio de 1,11 ano; e Grupo Controle, com idade inicial média \ud de 11,63 ano e observado por um período médio de 1,18 ano, sem nenhum tratamento. Utilizou-se as telerradiografias em \ud norma lateral para comparar os grupos quanto às variáveis cefalométricas das fases inicial e final. Para essas comparações, \ud aplicou-se o teste t de Student. Resultados: o aparelho MARA proporcionou efeitos na restrição do crescimento maxilar, \ud sem nenhuma alteração do desenvolvimento mandibular, com melhora da relação maxilomandibular, aumento da altura \ud facial anteroinferior e inclinação anti-horária do plano oclusal funcional. Na arcada superior, os incisivos foram lingualizados \ud e retruídos, e os molares foram distalizados e inclinados para distal. Na arcada inferior, ocorreu vestibularização e protrusão \ud nos incisivos, e mesialização e inclinação mesial dos molares. Por fim, observou-se uma redução significativa nos trespasses \ud horizontal e vertical, e uma melhora evidente na relação molar. Conclusão: pode-se concluir que o aparelho MARA foi \ud eficaz na correção da má oclusão de Classe II, 1ª divisão, promovendo alterações esqueléticas e, principalmente, dentárias

Mechanical strength of stainless steel and titanium alloy mini-implants with different diameters : an experimental laboratory study

Background: The mechanical strength of mini-implants is a critical factor due to their small diameters. Currently, it is not possible to state whether there is a relevant difference between the mechanical properties of stainless steel (SS-MIs) and titanium alloy mini-implants (TA-MIs). The objective of this study was to test the null hypothesis that there is no difference in the mechanical strength of SS-MIs and TA-MIs, and to analyze, by scanning electron microscopy (SEM), the SS-MI, and TA-MI threads resistance to morphological damage after insertion. Methods: A standardized sample of 504 SS-MIs and TA-MIs with diameters ranging from 1.2 mm to 1.8 mm was used. Torsional fracture was performed in 154 MIs. Flexural strength of 280 MIs was evaluated at 1 mm and 2 mmdeflection. The threads of 70 MIs were morphologically analyzed by scanning electron microscopy (SEM), before and after their insertion in high-density artificial bone blocks. Comparisons between SS-MIs and TA-MIs were performed with t tests or Mann-Whitney U tests. A multiple linear regression analysis was used to evaluate the influence of variables on the ranging of MI mechanical strength. Results: SS-MIs had higher fracture torque. The mean difference between the SS-MIs and TA-MIs fracture torque was of 4.09 Ncm. The MI diameter explained 90.3% of the total variation in fracture torque, while only 2.2% was explained by the metallic alloy. The SS-MI group presented a higher deformation force during the 1mm and 2mmdeflection. The mean difference between the flexural strength of SS and TA-MIs at 1 mm and 2 mm-deflection was of 18.21 N and 17.55 N, respectively. There was no noticeable morphological damage to the threads of SS-MIs and TA-MIs. Conclusions: The null hypothesis was rejected. SS-MIs were 13.2% and 20.2% more resistant to torsional fracture and deflection, respectively. The threads of the SS-MIs and TA-MIs were not damaged during the insertion and removal process. Thus, the use of SS-MI can reduce the fracture risk without increasing the MI diameter

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

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

A influência do tratamento ortopédico nas estruturas faciais de indivíduos com má oclusão de Classe II, 1&ordf; Divisão: um estudo comparativo

The purpose of this investigation was to comparatively evaluate the cephalometric changes in soft and hard tissues related to treatment of Class II, division 1 malocclusion with activator-headgear and Bionator appliances. Twenty-four individuals formed the activator-headgear group and twenty-five comprised the Bionator group, while other twenty-four presenting the same malocclusion did not receive any intervention and served as controls. Lateral headfilms were taken at the beginning and at the end of the observation period and were digitized with computerized cephalometrics; cephalometric analysis was performed and the results were submitted to statistical test. According to the methodology employed, our findings suggested that both appliances do not significantly alter the growth path, and also they were not able to modify the posterior inferior height and the sagittal and vertical position of the upper lip. The lower lip and the soft menton were only slightly modified by the orthopedic appliances, but the mentolabial sulcus showed a significant decrease in deepness compared to the control group. Of statistical significance, only the anterior inferior hard and soft facial heights and the lower lip height increased more in the treated groups.Esta pesquisa teve por objetivo avaliar, comparativamente, as alterações cefalométricas tegumentares e esqueléticas, decorrentes do tratamento das más oclusões de classe II, 1a divisão, com o ativador combinado com a ancoragem extrabucal e com o bionator. O grupo tratado com o ativador combinado com a ancoragem extrabucal foi composto por 24 indivíduos e o grupo tratado com o bionator compreendeu 25 pacientes, enquanto que outros 24 indivíduos compuseram o grupo controle, apresentando a mesma má oclusão, porém sem terem sido submetidos a nenhuma terapia ortodôntica. Obteve-se telerradiografias laterais de todos os indivíduos no início e final do período de observação que foram digitalizadas e seus traçados cefalométricos computadorizados realizados e submetidos ao teste estatístico. De acordo com a metodologia empregada, os resultados sugerem que ambos os aparelhos não foram capazes de alterar, significaticamente, o padrão de crescimento facial assim como a altura facial posterior inferior e o posicionamento sagital e vertical do lábio superior. Os aparelhos ortopédicos alteraram ligeiramente o lábio inferior e o mento tegumentar, porém o sulco mentolabial foi signifivativamente reduzido nos grupos tratados em comparação com o grupo controle. As alturas faciais esquelética e tegumentar, bem como a altura do lábio inferior foram significativamente aumentadas com a terapia ortopédica, alcançando diferença estatística em relação ao grupo controle