Treatment effects and lip profile changes following premolars extraction treatment vs fixed functional treatment in Class II division 1 malocclusion: A randomized controlled clinical trial

ABSTRACT Objective: The objective of this two-arm parallel randomized controlled trial was to evaluate the treatment effects and lip profile changes in skeletal Class II patients subjected to premolars extraction treatment versus fixed functional treatment. Methods: Forty six subjects fulfilling inclusion criteria were randomly distributed into Group PE (mean age 13.03±1.78 years) and Group FF (mean age 12.80±1.67 years) (n=23 each). Group PE was managed by therapeutic extraction of maxillary first premolars and mandibular second premolars, followed by mini-implant-supported space closure; and Group FF, by fixed functional appliance therapy. Skeletal, dental, and soft-tissue changes were analyzed using pre and post-treatment lateral cephalograms. Data obtained from this open label study was subjected to blind statistical analysis. Results: Extraction treatment resulted in greater increase of nasolabial angle (NLA: 3.1 [95% CI 2.08, 4.19], p<0.001), significant improvement of upper lip (UL-E line: -2.91 [95% CI -3.54, -2.28], p<0.001, UL-S line: -2.50 [95% CI -2.76, -2.24], p<0.001, UL-SnPog': -2.32 [95% CI -2.90, -1.74], p<0.01) and lower lip position (LL-E line: -0.68 [95% CI -1.36, 0.00], p<0.01, LL-S line: -0.55 [95% CI -1.11, 0.02], p<0.01, and LL-SnPog': -0.64 [95% CI -1.20, -0.07], p<0.01), lip thickness (UL thickness: 2.27 [95% CI 1.79, 2.75], p<0.001; LL thickness: 0.41 [95% CI -0.16, 0.97], p<0.01), upper lip strain (UL strain: -2.68 [95% CI -3.32, -2.04], p<0.001) and soft tissue profile (N'-Sn-Pog': 2.68 [95% CI 1.87, 3.50], p<0.01). No significant difference was observed between the groups regarding skeletal changes in the maxilla and mandible, growth pattern, overjet, overbite, interincisal angle and soft tissue chin position (p>0.05). Premolar extraction treatment demonstrated significant intrusion-retraction of maxillary incisors, better maintenance of maxillary incisor inclination, and significant mandibular molar protraction; whereas functional treatment resulted in retrusive and intrusive effect on maxillary molars, marked proclination of mandibular anterior teeth, and significant extrusion of mandibular molars. Both treatment modalities had similar treatment duration. Implant failure was seen in 7.9% of cases, whereas failure of fixed functional appliance was observed in 9.09% of cases. Conclusions: Premolar extraction therapy is a better treatment modality, compared to fixed functional appliance therapy for Class II patients with moderate skeletal discrepancy, increased overjet, protruded maxillary incisors and protruded lips, as it produces better dentoalveolar response and permits greater improvement of the soft tissue profile and lip relationship.

RESUMO Objetivo: O objetivo desse estudo randomizado controlado paralelo de dois braços foi avaliar os efeitos do tratamento e as mudanças no perfil labial em pacientes esqueléticos Classe II submetidos a tratamento com extração de pré-molares (EP) versus tratamento funcional fixo (FF). Métodos: Quarenta e seis indivíduos que preencheram os critérios de inclusão foram distribuídos aleatoriamente em Grupo EP (idade média 13,03±1,78 anos) e Grupo FF (idade média 12,80±1,67 anos) (n=23 cada). O grupo EP foi tratado com extração dos primeiros pré-molares superiores e segundos pré-molares inferiores, seguida de fechamento do espaço com ancoragem em mini-implantes; e o Grupo FF, com tratamento usando aparelhos funcionais fixos. As alterações esqueléticas, dentárias e de tecidos moles foram analisadas usando cefalogramas laterais pré e pós-tratamento. Os dados obtidos desse estudo aberto foram submetidos a análise estatística cega. Resultados: O tratamento com extrações resultou em maior aumento do ângulo nasolabial (ANL: 3,1 [IC 95% 2,08, 4,19], p<0,001), melhora significativa do lábio superior (Ls-Linha E: -2,91 [IC 95% -3,54, -2,28], p<0,001, Ls-Linha S: -2,50 [IC 95% -2,76, -2,24], p<0,001, Ls-SnPog': -2,32 [IC 95% -2,90, -1,74], p<0,01) e posição do lábio inferior (Li-Linha E: -0,68 [IC 95% -1,36, 0,00], p<0,01, Li-Linha S: -0,55 [IC 95% -1,11, 0,02], p<0,01, e Li-SnPog': -0,64 [IC 95% -1,20, -0,07], p<0,01), espessura dos lábios (espessura Ls: 2,27 [IC 95% 1,79, 2,75], p<0,001; espessura Li: 0,41 [IC 95% -0,16, 0,97], p<0,01), tensão do lábio superior (tensão Ls: -2,68 [IC 95% -3,32, -2,04], p<0,001) e perfil de tecidos moles (N'-Sn-Pog': 2,68 [IC 95% 1,87, 3,50], p<0,01). Nenhuma diferença significativa foi observada entre os grupos quanto às alterações esqueléticas na maxila e mandíbula, padrão de crescimento, sobressaliência, sobremordida, ângulo interincisal e posição dos tecidos moles do mento (p>0,05). O tratamento com extração de pré-molares demonstrou significativa intrusão-retração dos incisivos superiores, melhor manutenção da inclinação dos incisivos superiores e protração significativa dos molares inferiores; enquanto o tratamento funcional resultou em efeito retrusivo e intrusivo nos molares superiores, proclinação acentuada dos dentes anteriores inferiores e extrusão significativa dos molares inferiores. Ambas as modalidades de tratamento tiveram duração de tratamento semelhante. A falha do mini-implante foi observada em 7,9% dos casos, enquanto a falha do aparelho funcional fixo foi observada em 9,09% dos casos. Conclusões: O tratamento com extração de pré-molares é uma modalidade de tratamento melhor do que os aparelhos funcionais fixos para pacientes Classe II com discrepância esquelética moderada, sobressaliência aumentada, incisivos superiores protruídos e lábios protruídos, pois produz melhor resposta dentoalveolar e permite maior melhora do perfil dos tecidos moles e relacionamento labial.

Complications encountered during Forsus Fatigue Resistant Device therapy

ABSTRACT Introduction: Fixed functional appliances are non-compliant solutions to Class II malocclusion treatment. The clinician, however, should be careful of unexpected complications during the therapy. Methods: 58 female adolescents who presented with Class II malocclusion due to deficient mandible were treated with Forsus Fatigue Resistant Device (FFRD) therapy until an overcorrection to an edge to edge incisor relationship was achieved. Results: Incisor relationship and overjet were corrected successfully in all the subjects. Twenty-two patients had a complications-free treatment, while several complications were encountered with the remaining 36 subjects. In particular, mandibular canine rotation and development of posterior crossbites were the most common complications, with percentages of 51.7% and 25.9% respectively. Other complications included the breakage and shearing of the extraoral tubes of the first molar bands, and excessive intrusion of the upper first molars. Conclusions: FFRD is an efficient appliance for treatment of Class II malocclusion; however, different complications were encountered during the appliance therapy. A focus on taking precautions and applying preventive measures can help to avoid such problems, reducing the number of emergency appointments and enhancing the treatment experience with the appliance.

RESUMO Introdução: Os aparelhos funcionais fixos são uma solução para o tratamento da má oclusão de Classe II em pacientes não colaboradores. Porém, o ortodontista deve estar ciente das complicações inesperadas decorrentes do seu uso. Métodos: Cinquenta e oito pacientes adolescentes do sexo feminino com má oclusão de Classe II por deficiência mandibular foram tratadas com o aparelho Forsus FRD até se alcançar uma sobrecorreção, com relação de topo a topo dos incisivos. Resultados: A relação entre os incisivos e a sobressaliência foram corrigidas com sucesso em todas as pacientes. Vinte e duas pacientes não apresentaram complicações durante o tratamento, enquanto as demais trinta e seis pacientes apresentaram diferentes complicações. As complicações mais comuns foram a rotação do canino inferior e o desenvolvimento de mordida cruzada posterior, com prevalência de 51,7% e 25,9%, respectivamente. As demais complicações incluíram quebra e cisalhamento dos tubos extrabucais das bandas dos primeiros molares, e intrusão excessiva dos primeiros molares superiores. Conclusões: O FRD é um aparelho eficiente para o tratamento da má oclusão de Classe II. No entanto, diferentes complicações foram encontradas durante o uso desse aparelho. O foco na tomada de precauções e em medidas preventivas pode ajudar a evitar tais complicações, reduzindo o número de consultas de emergência e melhorando a experiência do paciente no tratamento com esse aparelho.

Twenty-year clinical experience with fixed functional appliances

ABSTRACT Introduction: Considering the large number of fixed functional appliances, choosing the best device for your patient is not an easy task. Objective: To describe the development of fixed functional appliances as well as our 20-year experience working with them. Methods: Fixed functional appliances are grouped into flexible, rigid and hybrid. They are different appliances, whose action is described here. Four clinical cases will be reported with a view to illustrating the different appliances. Conclusions: Rigid fixed functional appliances provide better skeletal results than flexible and hybrid ones. Flexible and hybrid appliances have similar effects to those produced by Class II elastics. They ultimately correct Class II with dentoalveolar changes. From a biomechanical standpoint, fixed functional appliances are more recommended to treat Class II in dolichofacial patients, in comparison to Class II elastics.

RESUMO Introdução: considerando-se o grande número de aparelhos propulsores mandibulares, não é uma tarefa fácil escolher o melhor deles para o seu paciente. Objetivo: descrever o desenvolvimento desses aparelhos e a experiência clínica de vinte anos dos autores na sua utilização. Métodos: os aparelhos funcionais fixos aqui apresentados foram classificados em flexíveis, rígidos e híbridos, e o modo de ação de cada um deles foi descrito e ilustrado por meio de quatro casos clínicos. Conclusões: os aparelhos propulsores rígidos fornecem mais resultados esqueléticos do que os flexíveis e os híbridos. Esses últimos têm efeito semelhante ao uso de elásticos com direção de Classe II e, basicamente, corrigem a má oclusão de Classe II com alterações dentoalveolares. Do ponto de vista biomecânico, os propulsores fixos estão mais indicados para tratar a Classe II em pacientes dolicofaciais do que os elásticos de Classe II.

Active-treatment effects of the Forsus fatigue resistant device during comprehensive Class II correction in growing patients / 대한치과교정학회지

OBJECTIVE: To evaluate the active-treatment effects of the Forsus fatigue resistant device (Forsus) during comprehensive correction of Class II malocclusion in growing patients. METHODS: Fifty-four patients (mean age, 12.5 +/- 1.2 years) with Class II division 1 malocclusion were consecutively treated with fixed app-liances in combination with Forsus. Lateral cephalograms were analyzed at the beginning of the fixed treatment (T1), Forsus insertion (T2), its removal (T3), and end of the comprehensive therapy (T4). Statistical comparisons were carried out by repeated-measures ANOVA with Tukey's post-hoc test (p < 0.05). RESULTS: The overall therapeutic effects were mainly dentoalveolar and occurred mostly during the active treatment with Forsus (T2-T3, mean duration = 0.5 +/- 0.1 years). The overjet and overbite decreased significantly (-3.5 and -1.5 mm, respectively) and the molar relationship improved by 4.3 mm. These changes were associated with significant retroclination of the maxillary incisors (-3.1degrees), proclination and intrusion of the mandibular incisors (+5.0degrees and -1.5 mm, respectively), and mesialization of the mandibular molars (+2.0 mm). CONCLUSIONS: Forsus had mainly dentoalveolar effects and contributed largely to the overall therapeutic outcome.

Treatment of division II malocclusion in young adult with Forsus™ fatigue-resistant device.

The traditional technique for correcting class II malocclusion - involving the use of class II elastics and headgear - has been problematic due to its dependence on patient compliance. Functional orthopedic treatment seeks to correct malocclusions and harmonize the shape of the dental arch and orofacial functions. Removable functional appliances are normally very large in size, have unstable fixation, cause discomfort, exert pressure on the mucosa, reduce space for the tongue, cause difficulties in deglutition and speech, and very often affect esthetic appearance. With a fixed appliance like the Forsus™ fatigue-resistant device (FRD), as the appliance is fixed, there is less dependence on patient compliance and the remaining growth after the pubertal growth spurt can be harbored effectively. The Forsus™ FRD is not as rigid as the previous fixed functional appliances and hence is comfortable for the patients. In this case report we describe a patient at the end of the growth stage who had mandibular retrognathia and was successfully treated with the Forsus™ FRD.

Treatment of skeletal class II malocclusion using the “Forsus” appliance: A case report.

Fixed functional appliances are valuable tools introduced to assist in the correction of skeletal class II malocclusions at the deceleration stage of growth for achieving stable results. The most commonly used such appliances are the Herbst appliance and the Jasper jumper. The recent advance in the field of fixed functional appliance is the Forsus appliance. We are reporting a 16 year old patient with a skeletal class II malocclusion treated using the Forsus appliance. The appliance was worn for 4 months after the initial alignment with fixed mechanotherapy (MBT O22). The mandible was brought forward to a class I skeletal and dental relationship by the end of this treatment.

A Case Report of Growing Skeletal Class II Treated Forsus Fatigue Resistance Appliance.

Growing skeletal class II malocclusions with mandibular deficiency have been treated for more than a century with different types of functional appliances. Removable or fixed functional appliances are available to advance the mandible. Fixed functional appliances have the advantage of not requiring patient compliance. They can also be used concurrently with brackets. This case report documents the successful treatment of mild skeletal class II in late stages of puberty by using Forsus fatigue resistance appliance. The Forsus appliance is a three-piece, semi-rigid telescoping system incorporating a super-elastic nickel -titanium coil spring that can effectively brings the mandible forward in a relatively shorter treatment time. It is compatible with complete fixed orthodontic appliances and can be incorporated into preexisting appliances.