Civil liability of orthodontists and aligner manufacturers in the treatment with orthodontic aligners

ABSTRACT Introduction: The use of clear aligners as an alternative to fixed orthodontic appliances has become popular due to the aesthetic demands of adult patients seeking orthodontic treatment. However, orthodontists' lack of knowledge about the legal consequences of their activities, and the lack of solid scientific evidence raise concerns regarding civil liability in this type of treatment. Marketing campaigns of manufacturing companies often exaggerate promises of results, and ignore the lack of scientific evidence. Patients, as consumers, are protected by the Consumer Protection Code, whereas orthodontists are considered treatment providers. Therefore, they can be held liable for damage caused to patients, whether by subjective or objective fault. Objective: This article aims to identify the civil responsibilities of orthodontists and aligner manufacturing companies, by means of a literature review, providing basic legal guidance to help professionals protect themselves from possible lawsuits related to treatment with orthodontic aligners. Conclusions: The study highlights the importance of knowledge of legal notions in treatments with orthodontic aligners by orthodontists, who should legally safeguard themselves through individual written contracts, avoiding obligation of results. In addition, in cases of legal claims, it is possible that the manufacturing companies are jointly and severally liable for possible damages claimed by the patient.

RESUMO Introdução: O uso de alinhadores transparentes como alternativa aos aparelhos ortodônticos fixos tem se tornado popular, devido às demandas estéticas dos pacientes adultos em busca de tratamento ortodôntico. No entanto, a falta de conhecimento dos ortodontistas sobre as consequências jurídicas de suas atividades, e a falta de evidências científicas sólidas levantam preocupações em relação à responsabilidade civil nesse tipo de tratamento. Muitas vezes, as campanhas de marketing das empresas fabricantes exageram nas promessas de resultados e desconsideram a falta de evidências científicas. O paciente, como consumidor, é protegido pelo Código de Defesa do Consumidor, e o ortodontista é considerado um fornecedor de tratamento. Portanto, ele pode ser responsabilizado por danos causados ao paciente, seja por culpa subjetiva ou objetiva. Objetivo: Identificar, por meio de uma revisão bibliográfica, as responsabilidades civis dos ortodontistas e das empresas fabricantes de alinhadores, fornecendo orientações jurídicas básicas para ajudar os profissionais a se protegerem de possíveis demandas judiciais relacionadas ao tratamento com alinhadores ortodônticos. Conclusões: O estudo destaca a importância do conhecimento de noções jurídicas em tratamentos com alinhadores ortodônticos, devendo o profissional resguardar-se juridicamente por meio de contratos individuais por escrito, prevenindo-se de assumir uma obrigação de resultado com o paciente. Além disso, em casos de demandas judiciais, é possível que as empresas fabricantes respondam solidariamente a possíveis danos reclamados pelo paciente.

Analysis on Mandibular Anterior Tooth Intrusion with Clear Aligners / 医用生物力学

国家自然科学基金项目(11932012、81400536),上海申康医院发展中心临床创新三年行动计划(SHDC2020CR3009A),上海交通大学医工(理)交叉基金(JYJC202130)

Orthodontic aligners: between passion and science

ABSTRACT Introduction: The benefits and safety of using orthodontic aligners have been reported more by clinical experience and expert opinion than by scientific evidence. Another important aspect is that aligners are constantly evolving. It is important to obtain evidence that allows for new updates in manufacturing technology, in the development of new movement planning protocols, in the incorporation and design of attachments, and in the aid of skeletal anchorage. Methods: Evidence retrieved from six electronic databases (CINAHL, MEDLINE, EMBASE, Psych Info, the Cochrane Library and the Joanna Briggs Library) is presented by means of questions and answers. Conclusions: There is evidence that the aligners presented different levels of difficulty in performing each type of movement, with rotational and vertical movements being the most difficult to perform. Regarding perception of pain due to tooth movement, it seems to have less impact at the beginning of treatment; but dealing with more phonoarticulatory changes seems to require more treatment time in more complex cases. Aligners do not prevent the occurrence of root resorption, although the incidence and severity of resorption may be reduced, making oral hygiene easier and accepting the risk of white spots, caries and periodontal disease. Given the conflicting evidence, the release of bisphenol-A from the aligner cannot be denied. Solutions must be found to reduce the environmental impact of aligners disposal. There is an urgent need for well-designed randomized controlled trials.

RESUMO Introdução: As vantagens e desvantagens do uso de alinhadores ortodônticos têm sido reportadas com base mais na experiência clínica e opinião de experts do que em evidências científicas. Outro aspecto importante é que os alinhadores estão em processo de evolução constante. Assim, torna-se importante obter evidências recentes, que abranjam as novas atualizações na tecnologia de confecção, no desenvolvimento de novos protocolos de planejamento para as movimentações, a incorporação e desenho dos attachments e o auxílio da ancoragem esquelética. Métodos: As evidências encontradas em seis bases de dados eletrônicas (CINAHL, MEDLINE, EMBASE, Psych Info, Biblioteca Cochrane e Biblioteca Joanna Briggs) serão apresentadas por meio de perguntas e respostas. Conclusões: Há evidências de que os alinhadores apresentam diferentes níveis de dificuldade para realizar cada tipo de movimento, sendo os movimentos rotacionais e verticais os mais difíceis de serem executados. Quanto à percepção da dor causada pela movimentação dentária, parece haver menos impacto no início do tratamento, mas os alinhadores produzem mais alterações fonoarticulatórias e parecem exigir mais tempo de tratamento em casos mais complexos. Não há evidência de diferença na estabilidade pós-tratamento, e os alinhadores não impedem a ocorrência de reabsorção radicular, apesar da incidência e a gravidade da reabsorção poderem ser menores, facilitam a higiene bucal, reduzindo o risco de manchas brancas, cáries e doenças periodontais. Dada a evidência conflitante, a liberação de bisfenol-A pelo alinhador não pode ser negada. É preciso encontrar soluções que reduzam o impacto ambiental do descarte dos alinhadores. Há uma necessidade urgente de ensaios clínicos randomizados bem desenhados.

Mandibular advancement with clear aligners and functional appliances in the treatment of skeletal ClassⅡmalocclusion: a systematic review and meta-analysis / 华西口腔医学杂志

OBJECTIVES@#This study aimed to conduct a meta-analysis of the efficacy of mandibular advance clear alig-ners with traditional functional appliances as the control group.@*METHODS@#PubMed, Web of Science, Embase, Cochrane Library, China Biomedical Abstracts Database, China Knowledge Network Database, Wanfang Database, and Weipu Database were used in this study. The two groups of researchers screened the literature and extracted data based on the inclusion and exclusion criteria established by PICOS entries, and used the ROBINS-I scale for quality evaluation. Revman 5.4 and Stata 17.0 software were used for meta-analysis.@*RESULTS@#Nine clinical controlled trials were included in this study with a total sample size of 283 cases. No significant difference was found in SNA, SNB, ANB, Go-Pog, U1-SN, Overjet, and other aspects between the invisible group and the traditional group in the treatment of skeletal class Ⅱ ma-locclusion patients; there was a 0.90° difference in mandibular plane angle between the two groups; the growth of the mandibular ramus (Co-Go) in the traditional group was 1.10 mm more than that in the invisible group; the lip inclination of the lower teeth in the invisible group was better controlled, 1.94° less than that in the control group.@*CONCLUSIONS@#The invisible group can better control the lip inclination of the mandibular anterior teeth when guiding the mandible. Furthermore, the mandibular plane angle (MP-SN) can remain unchanged, but the growth of the mandibular ramus is not as good as the traditional group, and auxiliary measures should be taken to improve it in clinical practice.

Factors influencing mechanical properties of clear aligners and research progress / 口腔医学

@#In recent years, clear aligner technology has been maturing and is rapidly gaining popularity in the orthodontic market for its aesthetic and removable properties. However, despite the background of its large-scale clinical application, mechanical properties of clear aligners need to be studied in depth. This paper reviews the factors influencing mechanical properties of clear aligners and the current status of research to provide evidence-based guidance for clinical application.

Response of masticatory muscles to treatment with orthodontic aligners: a preliminary prospective longitudinal study

ABSTRACT Introduction: The emergence of orthodontic aligners has provided an aesthetic and comfortable option for orthodontic treatment. However, the encapsulated design of the aligners can influence the masticatory muscles, and might compromise safe treatment. Objective: This preliminary longitudinal study aimed to investigate whether the use of orthodontic aligners affects the biting force and myoelectric activity of the superficial masseter and anterior temporal muscles. Methods: Ten subjects participated in the study and underwent treatment during an 8-month follow-up period. The root mean square (RMS), the median power frequency (MPF) of the surface electromyography (sEMG) signals, and the biting force (kgf) were recorded and normalized relative to the pretreatment condition. The data were analyzed by repeated-measure analysis of variance (ANOVA), with the significance level set at 5%. Results: Both the superficial masseter and the anterior temporal muscles presented an increase in sEMG signal activity during the treatment, with a marked increase in the latter compared to the former (p<0.05). Moreover, a significant decrease in bite force was evidenced (p<0.05). Conclusions: This preliminary study observed that the orthodontic aligners affected the muscle recruitment pattern of masticatory muscles, and reduced biting performance during the 8-month follow-up period.

RESUMO Introdução: O surgimento dos alinhadores ortodônticos tem proporcionado uma opção estética e confortável para o tratamento ortodôntico. No entanto, o design encapsulado dos alinhadores pode influenciar os músculos mastigatórios e comprometer a segurança do tratamento. Objetivo: Este estudo longitudinal preliminar teve como objetivo investigar se o uso de alinhadores ortodônticos afeta a força de mordida e a atividade mioelétrica dos músculos masseter superficial e temporal anterior. Métodos: Dez indivíduos participaram do estudo e foram submetidos a tratamento durante um período de acompanhamento de 8 meses. A raiz quadrada média (RMS), a frequência mediana de potência (FMP) dos sinais de superfície da eletromiografia (sEMG) e a força de mordida (kgf) foram registradas e normalizadas em relação à condição de pré-tratamento. Os dados foram analisados por análise de variância para medidas repetidas (ANOVA), com nível de significância estabelecido em 5%. Resultados: Tanto o masseter superficial quanto o temporal anterior apresentaram aumento da atividade do sinal sEMG durante o tratamento, com aumento acentuado desse último em comparação ao primeiro (p<0,05). Além disso, foi evidenciada uma diminuição significativa da força de mordida (p<0,05). Conclusões: Esse estudo preliminar observou que os alinhadores ortodônticos afetaram o padrão de recrutamento muscular dos músculos mastigatórios e reduziram o desempenho da mordida durante o período de acompanhamento de oito meses.

Morphology changes of maxillary molar distalization by clear aligner therapy / Cambios de la morfología en la distalización de molares maxilares mediante terapia con alineadores transparentes

SUMMARY: To evaluate the skeletal, dento-alveolar and soft tissue morphology changes after maxillary molar distalization by clear aligner therapy and identify the significant efficacy of molar distalization,18 patients in conformity with the inclusion criteria were selected. Pre- and post-treatment Cone Beam Computed Tomography (CBCT) were examined to measure the angular and linear parameters. All subjects were completed non-extraction clear aligner treatment by distalizing molars. A paired-t test and independent-samples t-test were performed to observe the difference between before and after treatment and the difference between the first molar and second molar respectively. P-values <0.05 were considered statistically significant. Predicted movement rate was calculated by the formula: (actual movement(mm)/planned movement(mm)) x100%. Most variables of pre- and post-treatment showed no statistical difference(P<0.05), excepting SNA angle (P<0.05) and Upper lip/E-line linear (P<0.01) due to incisor retraction. The first and second molar revealed a translation movement without significant tipping and vertical movement. Clear aligners provided a high predictability (83.44 %) of distalization the maxillary first molar, and 85.14 % of the maxillary second molar. Clear aligners can effectively achieve distal displacement of molars.

RESUMEN: Se seleccionaron 18 pacientes, de acuerdo con los criterios de inclusión, para evaluar los cambios en la morfología esquelética, dentoalveolar y de los tejidos blandos después de la distalización de los molares maxilares, mediante la terapia con alineadores transparentes e así identificar la significativa eficacia de la distalización de los molares. Se examinó a través de tomografía computarizada de haz cónico (CBCT) antes y después del tratamiento para medir los parámetros angulares y lineales. Todos los sujetos completaron el tratamiento con alineadores transparentes sin extracción mediante la distalización de los molares. Se realizó una prueba t pareada y una prueba t de muestras independientes para observar la diferencia entre antes y después del tratamiento y la diferencia entre el primer molar y el segundo molar, respectivamente. Los valores de p<0,05 se consideraron estadísticamente significativos. La tasa de movimiento prevista se calculó mediante la fórmula: (movimiento real (mm)/movimiento planificado (mm)) x 100 %. La mayoría de las variables de pre y postratamiento no mostraron diferencia estadística (P<0,05), excepto el ángulo SNA (P<0,05) y el labio superior/línea E lineal (P<0,01) debido a la retracción del incisivo. El primer y segundo molar revelaron un movimiento de traslación sin inclinación significativa y movimiento vertical. Los alineadores transparentes proporcionaron una alta previsibilidad (83,44 %) de la distalización del primer molar superior y del 85,14 % del segundo molar superior. Los alineadores transparentes pueden lograr efectivamente el desplazamiento distal de los molares.

Ortodoncia Digital. Sistema de Alineación Mediante Placas Transparentes: caso clínico / Digital orthodontics. Alignment system using transparent plates: a clinical case

El tratamiento ortodóncico permite rehabilitar la función como también la estética facial y de la sonrisa. En muchos casos, esto puede realizarse sin la utilización de brackets. Las placas alineadoras realizan movimientos en las arcadas dentarias y las posibilidades y los resultados obtenidos cada vez son mejores. La utilización del sistema de alineación con placas permite que muchos pacientes, que no están dispuestos a utilizar brackets, encuentren una respuesta a sus problemas de oclusión (AU)

Space closure using aligners

ABSTRACT Introduction: Due to the search for more aesthetic and comfortable alternatives to perform orthodontic treatments and to the great technological development, orthodontic aligners have assumed great importance. More and more complex treatments have been carried out with these appliances without, however, having all aspects involved in their use being studied in depth. Its biomechanical planning requires different approaches than those used in fixed orthodontics, as the force systems involved in movements, responses and side effects are distinct, and the professional must be prepared when opting for the technique. Objective: The objective of this article is to perform an evaluation of the force systems created on the space closure with aligners, its characteristics, and problems, as well as make some suggestions to overcome the difficulties inherent to its use. Conclusion: Space closure with aligners is possible, but depends on the correct selection of the patient, in addition to requiring the proper planning of the applied forces. The use of auxiliary resources and overcorrections to address the deficiencies of the aligner systems should always be considered. Digital planning should be used as a map of the force systems that will be applied, and not just as a marketing tool, keeping in mind that determining the objectives and the way to achieve them is the responsibility of the orthodontist, and that treatment plans must be individualized for each situation, following appropriate biomechanical precepts.

RESUMO Introdução: Devido à busca por alternativas mais estéticas e confortáveis para realizar tratamentos ortodônticos e ao grande desenvolvimento tecnológico, os alinhadores ortodônticos assumiram uma grande importância. Tratamentos cada vez mais complexos vêm sendo realizados com esses dispositivos sem que, no entanto, sejam estudados em profundidade todos os aspectos envolvidos na sua utilização. Seu planejamento biomecânico requer abordagens diferentes da Ortodontia fixa, pois os sistemas de forças envolvidos nas movimentações, respostas e efeitos colaterais são distintos, e o profissional deve estar preparado ao optar por essa técnica. Objetivo: O objetivo deste artigo é fazer uma avaliação dos sistemas de forças envolvidos no fechamento de espaços com alinhadores, suas características e problemas, bem como apresentar algumas sugestões para contornar as dificuldades decorrentes de seu uso. Conclusão: O fechamento de espaços com alinhadores é possível, mas depende da correta seleção do paciente, além de exigir o adequado planejamento das forças aplicadas. O uso de recursos auxiliares e sobrecorreções para suprir as deficiências dos sistemas de alinhadores deve ser sempre considerado. O planejamento digital deve ser usado como um mapa dos sistemas de forças que serão aplicados, e não apenas como ferramenta de marketing, tendo em mente que a determinação dos objetivos e da maneira de atingi-los é de responsabilidade do ortodontista e que os planejamentos devem ser individualizados para cada situação, seguindo preceitos biomecânicos adequados.

Aligners: The Science of Clear Orthodontics

Since their inception, clear aligners have undergone multitude of advancements that aimed to make the orthodontic treatment less conspicuous. Used for moving teeth for alignment and creating healthy and beautiful smiles, like many other orthodontic appliances, clear aligners have proven to be a much more comfortable and esthetic alternative. The treatment success relies on clinicians’ knowledge and experience with the aligners, proper case selection, and the patients’ adherence to the treatment protocols. The area of exploration of this review is limited to providing an overview of the clear aligner treatment including benefits and limitations, principles and biomechanics of clear aligner treatment, materials used, methods of fabrication, and wear time. Umpteen manufacturers have emerged accounting for the increased demand by patients seeking orthodontic treatment, with the number increasing every year. It is outside the purview of this article to elucidate and compare the array of clear aligner systems available today.

Tratamiento ortodóncico en pacientes adultos combinando CA Clear Aligner con brackets linguales y microimplantes / Orthodontic treatment in adult patients combining CA Clear Aligner with lingual brackets and microimplants

Los pacientes adultos normalmente prefieren tratamiento ortodóncico invisible. La ortodoncia puedemejorar la estética, alinear y nivelar los dientes mejorando la salud periodontal, y también la posiciónde los dientes para recibir tratamiento protésico con un mejor pronóstico.

Adult patients normally prefer invisible orthodontic treatment. Orthodontics can improvethe aesthetics, align and level the teeth improvingthe periodontal health and also position the teeth to receive the prosthetic treatmentwith a better prognosis.

Maxillary expansion efficiency with clear aligner and its possible influencing factors / 中华口腔医学杂志

Objective@#To evaluate the efficiency of maxillary expansion with clear aligners and to analyze the possible influence factors.@*Methods@#Thiry-one clear aligner cases (Invisalign) with maxillary expansion were enrolled in this study. The three-dimensional (3D) digital models of pre-treatment, planned in Clincheck software and post-treatment were collected. Upper dental arch width, buccal inclination of posterior teeth, and the expansion efficiency (expansion acquired/expansion planned) were measured and calculated. The impact of factors such as planned buccal inclination, planned expansion amount, attachment, and the mode of expansion on the expansion efficiency were analyzed.@*Results@#The increases of upper arch width in canine, 1st and 2nd premolar, 1st and 2nd molar were (2.0±1.3), (2.8±1.5), (3.0±1.4), (1.8±1.0) and 0.5 (0.1, 1.1) mm, with their efficiency of 68%, 70%, 68%, 55% and 29%, respectively. The posterior teeth showed significantly more buccal inclination than the planned position (P<0.05). However, the most buccally inclined tooth detected in 1st molars was only 3.1°±3.9°. When the planned inter-molar width increase was less than 2 mm (n=15), the expansion efficiency of premolars was higher compared with those cases with the planned inter-molar width increase more than 2 mm (n=16, P<0.05). The planned buccal inclination, attachments, and the expansion mode had no significant effect on the expansion efficiency (P>0.05).@*Conclusions@#The expansion of maxillary arch with clear aligners was achieved by the buccal movement of the posterior teeth with limited buccal inclination. The efficiency of expansion declines from 1st premolars to second molars. The planned inter-molar width had a significant influence on the efficiency of premolar expansion.

Advantages and disadvantages of clear aligner treatment in orthodontics / 中华口腔医学杂志

As biomaterial and biomechanics have been growing and developing rapidly, the indication of clear aligner treatment has been broadened from simple crowding or spacing to moderate malocclusion including either extraction or non-extraction cases. Considering the advantage of its prospective three-dimensional digital planning as well as the disadvantage of limited capability of three-dimensional tooth movement control, orthodontists have to be fully aware of the characteristics and weakness of this appliance so as to choose proper indications and achieve good treatment results. Meanwhile, orthodontists also have to play an important role in modifying the three-dimensional digital plan with pouring in their clinical experience on treating cases and estimating different tooth movement efficiency in various kinds of malocclusions.

Extraction cases using clear aligners / 中华口腔医学杂志

Clear aligner treatment achieves patients' precise tooth movements through utilizing patients' digital dental models and tooth movement planning by orthodontists. Originated from the rudimentary form in 1940's, clear aligner has undergone many innovations and developments. A strict selection of extraction patients for clear aligner treatments is a prerequisite of good treatment outcomes. Orthodontists should first master the unique features of aligner biomechanics and mechanisms. For extraction patients treated with clear aligners, orthodontists should focus on anchorage control, torque control and vertical control, and strictly monitoring treatment progressions, as to achieve satisfactory treatment outcomes. With the development of dental materials and techniques, we believe that clear aligner treatment will be a mainstay of future orthodontic treatments.

Invisible orthodontics: clear aligners and customized lingual appliances / 中华口腔医学杂志

In recent years, invisible orthodontics has been one of the concerns of both orthodontists and patients. As two types of invisible orthodontics, clear aligners fit for cases that have high demand for living quality, need distalization of molars or intrusion of incisors, suffer from severe periodontitis, or that have non-abundant time for visits. While customized lingual appliances fit for cases that have high demand for aesthetics, have deep overbite or complex malocclusion, need maxillary expansion or retraction of incisors, or that have low compliance and good economic conditions. Based on aspects of clinical application, this article presents the characteristics of these two types of invisible orthodontics, in order to provide reference for individualized options according to different situations.

Ortodontia lingual x alinhadores removíveis: quando utilizar / Lingual orthodontics x removable aligners: when to use

A Ortodontia está passando por uma nova fase. Muitos pacientes adultos estão buscando o tratamento atualmente e não querem usar um aparelho convencional. Isso tem feito com que a Ortodontia desenvolva novos métodos de tratamento mais estéticos e também aprimore os já existentes. Duas modalidades de tratamento têm ganhado muito destaque nos últimos anos: a Ortodontia Lingual e os Alinhadores Removíveis. O objetivo deste artigo é descrever a técnica lingual Harmony e os alinhadores removíveis Essix e Clear Aligner, comparando-os e mostrando o tratamento de dois casos clínicos. Para o caso tratado com a técnica Lingual foi escolhido o aparelho Harmony devido à necessidade de grande controle de torque nos incisivos superiores. O caso tratado com alinhadores era um caso simples de recidiva pós-tratamento ortodôntico. Os casos clínicos descritos evidenciaram o papel importante que as novas modalidades de tratamento estético podem ter na Ortodontia contemporânea. Cabe ao ortodontista clínico conhecer essas ferramentas e as utilizar nos casos apropriados.(AU)

Orthodontics is going through a new phase. Many adult patients are currently seeking treatment and do not want to use a conventional device. This has led Orthodontics to develop new aesthetic treatment methods, as well as to improve existing ones. Two treatment modalities have gained much prominence in recent years: Lingual Orthodontics and Removable Aligners. The purpose of this article isx to describe the Harmony lingual technique and the Essix and Clear Aligner removable aligners, comparing them and showing the treatment of two clinical cases. For the case treated with the lingual technique, the Harmony device was chosen due to the need for great torque control in the upper incisors. The case treated with aligners was a simple case of orthodontic posttreatment relapse. The clinical cases described evidenced the important role that the new modalities of aesthetic treatment can have in contemporary Orthodontics. It is up to the clinical orthodontist to know these tools and use them in appropriate clinical cases.(AU)

A oportunidade de tratamentos híbridos na era da ortodontia digital / Hybrid treatment option in the digital orthodontics era

Tratamentos híbridos associados à Ortodontia Digital são uma eficiente opção para tratamentos de casos clínicos simples e complexos. O propósito desse trabalho é atualizar os ortodontistas sobre a realidade e oportunidade de realizar tratamentos combinados, assim como usufruir das últimas tecnologias da odontologia digital para modernizar sua prática ortodôntica e consultório.(AU)

Hybrid treatments associated to Digital Orthodontics are an efficient treatment option to moderate and complex clinical cases. The aim of this paper is to offer an update to orthodontists about the reality and opportunity to perform combined treatments and to present the latest dental digital technologies for their practice as well.(AU)

The combined use of computer-guided, minimally invasive, flapless corticotomy and clear aligners as a novel approach to moderate crowding: A case report / 대한치과교정학회지

The aim of this case report was to describe an innovative orthodontic treatment method that combined surgical and orthodontic techniques. The novel method was used to achieve a positive result in a case of moderate crowding by employing a computer-guided piezocision procedure followed by the use of clear aligners. A 23-year-old woman had a malocclusion with moderate crowding. Her periodontal indices, oral health-related quality of life (OHRQoL), and treatment time were evaluated. The treatment included interproximal corticotomy cuts extending through the entire thickness of the cortical layer, without a full-thickness flap reflection. This was achieved with a three-dimensionally printed surgical guide using computer-aided design and computer-aided manufacturing. Orthodontic force was applied to the teeth immediately after surgery by using clear appliances for better control of tooth movement. The total treatment time was 8 months. The periodontal indices improved after crowding correction, but the oral health impact profile showed a slight deterioration of OHRQoL during the 3 days following surgery. At the 2-year retention follow-up, the stability of treatment was excellent. The reduction in surgical time and patient discomfort, increased periodontal safety and patient acceptability, and accurate control of orthodontic movement without the risk of losing anchorage may encourage the use of this combined technique in appropriate cases.

Changes in force associated with the amount of aligner activation and lingual bodily movement of the maxillary central incisor / 대한치과교정학회지

OBJECTIVE: The purposes of this study were to measure the orthodontic forces generated by thermoplastic aligners and investigate the possible influences of different activations for lingual bodily movements on orthodontic forces, and their attenuation. METHODS: Thermoplastic material of 1.0-mm in thickness was used to manufacture aligners for 0.2, 0.3, 0.4, 0.5, and 0.6 mm activations for lingual bodily movements of the maxillary central incisor. The orthodontic force in the lingual direction delivered by the thermoplastic aligners was measured using a micro-stress sensor system for the invisible orthodontic technique, and was monitored for 2 weeks. RESULTS: Orthodontic force increased with the amount of activation of the aligner in the initial measurements. The attenuation speed in the 0.6 mm group was faster than that of the other groups (p < 0.05). All aligners demonstrated rapid relaxation in the first 8 hours, which then decreased slowly and plateaued on day 4 or 5. CONCLUSIONS: The amount of activation had a substantial influence on the orthodontic force imparted by the aligners. The results suggest that the activation of lingual bodily movement of the maxillary central incisor should not exceed 0.5 mm. The initial 4 or 5 days is important with respect to orthodontic treatment incorporating an aligner.

Analysis of adverse events with use of orthodontic sequential aligners as reported in the manufacturer and user facility device experience database.

Background: Sequential aligners (SAs) introduced about a decade ago, changed the practice of orthodontics as we knew it but the adverse events and reactions (AER) associated with SA is not known. The Food and Drug Administration’s Manufacturer and User Facility Device Experience (MAUDE) database is a reliable database that has AERs reported. The manuscript attempts to review the AER associated with SA using the MAUDE database. Materials and Methods: The authors downloaded and reviewed the SA‑related AER from MAUDE for a period of 5 years. In‑depth analysis of the site and nature of intraoral and extraoral AERs were performed. We attempted to calculate the probability of pathologies being directly related to SA use, using Bayes’ theorem. Results: In the study period of 5 years, 175 cases of AER registered with MAUDE database owing to use of SA. Of the 175 cases, 129 (73.71%) instances were mandatory reports filed by the manufacturer. Of all AERs, 32 (18.29%) cases had been diagnosed/suspected to have an allergic reaction, 20 (11.43%) of them with anaphylactic reaction and 4 (2.29%) of them with angioedema. Lesions involving tongue, throat, and lip such as soreness, inflammation, and hives were more commonly reported. In addition, 12 cases (6.86%) reported of nausea, 11 (6.29%) of gastrointestinal issues (stomach upset, diarrhea, and vomiting), 13 (7.43%) of neuromuscular issues (muscle cramps, spasm, and pain), 13 (7.43%) of cough, 10 (5.71%) of persistent headache, 3 (1.71%) of fever, and 12 (6.86%) of cardiac‑related issues were identified. Conclusions: The AERs associated with SA has been described. Though the MAUDE database is not an exact, wholesome and reliable source to identify the potential AER, currently, it is the only available source of AERs associated with SA use. The nature of AERs with the use of SA and its potential pathogenesis and implications has been discussed.