Contribution of Digital Technology to the Surgical Technique of Miniscrew Insertion: a Literature Review

Orthodontic miniscrews are used to achieve absolute anchorage. Their insertion technique is simple but must be precise to avoid intra- and postoperative complications. This study aimed to review the literature on the role of digital technology in the precise placement of miniscrews and to describe the different stages of the insertion guide manufacturing chain. The databases used were PubMed, Science Direct, and Google Scholar, including the following English descriptors: "Orthodontic Anchorage Procedures," "Cone Beam Computed Tomography." Digital technology improves the accuracy of miniscrew placement by using 3D imaging to assess the quantity and quality of bone and the proximity of anatomical structures in the area to be implanted. By combining 3D imaging with the new techniques of 3D printing and virtual planning, the orthodontist can obtain a personalized placement guide for the patient using computer-aided design and manufacturing techniques. A digitally-assisted miniscrew insertion system is a promising technique for precise and safe miniscrew insertion but cannot be used routinely. Therefore, large-scale studies are needed to map miniscrew insertion in different areas, considering ethnicity, gender, and different anatomical characteristics.

Tomographic evaluation of mandibular buccal shelf in patients with different vertical growth pattern / Evaluación de la placa ósea mandibular en pacientes con diferente patrón de crecimiento vertical

The purpose of this research was the tomographic evaluation of the Mandibular Buccal Shelf (MBS) in orthodontic patients with different vertical growth pattern. An observational, descriptive, cross-sectional and retrospective study was conducted. Tomographic images of patients aged 14 to 40 years were observed and a database was formed with those that met the inclusion criteria. The sample size was 10 for each group according to vertical growth pattern (hypodivergent, normodivergent and hyperdivergent). Then four zones of frequent insertion of extralveolar mini-screws were selected in the MBS, taking as a reference the mesial and distal roots of the first and second mandibular molar. When comparing the characteristics of MBS between vertical growth patterns, between sexes and hemiarchs, no statistically significant differences were found. However, when the characteristics of MBS were compared according to the reference root, it was found that there were statistically significant differences. The vestibular area to the distal root of the second mandibular molar presented the highest values in terms of angulation, height and thickness. There are no significant differences in the bone characteristics of MBS according to vertical growth patterns, sexes or hemiarchs. Angulation, height and thickness progressively increase from the vestibular bone of the mesial root of the first mandibular molar to the distal root of the second molar.

El propósito de esta investigación fue la evaluación tomográfica de la placa ósea mandibular (POM) en pacientes de ortodoncia con diferente patrón de crecimiento vertical. Se realizó un estudio de tipo observacional, descriptivo, transversal y retrospectivo. Se observó imágenes tomográficas de pacientes de 14 a 40 años de edad y se formó una base de datos con las que cumplían los criterios de selección. El tamaño de muestra fue de 10 para cada grupo según patrón de crecimiento vertical (hipodivergentes, normodivergentes e hiperdivergentes). Luego se seleccionaron cuatro zonas de inserción frecuente de minitornillos extralveolares en la POM, tomando como referencia las raíces mesial y distal del primer y segundo molar mandibular. Al realizar la comparación de las características de la POM entre patrones de crecimiento vertical, entre sexos y hemiarcadas no se encontraron diferencias estadísticamente significativas. Sin embargo, cuando se comparó las características de la POM según la raíz de referencia se encontró que había diferencias estadísticamente significativas. La zona vestibular a la raíz distal de la segunda molar mandibular presento los mayores valores en cuanto angulación, altura y grosor. No existen diferencias significativas en las características óseas de la POM según patrones de crecimiento vertical, sexos o hemiarcadas. La angulación, la altura y el grosor aumenta progresivamente desde el hueso vestibular de la raíz mesial del primer molar mandibular hacia la raíz distal del segundo molar.

Short-term assessment of pain and discomfort during rapid maxillary expansion with tooth-bone-borne and tooth-borne appliances: randomized clinical trial

ABSTRACT Objective: The aim of this randomized clinical trial was to evaluate and compare, during the first week of rapid maxillary expansion (RME), the impact caused by two types of appliances: Hyrax and Hybrid Hyrax. Methods: Forty-two patients who met the eligibility criteria (aged 11-14 years, with transverse maxillary deficiency, posterior crossbite, and presence of maxillary first premolars and first permanent molars) were selected and randomly divided into two groups: TBB GROUP (tooth-bone-borne expander), treated with Hybrid Hyrax (12 females and 9 males, mean age 13.3 ± 1.3 years), and TB GROUP (tooth-borne expander), treated with Hyrax (5 females and 16 males, mean age 13.3 ± 1.4 years). Pain and discomfort were assessed in two times: after the first day of activation (T1) and four days after, by means of the numerical rate scale and the instrument MFIQ (Mandibular Functional Impairment Questionnaire). Descriptive statistics and the Mann-Whitney test were used for comparison between groups and between sexes. A 5% significance level was adopted. Results: Both appliances had a negative impact, generating pain and discomfort, and reducing functional capacity. However, the scores obtained were of low intensity and no significant differences were observed between the groups. Considering sexes, there were statistically significant differences, with the female sex presenting higher scores for pain and functional limitation. Conclusions: Despite causing impact in pain and increase in the functional limitation, these changes were of low intensity, with no statistical difference between the groups. Females were more sensitive to the impact caused by the RME.

RESUMO Objetivo: O objetivo deste ensaio clínico randomizado foi avaliar e comparar, durante a primeira semana de expansão rápida da maxila (ERM), o impacto causado por dois tipos de aparelhos: Hyrax e Hyrax Híbrido. Métodos: Quarenta e dois pacientes que atendiam aos critérios de seleção (idade de 11 a 14 anos, com deficiência transversal da maxila, mordida cruzada posterior e presença de primeiros pré-molares e primeiros molares permanentes superiores) foram selecionados e divididos aleatoriamente em dois grupos: Grupo DOS (expansor dento-osseossuportado), tratado com Hyrax Híbrido (12 mulheres e 9 homens, idade média 13,3 ± 1,3 anos), e Grupo DS (expansor dentossuportado), tratado com Hyrax (5 mulheres e 16 homens, idade média de 13,3 ± 1,4 anos). A dor e o desconforto foram avaliados em dois momentos: após o primeiro dia de ativação (T1) e após quatro dias, por meio da escala de frequência numérica e do instrumento MFIQ (Questionário de Limitação Funcional Mandibular). A estatística descritiva e o teste de Mann-Whitney foram utilizados para comparação entre os grupos e entre os sexos. Adotou-se nível de significância de 5%. Resultados: Ambos os aparelhos tiveram impacto negativo, gerando dor e desconforto e reduzindo a capacidade funcional. No entanto, os escores obtidos foram de baixa intensidade e não foram observadas diferenças significativas entre os grupos. Considerando os sexos, houve diferenças estatisticamente significativas, com o sexo feminino apresentando maiores escores para dor e limitação funcional. Conclusões: Apesar de causar impacto na dor e aumento na limitação funcional, essas alterações foram de baixa intensidade, sem diferença estatística entre os grupos. As mulheres foram mais sensíveis ao impacto causado pela ERM.

Stress distribution in lower second molar mesialization using mini-implants: a pilot study using 3D finite element analysis / Distribuição de tensões na mesialização do segundo molar inferior usando mini-implantes: um estudo piloto usando análise de elementos finitos 3D

Objective: to analyze the stress distribution in a 3D model that simulates second molar mesialization using two different types of mini-implants. Material and Methods: a mandible bone model was obtained by recomposing a computed tomography performed by a software program. The cortical and trabecular bone, a lower second molar, periodontal ligament, orthodontic tube, resin cement and the mini-implants were designed and modeled using the Rhinoceros 4.0 software program. The characteristics of self-drilling orthodontic mini-implants were: one with 7 mm length, 1 mm transmucosal neck section and 1.6 mm diameter and another with 5 mm length and 1.5 mm diameter. A total of 235.161 and 224.505 elements were used for the mesh. These models were inserted into the bone block and then subjected to loads of 200 cN (centinewton). The results were calculated and analyzed by the Ansys 17.0 software program for qualitative verification through displacement and maximum principal stress maps. Results: it was possible to observe that the periodontal ligament presented low displacement and stress values. However, the physiological values presented are among those capable to provide orthodontic movement, with compression and tensile area visualization staggered between 0.1 and -0.1 MPa (megapascal). Conclusion: within the limitations of the study, the mini-implants tested showed similar results where the load on the tooth allowed dental displacement (molar mesialization), with a tendency to rotate it, theoretically allowing the second molar to take the location of the first molar. (AU)

Objetivo: analisar a distribuição de tensões em um modelo 3D que simula a mesialização do segundo molar usando dois tipos diferentes de mini-implantes. Material e Métodos: um modelo de osso mandibular foi obtido por recomposição de uma tomografia computadorizada realizada por um software. O osso cortical e trabecular, um segundo molar inferior, ligamento periodontal, tubo ortodôntico, cimento resinoso e os mini-implantes foram projetados e modelados no software Rhinoceros 4.0. As características dos mini-implantes ortodônticos auto perfurantes foram: um com 7 mm de comprimento, 1 mm de secção transmucosa e 1,6 mm de diâmetro e outro com 5 mm de comprimento e 1,5 mm de diâmetro. Para a malha, foram utilizados 235.161 e 224.505 elementos. Esses modelos foram inseridos no bloco ósseo e então submetidos a cargas de 200 cN (centinewton). Os resultados foram calculados e analisados pelo software Ansys 17.0 para verificação qualitativa por meio de mapas de deslocamento e tensões máximas principais. Resultados: foi possível observar que o ligamento periodontal apresentou baixos valores de deslocamento e tensões. Porém, os valores fisiológicos apresentados são capazes de proporcionar movimentação ortodôntica, com visualização da área de compressão e tração escalonada entre 0,1 e -0,1 MPa (megapascal). Conclusão: dentro das limitações do estudo, os mini-implantes testados apresentaram resultados semelhantes onde a carga sobre o dente permitiu o deslocamento dentário (mesialização do molar), com tendência a girá-lo, permitindo teoricamente que o segundo molar ocupe do lugar do primeiro molar (AU)

Mechanical Properties of Mini-Implants Used in Extra-Radicular Anchorage

ABSTRACT Objective: To evaluate the mechanical properties of mini-implants (MIs) manufactured from stainless steel and compare them with conventional titanium-aluminum-vanadium alloy MIs. Material and Methods: The following groups were formed: G1 (n=24), 8×1.5 mm steel MIs; G2 (n=24), 12×2.0 mm steel MIs; and G3 (n=24), 10×1.5 mm titanium MIs. The 72 MIs were inserted in the infra zygomatic crest region of the maxilla and retromolar trigone in the jaw of 10 pigs. Pull-out, insertion torque, fracture and percussion tests were performed in order to measure the tensile strength, primary stability and fracture strength of MIs. A digital torque gauge was used to measure insertion and fracture torque, a universal mechanical testing machine was used for pull-out testing and a periotest device was used to measure the micromovement of MIs. For morphological and MI component evaluation, scanning electron microscopy (SEM) was performed. D'Agostino & Pearson, Kruskal-Wallis, and Dunn post-hoc and normality tests were used. Results: G2 insertion and fracture torques were significantly higher than G1 and G3 insertion and fracture torques (p<0.05). The pull-out and percussion tests presented similar values among the groups. SEM revealed that the fracture point was predominantly on the fourth thread for steel MIs (G1 and G2) and on the seventh thread for titanium-aluminum-vanadium MIs (G3). Conclusion: The mechanical properties of stainless steel MIs are superior to those of titanium-aluminum-vanadium alloy MIs.

Evaluation of the clinical effectiveness of miniscrews in class i and ii malocclusion patients: a systematic review and meta-analysis

Aim: The present systematic review and meta-analysis aimed to evaluate the clinical effectiveness of miniscrews in Class I and II Malocclusion Patients. Methods: From electronic databases, between 2010 and 2020, PubMed, Embase, Cochrane Library, ISI were used to conduct systematic literature. Two reviewers extracted data blindly and independently from the abstract and full text of the studies they used for data extraction. The mean differences between the two groups (miniscrews vs. conventional anchorage) with a 95 % confidence interval (CI), the Inverse-variance method, and the fixed-effect model were calculated. The Meta-analysis was evaluated using the statistical software Stata/MP v.16 (The fastest version of Stata). Results: A total of 186 potentially relevant titles and abstracts were found during the electronic and manual search. Finally, the inclusion criteria required for this systematic review were met by a total of seven publications. The mean difference of molar mesiodistal movement among seven studies and heterogeneity was -0.53 mm (MD, -0.53 95 % CI -0.69, -0.38. P= 0.00) (I2 = 96.52 %). This result showed maximum reinforcement in miniscrews with fewer mesial movements. Conclusion: The result of the current systematic review and meta-analysis shows that miniscrews in patients with class II and I malocclusion help maintain better anchorage preservation than traditional anchorage devices

Resultados del uso de mini-implantes como anclaje para el movimiento de intrusión molar en Ortodoncia / Outcomes on the use of mini-implants as an anchorage in Orthodontics molar intrusion movement

RESUMEN Fundamento: La intrusión dentaria es uno de los movimientos más peligrosos en ortodoncia, para lograrlo se requiere, en ocasiones, del anclaje máximo que ofrecen los mini-implantes. Objetivo: Evaluar el uso de mini-implantes como anclaje en el movimiento de intrusión molar. Metodología: Se realizó un estudio de tipo preexperimental con 6 pacientes que necesitaban intrusión del molar, en la Clínica Estomatológica Provincial de Sancti Spíritus en el periodo de 2011 a 2014. Se utilizaron métodos del nivel teórico y empírico y se estudiaron las variables: estabilidad, ubicación del mini-implante, magnitud de la fuerza, tiempo para lograr el movimiento de intrusión, alteraciones clínicas asociadas y aceptación del paciente. Resultados: Presentaron alta estabilidad de los mini-implantes 3 pacientes y movilidad inferior a 1 mm los 3 restantes. Las complicaciones clínicas más frecuentes fueron la inflamación y el sangrado; el movimiento de intrusión en un tiempo promedio de 8 a 9 meses se logró en 5 pacientes y solo 1 paciente requirió el retiro del mini-implante. El nivel de aceptación por parte de los pacientes fue Medio. Conclusiones: Los resultados del uso de los mini-implantes como anclaje para el movimiento de intrusión molar fueron favorables en los pacientes tratados.

ABSTRACT Background: Tooth intrusion is one of the most dangerous movements in orthodontics, it requires sometimes the maximum anchorage offered by mini-implants. Objective: To evaluate the use of mini-implants as anchorage in molar intrusion movement. Methodology: It was conducted a pre-experimental study with 6 patients who needed molar intrusion, at the Sancti Spíritus Provincial Stomatology Clinic from 2011 to 2014. Theoretical and empirical methods were used and the succeeding variables were studied: stability, mini-implant location, force magnitude, intrusion movement time, associated clinical alterations and patient acceptance. Results: 3 patients showed mini-implants high stability and mobility lower than 1 mm in the remaining 3. The most frequent clinical complications were inflammation and bleeding; intrusion movement was achieved in an average time from 8 to 9 months in 5 patients and only 1 patient required the mini-implant removal. The patient´s level of acceptance was Medium. Conclusions: Outcomes on the use of mini-implants as anchorage in molar intrusion movement were satisfactory in the treated patients.

Sitios anatómicos para la inserción de microtornillos interradiculares como dispositivos de anclaje temporal en tratamientos de ortodoncia / Anatomical sites for the insertion of interradicular miniscrews as temporary anchoring devices in orthodontic treatments

Los microtornillos interradiculares (MTI) son dispositivos de uso temporal diseñados para ser insertados en el hueso alveolar con la finalidad de mejorar el anclaje. El objetivo de este estudio fue presentar una guía para odontólogos que permita identificar los sitios anatómicos más apropiados para la inserción de estos dispositivos, logrando así, una mayor tasa de éxito clínico en los tratamientos. PUBMED, Google Académico y SciELO fueron las bases de datos utilizadas para la búsqueda de la literatura, se consideraron artículos publicados entre los años 2000 y 2020, en inglés y en español. Nuestra revisión sugiere según la bibliografía actual, realizar una planificación al comienzo del tratamiento de ortodoncia, utilizando guías generales para la inserción de MTI a través de mapas visuales de "zonas seguras" que existen entre los espacios interradiculares. Para estos, se consideró que la mínima cantidad de hueso alveolar debía ser de 3 mm.

Interradicular miniscrews (MTI) are temporary devices designed to be inserted into the alveolar bone in order to improve anchorage. The aim of this study was to present a guide for dentists that allows identifying the most appropriate anatomical sites for the insertion of these devices, thus achieving a higher clinical success rate in treatments. PUBMED, Google Scholar and SciELO were the databases used to search the literature; articles published between 2000 and 2020, in English and Spanish, were considered. Our review suggests, according to the current bibliography, planning at the beginning of orthodontic treatment, using general guidelines for the insertion of MTI through visual maps of "safe areas" that exist between the inter-root spaces. For these, it was considered that the minimum amount of alveolar bone should be 3 mm.

Anclaje esquelético para el tratamiento de las anomalías de clase II y mordida abierta anterior: informe de un caso / Skeletal anchorage for the treatment of class II anomalies and anterior open bite: report of a case

El reporte de este caso tiene como objetivo demostrar la utilidad de los anclajes esqueléticos temporarios como son las miniplacas cigomáticas y los microimplantes "buccal shelf" en el tratamiento ortodóncico, en una paciente de 17 años 10 meses de edad, clase II vertical, dólicofacial, con mordida abierta anterior y aumento de la altura facial inferior. Después de la primera fase de tratamiento, siguiendo la secuencia de arcos para completar la alineación, se utilizaron anclajes esqueléticos extrarradiculares con una mecánica de intrusión con fuerzas elásticas durante 10 meses. Se intruyeron sus piezas posteriores superiores e inferiores y se distalizó la arcada superior, corrigiéndose la oclusión. El mentón retrognático y su perfil convexo mejoraron con la autorrotación de la mandíbula (AU)

The objective of this report case is to demonstrate the usefulness of temporary skeletal anchors such as zygomatic miniplates and buccal shelf microimplants in orthodontic treatment, in a 17-year-old 10-month-old, vertical class II, dollicofacial patient with anterior open bite and increased lower facial height. After the first treatment phase, following the arch sequence to complete the alignment, extra-radicular skeletal anchors were used with intrusion mechanics with elastic forces for 10 months. Its upper and lower posterior pieces were intruded and the upper arch was distalized, correcting the occlusion. e retrognathic chin and its convex profile improved with autorotation of the jaw (AU)

Zygomatic-maxillary cortical bone thickness in hyper, normo and hypodivergent patients

ABSTRACT Objective: The aim of this study was to evaluate the thickness of the zygomatic-maxillary cortical bone using computed tomography in different skeletal patterns. Methods: A total of 54 patients of both sexes, divided into three groups according to the vertical skeletal pattern, were evaluated for cortical bone thickness of the anterior slope of the zygomatic process of the maxilla, using cone beam computed tomography. Measurements were made at 2mm, 4mm, 6mm, 8mm and 10mm above from first molar mesial root apex. Vertical skeletal pattern was determined by Frankfurt mandibular angle (FMA). Results: The hyperdivergent pattern had the lowest cortical thickness value, nevertheless, no patient in the hyperdivergent group presented cortical thickness exceeding 2mm, and no patient in the hypodivergent group presented cortical thickness less than 1mm. However, the correlation between cortical thickness and mandibular plane angle was weak and not significant. Conclusion: Although higher prevalence of thick cortical was observed in the hypodivergent patients, and thin cortical groups in the hyperdivergent group, the vertical skeletal pattern could not be used as determinant of the zygomatic-maxillary cortical thickness.

RESUMO Objetivo: O objetivo do presente estudo foi avaliar a espessura da cortical óssea zigomático-maxilar por meio de tomografia computadorizada em diferentes padrões esqueléticos. Métodos: Um total de 54 pacientes de ambos os sexos, divididos em três grupos, de acordo com o padrão esquelético vertical, foi avaliado quanto à espessura da cortical óssea na vertente anterior do processo zigomático da maxila, por meio de tomografia computadorizada de feixe cônico. As medidas foram feitas a 2mm, 4mm, 6mm, 8mm e 10mm acima do ápice da raiz mesial do primeiro molar. O padrão esquelético vertical foi determinado pelo Ângulo do Plano Mandibular (FMA). Resultados: O padrão hiperdivergente apresentou o menor valor de espessura de cortical. No entanto, nenhum paciente do grupo hiperdivergente apresentou espessura cortical superior a 2mm e nenhum paciente do grupo hipodivergente apresentou espessura cortical inferior a 1mm. No entanto, a correlação entre a espessura da cortical e o ângulo do plano mandibular foi fraca e não significativa. Conclusão: Embora tenha havido uma maior prevalência de cortical espessa no grupo hipodivergente e cortical fina no grupo hiperdivergente, o padrão esquelético vertical não pode ser utilizado como determinante da espessura cortical zigomático-maxilar.

Conservative treatment in adult patient with reimplanted anterior teeth after traumatic avulsion with extensive bone loss: an 8-year follow-up

ABSTRACT Introduction: Orthodontic treatment in patients with traumatized teeth is a condition that needs good planning in order to achieve satisfactory results. Objective: To discuss approaches to orthodontic treatment of malocclusions associated with trauma followed by avulsion of anterior teeth, reimplanted after a short period of time. Case report: The treatment started with the distalization of upper posterior teeth, with the aid of mini-implants and sliding jigs, followed by the inclusion of anterior teeth in the arch, followed by intrusion of these teeth. Results: With the treatment, improved mobility of the anterior teeth was achieved, with better insertion into bone tissue. The most important factor for satisfactory treatment and a good prognosis for avulsion is the time the tooth remains outside the socket. Orthodontic treatment in patients with traumatized teeth is not contraindicated; however, clinical and radiographic aspects must be considered. Conclusion: Among the feasible orthodontic treatment options, the conservative approach can be a very favorable treatment alternative.

RESUMO Introdução: O tratamento ortodôntico em pacientes com dentes traumatizados é uma condição que necessita de um bom planejamento, a fim de se conseguir resultados satisfatórios. Objetivo: Discutir as abordagens de tratamento ortodôntico de más oclusões associadas ao trauma seguido de avulsão de dentes anteriores, reimplantados após curto espaço de tempo. Relato do Caso: O tratamento realizado iniciou-se com a distalização dos dentes posteriores superiores, com auxílio de mini-implantes e sliding jigs, seguida da inclusão dos dentes anteriores na arcada e intrusão desses dentes. Resultados: Com a realização do tratamento, conseguiu-se melhoria na mobilidade dos dentes anteriores, com inserção mais favorável no tecido ósseo. O fator mais importante para o tratamento satisfatório e um bom prognóstico da avulsão é o tempo em que o dente permanece fora do alvéolo. O tratamento ortodôntico em pacientes com dentes traumatizados não é contraindicado; porém, aspectos clínicos e radiográficos devem ser considerados. Conclusão: Entre as opções de tratamento ortodôntico factíveis, a abordagem conservadora pode ser uma opção de tratamento bastante favorável.

Miniscrew-assisted rapid palatal expansion (MARPE): how to achieve greater stability. In vitro study

ABSTRACT Objective: Assess the influence of mono- and bicortical anchorage and diameter of mini-implants (MIs) on the primary stability of these devices. Methods: 60 self-drilling MIs were distributed in six groups according to diameter (1.5mm, 1.8mm or 2.0mm) and type of anchorage (monocortical and bicortical) in bovine rib. The primary stability was evaluated by insertion torque, micromobility and pull-out strength tests. ANOVA and/or Tukey analysis were used to conduct intergroup comparisons (p< 0.05). Non-parametric statistics (Kruskal-Wallis and Mann-Whitney) were performed when normality was not found (p< 0.05). Results: MIs with larger diameters and bicortical anchorage showed greater primary stability regarding insertion torque (p< 0.05) and micromobility (p< 0.05). Only MI diameter had an effect on the pull-out strength test. Larger diameter MIs presented better retention in pull-out strength tests (p< 0.001), regardless of mono- or bicortical anchorage. Conclusions: MI primary stability is dependent on its diameter and type of anchorage. Bicortical anchorage showed greater stability when compared with monocortical anchorage, independently of other variables.

RESUMO Objetivo: Avaliar a influência da ancoragem mono e bicortical e do diâmetro dos mini-implantes (MIs) na estabilidade primária desses dispositivos. Métodos: 60 MIs autoperfurantes foram distribuídos em seis grupos, de acordo com o diâmetro (1,5 mm, 1,8 mm ou 2,0 mm) e tipo de ancoragem (monocortical e bicortical), e inseridos em costela bovina. A estabilidade primária foi avaliada pelos testes de torque de inserção, micromobilidade e resistência à tração. ANOVA e/ou análise de Tukey foram usadas para realizar comparações intergrupos (p< 0,05). Estatística não paramétrica (Kruskal-Wallis e Mann-Whitney) foi realizada quando a normalidade não foi encontrada (p< 0,05). Resultados: MIs com diâmetros maiores e ancorados bicorticalmente apresentaram maior estabilidade primária em relação ao torque de inserção (p< 0,05) e micromobilidade (p< 0,05). Apenas o diâmetro do MI influenciou os resultados do teste de resistência à tração. MIs de maior diâmetro apresentaram melhor retenção nos testes de resistência à tração (p< 0,001), independentemente da ancoragem mono ou bicortical. Conclusões: a estabilidade primária do MI é dependente de seu diâmetro e tipo de ancoragem. A ancoragem bicortical apresentou maior estabilidade quando comparada à ancoragem monocortical, independentemente das demais variáveis.

Comprehensive approach to simultaneous molar intrusion and canine retraction in the treatment of Class II anterior open bite using miniscrew anchorage

ABSTRACT Introduction: Anterior open bite is one of the most difficult malocclusions to correct in orthodontic treatment. Molar intrusion using miniscrew anchorage has been developed as a new strategy for open bite correction; however, this procedure still has an important concern about prolonged treatment duration in the patient with anteroposterior discrepancy due to the separate step-by-step movement of anterior and posterior teeth. Objective: This article illustrates a comprehensive orthodontic approach for dentoalveolar open bite correction of an adult patient, by using miniscrew. Case report: A woman 19 years and 5 months of age had chief complaints of difficulty chewing with the anterior teeth and maxillary incisor protrusion. An open bite of -2.0 mm caused by slight elongation of the maxillary molars was found. The patient was diagnosed with Angle Class II malocclusion with anterior open bite due to the vertical elongation of maxillary molars. After extraction of the maxillary first premolars, concurrent movements of molar intrusion and canine retraction were initiated with the combined use of sectional archwires, elastic chains and miniscrews. Results: At 4 months after the procedure, positive overbite was achieved subsequent to the intrusion of maxillary molars by 1.5 mm and without undesirable side effects. Class I canine relation was also achieved at the same time. The total active treatment period was 21 months. The resultant occlusion and satisfactory facial profile were maintained after 54 months of retention. Conclusion: The presented treatment shows the potential to shorten the treatment duration and to contribute to the long-term stability for open bite correction.

RESUMO Introdução: A mordida aberta anterior é um dos tipos de má oclusão mais difíceis de se corrigir no tratamento ortodôntico. A intrusão de molares usando ancoragem em mini-implantes foi desenvolvida como uma nova estratégia para a correção da mordida aberta. Entretanto, ainda há preocupações quanto à longa duração desse tratamento em pacientes com discrepâncias anteroposteriores, já que os dentes anteriores são movimentados em etapa distinta dos posteriores. Objetivo: Este artigo descreve uma abordagem ampla para a correção da mordida aberta dentoalveolar em uma paciente adulta, usando mini-implantes. Relato de caso: Uma paciente de 19 anos e 5 meses de idade procurou tratamento apresentando como queixas principais a dificuldade de mastigar com os dentes anteriores e a protrusão dos incisivos superiores. Verificou-se, ainda, mordida aberta de -2,0 mm, causada por um comprimento levemente maior dos molares superiores. A paciente foi diagnosticada com má oclusão de Classe II de Angle com mordida aberta anterior devido à dimensão vertical aumentada dos molares superiores. Após a extração dos primeiros pré-molares superiores, iniciou-se movimentos simultâneos de intrusão dos molares e retração dos caninos, com o uso combinado de arcos seccionados, elásticos em cadeia e mini-implantes. Resultados: Após quatro meses em tratamento, alcançou-se uma sobremordida positiva, devido à intrusão de 1,5 mm dos molares superiores, sem qualquer efeito colateral indesejável. Ao mesmo tempo, também alcançou-se relação de Classe I nos caninos. O tempo total de tratamento ativo foi de 21 meses. A oclusão e o perfil facial satisfatório alcançados ao fim do tratamento mantiveram-se após 54 meses em contenção. Conclusão: A abordagem aqui apresentada tem o potencial de encurtar a duração do tratamento e contribuir para a estabilidade em longo prazo da correção da mordida aberta.

Severe hemorrhage in a patient with dengue hemorrhagic fever after insertion of orthodontic mini-implants. A case report / Hemorragia severa em paciente com dengue hemorrágica após instalação de miniimplante ortodôntico

The objective of this paper is to report a clinical case of a patient who after installing an orthodontic mini-implant returned to the dental office seven days later with a severe hemorrhage where it was inserted. Because of the severe character of the hemorrhage, the mini-implant was removed, local compression was performed, medication to control bleeding was given and some lab tests were requested. The patient returned in 24 hours with diagnosis of dengue hemorrhagic fever (DHF). The patient was referred to the specialized hematology service where the diagnosis was confirmed. Past the critical period, a new mini-implant was inserted to continue the orthodontic treatment. It can be concluded from this account that despite the mini-implants being devices of simple installation and easy removal, it is important that the patient's systemic conditions are optimal for their overall effectiveness (AU)

The objective of this paper is to report a clinical case of a patient who after installing an orthodontic mini-implant returned to the dental office seven days later with a severe hemorrhage where it was inserted. Because of the severe character of the hemorrhage, the mini-implant was removed, local compression was performed, medication to control bleeding was given and some lab tests were requested. The patient returned in 24 hours with diagnosis of dengue hemorrhagic fever (DHF). The patient was referred to the specialized hematology service where the diagnosis was confirmed. Past the critical period, a new mini-implant was inserted to continue the orthodontic treatment. It can be concluded from this account that despite the mini-implants being devices of simple installation and easy removal, it is important that the patient's systemic conditions are optimal for their overall effectiveness (AU)

Distalization of the entire maxillary arch with mini-implants in the posterior palatal alveolus- A case report / Distalização de todo o arco maxilar com mini-implantes na região alveolar posterior palatina - Relato de caso

A 22 year old male patient reported to the hospital with a chief complaint of forwardly placed teeth. On examination patient had Angle's Class I malocclusion and proclination of the anterior teeth. There were signs of frictional keratosis on the buccal mucosa. Treatment plan was to extract the third molars alone and distalize the entire maxillary arch with palatal mini-implants. 0.022 MBT brackets were bonded on the buccal aspect. 0.019" x 0.025" stainless steel wire was placed sequentially. Mini-implants were placed on the posterior alveolus on the palatal surface of maxilla. Retractive force was applied from an attachment bonded on the palatal aspect of the maxillary canine. Patient was reviewed periodically. Comparison of pre-treatment and post-treatment results revealed that the entire maxillary arch intruded and translated distally with a counter-clockwise rotation of the mandible with reduction in LAFH. There was a mild reduction in inter-canine with marginal expansion in the premolar and molar region. An improvement in facial profile was noted with no sign of root resorption. Thus, the posterior alveolus may be considered as a new and appropriate site for placement of mini-implant to bring about distal movement of the entire maxillary dentition (AU)

Um Paciente do sexo masculino, 22 anos, foi encaminhado ao hospital com queixa principal de dentes posicionados para a frente. Ao exame clínico o paciente apresentava má oclusão de Classe I de Angle e inclinação vestibular dos dentes anteriores. Havia sinais de queratose friccional na mucosa bucal. O plano de tratamento foi extrair os terceiros molares e distalizar todo o arco maxilar com mini-implantes por palatino. Bráquetes MBT 0,022 foram colados por vestibular. Fio de aço inoxidável 0,019 "x 0,025" foi colocado seqüencialmente. Mini-implantes foram instalados na região alveolar posterior da superfície palatina da maxila. A força de retração foi aplicada a partir de acessórios colados nas faces palatinas dos caninos superiores. O paciente foi reavaliado periodicamente. Os resultados da comparação pré-tratamento e pós-tratamento revelaram que todo o arco maxilar intruiu e transladou distalmente com rotação da mandíbula no sentido anti-horário com redução da AFAI. Houve uma ligeira redução na distância intercanina com expansão marginal nas regiões de pré-molar e molar. Foi percebida melhora no perfil facial sem sinal de reabsorção radicular. Assim, a região alveolar posterior pode ser considerada como um novo e apropriado local para instalação de mini-implante para promover movimento distal de toda a dentição maxilar. (AU)

Failure of miniscrews installed in maxilla and mandible: a systematic review and meta-analysis / Falha de mini-implantes instalados em maxila e mandíbula: uma revisão sistemática e meta-análise

Objective: The aim of this systematic review was to compare the clinical failure rate of orthodontic miniscrews in maxilla and mandible. Material and Methods: Randomized controlled trials of patients in orthodontic treatment, which required miniscrews for orthodontic intervention reporting the failure rate of miniscrews in the maxilla and mandible were searched in Pubmed database. Two authors independently reviewed all identified titles and abstracts for eligibility. Comparison between failures in maxilla and mandible were estimated using pairwise meta-analysis to calculate the relative risk (RR) of failure and the 95% confidence intervals using a random-effect model. The reports of randomized trials were assessed for bias using the Cochrane risk of bias tool. Results: Four studies fulfilled the eligibility criteria. 299 patients with a total of 628 miniscrews installed were included in the analysis. The analysis showed a 0.55 RR (95% CI 0.23­1.29) and I2 = 85%. All studies had an unclear risk of bias regarding to the two following items: allocation concealment, blinding of participants and personnel. All studies had a low risk of bias with regard to incomplete outcome data and selective reporting. The results did not demonstrate statistical difference between risk of failure of miniscrew between maxilla and mandible. Conclusion: The results of the meta-analysis showed that miniscrews installed in maxilla presents reduced risk of failure. A tendency of higher number of failures in mandible was also demonstrated. However, results should be interpreted with caution because of the very low quality of included studies and the differences among methodologies. (AU)

Objetivo: A presente revisão sistemática objetivou comparar a taxa de falha clínica de mini-implantes ortodônticos instalados em maxila e mandíbula. Materiais e Métodos: Ensaios clínicos controlados e randomizados que reportaram a taxa de falha de mini-implantes instalados em maxila e mandíbula de pacientes necessitando tratamento ortodôntico foram pesquisados na base de dados do Pubmed. Dois autores revisaram independentemente os títulos e resumos identificados com base nos critérios de elegibilidade. Comparações entre as falhas na maxila e mandíbula foram estimadas utilizando meta-análise pareada para cálculo do risco relativo (RR) de falha e dos intervalos de confiança de 95%, usando um modelo de efeito aleatório. Os reportes dos estudos incluídos foram avaliados quanto ao risco de viés seguindo os critérios da Cochrane para ensaios clínicos randomizados. Resultados: Quatro estudos preencheram os critérios de elegibilidade. No total, 299 pacientes e 628 mini-implantes instalados foram incluídos na análise. A análise apresentou um RR 0,55 (IC 95% 0,23-1,29) e I2 = 85%. Todos os estudos apresentaram um risco claro de viés em relação aos dois itens seguintes: ocultação de alocação, cegamento dos participantes e profissionais. Todos os estudos apresentaram um baixo risco de viés no que diz respeito a dados de desfecho incompletos e reporte seletivo. Não foi demonstrada diferença estatisticamente significativa entre mini-implantes instalados em maxila e mandíbula. Conclusão: Os resultados da meta-análise demonstraram um menor risco de falhas em mini-implantes instalados na maxila e uma tendência para maior número de falhas na mandíbula. Contudo, os resultados devem ser interpretados com cautela, dadas a baixa qualidade dos estudos incluídos e as diferenças entre suas metodologias (AU)

Open bite in adult patients

ABSTRACT Anterior open bite (AOB) is characterized by the lack of overlap or contact between maxillary and mandibular incisors, while the posterior teeth are in occlusion. Correction of this malocclusion is challenging due to difficulties in determining and addressing the etiologic factors, and the high relapse rate. A multidisciplinary approach may be necessary, with participation of Orthodontics, Surgery and Speech Therapy, to achieve adequate esthetic and functional results for long term stability. The present paper discusses the treatment options for AOB, their advantages and implications.

RESUMO A mordida aberta anterior (MAA) é caracterizada pela falta de cobertura ou contato entre os incisivos superiores e inferiores, enquanto os dentes posteriores estão em oclusão. A correção dessa má oclusão é considerada desafiadora, devido à dificuldade em se determinar e lidar com os fatores etiológicos e à alta taxa de recidiva. Uma abordagem multidisciplinar pode ser necessária, envolvendo a participação da Ortodontia, Cirurgia e Fonoaudiologia, a fim de que adequados resultados estéticos e funcionais sejam alcançados e se obtenha estabilidade em longo prazo. No presente artigo, o objetivo foi discutir as modalidades de tratamento da MAA, suas vantagens e implicações.

Rapid maxilary expansion in young adults: comparison of tooth-borne and bone-borne appliances, a cohort study / Expansión rápida maxilar en pacientes adultos jóvenes: comparación de aparatos dentosoportados y esqueletalmente soportados: estudio de cohorte

Introduction: Maxillary constrictions are one of the most frequent abnormalities, regardless of the type of dentition studied. They can be treated either with tooth-borne or bone-borne expander appliances, depending on the biological maturation of the patient. Treatment during prepubertal stages has been shown to be successful, but there is evidence of an open suture even in late adolescence stages. The aim of this study is to compare the effects of a rapid expansion bone-borne device to a tooth-borne device in young adults suffering from maxillary constriction, by means of Cone-Beam Computed Tomography. Materials and methods: A retrospective observational study was conducted in nine patients (three males, six females) with a mean age of 18±5.5 years, who attended the Dentistry Service of Universidad de Chile during 2014-2015. Six patients were treated with tooth-borne appliances (Hyrax type) and three patients with bone-borne appliances (MARPE). Linear measurements of the anterior and posterior transverse dimension and angular measurements of the inclination of molars and incisors were obtained through CBCT for each group in T1 and T2. Results: A significant increase in the posterior transverse dimensions in both groups was observed. Radiolucency of the suture was observed in all patients treated with miniscrews and in half of the patients treated with Hyrax. Greater angulation of molars was shown in the tooth-borne group in comparison with the bone-borne group. Conclusion: Both appliances caused an increase in the posterior transverse dimension, but bone anchored appliances achieved a more parallel and skeletal expansion. Randomized clinical trials with a larger sample and follow-up are needed.

Introducción: Las compresiones maxilares son una de las anomalías más frecuentes, independiente del tipo de dentición que se esté estudiando. Su tratamiento se puede realizar con un aparato expansor ya sea dentosoportado o esqueletalmente soportado, dependiendo de las consideraciones de maduración biológica del paciente. Se ha demostrado éxito en el tratamiento en etapas prepuberales, sin embargo, existe evidencia de una sutura abierta aún en etapas post adolescencia. El objetivo de este estudio es comparar, mediante Cone Beam CT, los efectos de un dispositivo de expansión rápida maxilar esqueletamente soportado, en relación a los dentosoportados, en adultos jóvenes con compresión maxilar. Material y método: Se realizó un estudio de tipo observacional retrospectivo, donde se evaluaron nueve pacientes (tres hombres y seis mujeres) con un promedio de edad de 18±5,5 años,que asistieron al Servicio de Ortodoncia de la Universidad de Chile, durante los años 2014-2015. Seis pacientes fueron tratados con aparatos dentalmente soportados (tipo Hyrax) y tres pacientes con apartos esqueletalmente soportados (MARPE). A través de CBCT se tomaron medidas lineares de la dimensión transversal anterior y posterior, y medidas angulares de la inclinación de molares e incisivos para cada grupo en T1 y T2. Resultados: Hubo un aumento significativo en la dimensión transversal posterior de ambos grupos. Se presentó radiolucidez de la sutura en un 100% de los pacientes tratados con microtornillos y 50% de los pacientes tratados con hyrax. Hubo mayor angulación de molares en el grupo dentosoportado en comparación al grupo esqueletalmente soportado. Conclusiones: Ambos aparatos lograron un aumento de la dimensión transversal posterior, sin embargo, los de anclaje esqueletal lograron una expansión más paralela y esqueletal. Hacen falta ensayos clínicos aleatorizados con mayor muestra y seguimiento.

Mechanical and histological evaluation of a titanium device for orthodontic anchorage, placed with or without cyanoacrylate adhesive

ABSTRACT Objective: The objective of the present study was to perform a histological evaluation of a titanium mini-implant for orthodontic anchorage. Shear strength and fracture patterns that occurred immediately, 30 and 60 days after insertion with or without N-2-butyl-cyanoacrylate adhesive were evaluated. Methods: Ninety-six mini-implants (Arrow, Peclab, Brazil) were placed in the tibia of 9 male rabbits, with or without an adhesive (Vetbond™, 3M, USA). Histological evaluation was done by optical light microscope. Shear strength testing was performed, followed by fracture analysis with visual inspection. Results: Close contact between the newly formed bone and the device was evidenced in the group without adhesive, whereas gaps in the group with adhesive were found. Tukey test showed similar values in both groups at the immediate time point (20.70 N without adhesive and 24.69 N with adhesive), and higher values for the non-adhesive group, after 30 and 60 days (43.98 N and 78.55 N, respectively). The values for the adhesive group were similar for the immediate time point (24.69 N), 30 days (18.23 N) and 60 days (31.98 N). The fractures were adhesive for both groups at the immediate time point. The fractures were cohesive in bone for the non-adhesive group after 30 and 60 days. Conclusions: The mini-implants showed close bone contact and required higher shear strength for removal at 30 and 60 days for the non-adhesive group. Further studies are needed to assess the proper way to remove the orthodontic anchorage without cohesive fractures in bone.

RESUMO Objetivos: este estudo teve como objetivo realizar uma avaliação histológica de um mini-implante para ancoragem em Ortodontia. Avaliou-se, também, a carga de cisalhamento e o padrão de fratura imediatamente e após 30 e 60 dias da sua inserção, com ou sem o uso do adesivo N-butil-2-cianoacrilato. Métodos: noventa e seis mini-implantes (Arrow, Peclab, Brasil) foram instalados na tíbia de nove coelhos machos, com ou sem adesivo (Vetbond™, 3M, EUA). A avaliação histológica foi realizada com uso de microscópico de luz óptica. Realizou-se o teste de resistência ao cisalhamento, seguido pela análise da fratura, por meio de inspeção visual. Resultados: um contato íntimo entre o novo osso formado e o dispositivo foi evidenciado no grupo sem adesivo, enquanto espaços foram encontrados no grupo com adesivo. O teste de Tukey mostrou valores semelhantes em ambos os grupos no tempo imediato (20,70 N sem adesivo e 24,69 N com adesivo), e valores maiores para o grupo sem adesivo após 30 e 60 dias (43,98 N e 78,55 N, respectivamente). Os valores para o grupo com adesivo foram semelhantes para os tempos imediato (24,69 N), 30 dias (18,23 N) e 60 dias (31,98 N). As fraturas foram adesivas para ambos os grupos, no tempo imediato. As fraturas foram coesivas no osso para os grupos sem adesivo, após 30 e 60 dias. Conclusões: os mini-implantes mostraram um contato íntimo com o osso e requereram alta carga de cisalhamento para sua remoção após 30 e 60 dias nos grupos sem adesivo. Estudos adicionais são necessários para avaliar um método para remoção do dispositivo ortodôntico sem fratura coesiva no osso.

Use of orthodontic mini-screws among orthodontists in Saudi Arabia

Background: Orthodontic anchorage is a technique used to avoid undesired tooth movement. The miniature screw (mini-screw) implant is an orthodontic innovation that was introduced to circumvent the limitations of conventional anchorage systems. Mini-screws, known as temporary anchorage devices (TADs), give clinicians good control over tooth movement in 3 dimensions and can assist orthodontists in anchorage-demanding cases.Methods: A questionnaire was distributed by online survey using SurveyMonkey and on paper during orthodontic meetings in Saudi Arabia. Collected data were analyzed using SPSS statistical software (version 23, IBM). A 2-way cross-tabulation and Fisher’s exact or Pearson chi-square tests were used to evaluate statistically significant differences. A P-value < 0.05 was considered to be statistically significant.Results: Of 133 respondents, 72 (54.1%) of practitioners worked in the governmental sector and 61 (45.9%) worked in the private sector. A total of (87.3%) of practitioners in the governmental sector and (80%) of practitioners in the private sector reported using mini-screws in clinical practice. Practitioners who reported that they did not use mini-screws in clinical practice listed the following reasons: “I don’t have enough information” (33.3%), “It’s a surgeon’s job” (11.1%), “Not available in the hospital” (29.6%), and “Other” (25.9%). A total of 60.2% of practitioners loaded mini-screws immediately, 8.3% loaded them 1 week after implantation, 11.3% loaded them 2-3 weeks after implantation, and 3.8% loaded them >3 weeks after implantation. Regarding the method of placement, 63.2% of practitioners used radiography for placement guidance/confirmation, 9.8% used a self-made guide, and 8.3% did not use a guide.Conclusions: Lack of education and training are major reasons that practitioners do not use orthodontic mini-screws in Saudi Arabia. Increased efforts to organize seminars and workshops may motivate practitioners to incorporate mini-screw usage into routine practice.