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OBJECTIVES: To synthesise the dentoalveolar, periodontal and skeletal changes that occur when using maxillary expansion techniques assisted by temporary anchorage devices compared to conventional protocols. METHODS: Five databases and grey literature were consulted, up to December 2023, focusing on intervention designs and excluding other type of studies. The quality assessment was conducted by using the adaptation for orthodontics of the CONSORT statement, the guidelines for reporting non-randomised studies, the RoB-2 tool, and the ROBINS-I tool. A descriptive summary and meta-analysis using RevMan 5.4 were performed. RESULTS: Nine clinical trials were included (n=377 patients, mean age 13.2±0.6) with a diagnosis of transverse maxillary deficiency. The analysed studies showed qualitative dentoalveolar and periodontal changes after expansion, which were greater on the maxillary first premolars in tooth-borne appliances. Meta-analyses for some effects were included from two studies (n=64); patients who used tooth-borne appliances had greater effects of buccal intercoronal width between the premolars with statistically significant differences (Std Mean difference 2.34; 95% CI: 0.04-4.65 p=0.05). Conversely, those patients who used bone-borne or hybrid appliances had greater effects of buccal intercoronal width between molars with statistically significant differences (Std Mean difference -0.64; 95% CI: -1.38-0.10; p=0.09). CONCLUSIONS: According to the studies analysed, all measurements increased in the intervention groups after expansion. Quantitative analyses show different findings at dentoalveolar level when tooth-borne, bone-borne or hybrid appliances are considered. Nevertheless, the results should be taken with caution due to the heterogeneity of the studies. The protocol was registered at PROSPERO (CRD42021283170), with no funding to report.

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OBJECTIVE: To evaluate the efficacy of microchips and 3D microsensors in the measurement of orthodontic forces. METHODS: Through September 2023, comprehensive searches were conducted on PubMed/MEDLINE, SCOPUS and SCIELO without restrictions. RESULTS: After removing duplicate entries and applying the eligibility criteria, 23 studies were included for analysis. All the studies were conducted in vitro, and slightly more than half of them were centred on evaluating orthodontic forces exerted by aligners. Eight utilized microchips as measurement tools, while the remaining studies made use of 3D microsensors for their assessments. In the context of fixed appliances, key findings included a high level of agreement in 3-dimensional orthodontic force detection between simulation results and actual applied forces. Incorporating critical force-moment combinations during smart bracket calibration reduced measurement errors for most components. Translational tooth movement revealed a moment-to-force ratio, aligning with the bracket's centre of resistance. The primary findings in relation to aligners revealed several significant factors affecting the forces exerted by them. Notably, the foil thickness and staging were found to have a considerable impact on these forces, with optimal force transmission occurring at a layer height of 150 µm. Furthermore, the type of material used in 3D-printing aligners influenced the force levels, with attachments proving effective in generating extrusive forces. Deliberate adjustments in aligner thickness were observed to alter the forces and moments generated. CONCLUSIONS: Microchips and 3D sensors provide precise and quantitative measurements of orthodontic forces in in vitro studies, enabling accurate monitoring and control of tooth movement.

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The purpose of this article was to describe a simple graphical driven method for determining the necessary two-vector mechanics (TVM) as an alternative solution to the ideal or single force. In orthodontics, some tooth movements are difficult to achieve, mainly because of the impossibility of getting the point of application for the necessary force system. Given two points in biomechanically accessible areas, adding together two vectors applied to those points will result in an equivalent force system. The method was developed based on previous research, 3,880 hypothetical cases were analyzed to determine the trends between the resulting forces and their relative locations. A graphical driven TVM method (GTVM) for establishing the necessary TVM is presented in a manner that combine different procedures from the traditional method that simplify the analysis and may allow the user to perform more complex orthodontic cases making easier to compare systems of force equivalents.

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A expansão rápida da maxila (ERM) representa o procedimento gold-standard para correção da deficiência transversal do arco dentário superior. Porém, a idade é fator limitante para o sucesso da ERM convencional. Recentemente, a expansão rápida da maxila assistida por mini-implantes (MARPE) ampliou o limite de idade para separação da sutura palatina mediana (SPM), permitindo a correção minimamente invasiva da atresia maxilar, em pacientes adultos. O objetivo deste artigo foi relatar um caso clínico de um paciente adulto com mordida cruzada posterior tratado com MARPE, avaliar os efeitos transversais, o reparo da sutura palatina mediana (SPM) e a estabilidade da expansão após 8 meses de contenção. Paciente de sexo masculino, de 25 anos de idade, apresentava-se com mordida cruzada posterior bilateral, má oclusão de Classe III bilateral e estágio de maturação da SPM avançado. Foi indicado o tratamento com MARPE com 4 parafusos, posicionados parassuturalmente, seguido de tratamento compensatório para Classe III. Após a fase ativa da expansão o aparelho foi mantido por 12 meses como contenção. Após os 6 meses foram removidas as hastes do expansor e foi instalado o aparelho fixo, com uso de elásticos intermaxilares O reparo completo da SPM foi observada após um período de 12 meses de contenção. Após a ortodontia corretiva, uma adequada relação oclusal de molar Classe I foi alcançada (AU)

Rapid palatal expansion (RPE) represents the gold-standard procedure for correcting transverse maxillary dental arch deficiency. However, age is a limiting factor for the success of conventional RPE. Recently, mini-implant-assisted rapid palatal expansion (MARPE) has extended the age limit for midpalatal suture (MPS) separation, allowing for minimally invasive correction of maxillary atresia in adult patients. The aim of this article was to report a clinical case of an adult patient with posterior crossbite treated with MARPE, to evaluate the cross-sectional effects, midpalatal suture (MPS) repair and expansion stability after 8 months of retention. A 25-year-old male patient presented with bilateral posterior crossbite, bilateral Class III malocclusion, and advanced PMS maturation stage. Treatment with MARPE with 4 screws, positioned parasuturally, was indicated, followed by compensatory treatment for Class III. After the active phase of expansion, the appliance was kept for 12 months as a retainer. After 6 months, the expander rods were removed and the fixed appliance was installed using inter maxillary elastics. Complete PMS repair was observed after a period of 12 months of retention. After corrective orthodontics, an adequate Class I molar occlusal relationship was achieved (AU)

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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.

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OBJECTIVE: To compare two methods of maxillary molar distalisation with skeletal anchorage using finite element analysis (FEA). METHODS: Two digitised models were created: the miniscrew-anchored distaliser, which consisted of a distalisation method anchored in a buccal miniscrew between the first molar and second premolar (Model 1), and the miniscrew-anchored palatal appliance, which consisted of a distalisation method anchored in a miniscrew on the anterior region of the palate (Model 2). FEA was used to simulate both methods, assessing teeth displacements and stress concentration. RESULTS: The miniscrew-anchored distaliser showed greater buccal than distal displacement of the first molar, while the opposite was observed in the miniscrew-anchored palatal appliance. The second molar responded similarly in the transverse and anteroposterior perspectives with both appliances. Greater displacements were observed at crown level than in apical regions. Greater stress concentration was observed at the buccal and cervical regions of the crown in the miniscrew-anchored distaliser and the palatal and cervical regions in the palatal appliance. The stress progressively spread in the buccal side of the alveolar bone for the miniscrew-anchored distaliser and in the palatal root and alveolar bone for the palatal appliance. CONCLUSION: FEA assumes that both appliances would promote maxillary molar distalisation. A skeletally anchored palatal distalisation force seems to provide a greater molar bodily movement with less undesirable effects. Greater stress is expected at the crown and cervical regions during distalisation, and the stress concentration in the roots and alveolar bone depends directly on the region the force was applied.

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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.

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OBJECTIVE: We report the orthodontic treatment of a class II malocclusion with anterior open bite and posterior crossbite in a patient with Down syndrome (DS) treated with mini-implants. METHODS: Treatment began with rapid maxillary expansion with a Haas appliance, followed by dental alignment and leveling with a fixed appliance and the correction of class II dental relationships with the use of orthodontic mini-implants associated with a sliding jig. RESULTS: The results obtained at the end of the treatment were satisfactory, with improvements in occlusion, including bite closure; maxillary expansion; and the correction of dental relationships. CONCLUSION: When well-planned, orthodontic treatment in a patient with DS achieves satisfactory results from a skeletal, occlusal, and facial perspective.

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INTRODUCTION: The intrusion of posterior teeth had been considered challenging up to the development of orthodontic mini implants. In periodontally compromised teeth, the challenge is even greater, because of the root resorption risk due to periodontal ligament over-compression. Still, the precise strategy to determine the force reduction level remains uncertain. OBJECTIVE: The objective of the study was to determine, by a finite element analysis (FEA), the force reduction needed to avoid root resorption and maintain the efficiency of orthodontic mechanics of periodontally compromised teeth similar to the sound one. METHODS: An anatomical model was constructed representing a premolar inserted into a maxillary bone. Based on the initial model (R0), three bone height loss conditions were simulated (R2 = 2 mm, R4 = 4 mm, and R6 = 6 mm). Two intrusive movements were simulated: pure intrusion (bilateral mini implant) and uncontrolled-tipping intrusion (buccal mini implant). The hydrostatic stress at the periodontal ligament was used to evaluate the risk of root resorption due to over-compression. RESULTS: For bilateral mini implant intrusion, the force had to be decreased by 16%, 32% and 48% for R2, R4 and R6, respectively. For buccal mini implant intrusion, the required reductions were higher (20%, 36% and 56%). A linear relationship between the intrusive force reduction and the alveolar bone height loss was observed in both intrusion mechanics. CONCLUSIONS: According to the FE results, 8% or 9.3% of force reduction for each millimetre of bone height loss is suggested for intrusion with bilateral or buccal mini implant, respectively. The buccal mini implant anchorage must be associated with a supplemental strategy to avoid buccal crown tipping.

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INTRODUCTION: The aim of the present study was to evaluate the thickness of the hard palate at the different angles formed by the palatal plane and the Frankfort horizontal line using computed tomography in patients with different facial patterns for planning the installation of MARPE. MATERIALS AND METHODS: The measurements were analysed in the hard palate of 106 patients. Four regions were selected passing through the mesial face, tangent at the level of the cemento-enamel junction of the premolars and molars. The bone thickness was measured from the floor of the nasal cavity to the cortical bone of the hard palate, 02 measurements with a distance of 05 mm between them (2.5 mm on each side starting from the midsagittal line) and 2 more with a distance of 7 mm between measurements (3.5 mm on each side starting from the midsagittal line). The palatal plane cant was determined based on the palatal plane and the Frankfort horizontal plane. The sagittal skeletal pattern was determined based on the ANB angle and the vertical skeletal pattern based on the SN.Go.Gn angle. RESULTS: Palatal bone thickness was greater in males than in females. Regarding the sagittal skeletal pattern, patients with Class II were found to have a thinner hard palate than Class I and Class III patients. No difference in the vertical skeletal pattern was observed between groups. Regarding the palatal plane cant, bone thickness was greater in patients with clockwise rotation. CONCLUSIONS: Careful planning should be considered in the case of female patients; patients with greater angles of the palatal plane cant and Class II patients have a smaller bone thickness.

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