The efficiency of a customized distalizer with Variety SP® screws anchored on palatal miniscrews for upper molar distalization

ABSTRACT Objective: To assess the effectiveness of a customized distalizer with Variety SP® screws anchored on palatal miniscrews for upper molar distalization. Methods: Seventeen patients aged between 12.5 and 24 years underwent distalization with a customized distalizer. Lateral cephalogram and cast analysis were performed before and after distalization. Linear and angular parameters of the upper first molar, first premolar, and central incisor were assessed. Results: Distalization with the force passing near the center of resistance (CRes) of the upper first molars resulted in distal movement, with minimal distal tipping (2.8±0.45°, p<0.05). However, distalization passing occlusal to the CRes led to greater distal tipping (13.6±1.63°, p<0.05). Statistically significant spontaneous distal tipping and distal movement of the upper first premolars occurred, with a mean of 6.2±1.24° (p<0.05) and 0.68±0.34 mm (p<0.05), respectively. The positional change of the upper central incisors presented a mean of -0.23±0.1 mm (p>0.05) and 2.65±1.1° (p<0.05). Upper first molar intrusion was statistically significant, with a mean of 0.88±0.2 mm (p<0.05). Upper right and left first molars rotation towards palatal midline presented mean of 4.1±0.19° (p<0.05) and 3.4 ±0.1° (p<0.05), respectively. Additionally, the distance between upper right and left first molars increased significantly, with a mean of 2.54±0.01 mm (p<0.05). Conclusion: The study successfully demonstrated the efficiency of molar distalization without anchorage loss using a customized distalizer anchored on palatal miniscrews.

RESUMO Objetivo: Avaliar a eficácia de um distalizador personalizado com parafusos Variety SP® ancorado em mini-implantes palatinos para distalização de molares superiores. Métodos: Dezessete pacientes com idade entre 12,5 e 24 anos foram submetidos à distalização com o distalizador customizado. Análises das radiografias cefalométricas laterais e dos modelos de gesso foram realizadas antes e depois da distalização. Foram avaliados parâmetros lineares e angulares dos primeiros molares, primeiros pré-molares e incisivos centrais superiores. Resultados: A distalização com a força passando perto do centro de resistência (CRes) dos primeiros molares superiores resultou em distalização com inclinação mínima (2,8 ± 0,45°, p<0,05). Entretanto, a distalização passando oclusal ao CRes levou a uma maior inclinação para distal (13,6 ± 1,63°, p<0,05). Ocorreu inclinação distal espontânea e movimento distal estatisticamente significativo dos primeiros pré-molares superiores, com média de 6,2 ± 1,24° (p<0,05) e 0,68 ± 0,34 mm (p<0,05), respectivamente. A mudança de posicionamento dos incisivos centrais superiores apresentou média de -0,23 ± 0,1 mm (p>0,05) e 2,65 ± 1,1° (p<0,05). A intrusão dos primeiros molares superiores foi estatisticamente significativa, com média de 0,88 ± 0,2 mm (p<0,05). A rotação dos primeiros molares superiores direito e esquerdo em direção à linha média palatina apresentou média de 4,1 ± 0,19° (p<0,05) e 3,4 ± 0,1° (p<0,05), respectivamente. Além disso, a distância entre os primeiros molares superiores direito e esquerdo aumentou significativamente, com média de 2,54 ± 0,01 mm (p<0,05). Conclusão: O estudo demonstrou com sucesso a eficiência da distalização de molares sem perda de ancoragem utilizando um distalizador customizado ancorado em mini-implantes palatinos.

Effect of flapless piezopuncture on maxillary canine distalization. A preliminary randomized controlled trial

Several methods have been described to shorten orthodontic treatments, but the main disadvantage is their invasiveness. Animal studies have shown that piezopuncture can accelerate the rate of tooth movement without causing collateral damage. Objective: To evaluate the clinical outcome, in terms of safety and efficacy, of a flapless piezopuncture on maxillary canine distalization. Methods: A split-mouth randomized clinical trial was carried out on five patients. Piezopuncture was performed on a random side of the maxillary arch to assess the rate of canine movement on the stimulated side, compared to the non-stimulated control side after 15 (T1), 30 (T2), and 60 (T3) days. Also, immediate side effects and changes in buccal bone thickness after one year were assessed. Results: Distalization on the intervention versus control side at T1 was 1.24±0.21mm versus 0.64±0.33mm (p=0.005); at T2 it was 2.00±0.28mm versus 1.36±0.49mm (p=0.046); and at T3 it was 4.28±0.66mm versus 3.65±0.88mm (p=0.102). No adverse effects related to the surgical procedure were observed or reported by patients. The thickness of the buccal bone plate showed no significant changes. Conclusions: Flapless piezopuncture accelerates the rate of tooth movement in orthodontic patients over the first 15 days and its effect declines over the next 45 days.

Comparative evaluation of displacement and stress distribution pattern during mandibular arch distalization with extra and inter-radicular mini-implants: a three-dimensional finite element study

ABSTRACT Objective: To compare the initial stress distribution and displacement on mandibular dentition using extra and inter-radicular mini-implants for arch distalization, by means of finite element analysis. Methods: For this study, two finite element models of the mandible were designed. The models consisted of periodontal ligament (PDL) and alveolar bone of all teeth until second molars. In the Case 1, bilateral extra-radicular buccal-shelf stainless steel mini-implants (10.0-mm length; 2.0-mm diameter) were placed between first and second permanent molars. In the Case 2, bilateral inter-radicular stainless steel mini-implants (10.0-mm length; 1.5-mm diameter) were placed between second premolar and first permanent molar. Power hook was attached between canine and first premolar at a fixed height of 8mm. In the two cases, 200g of distalization force was applied. ANSYS v. 12.1 software was used to analyze and compare von Mises stress and displacement in the mandibular dentition, PDL and bone. Results: Higher stresses were observed in mandibular dentition with the inter-radicular implant system. The amount of von Mises stress was higher for cortical bone (85.66MPa) and cancellous bone (3.64MPa) in Case 2, in comparison to cortical bone (41.93MPa) and cancellous bone (3.43MPa) in Case 1. The amount of arch distalization was higher for mandible in Case 1 (0.028mm), in comparison to Case 2 (0.026mm). Conclusion: Both systems were clinically safe, but extra-radicular implants showed more effective and controlled distalization pattern, in comparison to inter-radicular implants, in Class III malocclusion treatment.

RESUMO Objetivo: Comparar a distribuição da tensão inicial e o deslocamento na dentição inferior usando mini-implantes extra e inter-radiculares para distalização da arcada, por meio da análise de elementos finitos. Métodos: Dois modelos de elementos finitos da mandíbula foram criados, os quais consistiram de ligamento periodontal (PDL) e osso alveolar de todos os dentes até os segundos molares. No Caso 1, mini-implantes extra-radiculares de aço inoxidável (10,0 mm de comprimento; 2,0 mm de diâmetro) foram colocados bilateralmente na buccal-shelf entre o primeiro e o segundo molares permanentes. No Caso 2, mini-implantes de aço inoxidável inter-radiculares (comprimento de 10,0 mm; diâmetro de 1,5 mm) foram colocados bilateralmente entre o segundo pré-molar e o primeiro molar permanentes. Um Power hook foi preso entre o canino e o primeiro pré-molar a uma altura fixa de 8mm. Nos dois casos, foi aplicada força de distalização de 200g. O software ANSYS v. 12.1 foi usado para analisar e comparar a tensão de von Mises e o deslocamento na dentição inferior, ligamento periodontal e osso. Resultados: Maiores tensões foram observadas na dentição inferior com o sistema de implantes inter-radiculares. A quantidade de tensões de von Mises foi maior para osso cortical (85,66MPa) e osso esponjoso (3,64MPa) no Caso 2, em comparação com osso cortical (41,93MPa) e osso esponjoso (3,43MPa) no Caso 1. A quantidade de distalização da arcada inferior foi maior no Caso 1 (0,028 mm), em comparação com o Caso 2 (0,026 mm). Conclusão: Ambos os sistemas foram clinicamente seguros, mas os implantes extra-radiculares mostraram um padrão de distalização mais eficaz e controlado, em comparação com os implantes inter-radiculares, para tratamento da má oclusão de Classe III.

Three-dimensional finite element study of mandibular first molar distalization with clear aligner / 华西口腔医学杂志

OBJECTIVES@#This study aimed to construct the finite element model of the mandibular first molar with the invisible appliance and explore the dentition movement characteristics of the mandibular first molar when using micro-implant anchorage and different initial positions of the first molar.@*METHODS@#Models of the mandible, tooth, periodontal membrane, and invisible appliance were constructed using cone beam computed tomography (CBCT) data. The two groups were divided into the non-anchorage group and the micro-implant group (between the roots of the first molar and the second molar) based on whether the elastic traction of the micro-implant was assisted or not. The two groups were divided into the following conditions based on the starting position of the first molar: Working condition 1: the distance between the first molar and the second premolar was 0 mm; working condition 2: the distance between the first molar and the second premolar was 1 mm; working condition 3: the distance between the first molar and the second premolar was 2 mm; working condition 4: the distance between the first molar and the second premolar was 3 mm. The data characte-ristics of total displacement and displacement in each direction of dentition were analyzed.@*RESULTS@#In the non-ancho-rage group, all the other teeth showed reverse movement except for the first molar which was moved distally. Meanwhile, in the micro-implant group, except for a small amount of mesial movement of the second molar in wor-king condition 1, the whole dentition in other working conditions presented distal movement and anterior teeth showed lingual movement, among which the distal displacement of the first molar in working condition 4 was the largest. With the change of the initial position of the first molar to the distal, the movement of the first molar to the distal, the premolar to the mesial, and the anterior to the lip increased, while the movement of the second molar to the mesial decreased.@*CONCLUSIONS@#The micro-implant can effectively protect the anterior anchorage, increase the expression rate of molar distancing, and avoid the round-trip movement of the second molar. The initial position of the first molar movement is related to the amount of distancing and the remaining tooth movement.

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.

The Influence of Different Traction Hooks on Tooth Movement During Distalization of the Lower Dentition: A Finite Element Analysis / 医用生物力学

Objective To study stress distributions of lower dentition distally moved with miniscrews in external oblique line area when the traction hooks with different lengths were placed at different positions by the three-dimensional (3D) finite element method. Methods Based on cone beam computed tomography (CBCT) data from a patient, traction hooks with the heights of 2 mm and 7 mm were constructed and fixed between the lateral incisors and the canine brackets, as well as between the canines and the first premolar brackets. Four kinds of 3D finite element models of full dentition distally moved with miniscrews were constructed. The 3 N traction force was loaded between the traction hook and the miniscrews. The maximum von Mises stress and initial displacement of the mandibular teeth and dentition under four working conditions were analyzed. ResultsWhen the traction hook with 7 mm-height was placed between the lateral incisor and the canine, the lower central incisor rotated clockwisely, with the crown moving labially and the root moving lingually. But under the other three working conditions, the central incisor rotated counterclockwisely, and the crown and root moved lingually. When the traction hook with 7 mm-height was placed between the canine and the first premolar, the lower canine crown moved proximally. But under the other three working conditions, both the crown and root moved distally. Under four working conditions, the mandibular molars all rotated counterclockwisely,with the crown and root moving distally. Conclusions Through 3D finite element analysis, biomechanical mechanism of the effect of different traction hooks on mandibular tooth movement during distalization of the lower dentition was elucidated.With full understanding of the biomechanical mechanism, proper selection for length and placement of the traction hook can achieve distal movement of the entire mandibular dentition more efficiently.

Análisis comparativo de tres modelos de prótesis reversa de hombro basados en los nuevos ángulos de distalización y lateralización / Comparative analysis of three models of reverse shoulder prosthesis based on the new angles of distalization and lateralization

Resumen: Objetivo: Comparar resultados funcionales e imagenológicos de tres modelos protésicos según el índice de lateralización y distalización. En un grupo heterogéneo de diagnósticos (fractura, artropatía de manguito, secuela de fractura y artrosis glenohumeral). Material y métodos: Cohorte prospectiva de 33 pacientes sometidos a prótesis reversa de hombro entre Diciembre 2014 y Julio 2017 con un seguimiento mínimo de un año. Se definieron tres grupos, G: 10 pacientes con Grammont clásico (155o, Glena medializada); B: nueve pacientes con Bio-RSA (155o, glena lateralizada ósea); y A: 14 con Arrow (135o, glena lateralizada metálica). Las variables fueron: datos demográficos, clínicos, funcionales y radiológicos (ángulo de lateralización y distalización). Para el análisis estadístico se utilizaron pruebas de ANOVA, T-test y regresión lineal, con una significancia estadística de 5%. Resultados: El ángulo de lateralización del hombro (LSA) fue significativamente mayor en el grupo A (98o A, 79o G, 80o B) (p < 0.05). El ángulo de distalización del hombro (DSA) del grupo B fue significativamente superior al A (52o B, 39o A) (p < 0.05) y no significativamente superior al G (48o G) (p = 0.06). No se demostró una correlación entre el LSA y DSA con la rotación externa (p = 0.51) y elevación activa (p = 0.41), respectivamente. En índices clínicos (elevación anterior, rotación externa, rotación interna) y funcionales (índice Constant ajustado y evaluación subjetiva de hombro) no encontramos diferencias significativas entre los distintos modelos protésicos (p > 0.05). Conclusiones: El ángulo de lateralización fue mayor en el modelo Arrow y distalización en el modelo Bio-RSA. No encontramos correlación clínica-radiológica en esta serie heterogénea de pacientes.

Abstract: Purpose: Compare functional and radiological outcomes of three different designs of reverse shoulder arthroplasty according to distalization and lateralization shoulder angle, in heterogenic diagnostics (fracture, cuff arthropathy, fracture sequela and osteoarthritis). Material and methods: Prospective cohort of 33 patients of reverse shoulder arthroplasty (RSA) between December 2014 and July 2017 with a minimum one year of follow-up. We defined three groups, G: 10 patients with Grammont (155o, Medialized Glena), B: 9 patients with Bio-RSA (155º, lateralized bone glena) and A: 14 patients with Arrow (135o, lateralized metallic glena). We analyze demographic, clinical, functional and radiological outcomes (lateralization shoulder angle (LSA) and distalization shoulder angle (DSA)). For the statistical analysis, ANOVA, T-tests and linear regression tests were used, with a statistical significance of 5%. Results: The LSA was significantly higher in group A (98o A, 79o G, 80o B) (p < 0.05). In DSA, group B was significantly higher than A (52o B, 39o A) (p < 0.05) and not significant to G (48o G) (p = 0.06). There was no correlation of LSA and DSA with external rotation (p = 0.51) and active elevation (p = 0.41), respectively. There was no significant clinical (anterior elevation, external rotation, internal rotation) and functional outcomes (adjusted Constant score and subjective shoulder evaluation) differences between the different RSA models (p > 0.05). Conclusions: The LSA was higher in the Arrow and the DSA was higher in Bio-RSA. We did not find Clinical - Radiological correlation in this heterogeneous series of patients.

Corrección de la altura patelar en inestabilidad rotuliana / Correction of patellar height in patellofemoral instability

El manejo de la inestabilidad patelofemoral se basa en una adecuada evaluación de alteraciones anatómicas predisponentes. Patela alta es una de las causas más importantes de inestabilidad objetiva. La alteración biomecánica que ésta produce puede conducir a luxación patelar recurrente, dolor y cambios degenerativos focales. El examen físico es fundamental en la toma de decisiones. La evaluación imagenológica ha evolucionado desde métodos basados en radiografía hacia mediciones en resonancia magnética, que permiten una orientación más acabada de la relación existente entre la rótula y la tróclea femoral. El tratamiento se fundamenta en la corrección selectiva de los factores causales, donde la osteotomía de descenso de la tuberosidad anterior de la tibia y la reconstrucción del ligamento patelofemoral medial son herramientas que deben considerarse racionalmente. Este artículo realiza una revisión de la literatura, otorgando los fundamentos quirúrgicos que explican la importancia del tratamiento específico de patela alta en inestabilidad rotuliana.

Patellofemoral instability management is based on a thorough evaluation of predisposing anatomical factors. Patella alta is one of the utmost causes of objective instability. As a result, biomechanical disturbance can lead to recurrent patellar instability, pain, and focal degenerative changes. Physical examination is paramount in decision making. Imaging evaluation has evolved from X-rays based methods to magnetic resonance measurements, which allows a more accurate assessment of the patellotrochlear relationship. Treatment is based on a selective risk factors correction, where tibial tubercle distalization osteotomy and medial patellofemoral ligament reconstruction must be considered altogether. This article reviews the surgical rationale of patella alta treatment in patellofemoral instability.

Efficacy of mandibular molar distalization by clear aligner treatment / 中南大学学报(医学版)

OBJECTIVES@#At present, the research on clear aligner of molar distalization mainly focuses on the upper jaw, while the research on mandibular molars is few.This study aims to evaluate the therapeutic effect of mandibular molars distalization with clear aligner via cone beam CT (CBCT) and Dolphin software.@*METHODS@#Twenty cases of mandibular molars with clear aligner were included according to the inclusion and exclusion criteria. CBCT was taken before treatment (T0) and when the first molar was moved in place (T1). Dolphin software was used to measure the effectiveness of molar distalization. Three-dimensional changes in direction and the impact on the incisors and facial soft and hard tissues were evaluated.@*RESULTS@#The effective rates of crown and root distalization of the second and first mandibular molars were 74%, 49%, and 71%, 47%, respectively. The second and first molars were both the distal buccal cusp with the largest distalization [(2.15 ± 0.91) mm and (1.85±1.09) mm], respectively, with significant difference between the T0 and T1 (@*CONCLUSIONS@#Clear aligner can effectively move mandibular molars farther, the crown is more effective than the root, and it is tilted. The second mandibular molar is more effective than the first mandibular molar in its distant displacement and three-dimensional changes. Molar distalization causes minor changes in mandibular incisors and facial soft and hard tissues.

Non-Extraction Treatment of Severe Anterior Crowding with Unilateral Distalization

Introduction: Recent developments in mechanotherapy andchanges in concepts have reduced the need for extraction inseveral types of discrepancies.Case report: This case report explains a non-extractiontreatment in a patient with severe anterior crowding with theuse of a modified Hilger’s Pendulum appliance. The patientshowed unilateral half unit Class II molar relation on theleft. The appliance was modified to cater to the treatmentneeds and activation was done unilaterally to achieve thedesired results. Post distalization, fixed orthodontic treatmentwas initiated and crowding was relieved with levelling andaligning.Conclusion: An ideal overjet and overbite along withmaintenance of the pleasing profile was achieved at the endof the treatment

Resolución de clase II mordida profunda con distalamiento molar mini-iimplantoasistida: reporte de caso clínico / Resolution of a class II deep bite with mini-implant-assisted molar distal movement; report of a clinical case

En todos los tratamientos ortodónticos, el primer objetivo a cumplir es alinear y nivelar las piezas dentales. Para tal fin, deberíamos generar espacio dentro del arco dentario. Existen tres procedimientos diferentes para lograr este objetivo, según el grado de apiñamiento dental o Índice de nance, que son los siguientes: a) stripping o desgaste interproximal, b) exodoncia de piezas dentales y c) distalamiento. La distalización de los molares es una de las técnicas más antiguas de la terapéutica ortodóntica y se han empleado distintos recursos terapéuticos para tal fin, como pendulum, jig de jans, first class, entre otros; cada uno con sus ventajas y desventajas. La introducción de los mini-implantes dentro de nuestra especialidad ha revolucionado en forma drástica los conceptos de anclaje, brindándonos movimientos dentarios sin generar efectos colaterales indeseables. El objetivo de este caso clínico, es mostrar la utilización de un Orthorama modificado y mini-implantes como distaladores de los molares superiores (AU)

Combined operation involving tibial tubercle distalization for recurrent patellar dislocation with patella alta / 中国修复重建外科杂志

Objective: To explore the clinical effects of combined operation involving tibial tubercle distalization for the recurrent patellar dislocation with patella alta. Methods: Between April 2010 and May 2016, 14 cases of recurrent patellar dislocation with patella alta were treated with combined operation involving tibial tubercle distalization. There were 5 males and 9 females with an average age of 18.5 years (range, 13-26 years). The left knee was involved in 9 cases and the right knee in 5 cases. The patella had dislocated 3.3 times on average (range, 2-5 times). The interval between the first dislocation and admission was 19.7 months on average (range, 4-60 months), and the main symptoms were knee pain and limited knee movement. Preoperative X-ray films, CT, and MRI examinations of knee joint showed that the epiphyseal plate closed in all patients. Of all patients, 3 patients had avulsion fracture of the inner edge of patella, and 2 patients had free body in articular cavity. The tibial tuberosity-trochlear groove (TT-TG) distance, patellar-trochlear-groove distance, Caton-Deschamps index, knee range of motion (ROM), Lysholm score, International Knee Documentation Committee (IKDC) score, Kujala score, and Tegner score were compared pre- and post-operation. Results: All patients had primary wound healing. All patients were followed up 24-72 months with an average of 34.6 months. X-ray film and CT examination showed that the patellar dislocation was corrected and the osteotomy of the tibial tubercle healed with an average healing time of 3.8 months (range, 3-5 month). At 1 day and 1 year after operation, the TT-TG distance, patellar-trochlear-groove distance, and Caton-Deschamps index showed significant differences when compared with preoperative values ( P0.05). At the 1 year and 2 years after operation, the knee ROM, Lysholm score, IKDC score, Kujala score, and Tegner score showed significant differences when compared with preoperative values ( P0.05). Conclusion: Combined operation involving tibial tubercle distalization is a safe and reliable method, which has satisfactory short-term effectiveness for the recurrent patellar dislocation with patella alta.

Treatment of class II malocclusion and unerupted upper canines with self-ligating appliance

Treatments without tooth extractions have become more popular over the last two decades. In this context, expansion of the maxillary arch is an interesting treatment option for cases in which space is required and other factors not favoring extractions (such as the facial profile) are present. According to several authors, this posterior expansion can be obtained using a system comprising self-ligating brackets and superelastic nickel-titanium arches. The present article aims to report a case of a young patient with Class II, Division 2 malocclusion, with impacted upper canines and significant arch length-tooth discrepancy. Methods: The case was treated by means of a passive self-ligating appliance in association with Class II elastics and coil spring for distalizing the molars. This treatment alternative was effective for correcting Class II and obtaining space to correct tooth positioning.

The clinical effects of Invisalign-aided molar distalization in the treatment of mild or moderate crowding in anterior teeth / 口腔疾病防治

Objective@# The present study evaluated the clinical effects of Invisalign-aided molar distalization in the treatment of mild or moderate crowding in anterior teeth. @*Methods@#Eleven adults with class Ⅱ dental malocclusion and a class Ⅰ skeletal pattern were selected as subjects. The patients’ molar occlusion did not exhibit an end-to-end relationship. Subjects were selected for straight profile, mild or moderate crowding in maxillary teeth and normal or mild crowding in mandibular teeth. Nonextraction and Invisalign-aided molar distalization were planned for treatment. Model measurement and cephalometric analysis were performed before and after treatment. A paired t test was used for the statistical analysis.@*Results@#The crowding and class Ⅱ molar relationship were corrected in all 11 patients. The upper first molars were moved distally by 2.32 mm (t = 3.315, P < 0.01) and were inclined distally by 3.35° (t = 3.959, P < 0.01) on average. The central incisors were protruded by 1.72 ° (t = 3.274, P < 0.01) on average. The buccal movement of the upper first molars was 1.32 mm (t = 2.461, P < 0.05) on average. The above differences were statistically significant. @*Conclusion @#Upper molar distalization can be achieved using a class Ⅱ elastic-aided Invisalign technique. The end-to-end molar occlusion can be corrected, and front teeth with mild or moderate crowding can be aligned using our treatment protocol.

Distalizador PC ­ distalização de molares superiores em indivíduos Classe II dentária: uma nova versão / Distalization appliance PC ­ superior molars distalization on dental Class II malocclusion individuals: a new version

O presente artigo apresenta uma nova versão do aparelho de Distalização de molares superiores em indivíduos de Classe II dentária, nomeado DISTALIZADOR PC. A Distalização de molares com o uso dos aparelhos intrabucais atuais possui efeitos negativos, como a perda de ancoragem (efeito rebote), rotação e inclinação de molar, higienização precária (podendo gerar lesões no palato) e a necessidade da confecção de um novo aparelho para ancorar os molares após a distalização. O aparelho propõe uma nova mecânica, cujos efeitos positivos são a ausência de efeito rebote, a fácil confecção, a fácil adaptação pelo paciente (cuja dicção não é afetada), fácil higienização, baixo custo e a exclusão da necessidade de novo aparelho para ancoragem de molares, pois o mesmo se torna a ferramenta necessária para tal. Além disso, permite escolher a quantidade exata de distalização, sendo essa uni ou bilateral. O artigo apresenta, portanto, casos clínicos de sucesso em indivíduo jovem e jovem adulto, de-monstrando a instalação do DISTALIZADOR PC e sua performance, confirmando as vantagens acima mencionadas. Por fim, demonstra-se a confecção do aparelho, dispensando a fase laboratorial e mostrando sua simples montagem, de forma a reafirmar como o aparelho é próprio para o uso clínico fácil e prático para os profissionais da área.(AU)

This article presents a new version of molars distalization appliance for Dental Class II individuals, named DISTALIZATION APPLIANCE PC. The distalization of molars with the use of current oral appliances has negative effects, such as loss of anchorage (rebound effect), rotation and molar inclination, poor hygiene (which may cause lesions on the palate) and the need to make a new device to anchor molars after distalization. This new appliance proposes an innovative mechanic, whose positive effects are the elimination of rebound effect, easy manufacturing, easy adaptation by the patient (whose speech is not affected), easy to clean, low cost and the exclusion of the need for new equipment to anchor molars, as it becomes the necessary appliance to do it. In addition, it allows choosing the exact amount of distalization, which is unilateral or bilateral. The article therefore presents clinical case studies of young and young adults people, demonstrating the installation of DISTALIZATION APPLIANCE PC and its performance, confirming the above mentioned advantages. Finally, it demonstrates how to manufacture the appliance, eliminating the laboratory phase and showing its simple manufacturing, in order to reaffirm how the device is suitable for professional's easy and practical clinical use.(AU)

Evaluation of the invisible bracketless appliance on maxillary molar distalization / 实用口腔医学杂志

Objective:To evaluate the clinical effects of invisible bracketless appliance on the upper molar distalization.Methods:15 patients with class Ⅱ malocclusion(at the average age of 25.3 years) were treated by invisible bracketless appliance,the pre and post three-dimensional digital models were superimposed and measured,the effects of molar distalization were analysed.Results:After treatment,the maxillary first molars were distalized by 2.58 mm on both sides.The left and fight second molars were distalized by 2.57 mm and 2.68 mm respectively.Bilateral central incisors were moved mesially by 0.34 mm.There was no significant difference in the horizontal movement of central incisor.But the left and fight first molars were moved buccally by 0.96 mm and 0.97 mm respectively,the left and fight second molars were moved buccally by 1.01 mm and 1.11 mm separately.Bilateral first molars were intruded by 0.26 mm,the left and right second molars were intruded by 0.37 mm and 0.36 mm,respectively.But the central incisors had no significant vertical movement.There was no significant difference in the buccally or palatally rotation of bilateral first and second molars.Conclusion:Invisible bracketless appliance is efficient for distalization of upper molar,but it may result in mild molar intrusion and anterior anchorage loss.

Biomechanical analysis of distalization of mandibular molars by placing a mini-plate: A finite element study / 대한치과교정학회지

OBJECTIVE: The objective of this study was to analyze the patterns of tooth movements when distalization of mandibular molars using a mini-plate took place. A finite element analysis was applied to analyze patterns of tooth movements. METHODS: The model of the mandible and teeth were used to build a finite element analysis model, and a mini-plate was inserted in the mandibular ramus. Two different orthodontic forces were established for displacement of mandibular molars. Orthodontic forces were applied at the level of the bracket and at the level of the cemento-enamel junction in the mandibular canine respectively. RESULTS: orthodontic forces at the level of the cemento-enamel junction resulted in a greater biomechanical bodily movement in distalization of the mandibular molars compared to when the orthodontic forces were applied at the level of the bracket. Applying orthodontic forces to the cemento-enamel junction also resulted in unwanted greater extrusive movements in distalization of the mandibular molars compared to the bracket level. CONCLUSIONS: With considering the mode of orthodontic teeth movement, applying different vertical orthodontic forces for distalization of mandibular molars can lead to more effective distalization of teeth.

Immediate changes in the mandibular dentition after maxillary molar distalization using headgear / 대한치과교정학회지

The purpose of this study was to investigate immediate changes in the mandibular dentition after maxillary molar distalization using headgear in non-growing patients. Sixteen patients (mean age, 18.9 ± 2.0 years) with Class II molar relationship and crowding were included in the present study. To correct the molar relationship, headgear was used for maxillary molar distalization. Cone-beam computed tomography-generated half-cephalograms (CG Cephs) and dental casts were used to evaluate dental changes for each subject before and immediately after molar distalization using headgear. The mean duration that subjects wore the headgear was 6.3 months. CG Cephs showed that the first maxillary molars were distalized 4.2 ± 1.6 mm with 9.7°± 6.1° of distal angulation. The intercanine, interpremolar, and intermolar widths of the mandible increased after maxillary molar distalization. The present study's results suggest that maxillary molar distalization using headgear induces a spontaneous response in the untreated mandibular dentition of non-growing patients.

Distalización de molares maxilares utilizando dispositivos de anclaje esqueletal directo en pacientes con maloclusiones Clase II. Revisión bibliográfica

Introducción: La relación molar de Clase II de Angle se encuentra aproximadamente en un 20% de la población. Cuando la maloclusión es de origen dentario, generada principalmente por una migración de los segmentos laterales, la opción de tratamiento más frecuente para generar espacio y establecer una relación molar de Clase I, es la distalización molar. Un gran número de aparatos y protocolos de tratamiento se han descrito en la literatura. Uno de los más utilizados es el Péndulo, pero debido a su diseño que utiliza anclaje dentario, y a que su fuerza pasa a nivel de la corona de los primeros molares, presenta muchas desventajas. Objetivo: El propósito de esta revisión es analizar los dispositivos de distalización molar que utilizan anclaje esqueletal directo, en los que la fuerza aplicada pasa cerca del centro de resistencia del primer molar superior, con el objetivo de determinar si son superiores en cuanto a eficiencia y minimización de los efectos adversos, cuando se compara con los aparatos convencionales. Resultado: De un total de 25 artículos seleccionados con base en el año de publicación y el empleo de anclaje esqueletal, se utilizaron 7 artículos para revisión, basados en criterios de inclusión y exclusión. Discusión: Al comparar los aparatos, se observa gran variabilidad en duración de tratamiento, cantidad y tasa de distalización. A pesar de estas diferencias todos mostraron éxito clínico el finalizar la mecánica de distalización. Por otra parte, existe una distalización espontánea de los segundos premolares superiores e incluso de los primeros premolares, pero con estos dispositivos que no utilizan estas piezas dentarias como anclaje y que, por lo tanto, quedan libres y son distalizados con la ayuda de las fibras transeptales. Conclusión: Se concluye que la distalización molar ha demostrado ser un procedimiento eficaz cuando se utilizan aparatos con anclaje esqueletal directo y con un vector de fuerza que pase cerca del centro de resistencia de los primeros molares. Estos métodos no generan efectos secundarios en la región de anclaje cuando se compara con aparatos convencionales, donde existen migración mesial de premolares y piezas anteriores. En todos los casos analizados los molares superiores se distalizaron a una relación de clase I en un corto período , incluso a pesar de la presencia de los segundos y terceros molares maxilares.

Introduction: The Angle Class II molar ratio is approximately 20% of the population. When malocclusion is of dental origin, mainly generated by a migration of lateral segments, the most frequent treatment option to generate space and to establish a Class I molar relationship is molar distalization. A large number of treatment devices and protocols have been described in the literature. One of the most used is the Pendulum, but because of its design that uses dental anchorage and its force happens at the level of the crown of the first molars, presents many disadvantages. Objective: The purpose of this review is to analyze molar distalization devices using direct skeletal anchors, in which the applied force passes near the center of resistance of the upper first molar, in order to determine if they are superior in efficiency and minimization of adverse effects when compared with conventional appliances. Results: The search process included a total of 25 articles selected based on year of publication and use of skeletal anchorage, 7 articles were finally used for review, based on inclusion and exclusion criteria. Discussion: When comparing the devices, there is great variability in duration of treatment, amount of distalization and rate of distalization. In spite of these differences all showed clinical success to finalize the mechanics of distalization. On the other hand, here is a spontaneous distalization of the second upper premolars and even the first premolars with these devices that do not use these dental pieces as an anchorage, therefore, they remain free and are distalized with the help of the transseptal fibers. Conclusion: It is concluded that molar distalization has proved to be an effective procedure when using devices with direct skeletal anchors and with a force vector passing close to the resistance center of the first molars. These methods do not generate side effects in the anchoring region when compared to conventional apparatus where there is mesial migration of premolars and anterior parts. In all the cases analyzed, the maxillary molars were distalized to a class I relationship in a short period of time, even in spite of the presence of the second and third maxillary molars.

Changes produced by the pendulum appliance with skeletal anchorage and comparison with conventional pendulum appliance / Alterações produzidas com o aparelho pêndulo com ancoragem esquelética e comparação com o aparelho pêndulo convencional

Os propósitos destas pesquisas foram primeiramente avaliar as alterações esqueléticas, dento-alveolares e tegumentares obtidas com o aparelho pêndulo com ancoragem esquelética (BAPA) em pacientes com má oclusão Classe II e, posteriormente compará-los com os efeitos produzidos com o aparelho pêndulo com ancoragem convencional (CPA). A amostra composta de 18 pacientes (14 meninas;4 meninos) com idade média de 14.01 (D.P. 1.08) com má oclusão de Classe II tratados com BAPA como dispositivo distalizador antes do aparelho fixo, no Departamento de Ortodontia da Faculdade de Odontologia da Universidade Cidade de São Paulo. Telerradiografias laterais foram tomadas no início do tratamento (T0) e no final da distalização (T1), mensuradas e posteriormente analisadas estatisticamente. Apenas o período da distalização ativa foi avaliado. O grupo controle foi composto de 18 pacientes (14 meninas;4 meninos) com idade média de 13.61 (D.P. 1.24) com a mesma má oclusão tratados com CPA como dispositivo distalizador antes do aparelho fixo, no Departamento de Ortodontia da Faculdade de Odontologia de Bauru, Universidade de São Paulo. Para avaliar os efeitos desta amostra foi utilizada a mesma metodologia acima mencionada. Posteriormente, para comparar as alterações entre os grupos, a amostra tratada com CPA foi denominada Grupo 1 (G1), e a amostra tratada com BAPA denominada Grupo 2 (G2). O tempo médio de distalização foi 5.76 e 6.16 meses, no G1 e G2 respectivamente. Ambos os grupos foram compatibilizados em relação à idade inicial, tempo de tratamento, severidade da má oclusão de Classe II e características cefalométricas iniciais. A comparação intra-grupo foi realizada com teste t dependente, e a comparação intergrupos foi realizada com o teste t. Em G2 houve aumento significante da altura facial anteroinferior, distalização molar, inclinação distal e intrusão significante dos primeiros e segundos molares superiores. Os primeiros pré-molares apresentaram distalização e extrusão significantes. A sobremordida diminuiu e a relação molar melhoraram significativamente. Comparando as alterações do tratamento entre grupos, foram significativamente maiores a distalização, inclinação distal e intrusão dos primeiros molares no G2 comparados ao G1. Os incisivos superiores inclinaram para vestibular no G1, e ligeiramente retroinclinaram para lingual no G2, além disso os primeiros pré-molares foram distalizados no G2, porém foram mesializados no G1. O Grupo 1 apresentou aumento significativamente maior da sobressaliência, e menor correção da relação molar de Classe II do que G2. A distalização dos molares superiores foi obtida com sucesso em ambos os grupos, entretanto, utilizando o BAPA observou-se várias vantagens, tais como: Distalização exclusiva dos molares superiores; movimento distal espontâneo dos pré-molares superiores; sem efeitos colaterais indesejáveis nos incisivos superiores e nos lábios; e também o estabelecimento de uma relação molar de Classe I.(AU)

The purposes of these investigations were firstly to evaluate the dentoalveolar, skeletal and soft tissue effects obtained with the bone-anchored pendulum appliance (BAPA) in patients with Class II malocclusion and secondly, to compare these effects with the conventional pendulum appliance (CPA). A sample of 18 patients (14 females; 4 males) with a mean age of 14.01 years (S.D 1.08) with Class II malocclusion treated with BAPA as distalizer device before fixed appliance in Orthodontic Department at the Dental School, University of São Paulo City. Lateral headfilms were taken at the beginning of treatment (T0) and at the end of distalization period (T1), measured and then statistically analyzed. Only the active distalization period was evaluated. The comparison group was composed by 18 patients (14 females; 4 males) with a mean age of 13.61 years (S.D 1.24) with the same malocclusion treated with CPA before fixed appliance in Orthodontic Department at Bauru Dental School, University of São Paulo. To evaluate the effects in this sample was used the same methodology abovementioned. Then, to compare changes between groups, the sample treated with CPA was named Group 1 (G1), and the sample treated with BAPA was named Group 2 (G2). The average distalization period was 5.76 and 6.16 months, respectively for G1 and G2. Both groups were compatibilized regarding initial age, treatment time, severity of Class II malocclusion and initial cephalometric characteristics. Intragroup comparisons were performed using dependent t tests and intergroup comparisons were performed using t tests. In G2 there was significant increase in the lower anterior face height, molar distalization, distal tipping and intrusion of the first and second maxillary molars. The first premolars had significant distalization and extrusion. Overbite significantly decreased and molar relationship was significantly improved. Comparing the groups, there were significantly greater maxillary first molar distalization, distal tipping and intrusion in G2 compared to G1. The maxillary incisors were labially tipped in G1 and lingually tipped in G2. The first premolars were distalized in G2 while were mesialized in G1. G1 showed a significantly greater overjet increase and smaller Class II molar relationship correction than G2. Distalization of the maxillary molars was successfully achieved in both groups, but using the BAPA several advantages were observed including exclusive maxillary molars distalization, spontaneous distal movement of the maxillary premolars, no undesirable side effects in the maxillary incisors and lips and establishment of a Class I molar relationship.(AU)