Evaluation of Head and Cervical Spine Posture after Therapy with Maxillary Protraction Appliances / Evaluación de la Postura de la Cabeza y la Columna Cervical Después de la Terapia con Aparatos de Protracción Maxilar

SUMMARY: The objective of this study was to evaluate the changes of head and cervical spine posture of skeletal class malocclusion in adolescent with maxillary protraction. Thirty cases of skeletal class malocclusion were randomly selected from the Stomatological Hospital of Shanxi Medical University. High-quality lateral cephalograms were collected including pre- and posttreatment to compare the changes of head and cervical spine posture. Data were processed using SPSS 26.0 statistical software. The paired-t test was used to compare pre- and posttreatment mean angular measurements.A significant difference in the SNA(p<0.001), SNB(p<0.01), and ANB(p<0.001) between T1 and T2 showed an improvement in the sagittal relationships. A significant change was observed in middle cervical spine posture, while upper cervical spine posture variables showed no significant difference after treatment. Skeletal class with maxillary protraction appliance not only led to the improvement of sagittal relationship, but also changed the middle cervical spine posture.

El objetivo de este estudio fue evaluar los cambios en la postura de la cabeza y la columna cervical debido a la maloclusión clase esquelética en adolescentes con protracción maxilar. Treinta casos de maloclusión de clase esquelética fueron seleccionados al azar del Hospital Estomatológico de la Universidad Médica de Shanxi. Se recogieron cefalogramas laterales de alta calidad, incluidos el tratamiento previo y posterior, para comparar los cambios en la postura de la cabeza y la columna cervical. Los datos se procesaron con el software estadístico SPSS 26.0. Se utilizó la prueba t pareada para comparar las medidas angulares medias antes y después del tratamiento. Una diferencia significativa en SNA (p <0,001), SNB (p <0,01) y ANB (p <0,001) entre T1 y T2 mostró una mejora en las relaciones sagitales. Se observó un cambio significativo en la postura de la columna cervical media, mientras que las variables de postura de la columna cervical superior no mostraron diferencias significativas después del tratamiento. La clase esquelética con aparato de protracción maxilar no solo condujo a la mejora de la relación sagital, sino que también cambió la postura de la columna cervical media.

Correlation analysis of temporomandibular joint changes after maxillary protraction in adolescent patients / 口腔疾病防治

Objective @#To study the effect of anterior traction on the temporomandibular joint in adolescent patients with skeletal Class Ⅲ malocclusion.@*Methods@#Twenty-nine patients with early permanent dentition with skeletal class Ⅲ malocclusions were measured by cephalometry and a coordinate system before and after maxillary protraction. The correlation between dentofacial structures and the temporomandibular joint was analyzed. @*Results @# After maxillary protraction, cephalometric measurements showed that the dentofacial structure changed significantly; ANB increased by 3.97° ± 2.32° (P<0.001); U1-SN increased by 4.97° ± 5.51° (P<0.001); L1-MP decreased by 1.26° ± 1.41° (P = 0.008); and MP-SN increased by 1.02° ± 3.90° (P = 0.003). The coordinate system measurement showed that the S-Fpx was decreased by 0.16 ± 1.52 mm (P = 0.041), the S-Ciy distance was significantly decreased by 0.09 ± 2.03 mm (P = 0.028), and there was no significant change in the temporomandibular joint spaces (A, P, and C) (P>0.05). Correlation analysis showed a moderate negative correlation between the posterior margin of the temporomandibular joint fossa and U1-SN (r = -0.427, P = 0.042). There was a moderate positive correlation between the leading edge of the condyle and ANB (r = 0.425, P = 0.043); there was no correlation between the joint space and dentofacial changes. @* Conclusion@#After treatment with maxillary protraction for adolescent skeletal class Ⅲ malocclusion, maxillary protraction had some effect on changes in the temporomandibular joint fossa and condyle and had no effect on the joint space.

Influences of Stress Distribution on Bone-Anchored Maxillary Protraction at Different Protraction Sites / 医用生物力学

Objective To evaluate the influence of stress distributions on bone-anchored maxillary protraction at different protraction sites, so as to guide patients to choose an optimal protraction site in clinic. Methods A three-dimensional (3D) finite element model of child head with implant anchorages was establised. Four protraction sites were set according to the position of implant installation. Working condition 1: the alveolar bone at the intersection of distal 2 mm of primary lateral incisor crown distal surface and gingival cervical margin to 5 mm. Working condition 2: the alveolar bone at the intersection of mesial 2 mm of maxillary first primary molar crown mesial surface and gingival cervical margin to 5 mm. Working condition 3: the alveolar bone at the intersection of mesial 2 mm of maxillary first molar crown mesial surface and gingival cervical margin to 5 mm. Working condition 4: the alveolar bone at the intersection of distal 2 mm of maxillary first molar crown distal surface and gingival cervical margin to 5 mm. The finite element models were loaded with 500 g protraction force at each side with 30° forward direction to the occlusal plane. Stress distributions on each suture were analysed. Results The maximum stress of frontomaxillary suture was in working condition 2 (1 477-28 190 Pa). The maximum stress of nasomaxillary suture was in working condition 1 (5.296-924 Pa). The maximum stress of zygomaticomaxillary suture was in working condition 4(394.7-13 130 Pa). The maximum stress of zygomaticofrontalis suture was in working condition 4 (495.2-31 690 Pa). The maximum stress of zygomaticotemporal suture was in working condition 3 (1 148-15 870 Pa). The maximum stress of medianpalatine suture was in working condition I (6.479-730 Pa). Conclusions When the protraction sites are set in distal maxillary primary lateral incisor and mesial maxillary first primary molar, it is of positive significance to improve the concave profile, especially in nose root. When the protraction sites are set in mesial or distal maxillary first molar, it is of positive significance to improve the concave profile, especially in maxillary basal bone of the midface.

Corrección de una clase III esqueletal con anclaje óseo en paciente en crecimiento: Reporte de caso / Skeletal class III correction in growing patient with bone anchorage: CaseReport

Antecedentes: La clase III esqueletal, es una deformidad dentofacial donde el tercio inferior de la cara es más prominente, el tratamiento se decide según la etiología y la edad del paciente; si se encuentra en crecimiento la malformación puede ser tratada con un protocolo interceptivo y si es posible evitar la cirugía ortognática a futuro. Objetivo: Mejorar la clase esqueletal, descruzar la mordida u obtener mordida borde a borde, mejorar la posición del labio superior y evaluar el comparativo inicial-final de SNA y ANB. Reporte de caso:Paciente masculino de 13 años, sin antecedentes personales patológicos o familiares reportados; presenta clase III esqueletal responsiva bimaxilar, crecimiento vertical, clase molar I y canina III; fue tratado con el protocolo de mini placas BAMP (bone anchored maxillary protraction) por sus siglas en inglés, elásticos intermaxilares y un paladar con pistas planas. Resultados:La fase ortopédica duro cinco meses y se logró mordida borde a borde y clase I esqueletal. Discusión: Se obtuvieron resultados con el uso de mini implantes sin anclaje extraoral en menos tiempo a comparación de otros métodos que tienen que ser usados por 9-12 meses.Conclusión:El protocolo BAMP puede ser usado en pacientes en crecimiento sin máscara facial para corregir la clase III esqueletal.

Background: Skeletal class III is a dentofacial deformity where the lower third ofthe face is more prominent. The treatment is decided according to the etiology and age of the patient; If the patient is in growing, the malformation can be treated with an interceptive protocol and if possible, avoid a orthognathic surgery in the future. Objective: Improve the skeletal class, uncross the bite or obtain an edge-to-edge bite, improve the position of the upper lip and compare the initial-final relationship of ANS and ANB.Case report:13-year-old male patient, with no reported pathological or family history; presents skeletal class III, vertical growth, molar class I and canine III; he was treated with the protocol of mini BAMP (bone anchored maxillary protraction) plates, intermaxillary elastics and a palate with flat tracks. Results:The orthopedic phase lasted five months and an edge-to-edge bite and skeletal class I were achieved.Discussion:Results were obtained with the use of mini plates without extraoralanchorage in less time compared to other methods that have to be used for 9-12 months. Conclusion: The BAMP protocol can be used in growing patients without a face mask to correct skeletal class III.

Structural changes of the temporomandibular joint in adolescents with skeletal class III malocclusions after maxillary protraction: An X-ray measurement analysis / 中国组织工程研究

BACKGROUND: For skeletal Class III malocclusions, the positional relationship between the upper and lower jaws and abnormal occlusion can impact the shape of the condyle and the glenoid fossa, as well as the movement of the mandible and the function of the masticatory muscles. Maxillary protraction appliances are one of the effective methods for the treatment of skeletal Class III malocclusion in adolescents, which can reconstruct the positional relationship of the jaws and improve the glenoid fossa-disc-protrusion relationship in patients with skeletal Class III malocclusion. OBJECTIVE: To evaluate the temporomandibular joint changes in adolescents with skeletal Class III malocclusions treated with maxillary protraction. METHODS: Twenty-nine patients (11 girls and 18 boys; age range from 12-14, with a mean age of (12.90±0.99) years were treated with maxillary protraction. Lateral cephalograms were taken before and after treatment. A coordinate system was set to quantitatively analyze the changes of temporomandibular joint fossa, condyle and temporomandibular joint spaces in sagittal and vertical directions. RESULTS AND CONCLUSION: After maxillary protraction, no displacement of the gleniod fossa and the condyle in the sagittal direction was observed (P > 0.05). Simultaneously, in the vertical direction, there was no significant displacement of the gleniod fossa as well as no posterior and superior condyle displacement (P > 0.05). However, the anterior condyle moved upward (P 0.05). These findings indicate that maxillary protraction treatment can adaptively remodel the temporomandibular joint in adolescents with skeletal Class III malocclusion will undergo adaptive remodeling, but will not adversely affect the function of the temporomandibular joint due to the unchanged joint space.

Una Descripción General y Actualizada de Miniplacas y Minitornillos. Efectos Dentoalveolares y Esqueléticos / A General and Updated Description of Miniplates and Miniscrews. Dentoalveolar and Skeletal Effects

RESUMEN: En ortodoncia, las miniplacas se utilizan como dispositivo de anclaje temporal (TAD) para la realización de movimientos dentales que permiten el uso de fuerzas ortopédicas en ellos. En comparación con los mini tornillos, las miniplacas tienen la ventaja de una tasa de falla muy baja, pero la desventaja es que para la extracción se necesita el mismo acto quirúrgico que se realizó para la instalación. El objetivo de este estudio es realizar una revisión bibliográfica de las indicaciones de miniplacas en pacientes con mordidas abiertas, clase II y anomalías de clase III, y buscar cómo las miniplacas han mejorado los tratamientos de ortodoncia. La información principal se reunió buscando en PubMed con las palabras clave enumeradas a continuación. Afirmamos que las miniplacas están indicadas para la retracción en masa de la arcada, donde se observó que la fuerza de 150 g aplicada en los molares superiores es suficiente no solo para empujar los molares hacia atrás en una clase I corregida, sino también para iniciar la retracción de premolares, caninos e incisivos. En pacientes con mordida abierta, las miniplacas se definen como un método seguro, una alternativa rápida y menos costosa a la cirugía ortognática. Y en pacientes de las clases II y III se utilizan sin producir efectos dentoalveolares que sustituyan a los dispositivos extraorales como máscaras, con dispositivos intraorales y elásticos (BAMP).

ABSTRACT: In orthodontics, miniplates are used as a Temporary Anchoring Device (TAD) for the purpose dental movements, allowing the use of orthopedic forces. In comparison with mini-screws, miniplates have the advantage of a very low rate of failure. Nonetheless, their removal requires the same surgical procedure as during installation, which is an obvious disadvantage. The aim of this study is to review the indications of miniplates in patients with open bite, class II and class III anomalies, and review how miniplates improved orthodontics treatments. Information was obtained by a search in PubMed with the keywords listed below. Miniplates are indicated for retraction in mass of the arcade, where it was seen that the force of 150 g applied on maxillary molars, is sufficient not only to push the molars back into a corrected class I, but also to initiate retraction of premolars, canines, and incisors. In open-bite patients, mini plates, are achieved as a safe method, that is quick and a less expensive alternative to orthognathic surgery. Further, in class II and III patients they are used without producing dentoalveolar effects replacing extraoral devices as facemasks, with intraoral devices and elastics. (BAMP).

Immediate and late follow-up effects of class III early correction in cleft lip and palate patients treated with maxillary protraction / Efeitos imediatos e a longo prazo da correção precoce da classe III em pacientes com fissura lábio palatal tratados com protração maxilar

Abstract Introduction There is no consensus about the immediate and latte follow-up effects of maxillary protraction in cleft lip and palate patients. Objective To evaluate the stability of Class III early treatment in cleft lip and palate patients through maxillary expansion and protraction. Material and method The sample consists in three lateral cephalometric radiographs of 28 patients (mean pre-treatment age of 6.7±1.8 years) who presented cleft lip and palate and were treated with maxillary expansion and Petit facial mask. The angular (SNA, SNB, ANB, SN.GoGn, FMA, Z Angle) and linear (overjet, Co-A, Co-Gn, Nperp-A, Nperp-Pg, AO-BO) cephalometric measures were evaluated through the Dolphin® software, in three moments: T0 (initial), T1 (after treatment), and T2 (follow-up). Data were submitted to the analysis of variance (ANOVA) and Tukey-Kramer test. The correlation between cephalometric measures and patient's age was determined by Pearson's chi-squared test. Result The SNA, ANB, and AO-BO measures increased considerably (p<0.05), and they did not present any differences compared to the initial ones after the follow-up time. The overjet measure increased (p<0.05) after treatment and, even with its decrease at the follow-up time, it was still higher than at the beginning (p<0.05). The Z angle showed improvement with treatment and remained stable at the follow-up time. Conclusion After treatment (maxillary expansion associated with protraction), there was a skeletal pattern improvement. During the follow-up period, those alterations decreased to a measure close to the beginning. There was an improvement in the dental pattern and facial profile that continued in the follow-up period.

Resumo Introdução Não há consenso sobre os efeitos imediatos e tardios da protração maxilar em pacientes com fissura lábio palatal. Objetivo avaliar a estabilidade do tratamento precoce da Classe III em pacientes com fissura labiopalatina por meio da expansão e protração maxilar. Material e método A amostra consistiu de 28 pacientes com fissura lábio palatal com (média de idade pré tratamento de 6.7±1.8) com fissura lábio palatal transforame unilateral, tratados com disjuntor maxilar e com máscara facial de Petit. Por meio de análise em telerradiografias laterais as grandezas angulares (SNA, SNB, ANB, SN.GoGn, FMA, Ângulo Z) e lineares (overjet, Co-A, Co-Gn, Nperp-A, Nperp-Pg, AO-BO) foram avaliadas, com o software Dolphin®, nos tempos: inicial (T0), após o tratamento (T1) e acompanhamento de 2 a 6 anos (T2). Os dados foram submetidos à ANOVA e teste Tukey-Kramer. A correlação entre as grandezas cefalométricas e a idade do paciente foi determinada pelo teste de Pearson. Todas as análises foram realizadas com nível de significância de 5%. Resultado SNA, ANB e AO-BO aumentaram significativamente (p<0,05) e após o período de acompanhamento voltaram a ser semelhantes às iniciais (p>0,05). O overjet aumentou significativamente após o tratamento e mesmo tendo diminuído com o tempo, ainda se apresentava maior quando comparado ao momento inicial (p<0,05). O ângulo Z apresentou melhora com o tratamento e se manteve estável no período de acompanhamento (p<0,05). Conclusão após o tratamento (disjunção associada à protração maxilar) houve melhora do padrão esquelético. No período de acompanhamento, verificou-se que essas melhoras voltaram a medidas próximas das iniciais. Houve melhora no padrão dentário e no perfil facial que se manteve no período de controle.

The effects of maxillary protraction therapy with rapid maxillary expansion on class Ⅲ malocclusion: A meta-analysis / 实用口腔医学杂志

Objective:To evaluate the effects of maxillary protraction with or without rapid maxillary expansion in the treatment of Class Ⅲ malocclusion by Meta-Analysis.Methods:The randomized controlled trail,quasi-randomized controlled trail and the clinical controlled trail about the treatment of Class Ⅲ malocclusion by protraction with or without expansion were searched in the database of Cochrane Library,Embase,PubMed,Medline,CBM,Wan Fang,CNKI,VIP.2 authors qualified and extracted the data independently.Then the Meta-analysis was performed by using the RevMan 5.3 software.Results:7 studies with 228 cases were included,114 cases were treated by maxillary protraction with expansion and the other 114 cases by maxillary protraction without expansion.The Meta-analysis showed that:there was no significant difference in SNA,SNB,ANB and SN-PP except ANS-Me,U1-NA,SN-MP.A favorable improvement of the sagittal relationship between maxillary and mandibular was observed by using protraction whether with expansion or not.The expansion did not shorten the course of treatment,but it lowered the inclination of upper incisors,resulting in more clockwise rotation of mandibular plane and increase of the facial vertical dimension.Conclusion:Maxillary protraction with rapid maxillary expansion can be used in the treatment of class Ⅲ malocclusion with incisor labioclination.

Analysis of the profile esthetics of children with skeletal class Ⅲ malocclusion treated with micro-implant / 实用口腔医学杂志

Objective:To evaluate the profile esthetics of children with skeletal class Ⅲ malocclusion treated with micro-implant.Methods:20 patients (12 boys and 8girls) aged 11-13 years were treated by micro-implant and maxillary protraction for 8 to 10 months.The profile esthetic indexes were measured on pre-and post-treatment cephalometric radiography.Results:The esthetic of the patients were remarkably improved after treatment.The factors that influence the esthetic index of children were the anteroposterior relationship of the maxilla,the mandible and the thickness of soft tissue.The results were stable 1 year after treatment.Conclusion:Maxillary protraction by micro-implant can improve the profile esthetic of children with Class Ⅲ malocclusion,correct over-bite and over-jet.

Cone-Beam CT evaluation of upper airway following rapid maxillary expansion and maxillary protraction for the treatment of skeletal class Ⅲ malocclusion / 实用口腔医学杂志

Objective:To analyze the 3D changes of pharyngeal airway in patients with skeletal Class Ⅲ malocclusion after rapid maxillary expansion(RME)and maxillary protraction.Methods:53 patients underwent orthodontic treatment with Hyrax palatal ex-panders and maxillary protraction.Cone-Beam computed tomography(CBCT)scan was taken before treatment(T0),after 1 6 d RME (T1 )and after about 5 month maxillary protraction(T2).Data were reconstructed into 3D model,sagittal and transversal measure-ments,cross sectional areas,volumes of the pharyngeal airway were computed.Results:After RME,the transversal measurements, cross sectional areas,volumes of nasal passage were increased(P <0.05).After maxillary protraction,the 4 nasopharyngeal measure-ments were increased(P <0.05).Conclusion:RME and maxillary protraction may increase pharyngonasal airway.

New approach of maxillary protraction using modified C-palatal plates in Class III patients / 대한치과교정학회지

Maxillary protraction is the conventional treatment for growing Class III patients with maxillary deficiency, but it has undesirable dental effects. The purpose of this report is to introduce an alternative modality of maxillary protraction in patients with dentoskeletal Class III malocclusion using a modified C-palatal plate connected with elastics to a face mask. This method improved skeletal measurements, corrected overjet, and slightly improved the profile. The patients may require definitive treatment in adolescence or adulthood. The modified C-palatal plate enables nonsurgical maxillary advancement with maximal skeletal effects and minimal dental side effects.

Rotation trend of maxillary complex with mini-implant assisted protraction in different maxillary positions / 医用生物力学

Objective To investigate the differences in rotation trends of maxillary complex through planting mini-implants in different maxillary positions for the protraction of craniofacial suture, so as to provide reference and basis for the appropriate implantation location in clinical orthodontics. Methods The 3D finite element model of the maxillary complex with mini-implant assisted maxillary protraction was established, and the mini-implants were planted in maxillary infrazygomatic crest and the anterior region (6 mm above the root of bilateral incisors and canine), respectively. Traction force of 500 g was applied to analyze the differences in rotation trend of the maxillary complex at different maxillary positions and in different directions. Results When protracted in maxillary infrazygomatic crest region, the maxilla mainly showed counterclockwise rotation trend. When protracted in anterior region, the maxilla mainly showed clockwise rotation trend. Conclusions Protraction at infrazygomatic crest is more suitable for treating patients with hypodivergent crossbite, while protraction in maxillary anterior region is more suitable for treating patients with hyperdivergent crossbite.

A study on the relationship between maxillary protraction treatment and changes of nasomaxillary complex facial soft tissue of children with skeletal Class m malocclusion / 国际儿科学杂志

Objective To investigate nasomaxlllary complex facial soft tissue changes after the treatment with maxillary protraction appliance with skeletal Class Ⅲ malocclusion with a retruded maxilla.Methods Thirty growing subjects with skeletal Class Ⅲ malocclusions with maxillary retrognathism were selected and treated by facial mask(male 15,female 15,with an average age of 10.5).They were given a maxillary protraction treatment with face mask for 6-8 months.Cephalometric measurements about nasomaxillary complex soft tissue changes were analyzed to draw the statistic conclusion.Results After maxillary protraction treatment,PraY,nasofrontal angle,As-Y,UL-Y,UL-E,S-Ns-Sn increased (P ＜ 0.01) ; M-Y increased (P ＜ 0.05) ; LL-E,PosY,nasolabial angle decreased (P ＜ 0.05).There were no significant differences in the Ns-Y and columella-tip angle.Conclusion After maxillary protraction treatment,nasomaxillary complex area becomes more marked.Both the nasomaxillary complex soft tissue and lower facial profile are dramatically improved.The combining effect of these two changes results in a more harmony profile.

Comparison of frame and fixed protraction appliances in the treatment of skeletal Ⅲ malocclusion in mixed dentition / 实用口腔医学杂志

Objective:To compare the efficacy of casting frame and traditional fixed maxillary protraction appliances in the correc-tion of skeletal Ⅲ malocclusion in mixed dentition.Methods:30 cases with Class Ⅲ malocclusion in mixed dentition were random-ly divided into 2 groups.Casting frame maxillary protraction appliance was applied in group 1 (1 5 cases)and traditional fixed maxil-lary protraction appliance in group 2(15 cases).X-ray cephalometric examination results before and after treatment,treatment time, and the number of visit in 2 groups were analyzed with SPSS 1 3.0.Results:The treatment time in group 1 and 2 was (7.03 ±1 .32) and (9.07 ±1 .31 )months(P <0.05),the number of visiting was (8.00 ±1 .46)and (10.47 ±1 .85)(P <0.05),the cephalomet-ric measurement change of △U1 -SN was (3.85 ±0.95)°and (5.25 ±0.95)°(P <0.05),respectively.Conclusion:Casting frame protraction appliance is an efficient and practical intraoral device,which can prevent anterior upper teeth inclined to labial.

Bimax III – uma alternativa para o tratamento ou contenção ativa nos casos de Classe III precoce / Bimax III – an alternative for treatment or active retention in early Class III cases

A má oclusão de Classe III tem como aliada no tratamento precoce a protração maxilar por meio da máscara facial. Embora esse aparelho seja altamente efetivo, do ponto de vista esquelético e dentário, demanda colaboração total do paciente, o que nem sempre é atingido devido o aparelho ser externo e causar um problema estético, principalmente quando usado em público. Para ajudar no tratamento (às vezes até substituí-lo), é proposto um novo dispositivo, o Bimax III, aparelho dento-suportado utilizado em conjunto com elásticos de Classe III, que embora ainda não haja estudos comprovando sua eficácia esquelética, responde muito bem à movimentação dentária, pois é facilmente aceito pelo paciente. A proposta desse artigo é apresentar o referido aparelho e sugerir outras formas de tratamento para a correção da Classe III precoce.

The treatment of early Class III malocclusion has an ally in maxillary protraction through the facemask. Although this device is highly effective in terms of skeletal and dental outcomes, full compliance of the patient is needed. This is often hard to achieve since the device is external and cause an aesthetic problem, especial ly when used in public. To assist in the treatment (or sometimes even replace it) a new device is proposed, the Bimax III, a dental-supported device used in conjunction with Class III elastics. Although there are no studies proving its skeletal effectiveness, it responds very well to the tooth movement because it is readily accepted by the patient. The purpose of this paper is to present the mentioned appliance and suggest other forms of early Class III treatment.

Tração reversa da maxila associada à disjunção palatal / Maxillary protaction associated to palatal expansion

A tração anterior da maxila é parte do arsenal do ortodontista já há algum tempo no que se refere ao tratamento da má oclusão de Classe III de pacientes em crescimento. Paciente M.C. do sexo feminino, na época com 6 anos e 10 meses de idade, apresentou-se para tratamento ortodôntico. No exame extrabucal, apresentava sinais de hipoplasia de maxila: perfil côncavo e olheiras bem demarcadas. No exame intrabucal, possuía uma mordida cruzada anterior e posterior bilateral. A telerradiografia e o traçado cefalométrico confirmaram uma maxila retroposicionada (SNA=79º). Na radiografia panorâmica notava-se impacção do elemento 16 (em relação ao 55). Os objetivos do tratamento consistiram em aumentar a dimensão transversa da maxila para descruzar a mordida posterior e tracioná-la para uma posição mais anterior. A disjunção rápida da maxila associada à máscara facial de Petit foram utilizadas para alcançar estes objetivos. A mordida cruzada posterior bilateral foi corrigida completamente pela disjunção maxilar, assim como a posição da maxila foi melhorada pela força ortopédica anterior (SNA final=85º). A terapia teve de ser repetida aos 10 anos e 3 meses de idade. A terapia ortodôntica utilizada nesta paciente mostrou-se efetiva na correção da má oclusão inicial, além de mostrar-se estável após 33 meses de controle de contenção (após término da segunda fase do tratamento).

Introduction: Orthodontists have been using maxillary anterior traction on Class III patients that are going through their growth period. Description: A female patient M.C., 6 years and 10 months old, was taken to orthodontic treatment. The extra-oral examination presented signs of maxillary hypoplasia: concave facial profile and evident under eye dark circles. Intra-oral examination showed an anterior and bilateral posterior cross-bite. The teleradiography and cephalometric tracing confirmed posterior positioned maxilla (SNA=79º). In the panoramic radiograph an impaction of the element 16 on the 55 was easily noticed. Treatment plan: The treatment aimed at enhancing the maxilla’s transversal dimension to correct the bilateral posterior cross bite and to protract the maxilla anteriorly. The orthodontic devices utilized to address these objectives were the Haas palatal expander and Petit’s facial mask. Results: The posterior cross bite was fully corrected through the palatal expansion, as well as the maxillary sagittal position (SNA=85º) using anteriorly directed orthopedic force. The protraction therapy had to be repeated when the patient was aging 10 years and 3 months. Conclusion: The utilized therapies have proved to be effective in correcting the initial malocclusion. Furthermore, they have shown good stability 33 months after the removal of the fixed appliance (phase II).

Maxillary protraction and multiple loop edgewise arch wire technology in treatment of early mixed dentition skeletal class Ⅲ malocclusion / 中华医学美学美容杂志

Objective To evaluate the orthodontic effect of surgery on mixed dentition period class Ⅲ malocclusion and to investigate the effective therapeutic method of the skeletal class Ⅲ malocclusion.Methods A total of 20 patients aged 8.5 to 9.1 years with early mixed dentition class Ⅲ skeletal malocclusion.The treatment was divided into two phases.During the first phase,the entire stuffy group was treated with a bonded maxillary expansion and protraction.During the second phase,the entire study group received multiple loop edgewise arch wire (MEAW) treatment until an ideal occlusion relationship achieved.Comparison of the pre-and post-orthodontic treatment cephalometric radiographs had been done after maxillary protraction and MEAW were applied for patients.Results In the 20 patients after orthodontic treatment,Class Ⅲ skeletal facial profile was improved,the retraction of anterior teeth was obvious,and there were significant changes in dentition; the profile of soft tissue and satisfactory occlusion relationship were significantly improved,as compared with the changes between pre-treatment and post-treatment.Conclusions Skeletal Ⅲ malocclusion in early mixed dentition can be successfully treated.The results can be satisfied with improved class Ⅲ skeletal and molar relationship,high-angle and profile of soft tissue.

Má oclusão Classe III de Angle, subdivisão direita, tratada sem exodontias e com controle de crescimento / Angle Class III malocclusion, subdivision right, treated without extractions and with growth control

A Classe III de Angle é uma má oclusão caracterizada por discrepâncias anteroposteriores dentárias e faciais, normalmente acompanhadas por alterações esqueléticas, com componente genético associado. O diagnóstico precoce e correto e o tratamento adequado são de suma importância para promover o controle do crescimento e evitar recidivas. Este artigo relata o tratamento, executado em duas fases, de uma paciente do sexo feminino de 12 anos de idade, apresentando uma má oclusão de Classe III de Angle, subdivisão direita, com mordida cruzada anterior em máxima intercuspidação habitual (MIH) e topo em relação cêntrica (RC), apresentando, ainda, falta de espaço na maxila, que foi tratada sem exodontias e com controle de crescimento. Esse caso foi apresentado à Diretoria do Board Brasileiro de Ortodontia e Ortopedia Facial (BBO), representando a categoria 1, ou seja, uma má oclusão Classe III de Angle, tratada sem exodontias e com controle de crescimento, como parte dos requisitos para a obtenção do título de Diplomado pelo BBO.

Angle Class III malocclusion is characterized by anteroposterior dental and facial discrepancies usually accompanied by skeletal changes associated with a genetic component. Early, accurate diagnosis and appropriate treatment are of paramount importance to promote growth control and prevent relapse. This article reports the two-phase treatment of a female patient, aged 12 years, with an Angle Class III, subdivision right malocclusion with anterior crossbite in maximum intercuspation (MIC) and end-on bite in centric relation, further presenting with lack of maxillary space. The case was treated without extractions and with growth control. This case was presented to the Brazilian Board of Orthodontics and Facial Orthopedics (BBO) as representative of Category 1, i.e., Angle Class III malocclusion treated without tooth extractions, as part of the requirements for obtaining the BBO Diploma.

Establishment of an experimental animal model of maxillary protraction and cephalometric analysis / 实用口腔医学杂志

Objective: To establish an animal model for research of maxillary protraction. Methods: 16 pubertal rabbits were assigned randomly to 2 groups. Titanium bone markers were fixed on each side of mucogingival junction, 1 cm above incisor teeth. The experimental group underwent maxillary protraction by self-made distraction devices. A down and forward elastic force (about 3.43 N) was exerted for 30 days. Results: In 30 d, the distance of premaxilla movement in the experimental group was 1.89 mm averagely, while that in the control group was only 0.11 mm. Cephalometric analysis indicated that the maxilla of rabbits was moved forward obviously by appliance in the experimental group, and maxilla was not rotated. There was no obvious difference between the control and the experimental groups. Conclusion: Animal model used in this experiment for maxillary protraction is reliable. The appliance can move the rabbits maxilla forward obviously during the maxillary protraction.

Maxillary protraction treatment of skeletal Class III children using miniplate anchorage / 대한치과교정학회지

The maxillary protraction headgear has been widely used in the treatment of skeletal Class III children with maxillary deficiency. A variety of treatment objectives which allow dentoalveolar movements may be established, but when only maxillary protraction without dentoalveolar movement is needed, one of the limitations in maxillary protraction with conventional tooth-borne anchorage is the loss of dental anchorage. This is because a bone remodeling occurs not only at circummaxillary sutures but also within the periodontal tissues. During protraction treatment in the mixed dentition phase, in older children or for the patient with multiple congenitally missing teeth, it is not uncommon to observe undesirable mesial movement of maxillary teeth. Such a side effect can be eliminated or minimized using absolute anchorage such as skeletal anchorage. The purpose of this case report is to introduce a new technique of the maxillary protraction headgear treatment using surgical miniplates.