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.

Comparison of second molar protraction using different timing for piezocision application: A randomized clinical trial

ABSTRACT Objective: To compare second molar protraction between early, late and no piezocision groups. Material and Methods: Forty subjects with bilaterally extracted mandibular first molars were selected to participate in the study. Subjects were subdivided into two groups: piezocision and no piezocision. The piezocision group was further subdivided into two subgroups: early piezocision (piezocision performed immediately before second molar protraction) and late piezocision (piezocision performed three months after starting molar protraction). In the no piezocision group, molar protraction was done without surgery. The intervention (piezocision group and timing of piezocision/side within group) was randomly allocated using the permuted random block size of 2, with 1:1 allocation ratio. The amount of second molar protraction, duration of space closure and anterior anchorage loss were measured. A repeated measures analysis of variance was conducted to define the differences between the measured variables at the different time intervals. Differences between groups were assessed using ANOVA test. Results: No difference was detected between early and late piezocision groups in the amount of molar protraction at the end of space closure. Duration of complete space closure was 9 and 10 months in the piezocision and no piezocision groups. Anchorage loss was similar between the three studied groups. Conclusions: Early and late piezocision have similar effect and both increased the amount of second molar protraction temporarily in the first 2-3 months after surgery. Duration of mandibular first molar space closure was reduced by one month when piezocision was applied. Anchorage loss was similar in the three groups.

RESUMO Objetivo: Comparar o efeito dos tempos de aplicação precoce, tardia e sem piezocisão, na protração de segundos molares. Métodos: Quarenta indivíduos com os primeiros molares inferiores extraídos bilateralmente foram selecionados para participar do estudo, sendo divididos em dois grupos: piezocisão e sem piezocisão. O grupo de piezocisão foi subdividido em dois subgrupos: piezocisão precoce (piezocisão realizada imediatamente antes da protração de segundos molares) e piezocisão tardia (realizada três meses após o início da protração dos molares). No grupo sem piezocisão, a protração de molares foi feita sem cirurgia. A intervenção (grupo de piezocisão e momento da piezocisão/lado dentro do grupo) foi alocada aleatoriamente usando o tamanho de bloco aleatório permutado de 2 com proporção de alocação de 1:1. A quantidade de protração de segundos molares, tempo para fechamento de espaços e perda de ancoragem anterior foram medidos. Uma análise de variância para medidas repetidas foi realizada para definir as diferenças entre as variáveis medidas nos diferentes intervalos de tempo. As diferenças entre os grupos foram avaliadas pelo teste ANOVA. Resultados: Não foi detectada diferença entre os grupos de piezocisão precoce e tardia, em relação à quantidade de protração de molares ao fim do fechamento dos espaços. O tempo para o fechamento completo do espaço foi de nove e dez meses nos grupos piezocisão e sem piezocisão, respectivamente. A perda de ancoragem foi semelhante nos três grupos avaliados. Conclusões: As piezocisões precoce e tardia têm efeito semelhante e ambas aumentaram temporariamente a quantidade de protração dos segundos molares nos primeiros dois a três meses após a cirurgia. A duração do fechamento de espaço dos primeiros molares inferiores foi reduzida em um mês quando a piezocisão foi aplicada. A perda de ancoragem foi semelhante nos três grupos.

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).

Meta-analysis of the efficacy of bone anchorage and maxillary facemask protraction devices in treating skeletal class Ⅲ malocclusion in adolescents / 华西口腔医学杂志

OBJECTIVE@#To assess the efficacy of bone anchorage and maxillary facemask protraction devices in treating skeletal class Ⅲ malocclusion in adolescents.@*METHODS@#Articles relating to the use of bone anchorage and maxillary facemask protraction devices for treating skeletal class Ⅲ malocclusion in adolescents were searched from the databases of Cochrane Library, PubMed, EmBase, CNKI, and Wanfang database. Several inclusion and exclusion criteria were developed for the article screening. The clinical data were extracted, and the quality of the selected articles was evaluated. A Meta-analysis of SNA, SNB, ANB, ANS-Me, Wits, and U1-PP change was performed by using RevMan 5.3.@*RESULTS@#Seven studies (264 patients) were included in the Meta-analysis. Among these studies, three were randomized controlled trials, and four were non-randomized controlled trials. Compared with the maxillary facemask protraction device group, the bone ancho-rage device group had higher SNA changes and lower ANS-Me, Wits, and U1-PP changes (P<0.05). No significant differences were observed in the SNB and ANB changes between these two groups.@*CONCLUSIONS@#Compared with the maxillary facemask protraction device, the bone anchorage device can increase the extent of protraction of the maxilla and has better controls for the labial inclination of the maxillary anterior teeth in treating skeletal class Ⅲ malocclusion among adolescents. However, additional high-quality randomized controlled trials must be performed to verify the results.

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.

Effect of Shoulder Protraction Exercise on the Supine position for Selective Activation of the Serratus Anterior according to Weight in Winging Scapula

PURPOSE: This study investigated the effects of shoulder protraction exercise according to weight by examining the surface electromyography (EMG) amplitude in the serratus anterior (SA), upper trapezius (UT), and pectoralis major (PM) as well as the activity ratio of each muscle. METHODS: Twenty three winging scapula subjects participated in the study. The subjects performed scapula protraction at shoulder 90° flexion and 60° horizontal abduction with up to four (none, 1kg, 1.5kg, and 2kg) dumbbells in the supine position. The EMG data were collected from the dominant side muscles during a shoulder protraction exercise according to weight in the supine position. One way repeated measures analysis of variance (ANOVA) was used to compare the normalized activities of the SA, UT, and PM and the ratios of PM/SA and UT/SA. RESULTS: The results showed that the activities of both the SA and UT were highest for the shoulder protraction exercise at 2kg in the supine position. The UT/SA ratio also was the lowest for exercise at 2kg. On the other hand, the activities of both the UT and PM/SA ratio were similar under all conditions. CONCLUSION: These results show that there is a need to selectively strengthen the SA muscle in the case of patients with the shoulder dysfunction. In particular, it is necessary to weigh 2kg when performing shoulder protraction exercises in the supine position to activate the SA muscle in patients with a winging scapula.

Morphological changes of skeletal class III malocclusion in mixed dentition with protraction combined activities / Cambios morfológicos en maloclusión de la clase esquelética III en dentición mixta con actividades combinadas de protracción

The objective of the study was to investigate the morphological changes of skeletal class III malocclusion in mixed dentition with light force protraction combined activities. Randomly selected 30 cases of orthodontics in Shanxi Medical University orthodontics patients (ages: 6-10 years) of the lateral cephalograms. Using the oral maxillary casting type of pre-traction device, according to the condition of maxillary dentition to select the corresponding activities of the movable expansion appliance, each side of the force of about 150-200 g, requiring patients to wear 10-12 hours a day, the appliance should be removed after reaching normal occlusion. The correlation cephalometric profile of the cranial lateral radiographs before and after orthodontic treatment was measured. All patients with skeletal class III malocclusion were improved, concave type became direct type, measurements SNA, ANB, A-Ptm, MP-SN, ANS-Me/N-Me increased, maxillary advancement and reconstruction are more obvious; mandible rotates clockwise; the increase of lip inclination of anterior teeth compensatory changes, lower anterior tooth inclination changes smaller; upper lip forward, nasolabial angle decreased, improved appearance significantly. Light force protraction combined activities can make the mixed dentition of skeletal class III malocclusion in patients with significant improvement in profile appearance.

El objetivo de este estudio fue investigar los cambios morfológicos de la maloclusión clase esquelética III, en la dentición mixta, con actividades combinadas de protracción de la fuerza ligera. Se seleccionaron aleatoriamente 30 casos de ortodoncia en pacientes de ortodoncia de la Universidad Médica de Shanxi (edades: 6-10 años) a partir de cefalogramas laterales, utilizando el tipo de dispositivo de pretracción de vaciado maxilar oral, de acuerdo con la condición de la dentición maxilar para seleccionar las actividades correspondientes del dispositivo de expansión móvil, cada lado con fuerza de alrededor de 150-200 g, requiriendo que los pacientes los utilizaran de 10 a 12 horas al día. El dispositivo debía ser retirado después de alcanzar la oclusión normal. Se midió el perfil cefalométrico de correlación de las radiografías laterales craneales, antes y después del tratamiento ortodóncico. Se observó mejoramiento en todos los pacientes con maloclusión de clase esquelética. Las mediciones SNA, ANB, APtm, MP-SN, ANS-Me / N-Me aumentaron, el avance y la reconstrucción maxilar fueron los cambios más significativos; la mandíbula giró en el sentido de las agujas del reloj, se observó un aumento de la inclinación labial de los dientes anteriores. Fue reducida la inclinación anterior del diente inferior, el ángulo nasolabial disminuyó y en general mejoró significativamente la apariencia. Las actividades combinadas de protrusión de la fuerza radiante pueden llevar a una mejora signficativa en el perfil de pacientes con dentición mixta de maloclusión clase III.

Comprehensive Orthodontic Treatment in a Middle-Aged Patient with Missing Maxillary Left First Premolar: A Case Report

As the adult population continues to increase, orthodontic treatment for adult patients is becoming more common. This case report describes comprehensive orthodontic treatment of a middle-aged patient with closure of the extraction space without prosthetic restoration. A 55-year-old woman with her maxillary left first premolar extracted because of a periodontal problem, wanted to close the space with orthodontic treatment. Since she had generalized crowding and mild skeletal discrepancy, we planned comprehensive orthodontic treatment, including closure of the extraction space by protraction of the left maxillary molars using miniscrews and aesthetic alignment of anterior teeth. The total treatment period was 28 months. As a result of these treatments, the extraction space was successfully closed, good tooth alignment and satisfactory occlusion were achieved.

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.

3-D finite element study on maxillary body protraction using implant anchorage / 实用口腔医学杂志

Objective:To explore the stress change rule of craniofacial bone suture and the interface of bone-implant against differ-ent strength and direction of protraction on the implant anchorage in alveolar bone.Methods:The original DICOMdata of 2-D image of craniofacial complex were obtained by high resolution CT scanning.3-D finite element models of craniofacial complex were devel-oped according to the DICOMdata.Forces of 1 -1 0 N inclined at 0 -60°to Frankfort horizontal plane in the anterior and inferior di-rections were respectively applied on the implant anchorage in the alveolar bone at 32 23 .Data of principle stress and Von Mises Stress of each mode of each simulaton was caculated.Results:The change rule of the effectiveness of different force value of protrac-tion in the same direction was the same in different stress zone;that of the same force value of the protraction in differente direction differed in different stress zone.When the protraction angle was less than 30°,the maxillary complex will spin up.In the 30°,the maxillary complex showed the forward growth.Between 40°-50°,the growth direction was the same with the protraction direction. When the protraction angle was more than 50°,the maxillary complex showed down spin.Conclusion:Protraction force of 1 -1 0 N at 30°-50°to Frankfort horizontal plane on implant anchorage in the alveolar bone at 32 23 can induce maxillary complex grow for-ward.

Effect of Tilted Seat Surface on Front Protraction of Upper Limb and Postural Adjustment in Children with Spastic Cerebral Palsy / 中国康复理论与实践

Objective To explore the effects of tilted seat surface on front protraction of upper limb and postural adjustment while sitting in children with spastic cerebral palsy. Methods From 2010 to 2014, 15 children with spastic cerebral palsy (patients group) and 15 healthy children (control group) were recruited. They were asked to reach forward sitting on the tilted seat surface with different degrees (-15°, 0°, 15° ) to test the reaction time and movement time. The contraction times of rectus abdominis and back extensors were recorded and ana-lyzed. Results The reaction time and movement time were shorter, and the contraction rates of rectus abdominis and back extensors were lower in the degree with-15° than with 0° and 15° (P0.05), and the movement time was longer in the patients group than in the control group (P<0.001). The contraction rates were higher in the patients group than in the control group. Conclusion Anterior tilted seat surface may improve the front protraction function of upper limb and the postural adjustment in children with cerebral palsy.

Alternative treatment for open bite Class III malocclusion in a child with Williams-Beuren syndrome

Williams-Beuren syndrome (WBS) is a rare genetic condition that affects approximately 1 in every 20,000 - 50,000 live births. WBS children have specific skeletal deformities, dental malformations and rare lingual muscle dysfunction. The need for orthodontic and orthognathic therapy has arisen and has been considered a real clinical challenge even for experienced professionals, once it requires a complex and individualized treatment plan. This study reports a case of orthopedic expansion of the maxilla, in which a modified facial mask was used for protraction of the maxillary complex associated with clockwise rotation of the maxilla. In addition, special considerations about treatment time and orthopedic outcomes are discussed.

A síndrome de Williams-Beuren (WBS) é uma doença genética rara, acometendo, aproximadamente, de 1:20.000 a 1:50.000 crianças nascidas. As crianças com WBS têm deformidades esqueléticas específicas, má formações dentárias e, algumas vezes, disfunção muscular da língua. As necessidades ortodônticas e ortognáticas têm sido consideradas um verdadeiro desafio clínico, até mesmo para aqueles profissionais com vasta experiência, uma vez que requerem um plano de tratamento individualizado e complexo. Esse relato de caso aborda uma expansão ortopédica da maxila, em que foi utilizada uma máscara facial modificada para protração do complexo maxilar, acompanhada de uma rotação horária da maxila. Além disso, considerações especiais sobre o tempo de tratamento e resultados ortopédicos são discutidas.

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.