Changes of maxillary teeth and maxilla following quad helix maxillary expansion observed by Cone-Beam CT (CBCT) / 实用口腔医学杂志

Objective:To evaluate dental and skeletal changes following slow maxillary expansion with quad helix using Cone-Beam computer tomography (CBCT).Methods:13 patients(5males and 8 females,mean age 14.38 ±2.22 years)requiring maxillary ex-pansion as a part of their comprehensive orthodontic treatment were included.Each patient had CBCT images taken pre-(T1 )and post-(T2)maxillary expansion with quad helix.Changes of the distances between bilateral canines,first premolars,second premo-lars,first molars,the width of basal bone and palatal suture were measured.paired t-test results were analyzed using SPSS 17.0 soft-ware.Results:The distances between the 4 bilateral teeth increased by (2.47 ±1.05)mm,(2.97 ±1.90)mm,(2.79 ±1.21) mm and (3.15 ±1.15)mm,the apical distances decreased by (1.19 ±0.40)mm,(2.12 ±0.68)mm,(2.02 ±0.65)mm and (1.34 ±0.63)mm,respectively.The inclination of the first molars were decreased by (4.45 ±2.86)°and (4.02 ±1.45)°on the left and right side respectively.The width of basal bone and palatal suture increased by (2.37 ±0.96)mm and (1.21 ±0.50)mm respectively,the differences between T1 and T2 were all statistically different(P <0.001).Conclusion:Quad helix expands maxil-lary arch by greater dental changes than by skeletal changes.

Long-term effect of quad helix expansion of dental arch*☆ / 中国组织工程研究

BACKGROUND: Rapid expansion of the dental arch is an effective way to rapidly expanse the jaw. Compared with rapid expansion, the slow expansion has higher stability and less recurrence, but the reports on the long-term stability of quad helix expansion are rare. OBJECTIVE: To retrospectively analyze the clinical effect of quad helix expansion in orthodontics. METHODS: Twenty-two subjects with dental arch stenosis in mixed dentition and early permanent dentition who experienced an expansion of at least 3 mm with quad helix appliance were selected for this study. Plaster dental casts and posteroanterior radiographs were evaluated at the beginning of the treatment (T1), at the completion of phase I quad helix expansion or ful treatment (T2), and approximately 2 years fol owing the completion of treatment (T3). The distance between two first molars was measured on the model. J point was drawn on the posteroanterior radiograph in order to measure the distance between the bilateral base bones and the molar inclination, as wel as to evaluate the corrective and orthopedic effects of dental arch expansion. RESULTS AND CONCLUSION: Compared with that before expansion, the first permanent molar inclination and the distance between base bones on two sides were significant increased after quad helix expansion; there were no significant differences in the distance between two first permanent molars, first permanent molar inclination and the distance between bilateral base bones on two sides when compared after quad helix expansion and after 2-year fol ow-up (P > 0.05). The results indicate that the long-term effect of quad helix expansion is stable with orthopedic effect.

Mordida cruzada posterior, corrección y consideraciones: caso clínico con 7 años de seguimiento / Posterior crossbite correction and considerations: case report with 7 years of follow-

El tratamiento precoz de la mordida cruzada posterior unilateral funcional durante la dentición mixta es extremadamente importante para la Ortodoncia contemporánea porque provee un correcto posicionamiento de las bases óseas, dientes y de la articulación temporomandibular cuando el sistema estomatognático está en pleno crecimiento y desarrollo. Estos resultados generalmente producen una adecuada relación Craneofacial, reduciendo la necesidad de tratamientos cada vez más complejos en la dentición permanente. El propósito de este artículo fue presentar el caso de un niño que a los 8 años de edad fue diagnosticado, mordida cruzada posterior unilateral funcional, tratado por medio de un expansor fijo tipo Quad-helix donde enfatizamos la estabilidad a largo plazo. La maloclusión fue corregida en tres meses de uso activo del Quad-helix, tres meses de contención y fue realizado un seguimiento post tratamiento por siete años. La estabilidad a largo plazo del tratamiento de la mordida cruzada posterior unilateral funcional está íntimamente relacionada con el diagnostico precoz, la eliminación del factor etiológico asociado con la correcta aparatología y la mecánica de tratamiento

Early treatment of functional unilateral posterior crossbite during the mixed dentition is extremely important for contemporary Orthodontics, provides the correct positioning of osseous bases, teeth and temporomadibular joint when the stomatognathic system is in growth and development. These results generally develop into an adequate craniofacial relationship, reducing the necessity for more complex treatments at permanent dentition. The subject of this paper was to report patient 8 years old, diagnosed with functional unilateral posterior crossbite, and was treated by an expander appliance type Quad-helix emphasizing the long-term stability. The malocclusion was corrected in 3 months of active use of the appliance, 3 months for retention purposes and followed up during 7 years post-treatment. The stability in long term of functional unilateral posterior crossbite treated is closely related with early diagnostic, the elimination of the etiological factor associated with a correct appliance and the mechanic of treatment

Quad-helix vs placa removible con tornillo de expansión / Quad-helix vs removable screw plate expansion

La variedad de aparatología para el tratamiento de la mordida cruzada posterior hace con que el Ortodoncista evalúe algunos criterios para su selección y éxito en el tratamiento. El objetivo de este artículo es comparar dos métodos de tratamiento de mordida cruzada posterior en dos casos clínicos tratados con Quad-helix y Placa removible con tornillo de expansión. Podemos concluir que el Quad-helix es el método de tratamiento de primera elección en relación a la placa removible por el corto tiempo de tratamiento, las pocas visitas al ortodoncista, su bajo costo y por la poca colaboración que se necesita del paciente

The different kind of appliances for the treatment of posterior crossbite make that the orthodontist assess some criterions for their selection and success for the treatment. The aim of this paper was to compare two methods of treatment of the posterior crossbite by two case reports treated with Quad-helix and removable plate. Concluding that the Quad-helix is the appliance of first choice in relation of the removable plate for the short time of active treatment, the less visits and chair time, the fewer cost of treatment and the smaller cooperation of the patient

The clinical investigation of Quad-Helix appliance in expanding narrow dental arch / 实用口腔医学杂志

objective: To evaluate the effect of Quad Helix appliance in expanding narrow dental arch. Methods: 12 cases were treated by Quad Helix appliance. The effect was evaluated by measurement of the dental arch. Results: The dental arch of all the patients was expanded in half a year.The width between the maxillary first molars increased by 8.95 mm, and the width between maxillary first premolars increased by 5.7 mm. The average time of expanding was 20.75 weeks, the expanding efficiency was 0.43 mm per week. Conclusion: Quad Helix is an effective orthodontic appliance for correction of narrow dental arch.