To lower elongation molar with micro implant anchorage nail and Ni-Ti coil spring: a clinical study / 口腔疾病防治

Objective @# To investigate the clinical effects of micro implant anchorage nail and Ni-Ti coilspring to lower the elongation molar. @*Methods@#60 patients with the first maxillary molar elongation were divided into 2 groups. 30 of them were treated with micro implant anchorage nail and Ni-Ticoil spring to lower the molar (observation group), and the other 30 patients were treated with segmental arch to lower the molar (control group). The average lowering time, depth and pain degree of the 2 groups were compared. @*Results@#The average lowering time was faster and the overage lowering depth was greater in the observation group than that in the control group; the slight pain rate in the observation group was significantly higher than that in the control group (P<0.05), while the ratio of moderate pain and severe pain was significantly lower than that in the control group (P<0.05).@*Conclusion@# To lower the elongation molar with micro implant anchorage nail and Ni-Ti coilspring might have shorter course and less pain.

Load-deflection characteristics and plastic deformation of NiTi closed coil springs / 대한치과교정학회지

OBJECTIVE: NiTi closed coil springs were reported to have relatively constant unloading forces. However, the characteristics of NiTi closed coil springs from various manufacturers have not been elucidated. The purpose of this study was to compare load-deflection characteristics of various NiTi closed coil springs and to find out the optimal range of extension. METHODS: Seven kinds of NiTi closed coil springs from five manufacturers were tested. Load deflection curves were obtained at extension ranges from 2 mm to 30 mm. Also, springs were kept extended during a 4 week period, and then load deflection curves were obtained again. RESULTS: Sentalloy (Tomy) and Jinsung blue (Jinsung) showed superelasticity in every extension ranges tested and showed plastic deformation of less than 1 mm. Ni-Ti (Ormco) showed superelasticity only after the springs were extended at or more than 10 mm, thereby meaning that clinicians should extend these springs at or more than 10 mm to utilize the superelasticity. Orthonol (RMO) and Nitanium (Ortho Organizers) did not show superelasticity. After 4 weeks of extension, all springs showed plastic deformation less than 1 mm when the extension was at or under 25 mm. CONCLUSIONS: The superelastic behavior of NiTi closed springs were different among various NiTi spring products, and some NiTi closed springs failed to show superelasticity.

El Trípode en la distalización unilateral de molares superiores: cambios oclusales / The tripod in the unilateral distalization of superior molars: occlusal changes

Aumentar los conocimientos en los tratamientos distalizadores, se realizó este estudio con una técnica distalizadora novedosa: el Trípode. El estudio incluyó 6 pacientes con clase II de Angle por mesogresión de los molares superiores y con ausencia clínica del segundo molar superior. Se evaluaron las modificaciones a nivel dental producidas por el trípode. Los primeros molares superiores se distalizaron (3.36 mm), además, el molar sufrió una inclinación distal; las segundas bicúspides siguieron al molar en su movimiento distal, mientras que, la primera bicúspide del lado de la distalización se mesializó; los incisivos resultaron vestibularizados y la anchura transversal, medida a nivel de los primeros molares y primeras bicúspides, disminuyó, mientras que, en las segundas bicúspides aumentó. Los cambios producidos con esta aparatología a nivel dental han sido: distalización de los primeros molares superiores (3.36 mm), además, el molar sufrió una inclinación distal; las segundas bicúspides siguieron al primer molar en su movimiento distal, mientras que, la primera bicúspide del lado de la distalización se mesializó; los incisivos resultaron vestibularizados; la anchura transversal medida a nivel de los primeros molares y primeras bicúspides disminuyó, mientras que, en las segundas bicúspides aumentó(AU)

To enhance the knowledge of the distalizing treatments, a study was conducted with a distalizing novel technique: the tripod. The study included 6 patients with Angle class II due to mesogression of the superior molars and with clinical absence of the second superior molar. The modifications produced by the tripod at the dental level were evaluated. The first superior molars were distalized (3.36 mm). The molar also suffered a distal inclination, the second bicuspids followed the molar in its distal movement, whereas the first bicuspid of the side of the distalization was mesialized. The incisive were vestibularized and the cross-sectional width measured at the level of the first molars and the first bicuspids decreased, while in the second bicuspids increased. The changes caused by this apparatology at the dental level were the following: distalization of the first superior molars (3.36 mm); besides, the molar suffered a distal inclination; the second bicuspids followed the first molar in its distal movement, whereas the first bicuspid of the side of the distalization was mesialized; the incisives were vestibularized; the cross-sectional width measured at the level of the first molars and first bicuspids decreased, but in the second bicuspids it increased(AU)

A photoelastic study on the initial stress distribution of the molar anchoring spring(MAS) during retraction of the maxillary canine / 대한치과교정학회지

The efficiency of maxillary canine retraction by means of sliding mechanics along an 0.016 continuous labial arch and an 0.009 inch in diameter with a lumen of 0.030 inch NiTi closed coil spring was compared with that using the same NiTi closed coil spring and Molar Anchoring Spring(MAS) which was designed by author. MAS was made of .017" X .025" TMA wire and was given 60 degree tip-back bend on the wire close to the molar tube. This study was designed to investigate molar and canine root control during retraction into an extraction site with continuous arch wire system. Two techniques were tested with a continuous arch model embedded in a photoelastic resin. A photoelastic model was employed to visualize the effects of forces applied to canine and molar by two retraction mechanics. With the aid of polarized light, stresses were viewed as colored fringes. The photoelastic overview of the upper right quadrant showed that stress concentrations were observed in its photoelastic model. The obtained results were as follows. 1. Higher concentration of compression can be seen clearly at the distal curvature of the canine and mesial curvature of the molar and premolar when NiTi closed coil spring was applied only, which means severe anchorage loss of the molar and uncontrolled tipping of the canine. 2. The least level compression was presented at the mesial root area of the molar and premolar, and mesial root area of the canine when NiTi closed coil spring and MAS were used simultaneously. Especially mesial alveolar crest region of the canine was shown moderate level of compression that means MAS can be used as a appliance for anchorage control and prevention of canine extrusion and uncontrolled tipping during canine retraction.

Clinical application of coil-spring utility arch / 实用口腔医学杂志

Objective:To introduce the clinical application of the coil-spring utility arch for orthodontic treatment. Methods:A 35-year-old male patient with mild skeletal anterior crossbite was treated by fixed appliance combined with coil-spring utility arch for 16 months. Cephalometric analysis was conducted before and after treatment.Results:After treatment, the patient's appearance was improved,and the cephalometric analysis showed that SNA increased by 2?,SNB decreased by 1?,ANB increased by 3?,U1-NA increased by 1?,L1-NB increased by 3?.Conclusion:Coil-spring utility arch can expand anterior dental arch continuously and stably.