Biomechanics
Prerna Pahuja; Divya Yadav; Harshita Gupta; Gurkeerat Singh; Monika Dahiya; Arisha Izhar; Akanksha Shukla; Deepali Bisht
Abstract
Aim: Among various retraction methods for space closure in first premolar extraction, the palatal approach is preferred to labial appliances in cases having high aesthetic demand. A finite element model and clinical randomized prospective trial was undertaken to determine the possibility of en-masse ...
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Aim: Among various retraction methods for space closure in first premolar extraction, the palatal approach is preferred to labial appliances in cases having high aesthetic demand. A finite element model and clinical randomized prospective trial was undertaken to determine the possibility of en-masse retraction of maxillary anterior teeth using palatal TAD and a clear aligner-like appliance in patients undergoing extraction of maxillary first premolars and to study the effects of the above using three-dimensional scanned models and lateral cephalograms.Methods: A finite element model of maxillary dentition with alveolar bone, an acrylic splint on six anterior teeth, palatal implants, and short e-chain were produced to measure shifting when force was applied from three various levels. Thereafter, the finite element analysis findings were applied to 10 patients requiring fixed orthodontic treatment with first premolar extraction and fulfilling the inclusion criteria. Impressions were made and the rate of retraction was evaluated at 4-week intervals by superimposition of scanned models.Results: En-masse bodily retraction was seen when both canine hooks and palatal TAD was placed at 10 mm distance from the respective gingival margin. Clinically, subjects showed significant retraction at that level and statistically significant results in some cases. The maximum rate of retraction was seen in the first three months (average: 5.310 mm) with p-value <0.0001.Conclusion: Translational tooth movement was observed when line of force was at the level of the center of resistance.
Jasneet Singh; Gurkeerat Singh; Sridhar Kannan; Deepak Rai; Ashish Gupta; Gaurav Gupta; Raj Kumar Singh
Abstract
Background: Increase in the number of adult patients seeking orthodontic treatment for aesthetics, demand for a more aesthetic orthodontic appliance has become inevitable.
Objectives: This prospective study was undertaken to evaluate torque expression of 0.019” × 0.025” fiber composite ...
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Background: Increase in the number of adult patients seeking orthodontic treatment for aesthetics, demand for a more aesthetic orthodontic appliance has become inevitable.
Objectives: This prospective study was undertaken to evaluate torque expression of 0.019” × 0.025” fiber composite wire and 0.019” × 0.025” NiTi wire in a similar prescription bracket systems (MBT, 0.022” slot) using CBCT.
Methods: Twenty arches each (ten maxillary and ten mandibular), of 15 - 25 year old patients, were bonded with metal brackets and ceramic brackets having MBT prescription and 0.022”slot. Two CBCT images were recorded at T0 and Tx. T0 point represented the stage of transition from a 0.017” × 0.025” NiTi wire to a 0.019” × 0.025” fiber composite or NiTi archwire. The Tx time point represented the end of treatment phase using 0.019” × 0.025” dimension wire, i.e. after 3 months of T0 scan. Results: The mean angulation change from T0 to Tx in fiber composite wire group and NiTi wire group was tested using Wilcoxon signed rank test and showed that the difference was statistically non-significant (P > 0.05).
Conclusions: It was concluded that fiber reinforced composite wires were comparable to NiTi wires in their ability to deliver consistent forces and bring about comparable torque in individual teeth.