Biomechanics
Gregorio Bonfim Dourado; Ester Andrade Souza Neta; Marcelo Castelucci Barbosa; Thais Maria Freire Fernandes; Ricardo Alves de Souza; Ana Claudia de Castro Ferreira Conti
Abstract
Aim: We have reported a case of a 17-year-old patient with impaction of element 2.1 and severe incisors crowding and the treatment plan involved traction of the impacted teeth.Methods: First, rapid maxillary expansion was performed. Then elements 1.4, 2.4, 3.4, and 4.4 were extracted to dissolve the ...
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Aim: We have reported a case of a 17-year-old patient with impaction of element 2.1 and severe incisors crowding and the treatment plan involved traction of the impacted teeth.Methods: First, rapid maxillary expansion was performed. Then elements 1.4, 2.4, 3.4, and 4.4 were extracted to dissolve the crowding, and the fixed appliances were bonded. A NiTi coil spring was used to open the needed space for traction, and surgical exposure of the tooth for bonding a traction device was done. After the tooth erupted in the oral cavity, overlay mechanics was used to align and level it.Results: Despite being challenging, the conservative treatment resulted in satisfactory outcomes, and the objectives were achieved, restoring the patient's aesthetics and function.Conclusion: After correct planning of the case, the impacted central incisor was pulled, restoring the patient's function and aesthetics, with good preservation of the supporting structures.
Biomechanics
Sayyed Muhammad Ali; Javed Sodawala; Shaheen Hamdani; Sumit Gandhi; Harsha Malhotra; Gaurav Agrawal
Abstract
Aim: The purpose of this study was to compare labial and lingual forces of the rate of canine retraction and three dimensional control of the molar and canine using sliding mechanics.Methods: Ten patients with Angle’s class I malocclusion with bimaxillary protrusion referred for first premolar ...
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Aim: The purpose of this study was to compare labial and lingual forces of the rate of canine retraction and three dimensional control of the molar and canine using sliding mechanics.Methods: Ten patients with Angle’s class I malocclusion with bimaxillary protrusion referred for first premolar extraction enrolled in this split mouth study. Forty canines were placed into four groups according to the arch and type of force: UB (upper canine–labial force), LB (lower canine–labial force), UL (upper canine–lingual force), and LL (lower canine–lingual force). The rate of retraction of the canine, molar and canine rotation, molar and canine angulation, and molar anchorage loss in the sagittal and vertical plane was assessed using study models and orthopantomographs (OPG). The paired and unpaired t tests were used for intra and inter group comparison. The significance level was 0.05.Results: The rate of canine retraction was significantly faster for labial forces than lingual forces using sliding mechanics (P<0.001). However, significantly greater amount of molar rotation was observed using lingual forces (P<0.001). There was no significant difference regarding canine rotation using labial forces (P<0.05). The molar anchorage loss in the sagittal plane was significantly lesser using lingual forces (P<0.001).Conclusion: Canine retraction was faster when labial forces were applied using sliding mechanics whereas 3D-molar control was better when lingual forces were applied, which is advantageous for critical anchorage cases.
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.