IADR Abstract Archives
Three Dimensional Effects of Maxillary Canine Retraction Using T-loop versus NiTi Coil Spring
Objectives: The current study was carried out to compare three dimensionally the maxillary canine and first molar movement during retraction by NiTi closed coil spring versus T-loop, using Cone Beam Computed Tomography (CBCT).
Methods: Ten patients were selected in a split mouth study design who had a malocclusion that necessitates the extraction of maxillary first premolars and retraction of maxillary canines. The right maxillary canines were retracted using T-loops fabricated from 0.017 X 0.025 TMA wires on a standardized template and pre activation steps with anti-rotation bends. The left maxillary canines received NiTi coil spring with 150 gm of retraction force while the T-loop side was activated by separating the two legs 2mm to deliver 150 gm of retraction force. changes were evaluated using CBCT.
Results: NiTi coil spring showed significant decrease in the mean measurement of the bucco-lingual inclination from 80± 1.8(µ±SE) to 74.4± 2.3 (µ±SE) and mesio-distal rotation from 30.3± 2.8 (µ±SE) to 21.6± 2.5 (µ±SE) and a statistically significant increase in the mean measurements of the mesio-distal tipping from 78± 1.3 (µ±SE) to 84.3± 1.4 (µ±SE) of the canine. There was a statistically significant increase in mean measurements of antero-posterior position from 32.3± 1.1(µ±SE) to 33.6 ±1.2(µ±SE) of the maxillary first molar. The T-loop showed no statistically significant difference in the bucco-lingual inclination. When comparing post retraction results between the two groups, NiTi coil spring showed statistically significantly higher mean mesio-distal tipping with 84.3± 1.4 (µ±SE) .
Conclusions: The NiTi coil spring side showed significant distal crown tipping, buccal tipping and disto-palatal rotation for the canine while the T-loop side showed no change in these measurments. The Maxillary first molars showed no positional change in the T-loop group while they showed a significant mesial movement in the NiTi coil spring group.
Methods: Ten patients were selected in a split mouth study design who had a malocclusion that necessitates the extraction of maxillary first premolars and retraction of maxillary canines. The right maxillary canines were retracted using T-loops fabricated from 0.017 X 0.025 TMA wires on a standardized template and pre activation steps with anti-rotation bends. The left maxillary canines received NiTi coil spring with 150 gm of retraction force while the T-loop side was activated by separating the two legs 2mm to deliver 150 gm of retraction force. changes were evaluated using CBCT.
Results: NiTi coil spring showed significant decrease in the mean measurement of the bucco-lingual inclination from 80± 1.8(µ±SE) to 74.4± 2.3 (µ±SE) and mesio-distal rotation from 30.3± 2.8 (µ±SE) to 21.6± 2.5 (µ±SE) and a statistically significant increase in the mean measurements of the mesio-distal tipping from 78± 1.3 (µ±SE) to 84.3± 1.4 (µ±SE) of the canine. There was a statistically significant increase in mean measurements of antero-posterior position from 32.3± 1.1(µ±SE) to 33.6 ±1.2(µ±SE) of the maxillary first molar. The T-loop showed no statistically significant difference in the bucco-lingual inclination. When comparing post retraction results between the two groups, NiTi coil spring showed statistically significantly higher mean mesio-distal tipping with 84.3± 1.4 (µ±SE) .
Conclusions: The NiTi coil spring side showed significant distal crown tipping, buccal tipping and disto-palatal rotation for the canine while the T-loop side showed no change in these measurments. The Maxillary first molars showed no positional change in the T-loop group while they showed a significant mesial movement in the NiTi coil spring group.
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