Oral Biology Research

Table. 2.

The average force, hysteresis and unload/peak ratio during repeated extension of Memory chain (American Orthodontics, Sheboygan, MI, USA) and the percentage of the residual force to the force at the first extension

Cycle 12.5 mm peak 11.5 mm load 1 mm unload Hysteresis 1-mm-unload/peak ratio
1st cycle 366.1±5.3a 353.3±5.3a 298.8±4.5a 54.5±1.6a 81.6±0.35%d
100% 100% 100% 100%
2nd cycle 352.8±5.1b 318.7±4.9b 291.5±4.4b 27.2±1.2b 82.6±0.25%c
96.4±0.37% 90.2±0.38% 97.6±0.45% 49.9±2.2%
3rd cycle 346.3±5.1c 309.6±4.9c 287.8±4.6c 21.8±1.0c 83.2±0.35%b
94.6±0.44% 87.6±0.45% 96.3±0.36% 39.8±2.3%
4th cycle 341.2±4.8d 304.4±4.8d 284.9±4.5d 19.5±1.4d 83.6±0.36%a
93.2±0.45% 86.2±0.42% 95.3±0.51% 36.0±2.7%
5th cycle 338.0±4.8e 300.6±4.5e 282.5±4.3e 18.2±1.3e 83.7±0.39%a
92.3±0.40% 85.1±0.44% 94.5±0.59% 33.6±2.8%

Values are presented as mean±standard deviation. Unit: gram-force (gf).

a,b,c,d,eDifferent letters indicate significant statistical differences among cycles (p<0.05, Tukey HSD test).

Oral Biol Res 2022;46:71~77 https://doi.org/10.21851/obr.46.02.202206.71
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