Oral Biology Research

Table. 5. Table 5

Hysteresis by the manufacturers in repeated extensions

Cycle	Generation II power chain (Ormco)		Memory chain (AO)		Energy chain (RMO)

	Mean	SD	Mean	SD	Mean	SD
1st cycle	55.6,^b,c	2.5	54.5^c	1.6	59.2^a	1.5
2nd cycle	29.3^a	1.5	27.2^b	1.2	28.6^a	1.0
3rd cycle	23.6^a	1.5	21.8^b	1.0	23.2^a	1.3
4th cycle	21.2^a	1.4	19.5^b	1.4	20.3^a,b	1.4
5th cycle	19.5^a	1.3	18.2^b	1.5	18.8^a,b	1.3

Three manufacturers: Gereration II power chain (Ormco, Glendora, CA, USA), Memory chain (American Orthodontics, Sheboygan, MI, USA), Energy chain (RMO, Denver, CO, USA). Unit: gram-force (gf).

SD, standard deviation.

^a,b,cDifferent letters indicate significant statistical differences among manufacturers (p<0.05, Tukey HSD test).

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