Table 3.

Risk of bias considering parameters reported in reviewed articles.

No.	Study	Standardized magnet	Standardized treatment	Standardized measurement	Sample size descriptions	Blinding of the operator	One operator	Risk 1–2 = H; 3–4 = M; 5–6 = L
1	Yiu et al. 2004 [5]	Y	Y	N	Y	N	N	M
2	Chao et al. 2005 [14]	Y	N	N	Y	N	N	H
3	Ohashi et al. 2007 [15]	Y	N	N	Y	N	N	H
4	Huang, 2008 [16]	Y	N	N	Y	N	N	H
5	Boeckler et al. 2009 [17]	Y	Y	Y	Y	N	N	M
6	Akin et al. 2011 [18]	Y	N	Y	Y	N	N	M
7	Hasegawa et al. 2011 [19]	Y	N	N	Y	N	N	H
8	Yang et al. 2011 [20]	Y	Y	Y	N	N	N	M
9	Chung, 2011 [21]	Y	Y	N	Y	N	N	M
10	Akin et al. 2013 [9]	Y	Y	Y	Y	N	N	M
11	Hao et al. 2014 [22]	Y	N	N	Y	N	N	H
12	Lee et al., 2017 [23]	Y	N	Y	Y	N	N	M
13	Kang et al. 2019 (Materials, 2019; 12:1–12) [24]	Y	Y	Y	Y	N	N	M
14	Kang et al. 2019 (J Magn, 2019; 24 : 733–8) [25]	Y	Y	Y	Y	N	N	M
15	Kusumadewi et al. 2021 [26]	Y	N	N	Y	N	N	H
Note:	Y = reported in the article
N = Not reported	H = High risk	M = Medium risk	L = Low risk