Table 2.

Risk of bias assessment using the QUADAS-2 tool

Authors (year)	Risk of bias			Applicability concerns
	Patient selection	Index test	Flow and timing	Patient selection	Index test
a. CT
Van der Meij et al. (1993)12	‒	‒	+	+	+
Van der Meij et al. (2001)13	+	‒	+	+	‒
Ozawa et al. (2007)14	‒	‒	+	+	+
Nagashima et al. (2014)15	‒	‒	+	+	+
Tong et al. (2015)16	+	‒	‒	+	+
Takemaru et al. (2016)17	‒	‒	+	+	+
b. Stereophotogrammetry
Sander et al. (2011)18	+	‒	+	+	‒
c. 3D digitizer
Mishima et al. (1997)19	‒	‒	+	+	‒
Braumann et al. (2003)20	‒	‒	‒	+	‒
d. Laser scanner
Baek et al. (2006)21	‒	‒	+	+	‒
Schwenzer-Zimmerer et al. (2009)22	‒	‒	‒	+	+
Fuchigami et al. (2014)23	‒	‒	+	+	‒

+ = low risk; ‒ = high risk; ? = unclear risk; CT = computed tomography