Table 6: Univariable and multivariable population average GEE regression model results for the effect of participant characteristics on CAT system visibility.

	Univariable			Multivariable
	Odds Ratio	p-value	95% CI	Odds Ratio	p-value	95% CI
Sex
Male	reference
Female	0.15	0.317	0.88, 1.49
Expertise status
1st-year students	reference			reference
6th-year students	0.93	0.65	0.67, 1.28	0.82	0.49	0.48, 1.42
Instructors	1.39	0.05	1.00, 1.94	1.56	0.15	0.86, 2.85
Treatment history
No	reference			reference
Yes	0.73	0.02	0.56, 0.95	0.77	0.27	0.48, 1.23
Satisfaction with own dental esthetics
No	reference
Yes	1.05	0.71	0.80, 1.38
Interest in treatment
No	reference
Yes	0.77	0.05	0.58, 1.01	0.84	0.50	0.52, 1.38
CAT system
ClearCorrectTM aligner	reference			4.15	<0.01	1.72, 10.02
MODERN CLEAR system	16.52	<0.01	9.29, 29.39	69.94	<0.001	25.72, 190.18
Ortho Aligner	1.41	0.26	0.77, 2.56	6.06	<0.001	2.48, 14.79
Ideal Smile® ALIGNER	2.19	0.01	1.25, 3.87	9.86	<0.001	3.87, 25.16
Orthocaps® SLP 800	78.61	<0.01	28.58, 216.20	346.33	<0.001	109.05, 1099.87
Orthocaps® DLP 460	7.11	<0.01	3.87, 13.08	32.29	<0.001	11.99, 86.96
Orthocaps® DLP 580	16.52	<0.01	8.95, 30.49	78.25	<0.001	29.70, 206.11
No aligner	0.22	<0.01	0.09, 0.53	reference