Table 4.

Wilcoxon Signed-Rank Test Results of Speech and Language Pathologist Analysis of Speech Alteration of Invisalign and Fixed Groups at T₀, T₁, and T₂

	Invisalign Group (n = 24)		Fixed Group (n=20)
	z Value	P Value	z Value	P Value
T0 × T1	–6.6635	<.01**	–3.6303	<.01**
T1 × T2	–2.1533	.03*	–2.4569	.01*
T0 × T2	–5.9384	<.01**	–1.4085	.15

^*Significant by the Student's t-test at P < .05.

^**Significant by the Student's t-test at P < .01.