Effects of twin-block appliance on the anatomy of pharyngeal airway passage (PAP) in class II malocclusion subjects

Progress in Orthodontics

Table 4 The changes in the posterior pharyngeal wall thickness (PPWT) among treatment and control group subjects

Variables	Groups						Comparison of mean difference among treatment and control groups (P-value)
	Treatment group			Control group
	Pre-treatment (T₀)	6 months post-treatment (T₁)	Significance (P-value)	Pre-follow-up (T₀)	6 months Post-follow-up (T₁)	Significance (P-value)
	Mean ± SD	Mean ± SD	Significance (P-value)	Mean ± SD	Mean ± SD	Significance (P-value)
PPWT 1 (mm)	15.68 ± 4.15	15.97 ± 4.18	0.646^NS	16.06 ± 4.56	14.54 ± 3.36	0.015*	0.226^NS
PPWT 2 (mm)	11.02 ± 3.19	11.02 ± 3.00	0.991^NS	10.78 ± 2.99	10.23 ± 2.67	0.217^NS	0.370^NS
PPWT 3 (mm)	4.66 ± 1.41	4.84 ± 1.83	0.521^NS	5.52 ± 1.65	5.00 ± 1.84	0.209^NS	0.150^NS
PPWT 4 (mm)	4.38 ± 2.41	4.74 ± 2.27	0.338^NS	5.09 ± 2.84	4.65 ± 2.72	0.239^NS	0.875^NS
PPWT 5 (mm)	4.10 ± 1.04	4.10 ± 1.07	0.988^NS	4.45 ± 1.14	4.32 ± 1.22	0.534^NS	0.684^NS
PPWT 6 (mm)	3.28 ± 0.94	3.52 ± 0.84	0.242^NS	3.65 ± 1.05	3.44 ± 0.83	0.361^NS	0.896^NS

SD indicates standard deviation; NS, non-significant; *p<0.05.
PPWT1, posterior pharyngeal wall thickness at nasopharyngeal space 1; PPWT2, posterior pharyngeal wall thickness at nasopharyngeal space 2; PPWT3, posterior pharyngeal wall thickness at oro-pharyngeal space 1; PPWT4, posterior pharyngeal wall thickness at oropharyngeal space 2; PPWT5, posterior pharyngeal wall thickness at hypopharyngeal space 1; PPWT6, posterior pharyngeal wall thickness at hypopharyngeal space 2.