Control of anterior segment using an antero-posterior lingual sliding retraction system: a preliminary cone-beam CT study

Progress in Orthodontics

Table 2 Comparison of the changes in CBCT variables between T0 and T1 in each group

Variables	C-group (n = 18)				p value	AP-group (n = 16)				p value
Variables	T0	SD	T1	SD	p value	T0	SD	T1	SD	p value
Three-dimensional tooth movement
Maxillary central incisors
U1CP X′	4.94	1.78	4.79	1.81	0.383	4.71	1.92	4.58	1.79	0.563
U1CP Y	− 9.36	3.51	− 5.34	3.36	0.000***	− 7.64	5.34	− 3.83	4.26	0.000***
U1CP Z	− 80.57	2.39	− 80.37	2.45	0.188	− 85.37	4.35	− 83.38	3.87	0.000***
U1RP X′	3.20	0.99	3.21	1.29	0.917	3.73	1.83	3.83	1.56	0.393
U1RP Y	1.59	3.84	2.53	3.34	0.012*	− 0.47	3.29	1.44	3.36	0.000***
U1RP Z	− 60.17	2.23	− 59.21	2.58	0.000***	− 63.37	3.78	− 61.61	3.64	0.000***
Maxillary canines
U3CP X′	17.74	1.85	17.85	1.77	0.510	17.57	2.12	17.91	1.88	0.221
U3CP Y	0.65	3.82	4.45	3.99	0.000***	1.50	5.05	5.20	4.48	0.000***
U3CP Z	− 79.42	2.13	− 77.95	2.23	0.000***	− 83.53	3.67	− 81.51	3.59	0.000***
U3RP X′	13.43	1.77	13.59	1.72	0.270	14.70	1.47	15.14	1.51	0.053
U3RP Y	6.59	3.30	7.71	2.63	0.000***	5.48	2.94	6.34	3.22	0.017*
U3RP Z	− 54.77	1.76	− 52.81	1.71	0.000***	− 58.65	3.80	− 56.56	4.17	0.000***
Maxillary first molars
U6CP X′	26.54	1.81	25.76	1.85	0.002**	25.72	2.07	26.72	2.05	0.747
U6CP Y	21.54	3.59	20.08	3.12	0.000***	19.88	4.52	19.43	4.30	0.261
U6CP Z	− 74.54	2.15	− 75.19	2.14	0.000***	− 79.46	2.83	− 78.47	2.71	0.004**
Alveolar bone level
VABLl	1.29	0.29	1.36	0.25	0.186	1.70	0.59	1.38	0.61	0.007**
VABLp	1.37	0.28	3.74	2.56	0.001**	1.46	0.47	3.01	1.22	0.000***
Root resorption
ΔRL	23.62	1.28	22.96	1.59	0.003**	23.55	0.97	22.85	1.30	0.000***

Paired t test was performed. The points of #11, 13, and 16 (right sides) were reflected over the X-axis (U1CP X′, U3CP X′, U6CP X′, respectively); mirror transformation of X-axis. At any point, therefore, outward displacement had a positive value and inward displacement had a negative value
SD standard deviation, Group 1 C-lingual retractor group C-group, antero-posterior lingual retractor group AP-group, U1CP the maxillary central incisors cusp tip point, U1RP the maxillary central incisors root apex point, U3CP the maxillary canines cusp tip point, U3RP the maxillary canines root apex point, U6CP the maxillary mesiobuccal cusp tip point, X′ transverse direction (left: +, right: +), Y antero-posterior direction (mesial: −, distal: +), Z vertical direction (upward: +, downward: −), VABLl vertical alveolar bone level on labial side (distance from CEJ to alveolar crest), VABLp vertical alveolar bone level on palatal side, RL root length (distance from incisor tip to root apex point)
*p < 0.05; **p < 0.01; ***p < 0.001