Quantitative measures of gingival recession and the influence of gender, race, and attrition

Progress in Orthodontics

Table 4 Independent t-tests comparing the no recession to recession subgroups using the gingival margin-papillae measure for the combined four groups

Tooth class	Group	n	Mean	SD	t	p
U6	No recession	96	2.33	0.73	− 7.53	0.000*
U6	Recession	30	3.51	0.81	− 7.53	0.000*
U5	No recession	105	2.45	0.70	− 5.76	0.000*
U5	Recession	31	3.36	0.88	− 5.76	0.000*
U4	No recession	96	3.00	0.69	− 6.74	0.000*
U4	Recession	33	3.95	0.79	− 6.74	0.000*
U3	No recession	102	4.08	0.79	− 6.23	0.000*
U3	Recession	42	5.22	1.28	− 6.23	0.000*
U2	No recession	103	3.28	1.05	− 2.62	0.000*
U2	Recession	23	3.89	0.61	− 2.62	0.000*
U1	No recession	107	3.84	1.05	− 3.40	0.000*
U1	Recession	19	4.94	2.17	− 3.40	0.000*
L6	No recession	93	2.51	0.61	− 6.51	0.000*
L6	Recession	13	3.89	1.27	− 6.51	0.000*
L5	No recession	101	2.74	0.63	− 5.13	0.000*
L5	Recession	23	3.57	0.94	− 5.13	0.000*
L4	No recession	96	3.39	0.69	− 3.15	0.000*
L4	Recession	23	3.91	0.84	− 3.15	0.000*
L3	No recession	104	3.91	0.91	− 5.71	0.000*
L3	Recession	30	5.03	1.01	− 5.71	0.000*
L2	No recession	114	2.93	0.82	− 1.18	0.239
L2	Recession	11	3.27	1.33	− 1.18	0.239
L1	No recession	105	2.83	0.66	− 5.25	0.000*
L1	Recession	22	3.76	1.05	− 5.25	0.000*

*p < .05, indicating a difference and comparing the no recession and recession subgroups—a true positive value
Reprinted with permission from Eltink et al. [17, 27]