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

Progress in Orthodontics

Table 3 Independent t-tests comparing the no recession to recession subgroups using the clinical crown height measure for the combined four groups

Tooth class	Group	n	Mean	SD	t
U6	No recession	96	6.41	0.85	− 10.41
U6	Recession	30	8.25	0.83	− 10.41
U5	No recession	105	6.94	0.86	− 7.57
U5	Recession	31	8.28	0.88	− 7.57
U4	No recession	96	7.94	0.82	− 6.62
U4	Recession	33	9.06	0.91	− 6.62
U3	No recession	102	9.73	0.89	− 7.36
U3	Recession	42	11.02	1.10	− 7.36
U2	No recession	103	8.66	0.99	− 5.27
U2	Recession	23	9.80	0.63	− 5.27
U1	No recession	107	10.13	1.00	− 5.31
U1	Recession	19	11.49	1.17	− 5.31
L6	No recession	93	6.56	0.71	− 5.88
L6	Recession	13	7.92	1.19	− 5.88
L5	No recession	101	7.24	0.82	− 6.07
L5	Recession	23	8.41	0.92	− 6.07
L4	No recession	96	8.14	0.75	− 6.35
L4	Recession	23	9.25	0.75	− 6.35
L3	No recession	104	9.50	1.16	− 7.08
L3	Recession	30	11.11	0.80	− 7.08
L2	No recession	114	8.22	0.92	− 6.05
L2	Recession	11	9.98	0.97	− 6.05
L1	No recession	105	7.99	0.98	− 7.17
L1	Recession	22	8.58	0.74	− 7.17

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