Table 2.

Summary Statistics of the Non-normally Distributed Outcome Number of Failed Brackets Per Patient for Different Variables^a

Factor	Category	n	Median (IQR)	Range	Pb
	Overall	78	3.0 (2.0–5.0)	1.0–24.0
Gender	Female	50	3.0 (1.0–5.0)	1.0–21.0	.72
	Male	28	3.0 (2.0–4.5)	1.0–24.0
Deepbite	No	37	3.0 (2.0–5.0)	1.0–13.0	.78
	Yes	41	3.0 (2.0–5.0)	1.0–24.0
Crossbite	No	66	3.0 (1.0–5.0)	1.0–24.0	.38
	Yes	12	3.5 (3.0–5.5)	1.0–7.0
Anterior crowding	No	15	4.0 (2.0–7.0)	1.0–24.0	.27
	Yes	63	3.0 (1.0–5.0)	1.0–13.0
Bracket type	SSCL	25	3.0 (2.0–4.0)	1.0–10.0	.14
	CeramicCL	20	5.0 (2.5–8.0)	1.0–24.0
	SSSL	25	3.0 (1.0–5.0)	1.0–21.0
	Ni-freeSL	8	2.5 (2.0–4.0)	1.0–6.0
Extraction case	No	70	3.0 (2.0–5.0)	1.0–24.0	.75
	Yes	8	2.5 (2.0–4.0)	1.0–13.0
Auxiliary appliances used	No	72	3.0 (2.0–5.0)	1.0–24.0	.78
	Yes	6	3.0 (2.0–3.0)	1.0–9.0
Missed appointments, binary	No	25	2.0 (1.0–3.0)	1.0–13.0	.03
	Yes	53	4.0 (2.0–6.0)	1.0–24.0
Hygiene warning received	No	37	3.0 (2.0–5.0)	1.0–24.0	.63
	Yes	41	3.0 (2.0–5.0)	1.0–11.0

^aIQR indicates interquartile range; SS, stainless steel; _CL, conventionally ligated; _SL, self-ligated.

^bP values from Kruskal–Wallis tests.