Table 6.

Extent and Severity of Combined Attachment Loss by Cannabis Exposure Group

	Cannabis Exposure Group, %
	None	Some	Highest 20%	All Combined, %
Extent of 4 mm or greater CAL
Mean (SD)	0.9 (4.2)	1.7 (4.5)	4.7 (10.0)a	2.0 (6.1)
Median (interquartile range)	0.0 (0.0–0.0)	0.0 (0.0–1.2)	1.2 (0.0–4.8)	0.0 (0.0–1.2)
Extent of 5 mm or greater CAL
Mean (SD)	0.2 (1.9)	0.4 (1.4)	1.5 (5.1)a	0.6 (2.8)
Median (interquartile range)	0.0 (0.0–0.0)	0.0 (0.0–0.0)	0.0 (0.0–1.2)	0.0 (0.0–0.0)
Severity of CAL
Mean (SD)	3.1 (0.2)	3.1 (0.2)	3.3 (0.4)a	3.1 (0.3)
Median (interquartile range)	3.0 (3.0–3.0)	3.0 (3.0–3.2)	3.2 (3.0–3.4)	3.0 (3.0–3.2)

Abbreviation: CAL, combined attachment loss.

^aP < .001; Kruskal-Wallis test.