Table 4. Incidence and hazard ratio for the osteonecrosis cohort compared to the comparison cohort.

Annual Frequency of Dental Extraction	Comparison	Osteoporosis
		Mild	Serious	P for trend
Low*	1.00	1.69 (0.90–3.16)	2.19 (0.75–6.38)	0.08
Median †	3.11 (1.81–5.37)***	4.47 (2.41–8.31)***	7.12 (2.87–17.6)***	0.07
High ‡	15.9 (9.69–26.0)***	39.2 (23.9–64.4)***	46.6 (24.7–87.9)***	<0.0001
P for trend	<0.0001	<0.0001	<0.0001

Adjusted model; model adjusted for age, gender, hypertension, diabetes and cancer.

*Low: < once annually;

^†Median: once or twice annually;

^‡High: > twice annually.

***P<0.001.