Table 1. Prevalence of Alzheimer’s disease by sex, age group, and number of teeth present in subjects diagnosed as having periodontitis.

		Total subjects		Subjects with Alzheimer’s disease		p-value*
		N	%	N	%
Sex	Male	1,685,921	42.0	34,561	2.05	<0.001
	Female	2,323,424	58.0	86,607	3.73
Age group (y)	60–64	591,131	14.7	897	0.15	<0.001
	65–69	898,217	22.4	3,114	0.35
	70–74	823,287	20.5	7,331	0.89
	75–79	794,723	19.8	17,912	2.25
	80–84	538,301	13.4	32,311	6.00
	85–	363,686	9.1	59,603	16.39
Number of teeth present (excluding third molars)	20–28	2,483,055	61.9	48,360	1.95	<0.001
	10–19	1,066,458	26.6	41,276	3.87
	1–9	459,832	11.5	31,532	6.86
Total		4,009,345	100.0	121,168	3.02

*Chi-squared test.