The effect of missing teeth on dementia in older people: a nationwide population-based cohort study in South Korea

Table 1 Demographic characteristics of extraction and non-extraction cohorts

	Non-extraction Cohort		Extraction Cohort		p-value
	(people)	(%)	(people)	(%)
Total	104,903		104,903
Male	35,111	33.5	35,111	33.5	1.0
Female	69,792	66.5	69,792	66.5
Age					1.0
60–69	76,570	73.0	76,570	73.0
70–79	25,699	24.5	25,699	24.5
≥ 80	2634	2.5	2634	2.5
Residential Area					<.001^a
Urban	59,487	56.7	59,487	56.7
Rural	45,416	43.3	45,416	43.3
Eligibility					<.001^a
Head of household	44,292	42.2	43,901	41.8
Family member	52,292	49.8	55,647	53.0
Medical aid beneficiaries	8319	7.9	5355	5.1
Income level					<.001^a
First quintile	24,361	23.2	21,088	20.1
Second quintile	13,851	13.2	12,681	12.1
Third quintile	15,795	15.1	14,576	13.9
Fourth quintile	21,811	20.8	22,506	21.5
Fifth quintile	29,085	27.7	34,052	32.5
History of dental caries					<.001^a
No	74,615	71.1	50,473	48.1
Yes	30,288	28.9	54,430	51.9
History of periodontal treatment					<.001^a
No	73,599	70.2	42,282	40.3
Yes	31,304	29.8	62,621	59.7
Onset of dementia					<.001^a
No	93,711	89.3	92,051	87.7
Yes	11,192	10.7	12,852	12.3

ISSN: 1472-6831