. 2015 Dec 26;54(3):246–253. doi: 10.2486/indhealth.2015-0207

Table 3. Comparison of factors associated with having fewer than 20 teeth between professional drivers and white-collar workers using the chi-squared test.

			Professional drivers				White-collar workers

			Having fewer than 20 teeth				Having fewer than 20 teeth
	Factors		n₁	n₂	%	P values	n₁	n₂	%	P values
Characteristics	Age group (years)	30–49	297	41	13.8	<0.001	183	15	8.2	0.017
		50–69	295	82	27.8		145	25	17.2
	BMI	<25	396	78	19.7	0.389	228	28	12.3	1.000
		≥25	196	45	23.0		100	12	12.0
	Annual family income	<4 million yen	232	57	24.6	0.078	94	16	17.0	0.096
		≥4 million yen	360	66	18.3		234	24	10.3
Working environment	Working hours	<8 h	118	34	28.8	0.022	120	15	12.5	1.000
		≥8 h	474	89	18.8		208	25	12.0
	Shift work	Yes	284	69	24.3	0.054	86	11	12.8	0.849
		No	308	54	17.5		242	29	12.0
	Duration of employment	<10 years	368	80	21.7	0.531	179	27	15.1	0.091
		≥10 years	224	43	19.2		149	13	8.7
	Night work	Yes	138	33	23.9	0.338	73	10	13.7	0.686
		No	454	90	19.8		255	30	11.8
Systemic diseases	Diabetes mellitus	Yes	54	23	42.6	<0.001	29	5	17.2	0.374
		No	538	100	18.6		299	35	11.7
	Hypertension	Yes	141	42	29.8	0.004	59	9	15.3	0.509
		No	451	81	18.0		269	31	11.5
	Hypercholesterolemia	Yes	74	24	32.4	0.013	32	5	15.6	0.567
		No	518	99	19.1		296	35	11.8
	Cardiovascular disease	Yes	6	1	16.7	1.000	6	0	0.0	1.000
		No	586	122	20.8		322	40	12.4
	Lower back pain	Yes	96	18	18.8	0.681	43	6	14.0	0.626
		No	496	105	21.2		285	37	11.9
	Gastrointestinal disease	Yes	18	6	4.9	0.233	9	2	22.2	0.302
		No	574	117	20.4		319	38	11.9
Dental care utilization	Dental visits in past year	Yes	299	67	22.9	0.225	149	20	13.4	0.612
		No	293	56	18.7		179	20	11.2
	Visiting same dentist	Yes	351	78	22.2	0.305	182	23	12.6	0.866
		No	241	45	18.7		146	17	11.6
	Regular dental check-ups	Yes	244	55	22.5	0.411	126	19	15.1	0.227
		No	348	58	19.5		202	21	10.4
Life style	Frequency of eating breakfast on weekdays	Every day	378	60	15.9	<0.001	244	30	12.3	1.000
	Frequency of eating breakfast on weekdays	Not every day	214	63	29.4		84	10	11.9
	Frequency of eating dinner on weekdays	Every day	516	101	19.6	0.069	295	36	12.2	1.000
	Frequency of eating dinner on weekdays	Not every day	76	22	28.9		33	4	12.1
	Frequency of eating out on weekdays	1 time and more per week	191	53	27.7	0.005	111	16	14.4	0.378
	Frequency of eating out on weekdays	Never	401	70	17.5		217	24	11.1
	Smoking status	Smokers or ever smokers	471	113	24.0	<0.001	218	34	15.6	0.007
		Non-smokers	121	10	8.3		110	6	5.5
	Sleeping hours	<7 h	339	76	22.4	0.262	180	23	12.8	0.738
		≥7 h	253	47	18.6		148	17	11.5
	Eating snacks between meals	Yes	451	93	20.6	0.905	241	32	13.3	0.559
		No	141	30	21.3		81	8	9.9
Dental hygiene habits	Frequency of daily brushing	<2	254	64	25.2	0.024	110	11	10.0	0.476
		≥2	338	59	17.5		218	29	13.3
	Duration of brushing teeth	<3 minutes	286	74	25.9	0.003	163	24	14.7	0.180
		≥3 minutes	306	49	16.0		165	16	9.7
Timing of brushing teeth	Before eating breakfast	Yes	227	54	23.8	0.176	105	16	15.2	0.279
		No	365	69	18.9		223	24	10.8
	After eating breakfast	Yes	265	45	17.0	0.042	196	19	9.7	0.121
		No	327	78	23.9		132	21	15.9
	After eating lunch	Yes	73	18	24.7	0.441	66	5	7.6	0.291
		No	519	105	20.2		262	35	13.4
	After eating snack	Yes	14	6	42.9	0.050	6	0	0.0	1.000
		No	578	117	20.2		322	40	12.4
	After eating dinner	Yes	137	17	12.4	0.006	74	10	13.5	0.689
		No	455	106	23.3		254	30	11.8
	Before bed time	Yes	307	65	21.2	0.840	179	24	13.4	0.501
		No	285	58	20.4		149	16	10.7

n₁: total number of participants for each item, n₂: the number of participants who had fewer than 20 teeth