Table 1

		Study Group (n = 30)		OIN Subgroups (n = 11)			P
		HK (n = 19)	OIN (n = 11)	OIN1 (n = 5)	OIN2 (n = 4)	OIN3 (n = 2)	P
Age	Mean (SD)	55.05 (10.07)	53.09 (12.93)	57.60 (11.55)	53.25 (12.97)	41.50 (16.26)	0.966^a
	Median	53	56	57	56.5	41.5
	Min-max	34 - 75	30 - 71	40 - 71	35 - 65	30 - 53
Gender	M	13 (65)	7 (35)	2 (10)	4 (20)	1 (5)	1^b
Gender	F	6 (60)	4 (40)	3 (30)	0 (0)	1 (10)	1^b
Smoking	S	17 (70.8)	7 (29.2)	3 (12.5)	4 (16.7)	0 (0)	0.156^b
Smoking	NS	2 (33.3)	4 (66.7)	2 (33.3)	0 (0)	2 (33.3)	0.156^b
Alcohol	U	2 (40)	3 (60)	1 (20)	2 (40)	0 (0)	0.327^b
Alcohol	NU	17 (68)	8 (32)	4 (16)	2 (8)	2 (8)	0.327^b
Clinical type	C1	18 (78.3)	5 (21.7)	3 (13)	2 (8.7)	0 (0)	0.004^c
Clinical type	C2	1 (14.3)	6 (85.7)	2 (28.6)	2 (28.6)	2 (28.6)	0.004^c

^aStatistically no significant, Mann Whitney U test.
^bStatistically no significant, Fisher’s exact test.
^cStatistically significant at the level P < 0.01, Fisher’s exact test.
P values indicate HK vs OIN group comparisons.
SD = standard deviation; HK = hyperkeratosis; OIN = oral intraepithelial neoplasia; n = number of samples; M = male; F = female; S = smoker; NS = non-smoker; U = using; NU = non-user; C1 = homogenous type; C2 = non-homogenous type.