Table 4.

Relationship between SHS exposure and caries of permanent teeth sorted by age of children.

Study	Age (n)	SHS		Dental caries		Effect size OR c (95% CI d)
		Def a	%	Def b	%
Tanaka, 2006 [18]	1–14 (925)	HS	42.5	dft, DFT	61.2	1.26 (0.93, 1.69)
Aligne, 2003 [15]	4–11 (2,930)	SCL	54.2	DS	9.0	1.2 (0.8, 1.9)
				FS	18.9	0.9 (0.6, 1.3)
Tanaka, 2010 [26]	6–15 (20,253)	HSe	16.5	DFT	55.1	1.03 (1.00, 1.06) f
	6–15 (20,703)			dft, DFT	83.0	1.04 (1.03, 1.06) f
Bolin, 1997 [13]	12 (1,265)	MS	31.4 g	DMFS	62.8 g	1.40 (1.11, 1.78) g
Ayo-Yusuf, 2007 [20]	14.6 h (1,873)	HS	36.9	DT i	16.4	2.02 (1.22, 3.33)
Julihn, 2009 [25]	13, 19 j (15,538)	MSP	21.0	ACI k	38.6	1.33 (1.22, 1.44)
Ditmyer, 2010 [27]	12–19 (4,169)	HS	34.6	DMFT	NA l	1.42 (1.03, 1.53)

^adefinition of secondhand smoke: SCL, serum cotinine level; HS, household smoking; MS, maternal smoking; MSP, maternal smoking during pregnancy;

^bdefinition of dental caries: T, tooth; S, surface;

^codds ratio;

^dconfidence interval;

^ehousehold smoking ≥15 cigarettes daily;

^fprevalence ratio;

^gcalculated by reviewer based on data in the table in the original literature;

^haverage of high school students;

ⁱdecayed second molar;

^jcohort format between two ages;

^kapproximal caries increment;

^lnot available because of exclusion of middle group regarding severity of dental caries (4.0 > DMFT > 0).