Table 5.

Associations (odds ratios) of patient-, tooth-, and crack-level characteristics with cracked tooth being symptomatic, estimates from generalized estimating equations (GEE).

Characteristic1	Adjusted only for clustering2		Full model3		Reduced model4
	Odds Ratio	p-value	Odds Ratio	p-value	Odds Ratio	95% Confidence Interval	p-value
Patient level
Female	1.22	.004	1.19	.01	1.20	1.06–1.36	.006
Non-Hispanic White race	0.71	.001	0.74	.006	0.74	0.60–0.90	.005
Age less than 65 years	1.62	<.001	1.38	<.001	1.39	1.18–1.64	<.001
Clench, grind, OR press teeth together, either sleep or awake	1.40	<.001	1.29	.001	1.30	1.12–1.50	<.001
Tooth level
Molar	1.76	<.001	1.54	<.001	1.58	1.30–1.92	<.001
3 or more external cracks	1.19	.04	1.04	.6	-
Wear facet through enamel	1.25	.03	1.24	.04	1.22	1.01–1.49	.047
Exposed roots	0.83	.048	0.94	.5
Caries present	1.38	.003	1.31	.009	1.31	1.07–1.60	.009
NCCL present	0.71	.009	0.82	.17	-
Crack level
Extends to root	1.30	.047	1.32	.056
Stained	0.78	.01	0.67	<.001	0.68	0.55–0.84	<.001
Blocks transilluminated light	1.30	.006	1.30	.008	1.31	1.09–1.57	.006
Distal surface involved	1.40	<.001	1.30	.002	1.31	1.13–1.52	<.001

¹NCCL: Non-carious cervical lesion.

²All characteristics that were associated with cracked tooth being symptomatic at p<=0.05 after adjustment for clustering within practitioner using GEE are listed.

³Full model: All characteristics that were associated with cracked tooth being symptomatic at p<=0.05 after adjustment for clustering within practitioner using GEE were included in the model.

⁴Reduced model: Using GEE, starting with the full model, backwards elimination was used, removing one characteristics at a time, starting with highest p-value, retaining only characteristics with p < 0.05.