Cracked Teeth and Poor Oral Masticatory Habits: A Matched Case-control Study in China.

INTRODUCTION: Previous studies have suggested that masticatory forces are associated with cracked teeth, but it is not clear which specific poor oral masticatory habits may be more likely to cause cracks. The aim of this study was to quantitatively assess risk factors for cracked teeth among poor oral masticatory habits and create a model for individualized risk predictions. METHODS: We enrolled 35 patients with cracked teeth matched to 70 controls without cracked teeth by age, sex, position of the affected tooth, presence/absence of systemic disease, and diagnosis of symptomatic irreversible pulpitis from the Stomatology Hospital of Tianjin Medical University, Tianjin, China. Odds ratios (ORs) were calculated using conditional logistic regression analysis. RESULTS: Thermal cycling eating habits (OR = 3.296; 95% confidence interval [CI], 1.684-6.450), eating coarse foods (OR = 2.727; 95% CI, 1.340-5.548), chewing on hard objects (OR = 2.087; 95% CI, 1.041-4.182), and unilateral mastication (OR = 2.472; 95% CI, 1.255-4.869) were independent risk factors for cracked teeth. The corresponding risk scores were 2.182, 1.691, 1.467, and 1.589, respectively. The area under the receiver operating characteristic curve and its 95% CI were 0.920 (0.868-0.973); the sensitivity and specificity were 0.943 and 0.800, respectively. CONCLUSIONS: Thermal cycling eating habits were strongly associated with cracked teeth, whereas eating coarse foods, chewing on hard objects, and unilateral mastication were also independent risk factors for cracked teeth. These findings yield insights into ways to promote the prevention of risky behaviors for cracked teeth.