Risk Factors for Third Molar Occlusal Caries: A LongitudinalClinical Investigation
Methods: A prospective cohort study was used to study caries risk (crude increment and incidence rate) on retained and erupted to the occlusal plane third molars among a moderate-size (n=215) groups of health (American Society of Anesthesiologists class I and II) young adults (median age, 26 years) followed up for a mean of 4.6 years. Clinical data were gathered by calibrated examiners using visual-tactile and radiographic diagnostic methods on all molar teeth. The covariates incldued age at enrollment, gender, race, income, education, frequency of dental visits, oral hygeine behaviors, and smoking.
Method of Data Analysis: Summary statistics and visual methods were used for data description. The analyses relied on bivariate and muiltivariate methods using generalized estimating questions, extensions of Poisson modeling.
Results: Of the 215 patient, 33% developed occlusal caries on 1 or more retained third molars. The incidence rate was 0.11 (95% confidence interval 0.09 to 0.13) third molar “increments”/person-year. Those with any molar caries at baseline were 80% more likely to have a new third molar caries lesion at the end of follow-up compared with those with caries-free molars (prevalence ratio, 1.80; 95% confidence interval, 1.08 to 3.00). The third molar caries rate was halved for every approximately 9 years of the subjects’ baseline age. Favorable oral hygiene behaviors and better socioeconomic status were associated with decreased caries risk. However, independent of other covariates, smoking increased the third molar caries risk twofold.
Conclusions: Younger patient from lower socioeconomic strata, smokers, and those with poor oral hygeine behavior are at increased risk of occlusal caries development on the their retained third molars.