Caries or Malocclusion: Which Came First?

Objectives: Malocclusions, along with caries and periodontitis, are among the most common oral health impairments. Epidemiological studies have drawn attention to the association of malocclusions and dental caries, which was also confirmed in a meta-analysis. What is unclear is the direction of this association. Therefore, the aim of this study was to systematically generate hypotheses for both causal directions and test them tentatively with cross-sectional data.
Methods: For this question, data from an oral epidemiological study, the 6th German Oral Health Study (DMS 6), were analyzed. 1,892 individuals from the 2011 and 2012 birth cohorts were invited to participate in the study. A disproportionally stratified probability sample yielded 705 study participants with their respective data on malocclusions and oral health. For the most prevalent malocclusions hypotheses were generated for both causal directions of the malocclusion-caries link. Each hypothesis was then tested with adequate associational statistical methods.
Results: Clinically relevant malocclusions with a prevalence of at least 10% were investigated: Mandibular recession, deep bite, crowding, and lack of space. These are related to approximal caries of the supporting zones (canines, both deciduous molars, and six-year molars) with different associational strength.
Conclusions: Etiopathogenetically, both directions are conceivable: malocclusions can act as a risk factor for the development of caries and vice versa. The results of this study are hypothesis-generating because they were cross-sectional. The hypotheses can serve as a basis for longitudinal epidemiological follow-up studies and thus have preventive potential in translational research.