Masticatory efficiency in patients with partially dentate dentitions.

OBJECTIVES: To assess associations amongst masticatory performance, dental functional status, and perceived chewing problems with common soft and hard foods.

MATERIALS AND METHODS: 387 adult participants with reduced natural dentitions were included and underwent an oral examination, completed a written structured questionnaire and performed a two-color chewing gum test for masticatory efficiency. A multivariate regression model was used to analyze associations between masticatory efficiency and a number of dental conditions, with age, gender and perceived chewing difficulties as background variables. Likelihood ratios were calculated to analyze the relationship between masticatory efficiency and dental conditions within a validated hierarchical dental functional classification system expressed by (1) number of teeth in upper and lower jaw, (2) completeness of anterior regions, (3) number of premolar occluding pairs, and (4) number of molar occluding pairs.

RESULTS: The regression model showed a significant positive association between unmixed ratio and self-reported problems with chewing (p = .004), and age (p < 0.001), and negative associations with having a sufficient premolar region (p < 0.001). In the hierarchical dental functional classification system, the likelihoods of having a high unmixed ratio and chewing problems with hard foods were highest for the predictor 'less than 10 teeth in each jaw' (LRs 4.01, respectively 13.06).

CONCLUSIONS: In partially dentates people, perceived chewing difficulties were associated with lower objective masticatory efficiency. Having fewer than 10 teeth in each jaw and having an impaired premolar region were best predictors for low masticatory efficiency.

CLINICAL SIGNIFICANCE: This study shows that having fewer than 10 teeth in each jaw and having an impaired premolar region are associated with low masticatory efficiency and chewing problems. Preservation of at least 10 teeth in each jaw and 3 to 4 premolars is important for preventing chewing difficulties.