Chewing ability's association with oral health-related QoL in prosthodontic patients

Objectives: The aim of this study was to examine whether chewing ability was related to oral health-related quality of life (OHRQoL).

Methods: During the study period, 489 consecutive patients at Tokyo Medical and Dental University's Prosthodontic clinic were screened and agreed to participate in the study (mean age 63.0+/-11.5, 71.2% female). None of the patients exhibited signs or symptoms of acute oral disease. The 20-item chewing function questionnaire proposed by Sato et al. (1989) was used to assess perceived chewing ability. Patients were asked whether it was easy (“1”) or difficult (“0”) to chew the foods. Item responses were combined, producing a 0 to 20 summary score where a higher score indicates better chewing ability. For the evaluation of OHRQoL, a 14-item short version of Oral Health Impact Profile-Japanese version (OHIP-J14) was utilized. For each OHIP question, subjects were asked how frequently they had experienced the impact in the last month. Responses were made on a scale 0-never to 4-very often (range: 0-56 units, where a higher score indicates poorer OHRQoL). A Pearson correlation coefficient was calculated to assess the correlation between the two variables. In addition, the summary score of OHIP-J14 was considered the dependent variable and the chewing function ability score was considered the independent variable in a linear regression analysis.

Result: The mean chewing ability score was 12.1+/-4.8. The mean OHIP-J14 was 13.0+/-9.1. Chewing ability and OHRQoL were substantially correlated (Pearson correlation coefficient: -0.46, 95% confidence interval [CI]: -0.52 to -0.38), indicating that higher chewing ability was associated with lower OHIP-J14 summary scores (R2=0.21, p<0.001). A 1.0-unit increase in chewing ability was related to -0.87 (95% CI: -1.0 to -0.72, p<0.001) OHIP-J units, indicating less impaired OHRQoL.

Conclusion: Patients' perception of their chewing ability is substantially related to OHRQoL.