Association of symptomless TMJ sounds with occlusal force and masticatory performance in older adults

This study investigated associations between temporomandibular joint (TMJ) sounds and occlusal force or masticatory performance stratified by posterior occlusal supports in older Japanese adults. The subjects consisted of 1646 independently living people over 60 years. Masticatory performance, occlusal force, TMJ sounds and maximal mouth opening were examined. Posterior occlusal supports were classified by the Eichner Index. The prevalence of TMJ sounds was 27.7%, limitation of mouth opening (< 40 mm) was 7.9% and TMJ pain was only 1.5%. In the Eichner C group, TMJ sounds were significantly associated with lower occlusal force (OR = 3.20, P = 0.046) and lower masticatory performance (OR = 3.18, P = 0.041) after controlling for gender and age. These associations were not found in the Eichner A and B groups. Within the limitations of this study, the presence of TMJ sounds, even if they were symptomless, was associated with impairment of masticatory function in older adults with reduced occlusal support.