Occlusal Support and Temporomandibular Disorders Among Elderly Vietnamese

The aim of this study was to analyze the associations between missing teeth, occlusal support, and temporomandibular disorders (TMD) among elderly Vietnamese.

The study consisted of 145 TMD and 112 non-TMD (control group) participants aged 65 to 74 years. TMD was evaluated using Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) Axis I. An occlusal unit (OU) was defined as the cusp of a tooth coupled with the fossa of its antagonist tooth. A premolar pair was counted as one OU and a molar pair as two OUs. Dentition was divided into four occlusal support zones (OSZs) based on occluding pairs of posterior teeth by using Eichner classification: Class A had 4 OSZs, Class B had 1 to 3 OSZs or only anterior teeth, and Class C had no OSZ.

The TMD group lost significantly more posterior teeth (mean ± SD 5.1 ± 4.7) than the control group (4.0 ± 3.9, P = .033). The mean ± SD OUs of the TMD and control groups were 5.1 ± 4.6 and 6.0 ± 4.3, respectively, which was nonsignificant (NS). The distribution of Class A (40.7%), Class B (40.0%), and Class C (19.3%) among the TMD group was not significantly different from the control group (50.0%, 38.4%, and 11.6%, respectively, NS). The odds of having TMD were positively associated with total unilateral loss of OUs (OR = 3.4, 95% CI = 1.2-9.4, P = .020) and total bilateral loss of OUs (OR = 2.7, 95% CI = 1.2-6.6, P = .027).

Total loss of OSZs on one or both sides of the mouth were found to be predictors of TMD among elderly Vietnamese.