Occlusal Support and Temporomandibular Disorders Among the Vietnamese Elderly

Objectives: The aim of this study was to analyze the association between occlusal support and temporomandibular disorders (TMD) among the elderly.
Methods: A case-control study involved 145 TMD patients and 112 dental patients aged 65-74 years old. The occlusal unit (OU) defines as the cusp of a tooth couples with the fossa of an antagonist's tooth. One OU was accounted for premolar pairs, and 2 OUs for molar pairs. The occlusal support zone (OSZ) is divided into four regions according to the Eichner index classification of occlusal support, including Class A (4 OSZ), B (lack of 1- 4 OSZ) and C (no occlusal contacts in the dentition). The occlusion was analyzed with the Ortho-Analyzer software.
Results: TMD group had 5.14 OUs while the control group had 6.04 OUs. Only 27.4% of TMD and 31.2% of the control group had 10-12 OUs. 26.7% in TMD and 18.8% in the control group did not have any OU. Distribution of the Eichner classes A, B and C in TMD group was 40.7%, 40.0%, 19.3%; for those of the control group 50%, 38.4%, and 11.6% respectively. No significant differences were found related to the distribution of OU and Eichner's classification between the two groups (p≥0.05). The odds of TMD was significantly associated with bounded OU loss (OR=3.4, p<0.05) and complete OU loss (OR=2.7, p<0.05).
Conclusions: Total lack of occlusal support on one or both sides is the predictor for TMD among the elderly population.