Multivariate analysis of risk factors in relation to TMD symptoms

Abstract

The epidemiological studies on risk factors for temporomandibular disorders (TMD) are still extremely lacking. Therefore, their aetiological significance has scarcely been documented. The aim of this study was to quantitatively investigate the relationship between hypothesized risk factors and the precipitation and perpetuation of TMD symptoms. The same 672 adults who participated in a previous study (Matsuka et al., 1996) were selected for this study. All subjects had already answered a self-administered questionnaire and the same questionnaire was sent to them 4 years after the first survey. The questionnaire failed to reach 58 subjects at the second survey. Of the remaining 614 subjects, 367 (166 males and 201 females with a mean age of 53·1 ± 14·2 years) returned the questionnaire, for a return rate of 59·8%. Information about three TMD symptoms [temporomandibular joint (TMJ) pain, limitation of mouth opening, TMJ noise] was obtained from the questionnaire, and fluctuation of these symptoms was assessed by comparing three pairs of answers between the first and second surveys. Information about 18 hypothesized risk factors for TMD (age, sex, trauma, bruxism, malocclusion, oral habit, etc.) were also obtained from the questionnaire at the first survey. To evaluate how strongly each risk factor was associated with precipitation and perpetuation of TMD symptoms, odds ratio of each risk factors for precipitating or perpetuating TMD symptoms was calculated by means of logistic regression analysis. Statistically significant risk factors for precipitating TMD symptoms were lip biting for TMJ pain (3·65) and trauma for limitation of mouth opening (3·20), and statistically significant risk factors for perpetuating TMD symptoms were female for TMJ pain (4·50) and TMJ noise (3·85) (odds ratio in parenthesis). The possible aetiological significance of these factors in TMD should be validated by future research.