The dental occlusion as a suspected cause for TMDs: epidemiological and etiological considerations

Abstract

The relationship between the dental occlusion and temporomandibular disorders (TMDs) has been one of the most controversial topics in the dental community. In a large epidemiological cross-sectional survey - the Study of Health in Pomerania (Germany) - associations between 15 occlusion-related variables and TMD signs or symptoms were found. In other investigations, additional occlusal variables were identified. However, statistical associations do not prove causality. By using Hill's nine criteria of causation, it becomes apparent that the evidence of a causal relationship is weak. Only bruxism, loss of posterior support and unilateral posterior crossbite show some consistency across studies. On the other hand, several reported occlusal features appear to be the consequence of TMDs, not their cause. Above all, however, biological plausibility for an occlusal aetiology is often difficult to establish, because TMDs are much more common among women than men. Symptom improvement after insertion of an oral splint or after occlusal adjustment does not prove an occlusal aetiology either, because the amelioration may be due to the change of the appliance-induced intermaxillary relationship. In addition, symptoms often abate even in the absence of therapy. Although patients with a TMD history might have a specific risk for developing TMD signs, it appears more rewarding to focus on non-occlusal features that are known to have a potential for the predisposition, initiation or perpetuation of TMDs.

The association between Occlusion Time and Temporomandibular Disorders

“…Recent review articles (Luther, 2007;Türp and Schindler, 2012) underline that the evidence supporting a relationship between occlusion and TMD is still not voluminous, such that the authors suggested that the occlusion played a minor role in the development of the signs and symptoms Temporomandibular Disorders, noted that it would be important to establish evidence that a true cause and effect relationship exists between occlusion and TMD (Tecco et al, 2011).…”

Orthodontics is temporomandibular disorder–neutral

“…Such an approach is actually not supported, and systematic reviews of the literature provide evidence-based recommendations that there is a lack of causal relationship between TMD and occlusion; they also offer evidence that irreversible occlusal treatments are not more useful than conservative treatment alone to either manage or prevent TMD. [11][12][13][14] The literature [15][16][17] on the effects of orthodontic treatment supports the neutral effects on the temporomandibular joint (TMJ). In particular, a recent systematic review 16 concludes that there are insufficient research data on the relationship between active orthodontic intervention and TMD on which to base our clinical practice.…”

Retrospective magnetic resonance imaging study of risk factors associated with sideways disk displacement of the temporomandibular joint

“…Abnormal habits, bruxism, malocclusion, psychological problems, and anatomic vulnerabilities are related to TMD pathogenesis (19)(20)(21). However, the causes and pathology of TMD are considered multifactorial (19).…”