Sleep bruxism, nocturnal teeth grinding and clenching of the upper and lower jaw, can have a number of health impacts. A new study published in the Journal of Advanced Research found that certain tooth shapes and tooth locations could well lead to temporomandibular joint problems as a result of bruxism.
About 15% of the population grind their teeth while they are asleep, a condition which is more common among younger people. The\ pressure exerted on tooth surfaces and on the jaws can be immense and is thought to cause various dental health problems. It can also result in pain in the jaw muscles and headaches. Specific combinations of tooth shape and tooth location during grinding are theorised to have an influence on the mechanical load on the temporomandibular joint and can thus be considered a risk factor for temporomandibular joint (TMJ) disorders.
To investigate whether sleep bruxism has a negative impact on the TMJ structures, researchers used a state-of-the-art computer model of the masticatory region, which includes bone, cartilage and muscular structures. Such computer models can be used to investigate research questions when direct studies on patients are not feasible on ethical grounds.
The study investigated two factors thought to be involved: tooth shape and location, The study simulated the effects of lateral grinding on the first molar and on the canine with six different wear facet inclinations, resulting in a total of twelve simulated scenarios.
“Our results show that both the inclination and location of the wear facets have an influence on the strength of the mechanical load on the temporomandibular joint,” explained study leader Benedikt Sagl. “However, it would appear that the decisive factor is the steepness of the grinding facet. The flatter the tooth, the higher the loading on the joint and therefore the higher the risk of a TMJ disorder.” Conversely, if the dental cusps involved in bruxism have a steeper angle of inclination, the calculated joint loading was lower, even with the same “grinding force” (bruxing force). Further research, coupled with clinical investigations, will seek to establish whether this finding can be incorporated into the development of therapeutic interventions for sleep bruxism.
Source: Medical University of Vienna
