Therapy associated changes in cerebral representation of craniomandibular dysfunction.

• Applicants: Professor Dr. Bernd Kordaß; Professor Dr. Martin Lotze; Dr. Julia Wendt
• Subject Area: Dentistry, Oral Surgery ; Cognitive, Systems and Behavioural Neurobiology
• Term: from 2016 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 316998675

The mode of action of therapy approaches for craniomandibular dysfunction (CMD) is widely unknown. Research on the level of the temporomandibular jaw could not clearly differentiate pathology from the data of participants without CMD. Although it is known that psychological factors have an important role in the genesis of chronic pain, neurobiological basics of these factors are widely unknown. Our group already identified basics of functional representation of jaw movements and demonstrated characteristics of cerebral representation of occlusal movements in patients with CMD. Using functional magnetic resonance imaging (fMRI) in a longitudinal design, we demonstrated how the representation of occlusal movements in CMD patients were altered during a three week therapy with a Michigan splint. As a functional correlate of affective changes during therapy we identified the anterior insula. Together with other regions, this area has been already reported to show characteristic functional and structural changes generally associated with chronic pain. In the planned research project we investigate the specific effect of an occlusal contact relevant splint (Michigan type). We will do that by comparing changes on clinical (e.g. pain intensity) and neurophysiological (e.g. functional representation of occlusion) parameters over therapy with those of a splint not affecting the occlusal contact (palatine splint) in a waiting group design. By measurement of functional representation of the occlusion before and after therapy in addition to other parameters of occlusion (symmetry of occlusal movements; activity of the temporomandibular jaw musculature at rest and maximal occlusion) we will be able to identify specific aspects of functional representational changes associated with therapy. We here do evaluate local changes of representation but also changes in the network of regions processing movement control and pain perception. In addition, initial changes in functional representation in these patients and altered behavior and functional representation during emotional extinction will be compared with a matched group of control subjects. Hereby, we will increase insight in the alternations of these patients with respect to affective processing. By a better understanding of the specific effect of splint therapy on the processing of craniomandibular pain and associated affective components we intend to increase the efficiency of these therapies.

• DFG Programme: Research Grants