Chapter 4 – Occlusion and Adaptation to Change: Neuroplasticity and Its Implications for Cognition

Synopsis Occlusion should no longer be considered simply as the occlusal scheme determining the static or dynamic relationship between the dental arches or the jaw position. Rather, it should be regarded within a broader framework that considers the modulation of the somatosensory input from the periodontal, dental, and mucosal mechanoreceptors by the central nervous system, as well as sensorimotor neuroplasticity. These mechanisms, rather than the type of occlusion, ultimately determine whether an individual adapts to the oral perception changes inherent to all dental treatment. Central in this process is likely the patient's degree of vigilance to the somatosensory stimulus because attention increases perception, as well as how this somatosensory input is centrally processed. Notably, it is enough to attend to a stimulus to decrease the discrimination threshold. Thus patients who are hypervigilant to the oral environment are likely more sensitive to abnormal stimuli and therefore more at risk of not adapting even to minute oral or occlusal changes. Nevertheless, hypervigilance is likely to be a necessary but not comprehensive cause of maladaptation, as in the case of occlusal dysesthesia, which requires an imbalance between perceptual and cognitive processes, together with a negative affective response and abnormal illness behavior. Sensorimotor neuroplasticity is essential to adjust jaw movements to an altered occlusal and/or oral condition after changing jaw position or inserting new reconstructions, with altering tongue space. In some cases, however, this may lead also to maladaptive oral behaviors. Recognition that sensorimotor neuroplasticity does not always lead to a context-specific adaptation of motor behavior prevents performing incorrect and potentially harmful therapies.