Keynote Address: Neuroplasticity of Sensorimotor Cortex: Role in Learning and Adaptation of Orofacial Sensorimotor Control

The primary somatosensory and motor areas of the face sensorimotor cortex (face-SMCx) are known to be crucial for the initiation and regulation of orofacial sensorimotor functions, but there is emerging evidence from human and animal studies that through neuroplastic processes, face-SMCx is also important in sensorimotor learning and in adaptation of orofacial sensorimotor behaviours to pain and other changes in the oral cavity. For example, significantly increased tongue representation and corticomotoneuronal excitability occur in face-SMCx during the learning of a novel tongue-protrusion task, and intraoral pain can interfere with the task learning and excitability changes. Face-SMCx neuroplasticity reflected in altered tongue or jaw representation also occurs following other intraoral changes, eg intraoral nerve damage, occlusal alterations and dental implant replacement of lost teeth. Thus, orofacial motor skill acquisition and our ability to adapt (or not) to pain and other intraoral alterations, including dental rehabilitative procedures, may depend on face-SMCx neuroplasticity.