Neuroplasticity of edentulous patients with implant-supported full dentures

Edentulous patients with implant-supported prostheses report improved tactile discriminative capabilities and motor function compared with when they wore complete dentures. 'Osseoperception' is defined as the ability to identify kinesthetic sensation without the input from periodontal mechanoreceptors. This sensation is generated from the temporomandibular joint, masticatory muscle, mucosa, and periosteum, and provides sensory and motor information related to mandible movements and occlusion. The aim of this study was to analyze the cortical plasticity occurring in patients with implant-supported prostheses. Twenty edentulous patients with implant-supported full dentures or traditional complete dentures were recruited for a clenching task. They were scanned by functional magnetic resonance imaging (fMRI), and the data were analyzed using the spm99 software package to generate activation brain maps. Increased blood oxygen level dependent signals in the primary sensorimotor cortex were found in patients with implant-supported fixed dentures. Other activated areas included prefrontal cortex, Broca's area, premotor cortex, supplementary motor area, superior temporal gyrus, insular, basal ganglion, and hippocampus. We suggest that sensory and motor feedback to the central nervous system can be restored by implant-supported full dentures. Activation of the primary sensorimotor cortex in patients with implant-supported dentures might explain the improved tactile, stereognostic ability, and mastication functions, which are more similar to the natural dentition.