The neurophysiology of osseointegrated oral implants. A clinically underestimated aspect

Amputation of a limb or a tooth leads to the loss of a large number of exteroceptors. These play an important role in sensory perception and feedback, which tune the motor control. Even after rehabilitation with a prosthetic device, tactile function remains impaired. This can present a subsequent risk of overloading the prosthesis. The peri-implant interface of oral osseointegrated implants is characterized by the absence of a periodontal ligament, a crucial difference towards the natural dentition, from a biomechanical but also from a neurophysiologic point of view. Patients rehabilitated with osseointegrated implants seem subjectively not much impaired in their masticatory and other oral functions. This observation might be linked to the presence of some peripheral feedback pathway to the sensory cortex. It may be attributed to the activation of receptors in the peri-implant environment (either bone or periosteum). This phenomenon called osseoperception, when it relates to the consciousness of the applied stimuli, has been described for both oral and skeletal implants. In the present review, besides osseoperecption other neurophysiological aspects of oral implants, such their reflex function, will be outlined and their clinical meaning pointed out.