Can you be too old for oral implants? An update on ageing and plasticity in the oro-facial sensorimotor system.

This review focuses on the capacity of the brain for plasticity and the utility and efficacy of oral implants in helping to restore oro-facial sensorimotor functions, especially in elderly patients. The review first outlines the components of the oro-facial sensorimotor system which encompasses both oro-facial tissues and a number of brain regions. One such region is the sensorimotor cortex that controls the activity of the numerous oro-facial skeletal muscles. These muscles are involved in a number of functions including reflexes and the more complex sensorimotor functions of mastication, swallowing and speech. The review outlines the use by the brain of sensory inputs from oro-facial receptors in order to provide for exquisite sensorimotor control of the activity of the oro-facial muscles. It highlights the role in this sensorimotor control played by periodontal mechanoreceptors and their sensory inputs to the brain, and how oral implants in concert with the plastic capacity of the brain may, at least in part, compensate for reduced sensorimotor functioning when teeth are lost. It outlines findings of ageing-related decrements in oro-facial sensorimotor functions and control. The changes in oro-facial tissues and the brain that underlie these ageing-related functional alterations are also considered, along with adaptive and compensatory processes that utilise the brain's capacity for plasticity. The review also notes the evidence that rehabilitation that incorporates adjunctive approaches such as sensorimotor training paradigms in addition to oral prostheses such as implants may enhance these processes and help maintain or facilitate recovery of sensorimotor functioning in the elderly.