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

Abstract

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.

The role of progressive oral implant rehabilitation in mastication, cognition and oral health‐related quality of life outcomes—A pilot to define the protocol

“…It has been postulated that the extent to which the final prostheses approaches restoration of original function, the more the sensorimotor system will approach the re‐establishment of its original characteristics 127 . The results of our study are consistent with the literature which shows that oral implant rehabilitation in conjunction with neuroplastic adaptation may compensate for reduced sensorimotor function when teeth are lost 128 . This may be attributed to the improvement in retention, stability, muscular function, masticatory efficiency and sensorimotor feedback to the CNS with implant prostheses.…”

The Evolution of Neuroscience as a Research Field Relevant to Dentistry

“…NTS, solitary tract nucleus; sensory V, trigeminal brainstem sensory nuclear complex; V, VII, XII, motor nuclei of the trigeminal, facial, and hypoglossal nerves. Reproduced with permission from Sessle (2019).…”

“…Of related clinical relevance is the recent documentation of the neuroplasticity of the orofacial sensorimotor system. Neuroplasticity of the orofacial region of the sensorimotor cortex and other CNS areas has been shown to be critical in learning and memorizing orofacial sensorimotor skills and in adaptation to changes in the orofacial region brought about by aging, injury, pain, and even loss of teeth and oral rehabilitative procedures such as implants (Avivi-Arber et al 2011; Arce-McShane et al 2014; Kumar et al 2017; Avivi-Arber and Sessle 2018; Sessle 2019). The findings have clinical implications since plasticity can be tapped for learning, improving, or rehabilitating the orofacial sensorimotor skills of patients and their adapting to pain, loss of teeth, or other alterations in the face, mouth, or jaws.…”

Functional Adaptation of Oromotor Functions and Aging: A Focused Review of the Evidence From Brain Neuroimaging Research

“…Equalize the Oromotor Performance for Comparison ( Figure 1B) In older people, the 'overactivation' of some brain regions (e.g., the prefrontal recruitment during chewing) would indicate a compensatory process or 'working harder' than their younger counterparts (Reuter-Lorenz and Cappell, 2008). However, such an 'overactivation' may represent maladaptive neuroplasticity of sensorimotor functions, rather than an underlying compensation (Sessle, 2019). Therefore, the use of the term 'compensation' should be confined to situations where a substantial degree of functional performance was regained against the observed structural impairment.…”