Fifty years of development of neuroscientific insights into oro‐facial pain and its control

Abstract

When the Journal of Oral Rehabilitation was established in 1973, there was very limited understanding of the mechanisms underlying neurally based functions, including those unique to the face, mouth and jaws (e.g. dental pain, taste, chewing, swallowing and salivation). Since that time, technological and other advances have led to new insights into the structure, connectivity and function of cranial nerves and areas of the central nervous system (CNS) involved in oro-facial functions and disorders or related functions (e.g. cognition, emotion, stress, consciousness, sleep, learning and memory).This review focuses on the advances in understanding of the neural basis of oro-facial pain and its control over the past five decades. The review first briefly considers how oro-facial pain conditions are now classified, diagnosed and managed. It then outlines novel insights that have been gained over this period through neuroscience research into the neural basis of these oro-facial pain conditions and the clinical relevance to these insights to the diagnosis and management of these conditions. The review also identifies promising research directions and gaps in knowledge that still need to be addressed to improve the understanding, diagnosis and management of oro-facial pain conditions.

Longitudinal association of oral functions and dementia in Japanese older adults

“…There are several possible mechanisms for the relationship between swallowing function and dementia. Swallowing actions activate brain function and improve learning and memory skills 24 , 25 . It was also reported that swallowing actions increase cerebral blood flow and the partial pressure of oxygen in the brain 26 .…”

Pain-sensorimotor interactions: New perspectives and a new model

“…From here, the signals are passed to motoneurons in the brainstem motor nuclei (e.g. trigeminal motor nucleus) and to neurons in nociceptive circuits and pathways in brainstem and higher areas of the CNS comparable to those noted above for spinal nociceptive signals ( Sessle, 2006 , Chichorro et al, 2017 , Shinoda et al, 2019 , Chung et al, 2020 , Sessle, 2023 ). And like the spinal sensorimotor system, these nociceptive circuits and pathways are subject to descending modulation from higher CNS areas, sex differences exist in some of their features, and the pathways and circuits may express plastic changes following noxious stimulation or other peripheral manipulations (e.g.…”

“…And like the spinal sensorimotor system, these nociceptive circuits and pathways are subject to descending modulation from higher CNS areas, sex differences exist in some of their features, and the pathways and circuits may express plastic changes following noxious stimulation or other peripheral manipulations (e.g. trimming or extraction of teeth, nerve injury) and in association with the acquisition of novel sensorimotor skills ( Cairns, 2007 , Avivi-Arber et al, 2011 , Arce-McShane et al, 2014 , Cairns et al, 2014 , Chichorro et al, 2017 , Avivi-Arber and Sessle, 2018 , Yao and Sessle, 2018 , Shinoda et al, 2019 , Chung et al, 2020 , Tashiro and Bereiter, 2020 , Sessle, 2021 , Sessle, 2023 ). Furthermore, like the spinal sensorimotor system, the pain-related plastic changes in the CNS may result in altered sensorimotor behavior through changes to descending pathways such as those from SI and MI that influence brainstem motoneurons and/or through changes to descending pathways contributing to the modulation of central sensitization processes of nociceptive circuits within the trigeminal brainstem sensory nuclear complex and which can influence trigeminal motoneuron activity ( Sessle, 2006 , Sessle, 2011a , Chichorro et al, 2017 , Avivi-Arber and Sessle, 2018 , Shinoda et al, 2019 ).…”

“…In animal models of acute or chronic craniofacial pain, there is some evidence for genetic and epigenetic and allied environmental factors as playing important roles in influencing pain experience and pain-related sensorimotor behavior ( Xiao et al, 2016 , Sessle, 2021 , Sessle, 2023 ). Genetic factors may contribute to the sex differences that have been well documented in reflex and more complex behaviors as well as in CNS nociceptive processes in animal models of craniofacial pain ( Cairns, 2007 , Cairns et al, 2014 , Tashiro and Bereiter, 2020 , Sessle, 2021 ).…”

“…Strain differences in volumetric changes documented in sensorimotor and other CNS areas following tooth extraction ( Avivi-Arber et al, 2017 ) implicate genetic factors in the inter-individual variability in dental pain or responses to other orofacial manipulations. There is also some limited evidence that epigenetic factors are involved in craniofacial nociceptive processes ( Danaher et al, 2018 , Bai et al, 2020 , Fox et al, 2020 , Sessle, 2021 , Sessle, 2023 ) and may contribute to the sex and inter-individual variability in pain and pain-related sensorimotor behavior. And like the spinal sensorimotor system, epigenetic processes may have a vital role in linking gene expression changes to environmental influences in the craniofacial sensorimotor system since many of the same environmental factors outlined above in animal models in the spinal sensorimotor system may also play a role in modifying measures of pain experience and pain-sensorimotor behavior as well as contributing to the sex and inter-individual variability in animal models of craniofacial pain ( Sessle, 2021 ).…”