Greg Murray

The University of Sydney · Faculty of Dentistry

How pain and sensorimotor behavior interact has been the subject of research and debate for many decades. This article reviews theories bearing on pain-sensorimotor interactions and considers their strengths and limitations in the light of findings from experimental and clinical studies of pain-sensorimotor interactions in the spinal and craniofaci...

Background: Speaking depends on refined control of jaw opening and closing movements. The medial pterygoid muscle (MPT), involved in jaw closing, and the lateral pterygoid muscle (LPT), involved in jaw opening, are two key mandibular muscles in mastication and are likely to be recruited for controlled movements in speech. Objectives: Three hypot...

Objectives To test the hypotheses that (a) the force thresholds at onset of medial pterygoid muscle single motor unit (SMU) activity do not decrease with an increase in the rate of force generation in standardized vertical or horizontal jaw force tasks, and (b) there is evidence for functional heterogeneity within the medial pterygoid muscle. Meth...

Background Little is known regarding the functional properties of single motor units (SMUs) in the medial pterygoid muscle (MPt) during jaw movements. Objectives The aims are (a) to report the thresholds of onset of MPt SMUs during 4 goal‐directed jaw movement tasks, and (b) to determine whether the threshold of onset of SMU activation varies with...

There is evidence from preclinical models of chronic pain and human psychophysical investigations to suggest that alterations in endogenous brainstem pain-modulation circuit functioning are critical for the initiation and/or maintenance of pain. Whilst preclinical models have begun to explore the functioning of this circuitry in chronic pain, littl...

Pain is a complex phenomenon that is highly modifiable by expectation. Whilst the intensity of incoming noxious information plays a key role in the intensity of perceived pain, this intensity can be profoundly shaped by an individual’s expectations. Modern brain imaging investigations have begun to detail the brain regions responsible for placebo a...

Aims: To test the hypothesis that experimental noxious stimulation of the right masseter muscle results in a reorganization of motor unit activity within the right temporalis and right masseter muscles during jaw closing tasks. Methods: A total of 20 healthy participants received hypertonic saline (5% sodium chloride) infusion into the right mas...

Aims: To test the hypotheses that, in comparison to control, the effects of simultaneous noxious stimulation of the right masseter and anterior temporalis muscles on jaw muscle activity (1) vary with the task; (2) are different between different agonist or antagonist muscles involved in a task; and (3) are correlated with mood or pain-related cogn...

Aims: To test the hypotheses that, in comparison to control (isotonic saline), simultaneous noxious stimulation (hypertonic saline) of the masseter and anterior temporalis muscles would result in (1) reductions in amplitude and velocity of jaw movements during standardized open/close jaw movements and during free and standardized chewing and (2) c...

Objectives: To determine (a) whether the medial pterygoid muscle is active in an isometric vertical force task and in isometric horizontal force tasks in the contralateral, protrusion and ipsilateral directions, (b) whether the same single motor units (SMUs) could be active across different directions of isometric force generation, and (c) whether...

Most devices measuring the kinematics of masticatory function are cumbersome to setup and not portable. Data collection would be facilitated, particularly in the elderly, if the device used for the objective measurement of mastication was easily transportable and simple to setup. Accelerometers and gyroscope sensors are lightweight and portable and...

Aim To determine if the electromyographic (EMG) activity of the left and right masseter and anterior temporalis muscles is altered by experimental right masseter muscle noxious stimulation during goal‐directed isometric biting tasks in asymptomatic humans. Methods Isometric biting tasks (slow and fast ramp biting tasks, 2‐step biting task) were pe...

The aims were to test the hypotheses that experimental masseter muscle pain leads to recruitment and/or derecruitment of motor units at different sites within the masseter and that the patterns of change in motor unit activity differ between sites. Single motor unit (SMU) activity was recorded at two sites within the right masseter [superior/anteri...

The neural mechanisms underlying the development and maintenance of chronic pain following nerve injury remain unclear. There is growing evidence that chronic neuropathic pain is associated with altered thalamic firing patterns, thalamocortical dysrhythmia and altered infra-slow oscillations in ascending pain pathways. Preclinical and post-mortem h...

This chapter is a review of the physiology of the masticatory system from both a peripheral and central perspective. From the peripheral perspective, important components include the muscles that drive movements and the associated somatosensory and motor nerves. The basic functional unit of muscle is the motor unit. Most mandibular muscles have a c...

Aims: To determine if the effects of experimental temporalis muscle pain on jaw muscle activity vary with the jaw task performed, jaw displacement magnitude, participant being studied, and with psychological measures. Methods: Jaw movement was tracked, and electromyographic (EMG) activity was recorded from the masseter and anterior temporalis an...

Preclinical investigations have suggested that altered functioning of brainstem pain-modulation circuits may be crucial for the maintenance of some chronic pain conditions. While some human psychophysical studies show that patients with chronic pain display altered pain-modulation efficacy, it remains unknown whether brainstem pain-modulation circu...

It has been proposed that pain competes with other attention-demanding stimuli for cognitive resources, and many chronic pain patients display significant attention and mental flexibility deficits. These alterations may result from disruptions in the functioning of the default mode network (DMN) which plays a critical role in attention, memory, pro...

The jaw muscles move the jaw in a complex three-dimensional manner during jaw movements. There are three jaw-closing muscles (masseter, temporalis, and medial pterygoid) and two jaw-opening muscles (lateral pterygoid and digastric). The basic functional unit of muscle is the motor unit. The internal architecture of the jaw muscles is complex, with...

The aims of this study were to determine whether: (i) the jaw motor system develops a new pattern of jaw movement and/or jaw-muscle activity after resolution of an acute episode of jaw-muscle pain; and (ii) if jaw-muscle activity and jaw-movement features change progressively with repetition of a chewing sequence. Jaw movement and jaw muscle (masse...

To test the hypotheses that experimental noxious stimulation of the anterior temporalis muscle results in significant decreases in jaw movement amplitude and velocity, and there are significant correlations between scores of mood or pain-related cognitions and amplitude and velocity. The jaw movements of 14 asymptomatic participants were recorded d...

The neural mechanisms underlying the development and maintenance of chronic neuropathic pain remain unclear. Evidence from human investigations suggests that neuropathic pain is associated with altered thalamic burst firing and thalamocortical dysrhythmia. Additionally, experimental animal investigations show that neuropathic pain is associated wit...

Background: Pain catastrophizing significantly affects an individual's experience of pain. High pain catastrophizing is associated with increased fear avoidance behaviours, pain intensity and disability. The aim of this investigation was to determine the effect of pain catastrophizing on ongoing brain activity and movement-evoked brain activity du...

Temporomandibular disorders (TMD) are the most common orofacial musculoskeletal pain conditions, and while there are other musculoskeletal conditions, (e.g., some headaches, myositis, and contractures) that may be of relevance to the understanding of orofacial pain mechanisms, this chapter will focus on TMD, given that most human experimental studi...

Orofacial pain can disrupt oromotor functions such as chewing and talking. Orofacial pain can also disrupt sleep by delaying sleep onset or inducing a sensation of unrefreshing sleep at awakening. This chapter provides an overview of recent research insights into the impact and interactions between orofacial pain, motor functions, and sleep, as wel...

The role of personality in the experience of chronic pain is a growing field, with endless debate regarding the existence of a "pain personality". This study aims to compare different chronic pain types and consolidate the existence of a common personality. Thirty-two females with chronic orofacial pain and 37 age-matched healthy females were asses...

Accumulated evidence from experimental animal models suggests that neuronal loss within the dorsal horn is involved in the development and/or maintenance of peripheral neuropathic pain. However, to date, no study has specifically investigated whether such neuroanatomical changes also occur at this level in humans. Using brain imaging techniques, we...

Purpose: The aim of this study was to reveal the prevalence of orofacial pain in community health centers in Bandung, West Java, Indonesia as well as associations with age, gender, interference in physical activity, and socioeconomic status. Materials and Methods: Seven hundred patients aged at least 18 years from 35 Community Health Centers comple...

It is well established that gross prefrontal cortex damage can affect an individual's personality. It is also possible that subtle prefrontal cortex changes associated with conditions such as chronic pain, and not detectable until recent advances in human brain imaging, may also result in subtle changes in an individual's personality. In an animal...

The aims were to determine whether individuals with a past history of pain exhibit (i) altered jaw movement (e.g. reduced amplitude, increased jaw movement variability) in comparison with matched asymptomatic controls, and (ii) correlations between psychological measures (e.g. catastrophising) and altered jaw movement variables. Sixteen participant...

Aims: To investigate differences between higher and lower pain catastrophizers in the effects of hypertonic saline-evoked jaw muscle pain on pain perception and jaw movement. Methods: Repetitive open/close jaw movements were recorded in 28 asymptomatic participants (20 men, 8 women; ages 25 to 62 years) during continuous infusion of 5% hypertoni...

The aim of the study was to assess the reproducibility of vibrations recorded from the temporomandibular joint (TMJ) in a group of healthy subjects. The vibrations from TMJ were recorded bilaterally from 34 healthy subjects by electrovibratography in three sessions at intervals of 3 min and again after 1 week. The total integral of the vibration en...

The aim was to investigate the effects of isotonic resistance exercise on the electro-myographic (EMG) activity of the jaw muscles during standardised jaw movements. In 12 asymptomatic adults surface EMG activity was recorded from the anterior temporalis and masseter muscles bilaterally and the right anterior digastric muscle during right lateral j...

AIMS: The original Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis I diagnostic algorithms have been demonstrated to be reliable. However, the Validation Project determined that the RDC/TMD Axis I validity was below the target sensitivity of ≥ 0.70 and specificity of ≥ 0.95. Consequently, these empirical results supporte...

Unlabelled: Chronic pain resulting from physical stressors is often accompanied by psychological disorders such as depression. Although depressive disorders are associated with changes in brain anatomy, it remains unknown if changes in brain anatomy associated with increased state depression levels also occur in patients with chronic pain. When in...

Human brain imaging investigations have revealed that acute pain is associated with co-activation of numerous brain regions, including the thalamus, somatosensory, insular and cingulate cortices. Surprisingly, a similar set of brain structures are not activated in all chronic pain conditions, particularly chronic neuropathic pain which is associate...

This chapter focuses on the brainstem and higher brain center mechanisms involved in the execution, initiation, reflex regulation, and sensorimotor coordination of the masticatory musculature. A brief overview is given of masticatory musculoskeletal biomechanics, but other chapters may be consulted for general aspects of biomechanics related to mot...

The muscles of mastication are important in positioning the mandible and can therefore affect the patency of the upper airway. The aim of this study was to determine whether resting masticatory muscle activity influences the response to mandibular advancement splint treatment in patients with obstructive sleep apnea. Thirty-eight adult patients wit...

Unlabelled: Trigeminal neuralgia, painful trigeminal neuropathy, and painful temporomandibular disorders (TMDs) are chronic orofacial pain conditions that are thought to have fundamentally different etiologies. Trigeminal neuralgia and neuropathy are thought to arise from damage to or pressure on the trigeminal nerve, whereas TMD results primarily...

Human brain imaging has revealed that acute pain results from activation of a network of brain regions, including the somatosensory, insular, prefrontal, and cingulate cortices. In contrast, many investigations report little or no alteration in brain activity associated with chronic pain, particularly neuropathic pain. It has been hypothesized that...

Some management strategies for chronic orofacial pain are influenced by models (e.g., Vicious Cycle Theory, Pain Adaptation Model) proposing either excitation or inhibition within a painful muscle. The aim of this study was to determine if experimental painful stimulation of the masseter muscle resulted in only increases or only decreases in masset...

Aims: To determine whether mucosal pain, evoked through a novel topical capsaicin model, has an effect on jaw movement and whether psychologic factors have an association with any pain-induced movement effects. Methods: Mandibular movement was recorded from 26 asymptomatic subjects during free opening and closing, resistant opening jaw movements...

The somatosensory cortex remodels in response to sensory deprivation, with regions deprived of input invaded by neighboring representations. The degree of cortical reorganization is correlated with ongoing pain intensity, which has led to the assumption that chronic pain conditions are invariably associated with somatosensory cortex reorganization....

A major goal of motor coordination is the production of a smooth movement. Jerk-cost, which is an inverse measure of movement smoothness, has been evaluated during gum chewing in previous studies. However, the effect of the gum bolus is still unclear. The aims of this study were to compare the jerk-cost values of normal gum chewing with those of em...

Masticatory efficiency in individuals with extensive tooth loss has been widely discussed. However, little is known about jaw movement smoothness during chewing and the effect of differences in food bolus location on movement smoothness and masticatory efficiency. The aim of this study was to determine whether experimental differences in food bolus...

Oral rehabilitation restores form and function and impacts on general health. Teeth provide a discriminating sense of touch and directional specificity for occlusal perception, management of food with mastication and swallowing, and awareness of its texture and hardness. Peripheral feedback for control of jaw muscles includes the enamel-dentine-pul...

The human lateral pterygoid muscle plays an important role in the control of jaw movements. This review provides an update on some aspects of the normal function of the lateral pterygoid muscle and its response to alterations, including mandibular advancement, occlusal changes, and experimental orofacial pain. Both the upper or superior head (SHLP)...

To compare kinematic parameters (ie, amplitude, velocity, cycle frequency) of chewing and pain characteristics in a group of female myofascial temporomandibular disorder (TMD) patients with an age-matched control female group, and to study correlations between psychological variables and kinematic variables of chewing. Twenty-nine female participan...

The orofacial region is an important site of occurrence of acute and chronic pain (e.g. trigeminal neuralgia, burning mouth syndrome, temporomandibular disorders).. Chronic neuropathic orofacial pain affects up to 11% of the population (Torrance et al. 2006, Gustorff et al. 2008, Beniezky et al. 2005) and is caused by a primary lesion of the somato...

To develop and validate a short screening tool for temporomandibular disorders (TMD) from the comprehensive Research Diagnostic Criteria for TMD (RDC/TMD) assessment. Complete RDC/TMD assessments of four subject groups (96 TMD; 102 dental pain; 68 headache; 115 no-pain patients) were compared. Classification tree and multiple logistic regression an...

Trigeminal neuropathic pain (TNP) and temporomandibular disorders (TMD) are thought to have fundamentally different etiologies. It has been proposed that TNP arises through damage to, or pressure on, somatosensory afferents in the trigeminal nerve, whereas TMD results primarily from peripheral nociceptor activation. Because some reports suggest tha...

Objectives: Individuals who score high on pain catastrophizing exhibit more intense pain and higher pain-related disability (Sullivan et al. Pain 2004; 107:220-6). The fear-avoidance model predicts that pain catastrophizing has a role in influencing the effect of pain on jaw movement. The aim was to determine the effects of experimental jaw-muscle...

The degree to which neuropathic and non-neuropathic pain conditions differ in psychological and psychosocial status remains largely unexplored. A better understanding of these aspects would be of considerable benefit in helping to define whether similar psychological treatment strategies (eg, cognitive-behavioural therapy) can be adopted in the man...

Jerk-cost is an inverse measure of movement smoothness and can be calculated from the first-time derivative of acceleration obtained from a tri-axial piezoelectric accelerometer (TPA), or from the third-time derivative of position obtained from a jaw-tracking device. The aims of this study were to determine, in 10 asymptomatic subjects who are chew...

The conscious perception of somatosensory stimuli is thought to be located in the contralateral cerebral cortex. However, recent human brain imaging investigations in the spinal system report bilateral primary somatosensory cortex (SI) activations during unilateral noxious stimuli and that this ipsilateral spinal representation may be independent o...

To use functional magnetic resonance imaging (fMRI) to determine whether orofacial cutaneous or muscle pain is associated with changes in primary motor cortex (M1) activity that outlast the duration of perceived pain, and whether these M1 changes are different during cutaneous pain compared with muscle pain. fMRI was used in healthy subjects experi...

Objectives: The aims were (a) to compare kinematic parameters (i.e. amplitude, velocity, cycle frequency) of chewing and pain characteristics in a group of female myofascial TMD patients with an age-matched control female group; (b) to study correlations between psychological variables and kinematic variables of chewing. Methods: All participants (...

Objectives: To determine whether (a) there is an association between jaw motor changes in pain and signal changes in the face sensory-motor cortex (face MI/SI), and (b) activity changes in the face MI/SI are associated with catastrophizing. Methods: Pain was elicited in right masseter muscle in 10 healthy adults via 4.5% hypertonic saline infusion...

The human jaw's structure-function relationships are complex. A recent example of this complexity is the lateral pterygoid muscle which we now consider as a single unit made up of functional regions with activity in each dependent on the biomechanical demands of the task. We have also characterised the effects on the jaw motor system of pain or exe...

There is good evidence from animal studies for segregation in the processing of non-nociceptive and nociceptive information within the trigeminal brainstem sensory nuclear complex. However, it remains unknown whether a similar segregation occurs in humans, and a recent tract tracing study suggests that this segregation may not exist. We used functi...

The aim of this study was to investigate functional heterogeneity within the superior head of the human lateral pterygoid (SHLP) muscle by comparing the functional properties (e.g. firing rates) of single motor units (SMUs) between different arbitrarily defined regions of the SHLP, namely, medial, middle or lateral; origin or insertion; and superio...

Pain and limitation of movement are two cardinal symptoms of temporomandibular disorders but it is unclear how one influences the other. The relationship between pain and movement is clinically significant but controversial with two major theories having been proposed: the Vicious Cycle Theory and the Pain Adaptation Model. The Vicious Cycle Theory...

The mechanisms whereby orofacial pain affects motor function are poorly understood. The aims were to determine whether 1) lingual algesic chemical stimulation affected face primary motor cerebral cortex (face MI) excitability defined by intracortical microstimulation (ICMS); and 2) any such effects were limited to the motor efferent MI zones drivin...

To study the effects of masseter muscle pain on jaw muscle electromyographic (EMG) activity during goal-directed tasks. Mandibular movement was tracked and EMG activity was recorded from bilateral masseter, and right posterior temporalis, anterior digastric, and inferior head of lateral pterygoid muscles in 22 asymptomatic subjects at postural jaw...

Since there is limited information of the effects of orofacial pain on oromotor behaviour, the aim of this study was to test the effects of injection of the algesic chemical glutamate into orofacial tissues on licking behaviour in rats. Male Sprague-Dawley rats were trained to carry out stereotyped licking from a water spout connected to a force tr...

This tribute article to Professor Barry J. Sessle summarizes the 6 presentations delivered at the July 1, 2008 symposium at the University of Toronto. The symposium honored 3 "giants" in orofacial neuroscience, Professors B. J. Sessle, J. P. Lund, and A. G. Hannam. The 6 presentations paying tribute to Sessle spanned the period from the early phase...

To determine the effects of experimental jaw-muscle pain on jaw movements. Mandibular mid-incisor point was tracked in 22 asymptomatic subjects during standardized (at 2.2 mm/s) protrusion, contralateral excursion, and open jaw movements, as well as free, right-sided chewing and chewing standardized for timing (900 ms/cycle). Tonic infusion of 4.5%...

Making electromyographic recordings of the lateral pterygoid muscle (LP) is difficult because of potential electrode damage to, for example, the maxillary artery and long buccal nerve, and because of pain and reduced jaw mobility characteristic of many orofacial pain patients. The purpose of this study was to develop a reliable intraoral placement...

The superior head of the human lateral pterygoid muscle (SHLP) has been classically considered to have functions that are independent of the inferior head of the lateral pterygoid (IHLP). Recent evidence however suggests that some of the functional properties of the SHLP are similar to those of the IHLP. The aim was to determine whether the functio...

The hypothesis was that the superior head of human lateral pterygoid muscle (SHLP) plays a similar role in jaw movement as the inferior head of human lateral pterygoid muscle (IHLP). The aims were to determine the functional properties of SHLP single motor units (SMUs) and root mean square activity (RMS) of the SHLP during contralateral and protrus...

A systematic review identified randomised and other trials (1966-2006) of studies of occlusal design of crowns, complete (CRP) and partial (PRP) removable prostheses and implant-borne reconstructions, and whether occlusal design influenced diet, quality of life, bruxism and attrition. The search primarily included Cochrane Database of Systematic Re...

The superior head of the human lateral pterygoid muscle (SHLP) may play a similar role in jaw movement as the inferior head (IHLP). The aim was to determine whether threshold properties of single motor units (SMUs) within SHLP during jaw tasks were comparable to those identified for IHLP. In 24 human subjects, SMUs were recorded intramuscularly fro...

One of the jaw muscles particularly implicated in temporomandibular disorders (TMD), a common form of non-dental chronic orofacial pain, is the human lateral pterygoid muscle. The precise role of this muscle in TMD is unclear as is the nature of the interaction between pain and motor function particularly involving this muscle. This research group...

Two major theories proposed to explain the effect of pain on muscle activity are the Vicious Cycle Theory and the Pain Adaptation Model. Comprehensive reviews demonstrate conflicting or limited evidence in support of a critical aspect of the Vicious Cycle Theory, namely that pain leads to increased muscle activity. The Pain Adaptation Model propose...

This paper describes a method for studying superficial and deep jaw muscle activity during standardized jaw movements under experimental jaw muscle pain. In 22 healthy adults, pain was elicited in the right masseter muscle via tonic infusion of 4.5% hypertonic saline and which resulted in scores of 30-60 mm on a 100-mm visual analogue scale. Subjec...

The inferior head of lateral pterygoid (IHLP) is thought to play a critical role in the generation and control of lateral jaw movements. The aim was to test the hypothesis that a change to the lateral tooth guidance (working-side occlusal alteration, OA) results in a significant change in the electromyographic (EMG) activity of the IHLP during stan...

There is limited knowledge of the effects of the occlusion on temporomandibular joint function. The aim was to investigate the influence of a working-side occlusal alteration (OA, i.e. interference) on trajectories of working-side condylar points during standardized lateral jaw movements (laterotrusion) tracked by a jaw-tracking system. Ten trials...

There is controversy as to the jaw tasks for which the superior head of the human lateral pterygoid muscle (SHLP) becomes active. The aim was to describe the functional activities of SHLP single motor units (SMUs) during horizontal isometric force tasks. In 11 subjects, 48 SMUs were recorded from computer-tomography-verified SHLP sites during gener...

1. The lateral pericentral region of the cerebral cortex has been well documented in primates to be important in sensorimotor integration and control and in the learning of new motor skills. 2. The present article provides, first, an overview of limb sensorimotor cortical mechanisms and, second, outlines recent evidence pointing to an important rol...

(a) To describe the changes in electromyographic (EMG) activity from selected jaw muscles during a standardized lateral jaw movement with the teeth together, and (b) to investigate the effects on jaw muscle activity of changes in both the rate of lateral jaw movement and the relative magnitude of jaw-closing force. In 16 healthy volunteers, recordi...

In this paper the mechanics of human mandibular function is described in terms of the associated screws. The two distinct, yet related features of jaw mechanics, involving the motion itself as well as the forces, are both functions of the anatomical constraints, namely the contact areas that exist within the temporomandibular joint, and the forces...

The clinical notion that some disturbance to the activity of the lateral pterygoid muscle plays a role in the aetiology of temporomandibular disorders (TMD) is still widely accepted and influences management strategies. However, there is no rigorous scientific evidence to support this clinical notion and the role of the lateral pterygoid muscle in...

The minimal tonic firing rates (the lowest firing rates at which motor units fire regularly; MTFR) of single motor units (SMUs) within the lateral pterygoid muscle have not been widely investigated. The aims of this study were (a) to identify MTFR of SMUs within the inferior head (IHLP) and superior head (SHLP) of the lateral pterygoid muscle durin...

The activity of the superior head of the human lateral pterygoid muscle (SHLP) is controversial. Given the non-parallel alignment of some SHLP fibers, the SHLP may be capable of differential activation. The aims were to clarify SHLP activity patterns in relation to location within SHLP. In 18 subjects, SHLP single motor units were intramuscularly r...

In this paper the characterisation of jaw-mechanics by means of the motion screw and the wrench, is presented demonstrating its ability to provide a simplified, yet complete description of jaw function. Motion data and anatomical data from a single subject is used to implement the screw theory approach where the muscle forces are represented at eac...

The aim was to test the hypothesis that this head of the muscle plays a part in the generation and fine control of horizontal mandibular forces in a range of directions. Electromyographic activity was recorded from the inferior head of the lateral pterygoid of eight individuals during the generation such forces to a target in contralateral, ipsilat...

The precise function of the inferior head of the human lateral pterygoid muscle (IHLP) is unclear. The aim of this study was to clarify the normal function of the IHLP. The hypothesis was that an important function of the IHLP is the generation and fine control of horizontal (i.e., anteroposterior and mediolateral) jaw movements. The activities of...

The precise function of the inferior head of the human lateral pterygoid muscle (IHLP) is unclear. The aim of this study was to clarify the normal function of the IHLP. The hypothesis was that an important function of the IHLP is the generation and fine control of horizontal (i.e., anteroposterior and mediolateral) jaw movements. The activities of...

Previous studies have indicated that the location of a condylar point can significantly influence its trajectory. The aim of this investigation was to develop a method of registering the location of radiographically defined condylar points in the coordinate system of a six-degree-of-freedom jaw-tracking device and to determine the accuracy of this...

The present study was undertaken to determine the firing patterns and the mechanoreceptive field (RF) properties of neurons within the face primary motor cortex (face-MI) in relation to chewing and other orofacial movements in the awake monkey. Of a total of 107 face-MI neurons recorded, 73 of 74 tested had activity related to chewing and 47 of 66...