Pterygoid muscle activity in speech: A preliminary investigation.

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 hypotheses were investigated, that during speech the MPT and LPT: (1) were both active, (2) but exhibited different patterns of activity, (3) which fluctuated with the vowels and consonants in speech.

Threshold variations of medial pterygoid single motor units during vertical or horizontal force tasks.

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 standardised vertical or horizontal jaw-force tasks, and (b) there is evidence for functional heterogeneity within the medial pterygoid muscle.

Methods: In 14 healthy participants, electromyographic recordings of the right medial pterygoid muscle were performed with intramuscular fine-wire electrodes during four isometric force tasks: vertical, horizontal contralateral, horizontal protrusion and horizontal ipsilateral, performed at two rates of force development (slow ramp, fast ramp). Computer tomography scans confirmed electrode location within the muscle, which was divided into medial and lateral parts.

Thresholds, Firing Rates, and Order of Recruitment of Anterior Temporalis Muscle Single-Motor Units During Experimental Masseter Muscle Pain.

Aims: To test the hypothesis that, in comparison with control, experimental noxious stimulation of the right masseter muscle would result in significant changes in the firing rates, thresholds, and recruitment orders of single-motor units (SMUs) of the nonpainful, synergistic right anterior temporalis muscle during goal-directed isometric biting task performance.

Methods: Twenty healthy volunteers received an infusion of hypertonic saline (HS; 5% sodium chloride) into the right masseter to produce pain intensity of 40 to 60 on a 100-mm visual analog scale (VAS). Isotonic saline (IS) infusion was a control.

Functional properties of single motor units in the human medial pterygoid muscle: Thresholds.

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 the velocity of jaw movement and the location within the muscle.

Methods: Intra-muscular electrodes were inserted in the right MPt of 18 participants performing ipsilateral (right), contralateral, protrusive and opening-closing jaw movements recorded at 2 velocities.

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

Background: The implications of oral rehabilitation after tooth loss require further investigation.

Objectives: To conduct a pilot study to investigate: (a) changes in masticatory performance with progressive oral implant rehabilitation (POR); (b) association between POR and neurocognitive function using functional magnetic resonance imaging (fMRI); and (c) oral health-related quality of life (OHQoL) outcomes.

Methods: Four completely edentulous patients (mean age: 73 ± 1.

Simultaneous Noxious Stimulation of the Human Anterior Temporalis and Masseter Muscles. Part II: Effects on Jaw Muscle Electromyographic Activity.

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 cognition scores.

Methods: In 15 asymptomatic participants, recordings were made of jaw movement and electromyographic (EMG) activity of the right digastric and bilateral masseter and anterior temporalis muscles during standardized open/close and free and standardized chewing tasks. The tasks were repeated in three blocks: block 1 (baseline), block 2 (during simultaneous infusion of 5% hypertonic or 0.

Reorganization of Masseter and Temporalis Muscle Single Motor Unit Activity During Experimental Masseter Muscle Pain.

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 masseter muscle, and pain intensity was maintained at 40-60/100 mm on a visual analog scale. Standardized isometric biting tasks were performed with an intraoral force transducer while single motor units (SMUs) were recorded from the right masseter and temporalis muscles.

Simultaneous Noxious Stimulation of the Human Anterior Temporalis and Masseter Muscles. Part I: Effects on Jaw Movements.

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) changes in amplitude and velocity of jaw movements that relate to higher levels of negative mood or pain-related thoughts.

Methods: Standardized open/close and free and standardized chewing were recorded in 15 asymptomatic participants in three blocks: block 1 (baseline), block 2 (during 5% hypertonic or 0.9% isotonic saline infusion into the right masseter and anterior temporalis muscles simultaneously), and block 3 (infusion sequence reversed).

Single motor units from the medial pterygoid muscle can be active during isometric horizontal and vertical forces.

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 different regions of the medial pterygoid muscle exhibit different patterns of SMU activation during the generation of any one direction of isometric force.

Methods: Intramuscular electromyographic (EMG) recordings were made from the right medial pterygoid muscle in 15 healthy participants during isometric force tasks: vertical and horizontal contralateral, protrusion and ipsilateral. A computed tomography scan divided the EMG recording site into a medial or lateral part in each participant.

Reorganization of motor unit activity at different sites within the human masseter muscle during experimental masseter pain.

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/anterior, inferior/posterior (IP)] during isometric biting tasks (ramp, step level) on an intraoral force transducer in 17 participants during three experimental blocks comprising no infusion (baseline), 5% hypertonic saline infusion (pain), or isotonic saline infusion (control). A visual analog scale (VAS) was used to score pain intensity.

Rehabilitation of ectodermal dysplasia patients presenting with hypodontia: outcomes of implant rehabilitation part 1.

Purpose: This study has evaluated the pre and post perceptions of patients with ectodermal dysplasia (ED) who have been referred to Westmead Centre for Oral Health for treatment with dental implants.

Methods: Six patients with ED and hypodontia were treated with new maxillary complete dental prostheses or fixed implant prostheses, and a mandibular fixed dental prosthesis with implants. Patient perceptions were recorded with a 10cm visual analogue scale (VAS).

Experimental noxious stimulation of the right masseter muscle does not affect bilateral masseter and temporalis muscle activity and force parameters during standardised isometric biting tasks.

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 performed on an intraoral force transducer in 18 participants during the following blocks: baseline block, hypertonic saline infusion into the right masseter muscle (painful block) and isotonic saline infusion into the right masseter (control block). Bipolar surface electrodes recorded EMG activity from the bilateral masseter and anterior temporalis muscles.

The Effects of Experimental Temporalis Muscle Pain on Jaw Muscle Electromyographic Activity During Jaw Movements and Relationships with Some Psychological Variables.

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 and digastric muscles in 14 asymptomatic participants during standardized opening/closing jaw movement, free chewing, and standardized chewing tasks. Tasks were repeated in three blocks: Block 1 (baseline), Block 2 (during 5% hypertonic or 0.

Effect of a brief episode of experimental muscle pain on jaw movement and jaw-muscle activity during chewing.

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 (masseter, anterior temporalis, and digastric) activity were recorded during free and rate-standardized chewing in eight asymptomatic participants (pain infusion group), before and at three time blocks up to 45 min after a single 0.2-ml bolus infusion of 5% hypertonic saline into the right masseter muscle.

Oral health and dental care in aged care facilities in New South Wales, Australia. Part 3 concordance between residents' perceptions and a professional dental examination.

Objectives: To determine the perceptions of dental care held by the residents in aged care facilities (ACFs) in New South Wales (NSW) and to compare these perceptions with clinical observations.

Background: No specific data exist relating to NSW residents' perceptions of dental care compared with a clinical examination. Planning for appropriate oral health programs in ACFs necessitate such data.

Provision of dental care in aged care facilities NSW Australia- Part 2 as perceived by the carers (care providers).

Objectives: To investigate carers' perception of the provision of dental care in aged care facilities (ACFs) New South Wales (NSW), Australia.

Background: Carers are responsible for 'hands-on, day-to-day' care of residents, including dental care, yet there were no specific figures available concerning their role in NSW ACFs.

Materials And Methods: Questionnaires were mailed to 406 NSW directors of nursing (DONs) requesting completion by a carer who was proficient in English and without the influence of the DON.

Association between resting jaw muscle electromyographic activity and mandibular advancement splint outcome in patients with obstructive sleep apnea.

Introduction: 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.

Methods: Thirty-eight adult patients with obstructive sleep apnea were recruited for the study.

Neuroplasticity in the adaptation to prosthodontic treatment.

Aims: To investigate cerebral cortical changes by using functional magnetic resonance imaging (fMRI) after denture renewal and to test how these relate to prosthodontic treatment adaptability as measured by chewing efficiency and maximum bite force.

Methods: Ten complete denture wearers (five women and five men, mean age ± standard deviation: 70.3 ± 9.

Rehabilitation of children with ectodermal dysplasia. Part 1: an international Delphi study.

Purpose: An international Delphi study was undertaken to determine by consensus an agreed approach to the management of children with dental manifestations of ectodermal dysplasia, including the use of dental implants. This was done using a questionnaire developed by an interdisciplinary team.

Materials And Methods: The Delphi study questionnaire was built around 19 areas of clinical relevance and included 90 items.

The effects of capsaicin-induced intraoral mucosal pain on jaw movements in humans.

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, and free and standardized chewing, at baseline and in test sessions while the subjects were wearing a custom maxillary mouthguard coated with either capsaicin cream (pain group, 13 subjects) or placebo cream (control group, an additional 13 subjects). All subjects completed the Depression Anxiety Stress Scales (DASS) and the Pain Catastrophizing Scale (PCS).

Provision of dental care in aged care facilities, NSW, Australia - part 1 as perceived by the directors of nursing (care providers).

Objective: To ascertain the Directors of Nursing (DONs) perception of the provision of dental care and the difficulties in oral health maintenance for residents in New South Wales (NSW) aged care facilities (ACFs).

Background: There were no specific figures relating to DONs' perceptions of oral health needs and dental care nor obstructions to dental care of residents.

Materials And Methods: A total of 414 questionnaires, encoded for confidentiality, were posted to all DONs of ACFs in NSW and the data analysed.

Regional properties of the superior head of human lateral pterygoid muscle.

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 superior or inferior regions.

Effects of experimental pain on jaw muscle activity during goal-directed jaw movements in humans.

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 position, and during three tasks: (a) protrusion, (b) contralateral (left), (c) open jaw movement. Tasks were performed during three conditions: control (no infusion), test 1 [continuous infusion into right masseter of 4.

Experimental jaw-muscle pain has a differential effect on different jaw movement tasks.

Aims: To determine the effects of experimental jaw-muscle pain on jaw movements.

Methods: 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).

Activity of superior head of human lateral pterygoid increases with increases in contralateral and protrusive jaw displacement.

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 protrusive jaw movement tasks and to compare these features with those identified previously for the IHLP. In 22 human subjects, SMUs were recorded intramuscularly from computer tomography-verified sites within the SHLP during standardized contralateral and protrusive jaw movement tasks recorded by a jaw-tracking device.