Pain sensitivity after low-level clenching is influenced by preloading eccentric exercise.

Purpose: To examine the effect of preloading eccentric exercise on pain sensitivity in healthy volunteers.

Methods: In 20 healthy volunteers, pain-related sensations (6 items: pain, unpleasantness, fatigue, stiffness, tension, and soreness during maximum biting), and pain intensities induced by repeated electrical stimuli on the masseter and the hand palm were evaluated using a visual analog scale (VAS) of 0-100 mm. Eccentric exercise (6 min-test) or gum chewing (6 min-control) was used as preloading exercise to evaluate the effect on pain sensitivities before and after low-level clenching (15 min) performed 2 days after the preloading exercise.

The influence of thickeners of food on the particle size of boluses: a consideration for swallowing.

The purpose of this study was to examine the influence of thickeners with different levels of thickness on the sizes of particles in food boluses. In medical and nursing care, thickeners are used to make food safe for patients with dysphagia. However, the effect of thickeners on the foods they are added to, especially during swallowing, is still unclear.

Effects of exercise therapy on painful temporomandibular disorders.

Temporomandibular disorders (TMD) are common chronic musculoskeletal pain conditions among orofacial pain. Painful TMD condition such as myalgia and arthralgia can be managed by exercise therapy. However, as it is hard to access actual effect of each modality that is included in an exercise therapy programme due to multiple choice of the management modality, their efficacy remains controversial.

Short-term follow-up of masticatory adaptation after rehabilitation with an immediately loaded implant-supported prosthesis: a pilot assessment.

Background: When teeth are extracted, sensory function is decreased by a loss of periodontal ligament receptions. When replacing teeth by oral implants, one hopes to restore the sensory feedback pathway as such to allow for physiological implant integration and optimized oral function with implant-supported prostheses. What remains to be investigated is how to adapt to different oral rehabilitations.

Experimental low-level jaw clenching inhibits temporal summation evoked by electrical stimulation in healthy human volunteers.

Objective: To examine the effect of low-level jaw clenching on temporal summation in healthy volunteers.

Design: In 18 healthy volunteers, the pain intensities evoked at the masseter muscle and the hand palm by the first and last stimuli in a train of repeated electrical stimuli (0.3 or 2.

Modulation of neck muscle activity induced by intra-oral stimulation in humans.

Objective: To investigate the effect of painful electrical stimuli applied to intra-oral tissues around the teeth on the neck muscle activity in healthy humans.

Methods: Electromyographic (EMG) responses of the dorsal neck muscles evoked by intra-oral electrical stimulation were recorded before and after local anesthesia to the stimulus site in 17 healthy volunteers.

Results: Inhibition of dorsal neck muscle EMG activities on average 80% compared to baseline level was observed with a latency around 50 ms after the electrical stimulation before anesthesia, and the EMG activity inhibition decreased after anesthesia of the intra-oral stimulus site.

Effects of 2,2,2-trifluoroethyl methacrylate on properties of autopolymerized hard direct denture reline resins.

This study evaluated the effects of the fluorinated monomer of 2,2,2-trifluoroethyl methacrylate (TFEMA) on the properties of autopolymerized hard direct denture reline resins. Iso-butyl methacrylate (i-BMA) and 2-hydroxyethyl methacrylate (2-HEMA) containing 30% TFEMA by weight were used as monomers, while poly(ethyl methacrylate) was used as a powder. Setting characteristics, dynamic mechanical properties, and changes over time, as well as wettability were determined by use of an oscillating rheometer, dynamic viscoelastometer, and contact angle meter.

Effects of eccentric jaw exercise on temporal summation in jaw-closing muscles of healthy subjects.

Eccentric jaw exercises has been known to cause muscle soreness but no studies have so far examined to what extent temporal summation mechanisms within the exercised muscles are changed. The purpose of the present study was to investigate the effects of an eccentric biting exercise on the temporal summation, mechanical pressure sensitivity and jaw muscle activity. A total of 15 healthy men participated in a two-session-experiment: In one session, they performed 30 min controlled eccentric jaw exercise and the other session served as a no-exercise control.

Does eccentric-exercise-induced jaw muscle soreness influence brainstem reflexes?

Objective: To investigate the effects of soreness evoked by eccentric jaw exercises on two types of brainstem reflexes: the short-latency stretch reflex and the longer-latency exteroceptive suppression (ES), and to test for possible relationships between magnitude of soreness and reflex responses.

Methods: The brainstem reflexes of jaw-closing muscles were recorded before (Baseline), immediately after (Post-task), and 1 day after (1-day-after) a 30-min eccentric exercise in 15 healthy men. All subjects participated in a control session without exercise.

Effect of low-level clenching and subsequent muscle pain on exteroceptive suppression and resting muscle activity in human jaw muscles.

Objective: To investigate the effects of muscle fatigue induced by low-level isometric jaw-clenching and subsequent glutamate-evoked muscle pain on the exteroceptive suppression (ES) response and resting electromyographic (EMG) activities in human jaw muscles.

Methods: The resting EMG activity and the ESs were recorded before (baseline), after low-level jaw-clenching (Post1), after subsequent glutamate or isotonic saline injections into the left masseter (Post2), and 60 min after the clenching (Post3) in 23 healthy volunteers.

Results: The late ES (ES2) showed more inhibition at Post1 compared with baseline (P<0.

Effects of muscle fatigue induced by low-level clenching on experimental muscle pain and resting jaw muscle activity: gender differences.

The purpose of this study was to investigate the effects of jaw-muscle fatigue evoked by low-level tooth-clenching followed by the induction of experimental muscle pain by injection of glutamate on the perception of fatigue and pain and on the resting electromyographic (EMG) activity. In addition, the role of gender on these interactions was studied. The EMG activities of bilateral masseter (MAL, MAR) and temporalis (TAL, TAR) muscles in 11 healthy young women and 12 men were measured before (Baseline) and after tooth-clenching for 30 min at 10% of maximal force (Post1), after subsequent glutamate (Glu) or isotonic saline (Iso) injection into the MAL following the tooth-clenching (Post2) and 60 min after tooth-clenching (Post3).

A change of occlusal conditions after splint therapy for bruxers with and without pain in the masticatory muscles.

Bruxism has been suggested as an initiating or perpetuating factor in a certain subgroup of temporomandibular disorders (TMD), however, the exact association between bruxism and TMD remains unclear. This study aimed to demonstrate the difference in responses between bruxism and a subgroup of TMD to a full-arch maxillary stabilization splint from the standpoint of an occlusal condition. This study was conducted to verify the null hypothesis that there were no differences between bruxer groups with and without myofascial pain (MFP) with respect to the changes in occlusal conditions after the use of a splint.