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Biomedical subjects

E N Gale

Publications and source records attributed to E N Gale.

At least 19 recordsLinked to original sources
PubMed2002

Human masticatory muscle activity and jaw position under experimental stress.

The purpose of the present study was to determine whether stress induced a consistent pattern of increased electromyographic (EMG) activity in different masticatory muscles, and whether stress produced changes in jaw position. Thirty-five dental students at Taipei Medical College volunteered for this study. Mental arithmetic was used to create a stress condition and relaxation instruction was used to help relax the subjects. Subjects were asked to evaluate the stress they felt under each experimental condition with a visual analogue scale (VAS). Surface electrodes were used to monitor the EMG activities of the right masseter, right posterior temporalis and suprahyoid muscles. A kinesiograph was used to observe the jaw position. Data collected before mental arithmetic or relaxation monitored the baseline level. The VAS means were significantly increased during the stress condition and significantly decreased following relaxation, compared with the baseline. There was also a significant increase in EMG activity of all three muscles during mental arithmetic compared with baseline; different patterns of increased EMG activity were noticed in the three muscles under a continuous stress condition. Under stress, the incidence of tooth contact at intercuspal position was also increased.

Adult↗
PubMed1998

Psychophysiological assessment of stress in chronic pain: comparisons of stressful stimuli and of response systems.

Due to disparate findings across the published studies, the stress-hyperactivity hypothesis has never been fully accepted as a causal mechanism for chronic muscle pain. Two recent comprehensive reviews of the psychophysiological studies of chronic pain came to opposite conclusions about the viability of the hypothesis, which stemmed from differing importance placed on the experimental methodology: the adequacy of stress manipulation. The present study tested the hypotheses that the adequacy of stress manipulation is influenced by stress stimuli type, degree of personal relevance, and selection of criterion for verification of stress experience, and that these factors have a measurable impact on the related physiological responses in a manner that is consistent with a theory of stress applicable to clinical stress disorders. The three factors investigated were: task (imagery, reaction time), relevance (high, low), and manipulation criterion (autonomic, self-report). The tasks were presented to 16 chronic pain patients while muscle, electrodermal, and self-report responses were recorded. Reaction-time tasks and high-relevance conditions led to high muscle and electrodermal responses. Only the high-relevance imagery, however, produced high self-reported distress. Consistent with other research, the present overall data demonstrated differing physiological profiles for different stimuli types. More importantly, these data suggest that the manipulation type and the manipulation criterion influence outcomes of experimental tests of stress on physiological systems, which may directly lead to contrasting conclusions about causal relations between stress and chronic pain conditions.

Adult↗
PubMed1998

Stress in dentistry.

Dentists believe their profession is stressful. Research has indicated this belief is generally based upon patient behaviors and economic pressures. A discussion of stress and adaptation is presented. Since stress can lead to both physical and emotional problems, recognition of stress by the practitioner is discussed. While physical symptoms are easily recognized, emotional behaviors are often overlooked. The practitioner should become aware of these behaviors in the self as well as others. Methods to help reduce and control stress are given.

Breathing Exercises↗
PubMed1991

A 14-year clinical assessment of 12 amalgam alloys.

After 14 years, 40 patients from an in vitro/in vivo study of 12 amalgam alloys were evaluated. All these patients had been attending private practitioners over the past 10 years, and the clinical evaluation revealed that 320 restorations were intact and 47 (12.8%) had been lost. The majority (75.0%) of the lost restorations were lost to crown placement or the replacement with another amalgam restoration. The six high-copper alloys exhibited better clinical performance, in both loss rate and fracture at the margins, than did traditional low-copper materials. Fracture at the margins was a better predictor of the loss of a restoration than were mechanical properties.

Copper↗
PubMed1990

Reliability of surface electromyography of the masseteric and anterior temporal areas.

This was studied in 37 patients suffering from myofascial pain-dysfunction. Bipolar surface electrodes were used to record tonic, resting EMG activity for 2 consecutive trials. This protocol was repeated at a second recording session 2 weeks later. A custom-made, plastic template was constructed for each subject during the first visit in order to relocate the electrodes accurately at the second recording session. Correlation coefficients were calculated for each muscle area. Within-session (same day) r values ranged from 0.7620 to 0.8884 for the masseteric area and from 0.8686 to 0.9109 for the anterior temporal area. Across-session (different day) r values ranged from 0.5645 to 0.6503 for the masseteric area and 0.3309 to 0.4844 for the anterior temporal area. The lower correlation between different day recordings could reflect a methodological shortcoming in relocating the electrodes, particularly on the anterior temporal area. The greater variability recorded from the anterior temporal area could also reflect the dynamic role of the temporalis muscle in maintaining the postural rest position of the mandible.

Adult↗
PubMed1990

Relationship of restoration width, tooth position, and alloy to fracture at the margins of 13- to 14-year-old amalgams.

The effect of width of the restoration, tooth position, and amalgam type on the fracture of the margins of 13- to 14-year-old, high-copper, amalgam restorations was evaluated. The evaluation assessed 193 photographs of restorations by use of ridit analysis and a rank-ordering test. The results indicated that the width of the restoration was the predominant factor and that tooth position and the different high-copper alloys were less significant. Interactions between tooth position and width indicated that lower premolars with conservative restorations exhibited the least fracture at the margins, and upper premolars with a wide preparation exhibited the most. It is postulated that tooth deflection under mastication may play a role in long-term fracture at the margins of amalgams.

Analysis of Variance↗
PubMed1990

A 12-year clinical evaluation of two composite resins.

Two composite resin materials were clinically evaluated after 12 years in vivo. Although the Class III restorations did not have the benefit of acid etching and bevels, all 32 restorations in the nine patients who were located were intact, and none needed to be replaced. Stain was the most prominent problem, both at the margins and on the surface of the restorations. Neither wear or marginal integrity appeared to be a problem.

Color↗
PubMed1990

An exploratory study on increases in masseteric muscle activity induced by caffeine.

In a crossover double blind experimental design, the nocturnal masseteric activity of 14 selected volunteers was evaluated by means of a portable electromyograph recording unit. The recordings lasted for a period of 16 days following ingestion of caffeine or placebo for five specific days each. There were no significant differences between caffeine or placebo on masseteric activity associated with bruxism. But when the two periods were compared, there was a tendency towards reduction of masseteric area activity and increase of stress levels in the second period of ingestion.

Adult↗
PubMed1989

The relationship between condylar guidance and temporomandibular joint clicking.

The association between condylar inclination and temporomandibular joint (TMJ) clicking was tested by measuring the angles of condylar guidance in the sagittal plane during opening and closing movements in 12 subjects with temporomandibular joint clicks and 16 subjects without TMJ clicks. Each subject had tracings made by using a customized functional clutch. All subjects had full dentition and were without symptomatic mandibular dysfunction. Condylar inclinations were measured in parasagittal tracing planes. The travel path of the hinge axis of the condyle's movements was recorded, directly formed, and compared with a four-component axiograph recording that used the axis-orbital plane as a reference for the subjects. The measurements of angles along several distances (millimeters) of condylar guidance from the axis-orbital plane were obtained and evaluated. The measurements were made in the sagittal plane and through opening-closing movements starting from the actual occlusal vertical dimension of each subject. The results do not support the hypothesis that mean angles of the condylar guidance are significantly different in the group with TMJ clicking compared with the group without TMJ clicking.

Adolescent↗
PubMed1989

A simplified psychologic questionnaire as a treatment planning aid for patients with temporomandibular joint disorders.

Psychologic factors are often believed to have a significant role in the etiology and maintenance of temporomandibular joint disorders. Anxiety and depression have received the greatest focus. Approximately 132 patients with temporomandibular joint disorders completed seven self-administered depression questionnaires and four anxiety questionnaires. Correlation among all 11 questionnaires was significant. Factor analysis was interpreted as indicating the 11 questionnaires were measuring a single factor. For preliminary screening diagnosis, two questions were suggested to be a good approximation of the total battery of questionnaires.

Adult↗
PubMed1989

Methodological considerations concerning the use of Bruxcore Plates to evaluate nocturnal bruxism.

The purpose of this study was to evaluate the Bruxcore Plate (BP) as a dependent measure of nocturnal bruxing activity. As part of a bruxism treatment study, we evaluated 100 nocturnal bruxers for bruxing activity before, during, and immediately after treatment and again at a six-month recall. The first 40 subjects wore both a BP and an EMG (electromyographic) unit for every night of each 14-night evaluation period (baseline; post-treatment; six-month recall). During the treatment period, these subjects wore the EMG unit but no Bruxcore Plates. Another 40 subjects wore the EMG unit and never used Bruxcore Plates. We evaluated a 20-subject no-treatment control group by two methods. Ten control subjects were evaluated with the EMG unit and the BP and another ten with the EMG unit alone. We hypothesized that the BP would not measure the same construct as an accepted EMG measure of bruxing activity, and that the BP would effect changes in EMG measured nocturnal bruxing activity. The results supported the conclusions that the BP did not measure the same construct as the EMG measure, and that the BP did effect changes in nocturnal bruxing activity. Correlations of BP scores with EMG data for equivalent measurement periods were low or non-existent. For the control group and the massed practice (negative practice) treatment group, there were significant interaction effects for EMG-measured bruxing episodes per hour for BP vs. no-BP Groups, with respect to measurement periods (time). Interpretation of these results indicated that BP evaluation of nocturnal bruxing activity was confounded with measurable treatment effects.

Bruxism↗
PubMed1988

A comparison of different treatments for nocturnal bruxism.

One hundred bruxers were evaluated for bruxing activity before, during, and after treatment with a portable electromyograph (EMG). A six-month post-treatment follow-up of bruxing activity was obtained. Experimental treatment groups consisted of diurnal biofeedback, nocturnal biofeedback, massed negative practice, and splint therapy. A no-treatment control group was included. The comparative efficacy of treatments was determined by analyses of variance. Both EMG-measured frequency of bruxing episodes and duration of bruxing activity decreased significantly for nocturnal biofeedback and splint therapy treatments but not for massed negative practice, diurnal biofeedback (relaxation), or the no-treatment control group. The two-week treatment effects were transient, and bruxing activity generally returned to baseline levels when treatment was withdrawn. These findings are consistent with the findings of previous researchers with regard to nocturnal biofeedback and splint therapy but differ from previous findings for massed negative practice therapy.

Adolescent↗
PubMed1988

The effects of treatment on masticatory muscle activity and mandibular posture in myofascial pain-dysfunction patients.

The purpose of this study was to evaluate tonic masticatory muscle activity and the postural rest position of the mandible, pre- and post-treatment, in patients with TM disorders. Forty-one patients diagnosed as suffering from myofascial pain-dysfunction (MPD) were evaluated, with electromyography (EMG) used to measure the muscle activity of the masseteric and anterior temporal areas at rest. Postural rest position was assessed by measurement of interocclusal distance. Twenty-three asymptomatic subjects were also tested as controls. Treatment for the pain group emphasized cognitive awareness of dysfunctional orofacial behavior and biofeedback training of the masseteric area to teach masticatory muscle relaxation. The pre-treatment EMG values of both the masseteric and anterior temporal areas were significantly higher for the pain group than for the control group. Post-hoc division of the pain group into successful and unsuccessful subgroups was made on the basis of the degree of symptom improvement. EMG activity decreased significantly in the masseters of both subgroups, but only the unsuccessful subgroup showed a significant decrease in anterior temporal activity following therapy. Interocclusal distance was significantly increased in both subgroups. These results suggest that tonic masticatory muscle activity may be elevated in MPD patients. They also suggest that a decrease in EMG activity in the masseter and anterior temporalis muscles and an opening of the postural rest position of the mandible may accompany completion of psychophysiological therapy, but these changes do not correspond directly with the outcome of that therapy.

Adult↗
PubMed1987

Experimental masticatory muscle pain.

Ten female subjects with no history of temporomandibular disorders performed five exercises designed to induce masticatory muscle pain. Three of the exercises were replications of Christensen's tooth-clenching (1970) and tooth-grinding (1971) studies and Scott and Lundeen's mandibular protrusion (1980) study. The other two exercises were designed to induce specific unilateral masticatory muscle pain. The amount of muscle pain as well as the time of onset and the duration were assessed by a clinical palpation exam and a pain questionnaire. These five pain-inducing methods did not consistently produce masticatory muscle pain in non-pain subjects. However, certain individuals appeared to be very susceptible to developing pain during or after most of the exercises. These susceptible individuals demonstrated a bilateral muscle pain pattern after the unilaterally stressful exercises. None of the five exercises produced a statistically significant amount of site-specific masticatory muscle pain as determined by either the palpation examination or the pain questionnaire, even when the exercise was intended to produce such specificity. The fact that some subjects did develop masticatory muscle pain is indicative that muscle exercise and fatigue may lead to TMD-like symptoms.

Adolescent↗
PubMed1986

Predicting treatment completion in a behavioral therapy program for chronic temporomandibular pain.

The aim of this study was to identify factors useful in predicting whether chronic temporomandibular pain patients would complete a behavioral treatment program. Detailed clinical examination and interviews regarding demographic and social factors were given to 78 patients on week prior to treatment. They also completed a number of personality measures (depression, anxiety, locus of control) at that time and kept a pain diary during the following week to establish baseline levels. Motivation was also assessed. Patients were classified as completing (54%) or failing to complete (46%) the program. Social factors (family and generalized others' attitudes towards the patient's pain) were the only significant predictors of treatment completion. In a multiple regression analysis, these factors accounted for 43% of the variance. These results suggest the usefulness of including social-environmental factors when considering patient compliance. Implications for the conceptualization of social support are discussed.

Adult↗
PubMed1986

Psychophysiological therapy for tinnitus.

Twenty-two patients with complaints of severe tinnitus received psychophysiological therapy. Biofeedback sessions were supplemented with body relaxation techniques through the use of audio cassette tapes. The experimental group was matched to a control group according to age and sex. The individuals' names in the control group were placed on a waiting list and received no therapy. Evaluation of the success of the experimental group was obtained at a time period of 6 to 9 months following the therapy sessions. The individuals on the waiting list were also contacted at the same time to assess the severity of their tinnitus symptoms. Results revealed that 60% of the treatment group showed improvement compared to 5% of the control group. The effectiveness of psychophysiological therapy in reducing tinnitus symptoms is supported.

Adult↗