摘要:

SummaryCraniomandibular disorders have been investigated from many points of view, structurally and functionally. To evaluate the behaviour of the masticatory muscles, electromyography (EMG) has been widely used and the studies have emanated from many different paradigms. The purpose of this paper is to review articles in which EMG has been used to study symptomatic subjects.Findings from sleep studies and basic laboratory studies seem to support the hypothesis of a correlation between masticatory muscle hyperactivity and symptoms. Experimentally induced stress studies consistently show an increased activity in symptomatic subjects.Investigations of motor pauses, the often lengthened silent period, are summarized and discussed. Several different treatment strategies, particularly splints and biofeedback, have been evaluated using EMG, indicating a normalization, but controlled outcome studies are sparse. The use of EMG has thus substantially increased our knowledge of dysfunction of the masticatory system.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1989.tb01312.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SummarySixty‐two dental students judged not to be in need of treatment for craniomandibular disorder (CMD) were randomly divided into two groups, one receiving occlusal adjustment and the other mock adjustment. A double‐blind study design was applied. After 2 years of education in dentistry, including courses in stomatognathic physiology, the increase in the subjective symptoms of CMD was significantly greater in the placebo control group than in the treatment group. The difference between the groups in the increase of sites tender to palpation was less clear, showing only a trend. However, the increase was statistically significant within the placebo group but not within the treatment group. Prophylactic occlusal adjustment thus appears to be effective in reducing the occurrence of symptoms of CMD, and possibly also the occurrence of clinical si

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1989.tb01313.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SummaryIn this study the effect of free‐end removable partial dentures (RPD) on oral function was investigated by comparing subjects with shortened dental arches (SDA, n=55) and a group of subjects with SDA and RPD (n=25). In addition, a group of subjects were selected who had worn an RPD in the past (n=19). All subjects had a remaining natural dentition consisting of an intact front region and three to five occlusal units (OU) in the posterior area.On the whole, subjects with RPD had less natural OU compared with subjects without RPD. However, this is also true for those who had worn an RPD in the past. The oral functions of subjects with SDA did not differ significantly when compared with subjects with SDA and RPD.Significantly more subjects who had an RPD in the past reported a limited mobility of the mandible, an impaired chewing capacity and chewing with the front teeth. They also reported more aesthetic complaints due to missing posterior teeth.It is concluded that within the populations investigated in this study oral function is not evidently improved by the insertion of a free‐end

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1989.tb01314.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SummaryToothpastes arguably are the most common preparations used in the treatment of dentine hypersensitivity. Evidence for efficacy largely comes from clinical trials, and supports the role of the contained so‐called “active” ingredient. How such compounds produce therapeutic benefit has received limited attention. This study measured the availability and uptake onto dentine of fluoride and metal ions contained in commercial and test toothpastes. The effects of exposure of dentine sections to these toothpastes, and abrasive only pastes in particular, was investigated by scanning electron microscopy and X‐ray microanalysis. Aqueous extracts of the different toothpastes contained measurable concentrations of the incorporated metal and or fluoride, but usually considerably below that incorporated by the manufacturer. Extraction of dentine sections exposed to toothpaste slurries revealed levels of fluoride and metal ions, although post‐treatment washing in water reduced these levels. Surface changes at 1 and 10 h were not consistent with the uptake of fluoride or metals. These changes were almost certainly produced by the contained abrasives, including calcium carbonate, dicalcium phosphate, alumina and silica. In particular fume silica progressively accumulated on the dentine surface to narrow and occlude dentinal tubules. Unlike other abrasives fume silica was resistant to removal by washing. It would appear that insufficient attention has been given to the therapeutic potential of toothpaste ingredients, particularly abrasives, to produce benefit by occlusion of dentina

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1989.tb01315.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SummaryThe Electromyographic (EMG) Signal Acquisition and Analysis System is an integrated hardware and software system that digitizes multichannels of amplified EMG signals and stores them in user defined disc files before analysis. The software runs on all IBM PC and its compatibles with the appropriate analogue‐to‐digital (A/D) conversion board. Both time and frequency domain analyses can be computed on‐line. This system provides a low cost method of digitizing and analysing EMG signals on real‐time for clinical dental electromy

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1989.tb01316.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SummaryThe water sorption and solubility of three hybrid and one microfine composite are reported. The values obtained are dependent on composite type and resin system. Incomplete polymerization of the two materials resulted in increased solubility and sorption due to incomplete conversion of the monomer. The marked increase in both parameters will have clinical significance on the durability of the material.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1989.tb01317.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SummaryThe activity patterns of the masseter and the anterior temporal muscles were studied in twenty‐one healthy male subjects while clenching at 10, 20, 30, 40 and 50% of the maximum clenching level. At low clenching levels the temporal muscle activity tended to dominate, at high levels the masseter muscle activity was stronger (P<0.001). The asymmetry in muscle activity also depended upon the clenching level (P<0.001), while at each level the masseter muscle asymmetry was greater than the temporal muscle asymmetry (P<0.05–P<0.025). By comparing the electromyographic activities of the left and right side within each subject it was found that the masseter muscle with the higher electromyographic activity tended to have the larger cross‐sectional area (P<0.01) and at the 50% clenching level it tended to be on the side with the greater number of post‐canine tooth contacts (P

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1989.tb01318.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SummaryPrevious research has suggested a relationship between migraine pain and oral habits. The present study was designed as a replication of a prior study that found self‐reported higher frequencies of certain oral habits in migraine as opposed to tension headache and non‐headache groups. Three groups of subjects (common migraine, tension headache and non‐headache) were given a single questionnaire in which five oral habits (i.e. teeth clenching, jaw jutting, cupping the chin in the hand, and resting the right and left side of the face on the hand) were rated on a 0 (not at all) to 10 (almost always) scale. Significant main effects were obtained for groups and oral habits in a 3 (groups) ×5 (oral habits)anova.Post hocTukey tests revealed the common migraine group reported significantly more frequent oral habits than did the tension headache group. The non‐headache control group did not differ significantly from either headache group. Discussion focuses on the need for continued research in t

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1989.tb01319.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SummaryA survey of 233 elderly subjects living in the district served by the Halton Health Authority (Cheshire, England) investigated the relationship between the age of dentures, their need for replacement and the presence of any oral pathological lesions. The retention, stability, occlusion and cleanliness of the dentures were all found to be worse in the older appliances; perceived need for denture replacement was found to increase from 40% in 5‐year‐old dentures to 84% in dentures over 31 years old. While 41% of the sample had an oral pathological lesion, no significant relationship was found between denture age and pathology or place of residence. People resident in the community with no assistance had the highest incidence of oral pathology and those living in long‐stay hospitals the least. The absence of a relationship between denture age and oral pathology is considered to be a powerful indicator of the need for regular oral examination of the edentulous popul

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1989.tb01320.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SummaryOne of the prime requisites of an elastomeric impression material is that it should possess adequate elastic recovery on removal from undercut areas. Most standard methods of measuring elastic recovery rely on the preparation of specimens in moulds. The specimens are subsequently removed and subjected to compressive or tensile stresses several minutes after the setting time.The equipment described in this paper has been developed to enable elastic recovery values to be determined at times in the vicinity of the setting time. A shear strain is induced in the material for a short time and the resulting recovery recorded graphically. Results indicate that there is a significant improvement in elastic recovery from just prior to until just after the setting time.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1989.tb01321.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY