摘要:

summaryChildren, 4‐6 years old, 153 Caucasian and 50 African‐American, from a pre‐school and kindergarten programme in a low income industrial area, who participated in a voluntary oral health examination, were questioned and examined for signs and symptoms of craniomandibular disorders (CMD) and of oral parafunctions. Most of the CMD signs and symptoms were mild. Eight per cent had recurrent (at least 1‐2 times per week) TMJ pain, and 5% had recurrent neck pain, African‐American chil‐ dren more often than Caucasian children (P<0.05). Seventeen per cent had recurrent headache. Three percent had recurrent earache. Pain or tiredness in the jaws during chewing was reported by 25% of the children, more often by African‐American than by Caucasian children (P<0.001) and more often by girls than by boys (p<0.05). Pain at jaw opening occurred in 10% of the children, more often in the African‐American than in the Caucasian group (P<0.001). Thirteen per cent of the children had problems in opening the mouth. Deviation during opening was observed in 17% and reduced opening in 2%. Reduced lateral movements, locking or luxation were not observed in any child. Palpation pain was found in the lateral TMJ area in 16%, in the posterior TMJ area in 25%, in the temporalis and masseter areas in 10%, and pain for all regions was found more often in the African‐American than in the Caucasian children (P<0.01). Thirty‐four per cent of the African‐American, and 15% of the Caucasian children admitted to having ear noises (P<0.01). TMJ sounds, as recorded by auscultation, occured in 48% of the children, more often in the African‐ American than in the Caucasin children (P<0.001) and more often in girls than in boys (P<0.05). Bruxism was noted in 31% of the African‐American and in 17% of the Caucasin children (P<0.05). Thumb sucking was reported in 56% of the children, more in the girls than in the boys (P<0.01). The habit was still present in 29% of the children. Fifty‐five per cent had the parafunction nail biting. The results of this study showed that mild but distinct signs and symptoms of CMD already occur by the age 4‐6 with slight differences in distribution observed between the sexes and strong differences noted between the African‐A

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00240.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

summaryThe associations between oral parafunctions, signs and symptoms of craniomandibular disorders (CMD), race, and sex were analysed in recordings from 203 4‐6‐year‐old African‐American and Caucasian children. Significant correlations were found between bruxism, nail biting, thumb sucking and most of the CMD signs and symptoms. There were also significant associations between most of the signs and symptoms and race, while significant association with sex was found only regarding headache, TMJ sounds and chewing pain. Significant associations were found between most CMD signs and TMJ sounds supporting the view that joint sound recordings have diagnostic value. There were also significant associations between the pain variables recorded by questionnaire and those recorded by palpation, which indicates that reliable data can be obtained by interviewing children as young as five. The results of this study support the concept that oral parafunctions have a significant role in the aetiology of CMD. The results also show that race and sex need to be considered when analysing the possible aetiological role of oral parafunctions in CMD. Longitudinal studies, beginning with low age groups are needed to better determine the role of childhood oral parafunctions in CMD ae

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00241.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

summaryA marginal gap exists between the amalgam restoration and the cavity walls. At this interface, there is a constant percolation of fluid containing ions, molecules and bacteria. With time, corrosion products of the amalgam components seal the gap at the amalgam/tooth interface. The corrosion processes for conventional and high copper amalgam and factors affecting the corrosion deposites are reviewed. Better amalgam adaptation to the cavity walls improves the chances of sealing the restoration by corrosion products. The effectiveness of cavity varnish in preventing microleakage until corrosive deposits are formed in discussed.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00242.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

summaryThe influence of a three‐layered flexible coating of Polyactive® on bone stress distribution was investigated by three‐dimensional finite element models of mandibular bone, in which a titanium implant (coated or uncoated) was located. Poly‐active® is a system of poly(ethylene oxide) poly(butylene terephthalate) segmented co‐polymers with bone‐bonding capacity. In the case of sagittal and transversal loading, the use of a Polyactive® coating reduced both the minimum principal stress in the bone and the compressive radial stress at the bone‐implant interface. However, it raised the maximum principal and the tensile radial stress. In the case of vertical loading, the application of a flexible coating reduced the compressive radial stress at the bone‐implant interface around the neck of the implant by a factor of 6.6 and the tensile radial stress by a factor of 3.6. Variations in composition and thickness of the coating did not affect the resul

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00243.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

summaryThe aim of this study was to examine the centre and magnitude of a vertical component of occlusal forces in complete denture wearers during several activities using a newly developed method. A lower complete denture was divided into upper and lower parts parallel to the occlusal plane. They were connected by four force transducers which were embedded in the first premolar and the second molar portions on both sides of the denture base. Forces were recorded during tapping, chewing peanuts and raisins, and clenching. The centre and the magnitude of the forces were calculated from forces recorded by the four transducers. The maximum error of the centre was 1 mm, and the maximum error of the magnitude was 4%. The centre was observed between a first molar and the middle of the edentulous dental arch. Maximal mean value of the forces during chewing was 65‐110

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00244.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

summaryThe electrochemical corrosion behaviour of 16 currently marketed amalgams for dental fillings was studiedin vitro.Depending upon the type of amalgam and the treatment of the filling the electrochemical corrosion currents derived from cyclic voltammograms varied over several orders of magnitude. Their change as a function of time was also very different. Suggestions are made for a stability rating of the products based on the results obtained.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00245.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

summarythe present study was planned to determine the relationship between linear dimensions of human masseter muscle cross‐section and cross‐sectional area (CSA), and to assess symmetry between the two sides in normal young adults. Cross‐sectional images of the masseter muscle were measured bilaterally by real‐time ultrasound imaging in 39 healthy dentate subjects, 19 males and 20 females, aged 21‐47. From stored images, CSA and two linear measurements of muscle cross‐section were obtained (the shortest and the longest distance through the muscle group). Correlation and regression analyses were performed to examine the relationship between CSA and the linear dimensions (both individually and with the linear dimensions multiplied). Symmetry of CSA between the two sides of the face was examined using the pairedt‐test. The significance of correlation coefficients(r)and the difference between the slopes of the regression lines were also examined. Masseter CSA was larger in males than in females. All correlation values between CSA and linear measurements were significant but muscle CSA was most accurately predicted when the linear measurements were multiplied (r= 0.97;P

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00246.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

summaryThe flow and strength properties of dental waxes were examined following excessive and repeated heatings of the materials. For one product, the flow at 40±0.5°C was reduced by 25.3% following heating above 200°C. A decrease of the elastic modulus at 20±1°C by approximately 66% was observed in some cases after the heating temperature had been increased to 300°C Property variations were related to compsitional changes, which were investigated by infrared spectroscopy nad thermal analysis. Exposure of dental waxes to temperatures higher than 200°C, particularly if it is repeated, may affect the composition and properties, resulting in inferior mat

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00247.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

summaryThe effect of working interference on 13 bruxers and 14 non‐bruxers was studied by applying a metal overlay on the buccal cusps of the adjacent upper premolar and molar. The pattern and velocity of cyclic movement during gum chewing before and after overlay insertion were observed. EMG of the temporalis and masseter muscles was recorded bilaterally during the chewing movement. It was found that after insertion, one of the non‐bruxers complained of pain in the muscles, while such a complaint was not found in bruxers. Bruxing habit was reported to be less or eliminated in 44% of the bruxers, but no non‐bruxers became bruxers. The closing velocity was more often decreased immediately after overlay insertion, and the closing path near the occlusal phase was significantly narrower, with patterns of over‐extension and avoidance before reaching the occlusal phase. The delayed effects were a more vertically oriented chewing cycle without over‐extended closing movement, and an unretarded chewing velocity. It was concluded that within the experimental period a working side interference was tolerable in most of the subjects studied with or without a brux

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00248.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

summaryAnalysis of the reduction in sizes of particles after chewing has been a standard method for assessing masticatory efficiency for over 40 years, but the sizing of particles with sieves is very time consuming. A rapid simple method of measuring chewed almond particle sizes by an optical scanning method has been developed and is described. The aim of this study is to validate the accuracy, repeatability and speed of the application of an optical scanning system in measuring chewed particles. To determine the accuracy, paper circles were measured and compared with the travelling microscope measurements. The effect of orientation of the images was assessed by measuring three irregular shaped pieces of paper and three different sized pieces of chewed almonds. Measurements were taken singly at 18° increments from 0‐180° orientations with each piece of paper. To assess the repaeatability of measuring chewed particles, the particles from a single masticated almond washed with water and absolute alcohol were spread, separated and measured by the optical scanning system. The samples were then remeasured 10 times. The reproducibility of the method was investigated using three repeated masticatory tests for each subject in a group of 13 young dentate subjects. The speed of spreading the particles and of measurement was assessed. The absolute error range for a mean area of 31 mm2was 2.85% to 7.32% with a mean of 3.86%. The relative accuracy of measurement was higher for larger particles but in no case was the standard deviation>0.4 mm2. Therepeatability with different spreads of a chewed almond showed each time the particles were spread there was a small difference in sizing. This was again ±0.44mm2for an average sized particle (CV = 5.4%). The overall spreading, plus the machine time for measuring the total number and sizes of particles>1 mm, plus anaylsis of size distribution could normally be completed within 6 min. It can be concluded that the application of the optical scanning method gives fast and accurated measurement, counting and sizing of chewed parti

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00249.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY