摘要:

SummaryDifferences in prevalence of head or neck trauma, orthodontic treatment and molar oral surgery procedures reported by individuals were compared among patients with temporomandibular disorders (TMD) and with two comparison groups (a sample of asymptomatic individuals, and a sample with mild or early signs). Association to specific TMD symptoms was tested amongst the comparison groups.Trauma was the most significant factor characterizing TMD patients. History of trauma was also more common among those otherwise normal but symptomatic individuals in the non‐patient comparison group. Specific TMD symptoms were significantly associated with history of trauma in the comparison group. Significantly more women TMD patients had a history of orthodontic and molar oral surgery treatment than the asymptomatic comparison group. History of orthodontics was also associated with the symptomatic sample of the comparison group in women, but it was not significantly related to any specific TMD symptoms. Symptomatic members of the comparison group could not be differentiated based upon history of molar oral surgery.Certain risk factors may have been delineated, but causal relationship of treatment requires study of co‐existing and predisposing behavioural and structural fact

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1988.tb00760.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryDental elastomeric impression materials of different consistencies, representing addition and condensation silicones, polysulphides and a polyether, were studied to determine their mechanical properties in terms of tearing energy, tensile properties and modulus determined at high strain rates. Whilst the polysulphides had the greatest resistance to tearing, they were more extensible, had lower moduli of elasticity and lower tensile strengths than the silicones. The polyether resembled the silicones in many respects.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1988.tb00761.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryFifty dentate maxillary casts, obtained from thirty‐four males and sixteen females, were mounted in the three‐dimensional co‐ordinate system of a contour meter. A transverse line of reference (x‐axis) was drawn through the distal contact points of the maxillary canines, at a right angle to the y‐axis which passed through the contact points of the maxillary central incisors. Relative to the canine‐to‐canine baseline, the locations of the lateral borders of the right and left first primary rugae were determined. The rugae were distributed on both the anterior and posterior sides of the baseline, and the anterior and posterior distances from the baseline were on the average about 1 mm. The age of the subjects, ranging from 12 to 52 years, appeared to be unrelated to the frequencies of anteriorly and posteriorly positioned rugae. Right and left first primary rugae, located on the anterior side of the baseline, showed a minute asymmetry in their topography. By contrast, there was topographical symmetry when the rugae were located on the posterior side of

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1988.tb00762.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryTriangular defects were made in different locations of the disc in rat temporoman‐dibular joints. After 3 months the following effects were observed. Central defects had become rounded without gross changes in the mandibular head. Peripheral defects were enlarged towards the centre, occasionally accompanied by condylar hyperplasia. Microscopically the cartilagenous covering of the mandibu‐lar head in all operated cases was characterized by thickening, dispersion of cells normally closely packed in the intermediate zone, and the constant appearance of a tear parallel to the surf

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1988.tb00763.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryA case of hypomineralized type of amelogenesis imperfecta has been evaluated by using microscopic, submicroscopic and cytogenetic techniques. It has been observed that some of the enamel contained hydroxyapatite crystals and showed normal mineralization, but some others consisted of transparent, crystal plates of octacalcium phosphate, revealing that these enamel prisms have hypomature characteristics. Extra chromosomes which belong to D‐autosomes were found in the culture obtained from the peripheral blood of the patient, suggesting that the patient has 15% hyperdiploids. It is suggested that the structural disorders in some of the enamel prisms resulted from alterations in the environmental conditions related to chromosome anomalie

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1988.tb00764.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryPalladium‐enriched alloys are sensitive to carbon absorption. High carbon levels in ceramic alloys negatively influence some mechanical properties and cause porosities in the porcelain during the firing process. The influence of the palladium content on carbon absorption of alloys with a range of palladium content from 5 to 80% approximately was investigated. Carbon content was measured for alloys in the ‘as received’ condition as well as after melting once and three times. Carbon contents up to 200 ppm were measured in the case of a high‐palladium

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1988.tb00765.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryThe effect of exposure time of a visible light source on the depth of polymerization and degree of hardness of a sample of Occlusin posterior composite resin was investigated. The border between cured and non‐cured composite resin was identified by a change in colour and by applying pressure with a scalpel. Knoop hardness tests were performed perpendicular to the long axis of illumination.The composite resin nearer to the light source underwent more complete polymerization. Increased exposure time resulted in greater depth of cure. The rate of polymerization was greatest in the first 10 s. Maximum hardness measured up to a depth of 1 mm obtained after 80 s of exposure time. At greater depth, a decrease in Knoop hardness was observed. At exposures under 80 s, maximum hardness was not achieved even at a depth of only 1 m

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1988.tb00766.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryA study using a HunterLab colorimeter was conducted to determine the colour effect of denture base materials on denture tooth acrylics.The results show that denture base materials create a measurable change in the chroma of denture tooth acrylics and suggest that optimal shade selection of teeth should include a determination of the background effects of denture base materials.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1988.tb00767.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1988.tb00768.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY