bluuebunny/crossref_metadata_2025_split huggingface dataset:
Shortened dental arches and oral function
Authors: KÄYSER A. F. 
Published: June 2007

SummaryTo acquire more information concerning the changes of the oral functions in shortened dental arches, a cross‐sectional clinical investigation was carried out among 118 subjects. They were classified into six classes, according to the degree and the symmetry of the shortened condition. The method was based on the measuring of variables which were derived from the oral function. The results showed two patterns of change in oral functions: oral functions that change slowly until four occlusal units are left and then change rapidly, and oral functions that change progressively without a sudden change. The preliminary conclusion is that there is sufficient adaptive capacity to maintain adequate oral function in shortened dental arches when at least four occlusal units are left, preferably in a symmetrical position.
Optical properties of composite resins
Authors: GRAJOWER RAFAEL , WOZNIAK WAYNE T. , LINDSAY JAMES M. 
Published: June 2007

SummaryThe translucency and colour of a composite resin are characterized by two wavelengthdependent parameters: the absorption coefficient, K and the scattering coefficient, S. These parameters were calculated according to the Kubelka‐Munk (1931) equations for two commercial resins. The calculations were based on reflectance spectra of samples of different thicknesses which were placed on a black and a white background. Employing the values of these parameters, calculated spectra were obtained of samples on the same as well as different backgrounds. The difference between the experimental and the calculated spectra was evaluated in terms of Friele‐MacAdamChickering (Hemmendinger, 1970) colour differences. The Munsell colour values, corresponding to the spectra were evaluated. It was found that the colour of a resin sample of a specified thickness which is placed on a particular background may be predicted to a fair degree of accuracy from calculations employing the K and S values of the resin and the reflectance spectrum of the background. It has been demonstrated that illuminating the sample at 45° instead of using diffuse illumination, affected the results only to a small extent. The effect of internal reflections at the resin surface on the reflectivity on the sample is discussed. An expression has been derived for computing the reflectivity of a sample on any background from its transmittance and reflectivity on a completely absorbing background.
A new laboratory method for evaluating the relative solubility and erosion of dental cements
Authors: BEECH D. R. , BANDYOPADHYAY S. 
Published: June 2007

SummaryA method for accelerating the dissolution and erosion of ‘acidic’ dental cements has been developed which gave relative solubilities in accordance with in vivo observations, in contrast to the conventional test. It involves subjecting 24‐h‐old specimens to a jet of dilute acid (lactic or citric) and determining weight loss. The relative ranking for ‘acidic’ cements in the apparatus and in vivo was: glass ionomer zinc < silicophosphate < zinc phosphate < polycarboxylate.The method was not valid for reinforced zinc oxide/eugenol/EBA cements. Of the two polycarboxylate cements studied, a brand which has the acid in the powder was found to be more soluble than the conventional material. It is proposed that the method be the basis of a new solubility/erosion test in national and international standards for ‘acidic’ dental cements.
The anatomy and electrical activity of the platysma muscle
Authors: WIDMALM S‐E. , NEMETH P. A. , ASH M. M. , LILLIE J.H. 
Published: June 2007

SummaryDissection of seven cadavers showed that the platysma muscle may cover large parts of the masseter muscle. The platysma may thus be a significant source of artefact activity when recording the masseteric activity with surface electrodes. This is illustrated by a patient‐case.The electrical activity of the platysma muscle was studied during jaw movements in normal, healthy subjects. Activity was regularly recorded during the latter half of large vertical jaw opening movements and, in five of the seven subjects, in the ipsilateral platysma muscle also during combined lateral–vertical jaw opening movements. The platysma may, therefore, in some individuals, have a functional role during the opening phase of chewing cycles when this has a marked lateral component.
Lateral preference in mastication: an electromyographic study
Authors: CHRISTENSEN L. V. , RADUE J. T. 
Published: June 2007

SummaryTo study concurrence of specific electromyographic chewing patterns and the side of mastication, twelve subjects chewed gum for 15, 20 and 25 s. Gum bolus placement on the right or left side of the dentition was estimated by three series of visual inspections. Contraction patterns of the chewing and non‐chewing side masseter muscles were appraised by integrated and cumulative surface electromy‐ography. Consistent and predominant gum bolus placement on the right side of the dentition could be predicted fairly reliably from comparative electromyographic observations. This was also the case in instances of consistent left‐sided gum bolus placement, but not in predominant left‐sided bolus placement. The latter phenomenon was explained by deviant observations made in two subjects only. Agreement between a presumed chewing side and a predictive contractility pattern was established in 78% of observations (P>0‐001).
Personality and quantified neuromuscular activity of the masticatory system in patients with temporomandibular joint dysfunction
Authors: SCHUMANN N. P. , ZWIENER U. , NEBRICH A. 
Published: June 2007

SummaryPatients suffering from temporomandibular joint dysfunction syndrome (TMJS) and healthy volunteers were examined by means of MMPI questionnaire and electromyography (masseter, anterior temporal and anterior digastric muscles) at rest and during natural chewing. In response to mental load (arithmetic chain task) TMJS patients showed an increase in postural activity and partly rhythmical short augmentations above the mean level of this activity. Chewing potentials were considerably diminished in patients compared with controls. There was evidence for neurotic disorders in the patients MMPI (neurotic triad: higher scores on hypochondria, depression, hysteria). Significant differences (multivariate variance and discriminant analysis: P<0.001) between patients and controls were found both in the group with psychic signs (MMPI scales) and in the group of quantitative electromyographic parameters. However, a sufficient discrimination was only obtained by a combination of both parameter groups. The results show that within the masticatory system, are important in the aetiopathogenesis of TMJS.
Degree of conversion of seven visible light‐cured posterior composites
Authors: CHUNG K. , GREENER E. H. 
Published: June 2007

SummaryThe infrared spectra of seven commercially available posterior composite resins were analysed by ratioing the C = C aliphatic peak to the C = C aromatic peak. The degree of conversion ranged from 43–5 to 73–8%. The result was similar to the range previously obtained from unfilled Bis‐GMA based resins and commercial anterior composites.
Tooth positions in the natural and complete artificial dentitions, with special reference to the incisor teeth: an interactive on‐line computer analysis
Authors: WATSON R.M. , BHATIA S.N. 
Published: June 2007

SummaryA comparison of tooth positions and soft tissue profiles was made between samples of edentulous patients recently provided with new complete dentures, and dentate subjects. The dentures were marked with lead foil on the most prominent incisor teeth and labial surfaces of the flanges. Lateral skull radiographs were made with the jaws in centric relation. The dentate subjects were recorded with the teeth held in centric occlusion. Discrete soft and hard tissue landmarks were identified and recorded using an interactive on‐line computer system, enabling linear and angular measurements to be made. A mathematical comparison was produced employing a series of independent t‐tests. Composite computer tracings were also produced. Important differences were found between the two groups, in which the influence of the upper lip length, mandibular resorption, and selected overbite were identified as factors determining artificial tooth position.
Effect of mucin on the corrosion behaviour of dental casting alloys
Authors: MEZGER P. R. , VAN'T HOF M. A. , VRIJHOEF M. M. A. , GRAVENMADE E. J.'S , GREENER E. H. 
Published: June 2007

SummaryThe influence of mucin on the corrosion behaviour of seven typical dental casting alloys was investigated. A commercial saliva substitute (Saliva Orthana®) containing mucin, and a control from which the mucin had been removed, were used.The electrochemical behaviour of the test alloys was evaluated around the open circuit potential (OCP) utilizing standard potentiodynamic techniques, as a function of oxygen concentrations and pH.The results of the corrosion measurements were analysed by a four‐way ANOVA to detect the influence of alloy, environment and possible interactions. Mucin seems to act as a cathodic inhibitor at pH. 6.7 but not at pH 4.6. An unidentified component (e.g. benzoate) of the saliva substitute probably acts as an adsorption inhibitor. Anodic passivation is also correlated with the artificial saliva composition.
Aetiological factors of craniomandibular disorders in completely edentulous denture‐wearing patients
Authors: FAULKNER K.D.B. , MERCADO M.D.F. 
Published: June 2007

SummaryA total of 201 completely edentulous patients awaiting treatment for new complete dentures at the Royal Dental Hospital of Melbourne were examined for signs and symptoms of craniomandibular disorders, and a history was taken regarding their dentures. Statitical analysis by means of Student's t‐test showed that the only reliable indicator of craniomandibular disorder was the patient's sex, i.e. female subjects tend to show more symptoms of craniomandibular disorders than male subjects. When regression and multiple regression analyses were applied, it was found that subjects with a history of fewer sets of complete dentures worn appeared to be correlated with an increase in the number of signs and symptoms of cranimandibular disorders. However, this correlation had a weak predictive power, although it was significant enough to indicate that such a relationship could exist in the general population.
Reproducibility of temporomandibular joint vibrations (electrovibratography)
Authors: CHRISTENSEN L.V. , ORLOFF J 
Published: June 2007

SummarySurface electrovibratographic (EVG) recordings were obtained from the temporomandibular joints (TMJ) of clinically normal subjects (absence of TMJ sounds) and clinically abnormal subjects (presence of TMJ sounds). As examined through single factor analyses of variance and coefficients of intraclass correlation, the EVG recordings showed excellent reproducibility. The analyses showed also that, in comparison with clinically normal TMJs, the vibrations of clinically abnormal TMJs had higher median (+79%) and peak (+ 137%) frequencies, higher peak amplitudes (+ 740%), and higher intensities as expressed through the estimated total energy contents (+ 1843%) and the integrals (+ 1215%) of power spectrum density functions.
A system for assessing the severity and progression of occlusal tooth wear
Authors: JOHANSSON A. , HARALDSON T. , OMAR R. , KILIARIDIS S. , CARLSSON G. E. 
Published: June 2007

This study represents an attempt to introduce a system for the longitudinal evaluation of the severity and the rate of progression of tooth wear. The material comprised a selected group of 10 males and 10 females, examined twice within an 18‐month period. The subjects were predisposed to advanced occlusal wear and had a mean age of 32 years within the range of 16‐56 years. Evaluation of occlusal wear was performed on a tooth‐by‐tooth basis, on study casts, using two ordinal scales, one for assessing the severity, and the other the progression of occlusal wear. The reliability of the scales was assessed by percentage inter‐observer concordances.The sample exhibited higher occlusal wear scores in the incisor and canine regions compared to the posterior region. It was found that the overall progression in an 18‐month follow‐up period was slow. The inter‐observer concordance in the evaluation of the severity of wear was 88%, and 91% in the progression of wear. Within the limitations of the described system, the scales may be utilized for determining the severity of occlusal wear and the rate of its deterioration in an individual's dentition. From a clinical standpoint, the need for future treatment may be based on such an evaluation of the progression of wear.
Fatigue and EMG changes in the masseter and temporalis muscles during sustained contractions
Authors: LYONS M.F. , ROUSE M.E. , BAXENDALE R.H. 
Published: June 2007

Local muscle fatigue was investigated in the anterior temporal and masseter muscles during sustained isometric contractions. The volunteers’ subjective perception of fatigue or pain was recorded at intervals during the sustained contractions, and this level was then compared to objective measures of fatigue. These objective measures included shift in median frequency of the power spectrum of the surface‐detected EMG signal, and change in signal amplitude.The relationship was investigated while closing on a bite force meter placed between the second premolars and first molars unilaterally, and while simply clenching with the teeth together without the bite force meter.It was found that the subjective perception of fatigue, as measured on a visual analogue scale (VAS), had a nearly linear relationship with time, and that the relationship between the VAS score and median frequency shift was rather closer than the relationship with amplitude change.
Dental high‐speed cutting of four cast alloys
Authors: MIYAWAKI H. , TAIRA M. , WAKASA K. , YAMAKI M. 
Published: June 2007

SummaryThe purpose of this study was to evaluate dental high‐speed cutting behaviour of four cast alloys, namely Ag‐Pd‐Cu‐Au alloy, Ag‐Zn‐In‐Sn alloy, Ni‐Cr alloy and Ti. Weight‐load cutting tests were conducted on four cast alloys, using two rotary cutting instruments, namely a diamond point and a carbide bur, both driven by an air‐turbine handpiece. While the constant transverse load of 80g was applied on the workpiece for 5s, the handpiece speed was measured during cutting as well as the volume of workpiece removal which took place. The cutting tests were repeated 10 times. We found that the cutting volumes of soft Ag‐Pd‐Cu‐Au alloy and Ag‐Zn‐In‐Sn alloy were considerably larger than those of hard Ni‐Cr alloy and Ti. It was also clarified that the cutting effectiveness of the carbide bur was generally superior to that of the diamond point. With continuing use, however, the cutting capability of the carbide bur tended to decline while that of the diamond point remained quasi‐constant.
Location of implants in the interforaminal region of the mandible and the consequences for the design of the superstructure
Authors: MEIJER H.J.A. , STARMANS F.J.M. , STEEN W.H.A. , BOSMAN F. 
Published: June 2007

SummaryThe location and the number of implants to support an overdenture is of major importance for the superstructure design. Sometimes, jaw bone anatomy or posteriorly placed implants enforce the use of an angular bar to achieve a position above the alveolar ridge. Loads on such a bar may introduce a moment on the implants which can result in high bone stresses and eventually the loss of the implants.This study on stress distribution in the bone around the implants in an edentulous mandible was performed using a three‐dimensional finite element model. One model with two implants placed just anteriorly of the mental foramen and connected with an anteriorly placed bar, following the curvature of the alveolar ridge, was compared with two other designs. First with a similar model but now without a bar and secondly with a model with four implants connected with straight bars.It is concluded that loading a bar, which is placed anteriorly of the interconnecting line between two implants, causes extremely large compressive and tensile stress concentrations in the bone around the implants. Therefore, in those cases, it is advised not to connect the implants or, in case a bar‐clip attachment is preferred, to place additional implants in the frontal region.
Urban mammals: what does the future hold? An analysis of the factors affecting patterns of use of residential gardens in Great Britain
Authors: BAKER PHILIP J. , HARRIS STEPHEN 
Published: June 2007

ABSTRACTUrban areas are predicted to grow significantly in the foreseeable future because of increasing human population growth. Predicting the impact of urban development and expansion on mammal populations is of considerable interest due to possible effects on biodiversity and human‐wildlife conflict.The British government has recently announced a substantial housing programme to meet the demands of its growing population and changing socio‐economic profile. This is likely to result in the construction of high‐density, low‐cost housing with small residential gardens. To assess the potential effects of this programme, we analysed the factors affecting the current pattern of use of residential gardens by a range of mammal species using a questionnaire distributed in wildlife and gardening magazines and via The Mammal Society.Twenty‐two species/species groups were recorded. However, the pattern of garden use by individual species was limited, with only six species/species groups (bats, red foxVulpes vulpes, grey squirrelSciurus carolinensis, hedgehogErinaceus europaeus, mice, voles) recorded as frequent visitors to > 20% of gardens in the survey.There was a high degree of association between the variables recorded in the study, such that it was difficult to quantify the effects of individual variables. However, all species/species groups appeared to be negatively affected by the increased fragmentation and reduced proximity of natural and semi‐natural habitats, decreasing garden size and garden structure, but to differing degrees. Patterns of garden use were most clearly affected by house location (city, town, village, rural), with garden use declining with increasing urbanization for the majority of species/species groups, except red foxes and grey squirrels. Increasing urbanization is likely to be related to a wide range of interrelated factors, any or all of which may affect a range of mammal species.Overall, the probable effects of the planned housing development programme in Britain are not likely to be beneficial to mammal populations, although the pattern of use examined in this study may represent patterns of habitat selection by species rather than differences in distribution or abundance. Consequently, additional data are required on the factors affecting the density of species within urban environments.
Cognition genes on autosomes: the paradox
Authors: Willems PJ 
Published: June 2007

Homozygosity mapping in consanguineous families reveals extreme heterogeneity of non‐syndromic autosomal recessive mental retardation and identifies eight novel gene loci Najmabadi H et al. (2007) Human Genetics 12: 43–48A new locus for autosomal recessive non‐syndromic mental retardation maps to 1p21.1–p13.3 Uyguner O et al. (2007) Clinical Genetics 71: 212–219
Validation of a rhinitis symptom questionnaire (ISAAC core questions) in a population of Swiss school children visiting the school health services
Authors: Braun‐Fahrländer Charlott , Wüthrich Brunello , Gassner Markus , Grize Leticia , Sennhauser Felix H , Varonier Hubert S , Vuille Jean‐Claude 
Published: June 2007

The primary aim of the study was to assess the validity of the ISAAC core questions on rhinitis in a population of Swiss school children by comparing them to skin prick test results. Second, the positive predictive value in detecting atopy among children with rhinitis symptoms was determined. Third, agreement between parental reports of hay fever and rhinitis symptoms was evaluated, since earlier Swiss prevalence surveys had exclusively relied on reported hay fever.Material and methods: Two thousand nine hundred and fifty‐four (81. 2%) parents of 7, 10 and 14‐year old children filled in an exhaustive questionnaire which included the ISAAC core questions on rhinitis. Two thousand one hundred and twenty children also underwent skin prick testing against six common aeroallergens (grass mixture, birch, mugwort, D. pteronyssinus, cat and dog dander). The analysis is restricted to children with both questionnaire data and skin prick test results.Results: Sensitization to any allergen was most strongly associated with reported hay fever (OR = 5. 7, 95% CI 4. 4—7. 4), nose problems accompanied by itchy‐watery eyes (OR = 4. 4, 95% CI: 3. 3—5. 7), symptoms occurring only during pollen season (March through September) (OR = 4. 9, 95% CI: 3. 6–6. 5) and a combination of these latter two symptoms (OR = 5. 8, 95% CI: 4. 1—8. 1). The association was stronger for a sensitization to outdoor allergens than for indoor allergens. The specificity of the various questions was high, ranging from 77. 5% to 97. 6%, but the sensitivity was low (2. 6% to 42. 7%). The positive predictive value for atopy among children with symptoms was 63% for sneezing accompanied by itchy‐watery eyes, 67% for symptoms occurring only during the pollen season and 70% for reported hay fever. However, agreement between reptirted rhinitis symptoms and hay fever was only moderate. About one third of the children with symptoms indicative of seasonal rhinitis did not report the label “hay fever”. Conclusions: We conclude from our analyses that the ISAAC core questions on rhinitis are highly specific and therefore useful in excluding atopy. In addition they have a high positive predictive value in detecting atopy among children with symptoms, but they are not helpful for detecting atopy in a general population of children (low sensitivity). To monitor time trends in the prevalence of allergic rhinitis in Switzerland, questions on rhinitis symptoms as well as on the diagnostic label “hay fever” have to be included in a questionnaire because they contain complementary information since under‐diagnosis of allergic rhinitis is common.
Apnea in a child after oral codeine: a genetic variant – an ultra‐rapid metabolizer
Authors: VORONOV POLINA , PRZYBYLO HENRY J , JAGANNATHAN NARASIMHAN 
Published: June 2007

SummaryWe present a case of a 29 months old previously healthy child who experienced apnea resulting in brain injury following a dose of acetaminophen and codeine 2 days after an uneventful anesthetic for tonsillectomy. A genetic polymorphism leading to ultra‐rapid metabolism of codeine into morphine resulted in narcosis and apnea. This paper discusses the use of codeine for pain relief, obstructive sleep apnea, the alteration of the CYP2D6 gene and the resulting effect on drug metabolism.