bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of occlusal splints on the EMG activity of masseter and temporal muscles in bruxism with clinical symptoms
Authors: HAMADA T. , KOTANI H. , KAWAZOE Y. , YAMADA S. 
Published: June 2007

SummaryAn electromyographic study of the masseter and anterior temporal muscles was performed on fifteen bruxism patients with clinical symptoms such as muscle pain, fatigue and tenderness. The slopes of the voltage tension (V/T) curves (calculated as the value of the relative inclination between the integrated electromyogram and the biting force) were compared before and after treatment with an occlusal splint. Following use of the splint, the steep slopes of the V/T curves, common in bruxism, became gentle and similar to those of healthy subjects. The differences found in the slopes of different types of bruxism (grinding, clenching, grinding and clenching) might be useful as a diagnostic tool. Follow‐up recording of the slopes was considered to be a useful indicator of treatment effectiveness.
Muscles involved in voluntary mandibular retrusion in man
Authors: DUTHIE N. , YEMM R. 
Published: June 2007

SummaryIt is generally accepted that voluntary mandibular retrusion, with the mouth closed, is brought about by contraction of the posterior fibres of the temporal muscle. The present experiments have shown that, in each of a small series of subjects, activity of some submandibular muscles, normally associated with jaw‐opening, was involved. It is suggested that a retruded posture is the effect of balanced activity of both temporal and submandibular muscles. This finding can be confirmed by palpation.
Analysis of the mandibular relationship of TMJ dysfunction patients using the Mandibular Kinesiograph
Authors: MARUYAMA TAKAO , MIYAUCHI SHUHEI , UMEKOJI EISHUN 
Published: June 2007

SummaryAnalyses of the relationship between centric relation and centric occlusion were performed using the Mandibular Kinesiograph to show the abnormality of mandibular positions of the TMJ dysfunction patients.The distance between centric relation and centric occlusion in antero‐posterior, left, and linear direction showed significant differences between the normal subjects and the TMJ dysfunction patients. In the TMJ dysfunction patients, the number of the subjects who showed larger deviation between centric relation and centric occlusion increased remarkably when compared with normal subjects.It is suggested that the slide between centric relation and centric occlusion can be one of the causes of the TMJ dysfunction.
Evaluation of the bonding of cervical restorative materials
Authors: VOUGIOUKLAKIS G. , SMITH D. C. , LIPTON S. 
Published: June 2007

SummaryVariable results have been reported for the bonding of cervical lesion restorative materials to enamel and dentine. The effect of surface condition on bond strength was studied for two glass ionomer and one polycarboxylate cements and one composite resin material.Flat surfaces of human enamel and dentine, prepared by wet grinding on 600 grit silicon carbide paper, were treated respectively with water, phosphoric acid, citric acid, EDTA and/or remineralizing solution. Using an improved bonding device the cements and the composite resin were bonded to the prepared enamel and dentine surfaces. After 24 h in water at 37°C a tensile bond strength was determined. The bond fracture surfaces were examined in the scanning electron microscope. The results showed good bonding of the materials to enamel after the recommended surface treatments with cohesive failure and values 60–120 kg/cm2Bonding to dentine was more variable and was critically dependent on surface preparation.Caulk‐ASPA bond strengths that were obtained after various treatments ranged from 34 kg/cm2 (untreated dentine) to 54 kg/cm2 (citric acid treatment).Fuji ionomer bond strengths that were obtained after various treatments ranged from 42 kg/cm2 (citric acid treated dentine) to 56 kg/cm2 (EDTA treated).Durelon bond strengths that were obtained after various treatments ranged from 24 kg/cm2 (citric acid treated dentine), to 69 kg/cm2 (remineralizing solution treated dentine).The bond strengths that were obtained with Cervident after various treatments ranged from 0 kg/cm2 (untreated dentine) to 30 kg/cm2 (phosphoric acid treated dentine plus the adhesion promoter).SEM examination showed micromechanical bonding through penetration into dentinal tubules for all materials.
Identifying the denture space
Authors: NEILL D. J. , GLAYSHER J. K. L. 
Published: June 2007

SummaryIn the absence of pre‐extraction records, the positioning of teeth on complete dentures is a somewhat arbitrary procedure. The present study was designed to evaluate a number of different criteria for tooth placement.Miniature foil strain gauges were used to measure the forces brought to bear on complete dentures by the lingual and peri‐oral musculature.Previous studies of the pattern of post‐extraction resorption found that the vestige of the lingual gingival margins of the maxillary teeth could be identified on the cast and it was suggested that these biometric guides are reliable for the correct placement of the upper artificial teeth. The results reported confirmed the use of biometric guides to tooth placement as a reliable method of positioning the teeth in Class I edentulous cases.
Perception of vertical dimension
Authors: GAMON JOHN A. , WRIGHT SUSAN M. 
Published: June 2007

SummaryTen edentulous adults were investigated to learn more about the preferred vertical dimension of occlusion (PVDO) and the comfortable zone. A screw jack device was employed, using the forced‐choice and external approach methods. The dimensional discrimination ability of each subject was assessed at the mean PVDO, and at points 3 mm above and below it.For each subject, both the forced‐choice and external approach methods gave a mean PVDO value which was reasonably constant. The comfortable zone widths were less consistent. In all but two of the subjects the mean PVDO values appeared consistent with a clinically acceptable occlusal vertical dimension.No relationship was found between the dimensional discrimination ability of the subjects and their definition of PVDO and comfortable zone.
Lip morphology and area changes associated with surgical correction of mandibular prognathism
Authors: WEINSTEIN S. , HARRIS E. F. , ARCHER S. Y. 
Published: June 2007

SummaryChanges in lip morphology and area, measured in two dimensions from standardized lateral head films, were assessed in a series of twenty adults at three times: pre‐surgically, 8–14 months post‐surgically, and a long‐term follow‐up at 5–7 years. All individuals received the same, single surgical procedure (Obwegeser sagittal split for correcting mandibular prognathism. Upper and lower lip changes were quantified as millimetres displacement of the lip centroid vertically and horizontally, plus changes in cross‐sectional area. Direction and amount of change, its dependency on the amount and kind of surgically induced symphyseal changes, and the intercorrelations among lips and among lip and symphysis variables were statistically evaluated, both univariately and multivariately. Three measures are made of symphysis change: horizontal and vertical repositioning and amount and direction of rotation. Horizontal repositioning primarily affected the lengthening and areal increase of the upper lip. Vertical repositioning had its major influence in the height and cross‐sectional area of the lower lip: a superior shift of the mandible made the lower lip shorter, more protrusive and smaller in area; an inferior shift produced an increase in lower lip height with increased area. The third variable, symphyseal rotation, had its greatest influence on the labial‐lingual shift of the upper lip's centroid. The long‐term follow‐up showed little change from the 1 year post‐operative conditions; equilibrium of the soft tissue components was then achieved fairly soon after surgery.
A laboratory and clinical study of Trevalon® denture base material
Authors: MURPHY W. M. , HUGGETT R. , HANDLEY R. W. 
Published: June 2007

SummaryTrevalon is a denture base material which can be cured by three basic alternative curing cycles, thus providing a choice of processing technique which can be selected to suit laboratory or clinical needs. The flexibility of working properties is probably due to the interaction between on the one hand, the high molecular weight of the powder and on the other hand, the particle size distribution which are important factors influencing the doughing time (14 min), working time (40 min) and the exothermic reaction. The effect of each curing cycle upon the following properties of the material was investigated; dimensional accuracy, Young's modulus, modulus of rupture, impact resistance, water sorption, indentation resistance, creep and transverse bend behaviour. The particle size and molecular weight distribution of the powder were also evaluated. A clinical investigation of Trevalon was carried out by constructing complete dentures for a sample of patients, divided into three groups, each group having dentures processed by one of the three alternative curing cycles. Although some laboratory tests demonstrated that there were statistically significant differences between specimen bases, no clinical differences were recorded between dentures 1 year after construction.
In vitro plaque formation on commonly used dental materials
Authors: DUMMER P. M. H. , HARRISON K. A. 
Published: June 2007

SummaryAn in vitro method has been developed for the study of microbial plaque formation on commonly used dental restorative materials. Standard samples of the materials to be studied are suspended in a complex culture medium inoculated with a bacterial suspension. The samples are transferred daily into freshly inoculated medium for a total of 4 days. The resultant microbial plaques are then graded, weighed and assessed for a number of colony forming units (viable count).In this preliminary experiment samples of amalgam, composite cement, gold and porcelain were examined. Significantly less plaque was formed on amalgam than on any of the other materials.
A retrospective study of the fit of jacket crowns placed around gold posts and cores, and the associated gingival health
Authors: TURNER CHRISTOPHER H. 
Published: June 2007

SummaryA retrospective study has been carried out of the marginal fit and associated gingival health of jacket crowns placed around gold posts 5 years previously. Crown fit was classified as either visibly or palpably satisfactory, overhanging or deficient. 67.2% of crowns showed one or more discrepancies of marginal fit, and this varied with the position around the tooth. Palatal margins of maxillary porcelain jacket crowns fitted poorly and there was frequent caries at this site. Periodontal pocketing developed mesially and distally, and little gingival recession. In contrast gingival recession, exposing the crown margins, occurred frequently labially and palatally, but the mean periodontal pocket depth remained within normal limits.
Maximal bite force with centric and eccentric load
Authors: WIDMALM SVEN ‐ ERIK , ERICSSON SVEN GOTTMAR 
Published: June 2007

SummaryPremolar bite force was measured conventionally with a pressure transducer. During biting the tips of the buccal cusps made contact with the transducer. It was shown that the maximal bite force increased significantly if the eccentric load on the upper premolar was made centric and axial with respect to the transducer by covering the whole occlusal surface of the tooth with a plastic filling. Possible neurophysiological explanations of the difference in bite force are discussed. It is concluded that biting on a pressure transducer with an eccentric load cannot give a fair estimation of the true value of the maximal bite force during clenching in the position of intercuspidation.
The measurement of masseteric silent periods after experimental tooth grinding
Authors: COX P. J. , AL‐KHATEEB T. L. , ROTHWELL P. S. , DUXBURY A. J. 
Published: June 2007

SummaryMasseteric silent periods were recorded in normal subjects who performed experimental bruxism. All subjects showed a significant increase in silent period duration immediately following and 3 h after a session of experimental bruxism. The silent period had returned to presessional levels by 3 weeks.
Contacts in maximal occlusion
Authors: BATTISTUZZI P. G. F. C. M. , ESCHEN S. , PEER P. G. M. 
Published: June 2007

SummaryOcclusion, defined as the presence of contact of antagonistic teeth, has been measured. This has been done by measuring the amount and magnitude of holes in bite registration materials taken from nine persons with complete natural dentitions.In spite of clear differences between the bites found by inspection, small differences have been found by measurement. Bite‐, day‐ and testee‐effects were controlled. The implications of the findings are discussed in terms of reliability and also of the epidemiological and clinical applicability of the method.
Reproducibility of chewing rhythm and of mandibular displacements during chewing
Authors: JEMT TORSTEN , HEDEGÅRD BJÖRN 
Published: June 2007

SummaryIn a small group of individuals the chewing behaviour was recorded through light‐emitting diodes in the Selspot system repeatedly over a 7‐month period. The test food was crispbread of a standard size. It was shown that a characteristic chewing pattern can be recognized in each test person, and that the pattern was stable during the test period with only insignificant variations in chewing rhythm and magnitude of mandibular displacement.
Subcutaneous tissue response in rats to an aluminoborate cement
Authors: WATTS TREVOR L. P. , BERTENSHAW BARRY W. 
Published: June 2007

SummaryIn the interests of producing an improved periodontal dressing material, adhesive cements are under consideration. A new glass ionomer system—aluminoborates—shows some potential in this respect, and a relatively soluble formulation was chosen for a simple biological test in rats, by means of implantation in polypropylene tubes. As a positive control, the widely used aluminosilicate cement Aspa® was employed, and empty tubes were used as negative controls. A simple scoring system using interval measurements was employed, and showed no difference at the 5% level between the experimental cement and either control, although slight differences were discernible between controls. The study also indicated that the side of a filled tube is not the best control for assessment of reaction at tube ends.
The masseteric silent period following experimental bruxism in subjects wearing acrylic anterior bite planes
Authors: COX P. J. , ROTHWELL P. S. , DUXBURY A. J. 
Published: June 2007

SummaryMasseteric silent periods were recorded in normal subjects who performed experimental bruxism whilst wearing an acrylic anterior bite plane. No significant increase of the silent period duration occurred. The results are compared with similar studies without the anterior bite plane.
Denture mobility and bolus position during mastication in patients wearing conventional and pelotte‐retained full upper dentures: a cineradiographic study
Authors: KARLSSON STIG 
Published: June 2007

SummaryWith cineradiographic technique an assessment was made of the denture mobility of conventional and pelotte dentures in the upper jaw and of the position of the bolus during chewing of meat and bread. Five randomly selected edentulous patients with moderate alveolar ridge resorption rehabilitated with dentures of conventional design, and another five with dentures furnished with subnasal retentive pelottes, were incorporated in the study. Cineradiographic registrations were made in lateral and frontal projections with a picture frame speed of 38/s.Analysis of the cineradiographic films revealed only small differences for the denture mobility for the two patient groups. This indicated in the patients with severe ridge resorption, an obvious reduction of denture displacement through the use of the nasal pelotte or prong. The displacement was of similar magnitude as for those dentures where an alveolar ridge creates effective retention and limitation of horizontal movements. The analyses of the bolus position during chewing gave the information that in all individuals wearing pelotte dentures, the bolus was positioned more distally, than for patients with conventional dentures. Presumably this was in order to reduce discomfort in the frontal region, i.e. the region of the pelottes. Patients with conventional dentures showed a more even distribution of the bolus to all regions.
A method for sampling the cavity wall/material interface for microbiological culture
Authors: BROWNE R. M. , SIDAWAY D. A. , TOBIAS R. S. , BOVIS S. C. , BRITTEN A. S. 
Published: June 2007

SummaryA punch method for sampling the cavity wall/material interface for microbiological culture is described. Good correlation was obtained between the recording of micro‐organisms by this method and from histological sections.
Influence of experimental interfering occlusal contacts on the activity of the anterior temporal and masseter muscles during submaximal and maximal bite in the intercuspal position
Authors: SHEIKHOLESLAM A. , RIISE C. 
Published: June 2007

SummaryThe effects of an intercuspal occlusal interference on the pattern of activity of the anterior temporal and masseter muscles during submaximal and maximal bite, were studied in eleven volunteers with complete, natural dentitions.The results show that, during maximal and submaximal bite an occlusal interference (about 0.5 mm) in the intercuspal position is able to disturb the almost symmetric pattern of muscular activity in the anterior temporal and masseter muscles. Further, the level of muscular activity during maximal bite decreased significantly in all muscles studied. In some subjects, the decrease of muscular activity could still be observed one week after insertion of the interfering contact. After eliminating the interference, the muscular co‐ordination pattern improved and the level of muscular activity increased significantly.
An analysis of tooth position on initial tooth contact
Authors: FAULKNER K. D. B. , ATKINSON H. F. 
Published: June 2007

SummaryA closed circuit television movement detector was used to study mandibular movement in the form of tooth tapping, in subjects with no apparent dental disease or malocclusion. The velocity and form of various phases of movement was studied, in the transverse, sagittal and coronal planes, from measurements made on u.v. charts and X‐Y recordings. It was shown that closing movements were more direct and faster than opening movements; that initial contact on closing is in a well‐defined contact area, followed by a sliding of cusps over each other to a final centric position and that the closing path of the mandible in tapping movements is in the form of a smooth curve showing simple axis rotation through distances normally greater than those accepted clinically. It was also shown that microphone signals can be detected at times other than when normally expected, indicating displacement with tooth contact, at times other than at the fully intercuspated position.
Development of the swallowable composition of food in normal dentate subjects
Authors: JIFFRY M. T. M. , MOLLIGODA A. 
Published: June 2007

SummaryThis study aimed to find out the changes which occur in the frequency distribution of the size of particles produced during mastication of a convenient mouthful of hard‐baked soya beans to its swallowable composition (SC), and to identify the particles which undergo rapid pulverization.In this group the total number of masticatory strokes utilized to prepare food for the SC varied between forty and eighty masticatory strokes. All the subjects produced a similar pattern of the frequency distribution of particles produced at the end of mastication and when mastication was interrupted at a particular phase. Particles larger than 1180 μm were pulverized to form particles smaller than 1180 μm. Most rapid pulverization was seen in particles of 2400 μm whereas particles of average size 655 μm, formed rapidly.
Magnetic retention units for overdentures
Authors: SMITH G. A. , LAIRD W. R. E. , GRANT A. A. 
Published: June 2007

SummaryMechanical attachments used to improve retention of overdentures have their limitations. With the recent development of the cobalt‐samarium magnet an alternative method of achieving increased overdenture retention is offered. The most suitable form of magnet appears to be of a reverse split pole design with a ferromagnetic disc or keeper which will ensure a closed magnetic field. Clinical techniques involve conventional endodontic therapy, and the basic method of overdenture construction can be followed with only minor modification.
A standardized programme for studying the occlusal force pattern during chewing and biting in prosthetically restored dentitions
Authors: LAURELL LARS , LUNDGREN DAN 
Published: June 2007

SummaryA recently described method for studying occlusal forces in prosthetically restored dentitions (Lundgren & Laurell, 1984) was applied in a standardized programme to elucidate the occlusal force pattern and the functional capability of a dentition during chewing and biting. The method is based on the use of strain gauge transducers mounted into preformed matrices evenly distributed over the tooth‐arch. The programme was tested in a subject prosthetically restored with a fixed bridge of crossarch design in the upper jaw, and with unsplinted teeth in the lower jaw. It involved chewing of (a) peanuts, (b) roast beef with potato salad, biting with maximal strength in habitual occlusion and biting over one limited contact area at a time.The magnitude of the occlusal forces developed during chewing and swallowing was well below all biting forces.The magnitude of the total force acting over the entire dentition when biting at maximal strength in habitual occlusion did not seem to be limited by reactions from the teeth or the periodontal tissues but, seemingly, by the capability of the jaw‐closing muscles themselves. The magnitude of the local bite force over one limited contact area at a time was much smaller than that which the jaw‐closing muscles were able to develop. This indicated that feedback mechanisms in the periodontal tissues and/or the temporo‐mandibular joints were limiting factors for these forces.The programme will be applied to studies of dentitions supplied with prosthetic constructions of various design and with different distribution of periodontal support.
Fluoride enhancement of chlorhexidine uptake by hydroxyapatite and enamel powders
Authors: BEN‐YAAKOV D. , FRIEDMAN M. , HIRSCHFELD Z. , GEDALIA I. 
Published: June 2007

SummaryThe purpose of the present study was to examine the in vitro adsorption of Chlorhexidine and fluoride to hydroxyapatite and tooth enamel powders. Samples of hydroxyapatite or enamel powder were suspended in aqueous solutions of chlorhexidine gluconate 2.0; chlorhexidine acetate 1.5%; sodium fluoride of various concentrations (0.2%, 1%, 2%) and mixtures of sodium fluoride and chlorhexidine. The data obtained in the study show that chlorhexidine and fluoride adsorb to hydroxyapatite and tooth enamel in vitro. Furthermore, the amount of fluoride adsorbed to hydroxyapatite is reduced in the presence of chlorhexidine in the solution. A probable explanation for this effect may be that there is a competitive adsorption of fluoride and chlorhexidine on to the same binding sites on the hydroxyapatite. Additionally, the presence of fluoride dramatically increases the affinity of chlorhexidine for hydroxyapatite. The fact that fluoride strongly enhanced the adsorption of chlorhexidine to hydroxyapatite and enamel, indicates that fluoride may be of clinical interest beyond the prevention of caries.