bluuebunny/crossref_metadata_2025_split huggingface dataset:
Jaw morphology in edentulous individuals: a radiographic cephalometric study
Authors: ENGSTRÖM C. , HOLLENDER L. , LINDOVIST S. 
Published: June 2007

SummaryThe jaw morphology in the mandible and maxilla was studied by cephalometric analysis in two groups of edentulous subjects and in two groups of individuals in possession of all teeth. The predominating facial type in these groups was the orthognathic type. The alveolar bone height differed significantly between men and women in the edentulous groups but not in the subjects in possession of all teeth. Thus, there seemed to be a sex difference in alveolar bone diminution after extraction of all teeth. The gonial angle was significantly greater in both men and women in the edentulous groups than in either sex in the groups in possession of all teeth. Thus, the basal bone morphology in the mandible seemed to be changed in the same manner in both sexes in the edentulous groups after extraction of all teeth, in contrast to the alveolar bone diminution. Indications were found that the gonial angle might be age related.The chin angle as such was found to be less than 60° in the majority of edentulous individuals which makes this value seem to be of minor importance when selecting edentulous individuals for surgical deepening of the vestibular sulcus.
The electrochemical activity of the oral cavity—a new approach
Authors: EWERS G. J. , GREENER E. H. 
Published: June 2007

SummaryIn order to develop model systems for studying and understanding corrosion phenomena in the oral cavity the electrochemical nature of the oral cavity must be known.Accordingly, the PH and oxidation potential Eh (SCE) were measured in vivo in nine patients utilizing microelectrode techniques. Three of the patients had periodontal therapy and three had received minimal dental care. Sampling was always performed at five specific sites and in periodontal pockets greater than 4 mm when available. In the five sites common to all subjects the oxidation potential ranged from −58 to +212 mV (SCE) and the pH ranged from 6.1 to 7.9. For patients undergoing periodontal therapy the pH/potential clustered around acidic pH (6.6) and an oxidation potential range of 270 mV, whereas minimal dental care revealed a pH range from 6.3 to 7.9 and a small range (57 mV) of oxidation potential. Differences in pH and oxidation potential are related to site of measurement, periodontal health of patient and nature and quantity of restorations present.
An electromyographic study of the immediate effect of an occlusal splint on the postural activity of the anterior temporal and masseter muscles in different body positions with and without visual input
Authors: HOLMGREN K. , SHEIKHOLESLAM A. , RIISE C. 
Published: June 2007

SummaryWith the mandible at rest, the clinical postural position was measured and electromyographic recordings (in seated and supine position, eyes open and eyes closed, before as well as 15 min after insertion of an occlusal splint) were from the anterior temporal and masseter muscles in thirty‐one patients with signs and symptoms of mandibular dysfunction and nocturnal bruxism. The results indicated that when the patients were seated upright, there was a distinct postural activity in the anterior temporal and in some patients also in the masseter muscles. This postural activity decreased significantly with closure of the eyes and in supine position. Fifteen minutes after insertion of an occlusal splint, the postural activity in the temporal muscles decreased in 52%, increased in 22% and remained unchanged in 26% of the patients. Moreover, the postural activity reached its lowest level in supine position. The results indicate that the supine position is the body position to be preferred for centric relation recording as well as for occlusal and splint adjustment.
Isometric endurance of the human masseter muscle during consecutive bouts of tooth clenching
Authors: CHRISTENSEN L. V. , MOHAMED S. E. , RUGH J. D. 
Published: June 2007

SummaryThree human subjects performed teeth clenching at maximum voluntary contraction strength (MVC) of the mandibular elevator muscles. At intervals of 10 s, ten successive bouts of MVC clenching were exercised until total exhaustion of the contracting muscles (isometric endurance). Isometric endurance time decreased exponentially from 59 to 12 s. The curve of the decrease showed a monotone power function (y=x−1). Electromyographic recordings from masseter muscles suggested that fatigable motor units, possibly fast glycolytic units, dropped out during the initial stages of maintained MVC isometric activity. The silent period of the monosynaptic jaw jerk reflex was increased by about 35% following exhaustion of the masseter muscle.
Periodontal problems associated with use of distal extension removable partial dentures—a matter of construction?
Authors: BERG E. 
Published: June 2007

SummaryIt is commonly assumed that a distal extension partial removable dentures rotates around the supporting rests when the saddle is occlusally loaded and that this rotation may expose the abutment teeth to a distal torque believed to be potentially harmful to their periodontal tissues. Attempts are therefore often made to counteract this effect through the denture construction. However, a review of relevant literature does not appear to substantiate an unqualified acceptance of the above mentioned assumptions, nor of the beneficial effect of special denture constructions designed to reduce the abutment loading. On the other hand, well controlled longitudinal studies seem to indicate that a favourable periodontal prognosis may be expected in such cases provided the following conditions are satisfied:(1) Periodontal problems should be treated and an adequate oral hygiene established prior to the insertion of the denture;(2) The periodontal health and oral hygiene should be maintained through regular recalls. During these recalls possible prosthodontic defects should be diagnosed and necessary measures implemented.
Tooth loss, attrition and temporomandibular joint changes in a Romano‐British population
Authors: WHITTAKER D. K. , DAVIES G. , BROWN M. 
Published: June 2007

SummaryMandibular condyles and temporal fossae were studied in a large Romano‐British collection of skulls.The size and shape of the condyles differed from those in previous populations studied. Changes in form or shape of the condyles were age‐related and could be correlated to the number of teeth lost on the same side and on the contralateral side. No statistically significant correlations were seen between attrition and condylar form and surface change.
An investigation into the compatibility of some irreversible hydrocolloid impression materials and dental gypsum products
Authors: OWEN C.P. 
Published: June 2007

SummaryPart I of this study considered the ability of alginate and gypsum combinations to reproduce a line on a test block. Part II describes a refined discriminatory procedure in the evaluation of the compatible combinations. Statistical analysis showed this procedure to be consistent, and that it could be expected to be repeatable. On the basis of this analysis, it was found that one alginate was clearly superior to all others, and that it was possible to distinguish a further group of combinations within the group that reproduced the 0.050mm line. Surface treatment of the alginates by fixing solutions showed that none of the treated materials could be improved to the extent of equating them with the best of the naturally compatible combinations.It is recommended that manufacturers pay more strict adherence to the requirements of the ISO Standard with regard to the availability and recommendation of suitable compatible gypsum products, and also that perhaps the actual Standard should be modified to be more realistic in its demands, and more discriminatory in its evaluation procedure.
Contact allergy to dental materials in patients with orofacial complaints
Authors: YONTCHEV E. , MEDING B. , HEDEGÅRD B. 
Published: June 2007

SummaryTwo groups of individuals were patch tested for frequencies of contact allergy to dental materials. The patient group with orofacial and distant symptoms and complaints referred to the Department of Prosthetic Dentistry were compared with an age–sex matched control group of individuals referred to the Department of Dermatology. The results did not show any differences in patch test reactions between the patient and control groups. The study did not prove any obvious associations between the patients' symptoms or objective findings and the patch test results.
Food breakdown patterns produced by human subjects possessing artificial and natural teeth
Authors: LUCAS P. W. , LUKE D. A. , VOON F. C. T. , CHEW C. L. , OW R. 
Published: June 2007

SummaryThe abilities of thirty‐two complete denture wearers and thirty‐two dentate subjects to break down raw carrot particles were compared. The particle size distributions produced were broader in those subjects that broke down food rapidly per chew and, conversely, narrower in those that were slower. This did not appear to depend on dental status.An analysis of mastication as composed of two separable processes, one describing the means by which particles come to be broken (selection) and the other, the size distributions of a particle upon fracturing (breakage), indicated that both processes were variable. It is concluded that no qualitative differences in the manner by which the two groups reduce food is apparent. To support this, a small study on dentate subjects suggests the covering of the palatal mucosa with an acrylic plate does not affect masticatory performance.
Further abrasion resistance and bond strength studies of fissure sealants
Authors: STRANG R. , CUMMINGS A. , STEPHEN K. W. , McMENEMY P. 
Published: June 2007

SummaryAs part of a laboratory evaluation, measurements of abrasion loss and tensile enamel–sealant bond strengths have been made on three visible light cured sealants (two filled, one unfilled), two chemically cured sealants (one filled and one unfilled) and an experimental sealant with alumina filler particles. A UV‐cured filled sealant was used as a control. The unfilled sealants had abrasion loss approximately twice that of the filled commercial sealants. The experimental sealant, with filler content above 50%, had an abrasion loss approximately half that of the filled commercial sealants. The chemical cured sealants had bond strengths lower than the UV‐cured control, while the bond strengths of the two visible light‐cured filled sealants and the experimental sealant were not statistically different from either the unfilled visible light‐cured sealant or from the UV‐cured filled sealant.
Criteria leading to patient loss from dental school clinics
Authors: XHONGA‐OJA F. A. , SONNABEND E. , KRAPP H. 
Published: June 2007

SummaryThe study was conducted at two different dental school clinics. The summary of the questionnaires revealed that patients in both cities are similar in their dental needs and expectations of treatment.In order to solve the problem of losing patients from dental school clinics, several recommendations have been made.
Inaccuracies and defects in frameworks for removable partial dentures
Authors: EERIKÄINEN E. , RANTANEN T. 
Published: June 2007

SummaryWe studied the accuracy of 167 removable partial denture frameworks made in five commercial dental laboratories according to detailed instructions given by dental students, under the supervision of experienced teachers. Fewer than one half of the frameworks proved to be perfect. Some of the faults were accepted in the clinic, but 42% had to be corrected: 26% in the clinic, and 16% in the laboratory. Laboratory problems could be blamed for two‐thirds of the faults, and one‐third seemed to be attributable to the clinic. The advantages of, for example, new impression materials seemed to disappear under other factors.
Common migraine: a review and proposal for a non‐vascular aetiology
Authors: RUFF G. A. , MOSS R. A. , LOMBARDO T. W. 
Published: June 2007

SummaryA brief review of the literature related to migraine headaches is presented. Information is presented on the epidemiology and diagnostic criteria of migraine headaches and is followed by a discussion on the problems inherent in the current classification system. Previously proposed vascular mechanisms of common migraine are discussed in the light of recent non‐supporting data and a possible link between common migraine and orofacial pain dysfunction syndromes is proposed. The role of oral behavioural patterns and related muscular/ temporomandibular joint problems are advanced as probable factors related to common migraine. The discussion focuses on the need to distinguish classic from common migraine headache sufferers in assessment and treatment outcome studies, as well as suggesting future avenues of research.
Solid soliubility of tin in silver–mercury γ1 in dental amalgams
Authors: SARKAR N. K. , EYER C. S. 
Published: June 2007

SummaryThe solid solubility of Sn in γ1 has been studied by examining a series of γ1 samples containing 0.25–2.0 wt% Sn by scanning electron microscopy and energy‐dispersive X‐ray analysis. It has been observed that the addition of Sn to γ1 leads to the formation of mainly an intergranular Sn‐Hg compound. On the basis of this observation it has been concluded that the solubility if Sn in γ1 si virtually nil.
The amplitude distribution of electromyographic activity of masticatory muscles during unilateral chewing
Authors: HAGBERG C. 
Published: June 2007

SummaryThe amplitude probability distribution function (APDF) of electromyographic activity was used to describe the variation in relative masticatory force in the superficial masseter muscle and the anterior temporal muscle during unilateral chewing. The masticatory force, predicted from an isometric reference contraction, increased significantly in both muscles when chewing an almond compared to chewing half a stick of gum. Analysis of the distribution levels of contraction showed that the significant differences in relative masticatory forces were found for high levels of contraction. The individual variations were large when masticatory force between the muscles was compared. Maximal loading of the masseter muscle and the anterior temporal muscle exceeded 100% of the reference voluntary contraction in six females out of nine, mainly during chewing of an almond. The results indicated that APDF can be useful for analysing chewing when estimations of relative masticatory force and a measure of the distribution of different levels of contractions are desirable.
Post‐stimulus EMG complexes in the masseter muscle following gingival electrical stimulation in man
Authors: CARELS C. , VAN STEENBERGHE D. 
Published: June 2007

SummaryPost‐stimulus EMG complexes (PSECs) were elicited by means of electrical stimulation of the gingiva in six subjects during clenching in three biting positions, namely the maximal occlusion, the incisor edge‐to‐edge and the hyperpropulsive biting position. No interrelationship was found between the mechanically and electrically elicited PSECs. With electrical stimulation the PSEC morphology was not related to the biting position in contrast with the PSECs elicited with mechanical stimulation. Following gingival electrical stimulation, a P wave was not present in the PSEC.
Physiology and pathophysiology of skeletal muscle contractions
Authors: CHRISTENSEN L. V. 
Published: June 2007

SummaryAn overview is presented of the physiology and so‐called pathophysiology of static muscle contractions in the intact living organism. Static muscle activity produces no external mechanophysical work, but is used for fixation. Contingent upon the levels of the generated forces, and the duration of the isometric contractions, static activities give rise to fatigue and pains. The discomforts are viewed as somatic responses that are normally within physiological limits. That is, upon cessation of isometric contractions there is usually rapid recovery from the discomforts, and they do not normally induce chronic lesions.
Changes in masticatory movement parameters within the chewing period in young dentate persons and patients rehabilitated with bridges supported by implants in the mandible
Authors: JEMT T. 
Published: June 2007

SummaryExperiments were carried out to study changes in masticatory movements in the chewing sequence of young dentate persons and complete denture wearers rehabilitated with bridges on osseo‐integrated implants (OIB) in the lower jaw. Two test foods were used in the dentate group (apple, bread) and bread in the OIB group. A computer‐based opto‐electronic system (Selspot) was employed to record and analyse all single chewing cycles, regarding parameters reflecting, chewing rhythm, mandibular velocity and displacement. The different parameters were tested both intra‐ and inter‐individually versus the series of the single and overall chewing cycles in the masticatory sequences respectively. The results indicated that different subjects performed different patterns of mastication within the chewing period when chewing the same type of food. Different test foods (texture, size) also seemed to affect the chewing pattern in a different way, e.g. mandibular displacement showed an obvious reduction when chewing apple, probably due to the bigger size of the bolus. The inter‐ and intra‐individual analysis showed in some parameters discrepancies implying problems in analysing the chewing pattern within the chewing sequence without using both methods.
Six months clinical evaluation of prefabricated veneer restorations after partial enamel removal
Authors: JENSEN Ø. E. , SOLTYS J.L. 
Published: June 2007

SummaryThirty‐three preformed plastic laminate veneers were placed in maxillary anterior teeth of twenty‐one subjects. The indications for veneer placement were intrinsic staining of large conventional composite restorations or discolouration caused by previous endodontic therapy. The veneer restorations were evaluated clinically over a 6‐month period for retention, colour match, surface texture, marginal integrity and gingival response. Twenty‐nine restorations were available for evaluation at 6 months. Three restorations exhibited bonding failure during the study period, giving an overall retention rate of about 91%. Deep brown discolouration in two teeth could not be adequately matched with the opaquer and shader pastes supplied with the kit. Only one patient exhibited any change in veneer surface texture during the study period. Slight, but clinically inconsequential deterioration of marginal integrity was also noted in several restorations. The gingival response to the veneer restorations was uniformly excellent. It was concluded that restoration with preformed veneers, using the enamel reduction and heat adaptation techniques, provided an aesthetic, conservative and functional alternative to fixed prosthodontic therapy in selected cases.
Investigations on the relation of dysgnathias and S‐sound pronunciation
Authors: MEHNERT T. 
Published: June 2007

SummaryA registration‐form phonetic test has been developed which incorporates an established method for checking fine motor skills. Using an objective measuring and computing technique (electro‐acoustic sound analysis according to the sound‐seeking method), the author studied the pronunciation of the S‐sound of one group of eugnathic and three groups of dysgnathic test persons. There were significant differences in sound characteristics between the normal group and all groups with dysgnathia (P=0.001). Therefore it is considered that not every patient with an anomaly of the tooth position must have a disturbance of the S‐sound. In contrast to the relatively narrow variations in the normal group, in all groups with dysgnathia considerable dispersions were registered. The anterior open bite occupies first place with regard to its susceptibility to disturbances of the S‐sound. The statistical analysis of the partial energy values of all the S‐sound spectra revealed typical normal behaviour on the one hand, and characteristic differences between the groups with dysgnathia and the group with eugnathia on the other. The information which is most important for the valuation of the S‐sound are contained in the frequency area up to 9 kHz.
Periodontal disease in partial denture wearers—a biological index
Authors: WILDING R. J. C. , REDDY J. 
Published: June 2007

SummaryStudies on the adverse effects of partial dentures on the remaining tissues require both a yardstick of measurement to record the level of oral disease, and the use of controls, preferably within the same patient. A method was devised for pooling the individual values related to the level of periodontal disease on abutment and control teeth in partial dentitions. The difference in these combined values was expressed as the Biological Price. This value provided a useful means of evaluating partial denture designs and patient features, in attempting to assess the major contributing factors responsible for the Biological Price levied by the denture.Whilst wearing an acrylic partial denture at night adds to the price paid by the remaining tissues, the mechanical features of the partial denture, and the overall features of the patient and his remaining dentition appear to be insignificant in determining the Biological Price.
The prevalence of temporomandibular joint dysfunction in edentulous non‐denture wearing individuals
Authors: WILDING R. J. C. , OWEN C. P. 
Published: June 2007

SummaryThis study reports on the prevalence of temporomandibular joint dysfunction in a sample of fifty‐one edentulous non‐denture wearing individuals. In comparison with other studies using similar criteria, and considering the anomalous mandibular postures observed, this sample of patients appears to have a low prevalence of dysfunction. Loss of vertical occlusal height on its own may not be responsible for the temporomandibular joint dysfunction occasionally seen in denture wearers with reduced vertical height. The possibility that posterior occlusal wear producing incisal interference is an aetiological factor, is discussed.
Radiological findings in 1135 edentulous patients
Authors: KEUR J. J. , CAMPBELL J. P. S. , McCARTHY J. F. , RALPH W. J. 
Published: June 2007

SummaryA sample consisting of 1135 edentulous patients with clinically healthy denture bearing areas, was examined radiologically. It appears that the diagnostic yield is high whereas the expected radiation induced risk is low. Patients should therefore be examined radiologically prior to full denture construction.
The accelerative component of EMG in bite force development in man
Authors: WASTELL D. G. , DEVLIN H. 
Published: June 2007

SummaryMasseter EMG and bite force recordings were made from six subjects. Multiple regression analysis was performed and an equation produced relating EMG and bite force in SI units. Evidence is presented for a component of masseter EMG which can be related to the acceleration of bite force during onset of a clench.
Effect of clasp design on gingival health
Authors: BAZIRGAN M. K. , BATES J. F. 
Published: June 2007

SummaryA comparison has been made of the effects on the gingivae of occlusally and gingivally approaching clasps. The effect on the gingivae has been assessed by measuring plaque accumulation, crevicular temperature and microbial distribution in patients and students wearing appliances. Habitual and nil oral hygiene regimes have been used to demonstrate changes. It was concluded that the gingivally approaching clasp is potentially damaging.