摘要:

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

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1985.tb01291.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SummaryTen subjects performed deliberate right and left‐sided chewing of gum, each exercise with a duration of 60 s, followed by maximum voluntary teeth clenching (MVC) until onset of pains in the masseter muscles (pain threshold). Contractile activities of the right and left masseter muscles were assessed by integrated and cumulative surface electromyography (EMG). When the right and left muscles functioned as chewing side muscles only, they generated practically identical levels of chewing force; the same applied when they functioned as non‐chewing side muscles only. During identical functions, EMGs suggested identical motor unit recruitment and firing patterns in the two paired muscles; i.e., units producing relatively high tensions for chewing side activity, and other units producing relatively low tensions for non‐chewing side activity. During isometric MVC activity, until onset of pains, the right and left muscles generated practically identical levels of bite force, but right and left motor unit activity patterns seemed to differ. Right and left motor units might have fired at different rates or begun to drop out at different times. In the latter case, rapidly before slowly fatigued units. There was a tendency for a low pain threshold with high chewing side activity in both masseter muscles. Motor units producing high levels of tension, but easily fatigued, might have caused early onset of muscle pains. No relationships could be established between preferred chewing side and side of initial muscle pains, nor between MVC activity and side of pain onset and preferred chewing

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1985.tb01292.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

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 measuredin vivoin 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 presen

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1985.tb01293.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SummaryMaximal mouth opening, translatory condylar motion (radiographically assessed) and bite force in sixteen adults with rheumatoid arthritis and radiographic temporomandibular joint abnormalities were compared with data from sixteen individuals without joint disease. Mean mouth opening in the arthritis group was reduced, but not statistically significant. Condylar translation and bite force showed significantly lower values than in the healthy individuals. Maximal mouth opening seemed to be the most uncertain parameter for the estimation of jaw function. In seven patients with a normal mouth opening (40–46 mm), both the condylar translation and the bite force were significantly impaire

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1985.tb01294.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

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 adjustmen

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1985.tb01295.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SummaryA sample of 575 palatal casts was studied and found to possess varying degrees of papillary convolutions between and around the palatal rugae. No palatal appliances were worn and no irritative influence was present. A classification of 1–4 was established and the peak incidence was Class II at 48.4% (Class I, being an absence of papillarity, was 7.3%). It is postulated that the presence of a denture may well cause an inflammatory papillary hyperplasia to arise not by a progression through the various stages of denture stomatitis but directly, in an individual with a papillary palat

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1985.tb01296.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SummaryA three‐dimensional photoelastic model was reproduced from a human skull. The insertions of the superficial and deep portions of the masseter muscle, the temporalis muscle, the medial pterygoid muscle and the temporalis fascia were simulated with leather bonded to the appropriate areas. The following loading conditions were employed: (i) all three muscles were bilaterally loaded without occlusal loads; (ii) all three muscles were bilaterally loaded while occlusal loads were simultaneously applied on the maxillary teeth. The stress freezing technique was used to lock the resulting stress patterns into the model skull. The stress trajectories were observed and photographed in a circular polariscope.The mandibular closing muscles and the occlusal loads produced stresses which progressed through the maxilla, following a nasal, a zygomatic and a pterygoid route, while stress concentrations were seen in the frontonasal, zygomaticomaxillary and the pterygopalatine sutures. In the malar bone area the stresses were seen to branch superiorly to the frontozygomatic suture and posteriorly along the zygomatic arch to the zygomaticotemporal suture and the temporal bone. Generally, the stresses were concentrated in those areas of the skull where architectural reinforcement had been demonstrated by other method

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1985.tb01297.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

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 muscl

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1985.tb01298.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SummaryIn this article the results are presented of an evaluation of crowns and bridges in a general practice. The study includes 601 solitary crowns, 213 crowns on bridge abutments and 103 crowns on RPD abutments. In total eighty‐four bridges were examined. All these restorations were constructed during a period of 11.5 years. By means of the Kaplan‐Meier method a prognosis is given of the life span of the different solitary crown‐types over periods between 1 and 11 years. The total amount of failures and follow‐up treatments on bridge and RPD abutments was very small. The authors also examined whether the bridges were constructed according Ante's law. A follow‐up of this study in other Dutch general practices in combination with experimental clinical trials is

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1985.tb01299.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1985.tb01300.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY