摘要:

This report describes the alignment condition and incisal wear of the anterior teeth in individuals 16–19 years of age. Tooth alignment and incisal wear were assessed on casts in accordance with two index systems NONAT (non‐aligned tooth) and IwI (incisal wear index). Tests of the methods showed that the reproducibility of the assessments of tooth alignment and incisal wear were satisfactory. The results of the study of tooth irregularity demonstrated that the prevalence of non‐alignment of one or more of the anterior teeth were much the same (∼50%) for the maxillary and mandibular jaws. The highest frequency was found for the maxillary lateral incisors and the mandibular central incisors (∼45%). A relationship between the alignment conditions and incisal wear of the anterior teeth was established. It appeared that non‐alignment of one or more teeth in one or both jaws was associated with less severe incisal wear of the anterior teeth. This was most pronounced for non‐aligned maxillary central incisors and non‐aligned mandibular c

ISSN:0305-182X    

DOI:10.1046/j.1365-2842.1996.00428.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

The aim of this study was to document the number of remaining natural teeth, to examine the prosthetic rehabilitation and to evaluate further prosthetic treatment needs among a representative sample of 76–86‐year‐old inhabitants of Helsinki. The edentulous made up 46% (168) of the subjects, 40% of the men and 48% of the women. Of these edentulous, 94% (158) wore complete dentures in both jaws, 2% wore only a maxillary denture, and 4% wore no dentures at all. One edentulous subject had an implant‐supported overdenture in the lower jaw. More than half (54%) of all subjects had 1–32 natural teeth left. These dentate subjects had 47% (mean 13·2, excluding the wisdom teeth) of their natural teeth remaining. Of the remaining teeth, 13% (mean 1·8) were crowned and 5% (mean 0·6) were indicated to be extracted. Among the dentate, 37% (mean 10·4) of their natural teeth were missing and replaced by some type of fixed or removable prosthesis. Eleven per cent (mean 3·1) of missing teeth had not been replaced and were considered not to need prosthetic replacement. However, 5% (mean 1·3) of the missing teeth without prosthetic replacement were judged to need a prosthesis. Among the dentate, 37% wore a complete denture in one jaw; 34% of the dentate subjects used acrylic removable partial dentures (ARPD), and 19% used metallic removable partial dentures (MRPD). Of the dentate, 45% had crowns and fixed bridges. Altogether, 25% wore some kind of combination of fixed and removable prosthesis, whereas 14% had no type of prosthetic rehabilitation at all. The age of the current prosthesis varied from less than one year to over 50 years. Of all the subjects, 37% (6% of the edentulous and 63% of the dentate) had experienced inadequate prosthetic

ISSN:0305-182X    

DOI:10.1046/j.1365-2842.1996.00420.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

The effect of adding two bisguanide antimicrobial agents (chlorhexidine and PHMB) on some physical properties of the light‐cured periodontal dressing material Barricaid®are reported. The physical properties tested were elastic modulus, initial and 10 min recovery strains, and tear stress. The addition of both chlorhexidine and PHMB solutions reduced the elastic modulus as did water. The addition of PHMB to Barricaid®produced greater initial recovery in the strain test than either the addition of chlorhexidine or water, but there were no differences between the treatments after 10 min. Tear stress was also reduced by the addition of water and the chlorhexidine and PHMB solutions. These results suggest that as far as the physical properties of Barricaid®are concerned the addition of the antimicrobial agent PHMB had no long‐term advantages over chlorhe

ISSN:0305-182X    

DOI:10.1046/j.1365-2842.1996.00433.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

This study was performed to assess the prevalance of signs and symptoms of temporomandibular disorders (TMD) in patients with cervical spine disorders (CSD) and to compare patients with CSD and subgroups of patients with TMD with regard to the results of orthopaedic tests of the stomatognathic system. A group of 103 consecutive patients with signs and symptoms of CSD and a group of 111 consecutive patients with TMD were examined. All subgroups of TMD patients showed a significantly smaller range of motion than the CSD patients. Patients with TMD had limited mouth opening (<40 mm) on active and passive mouth opening more often than CSD patients. TMD patients with myogenous problems reported oral habits more often than CSD patients, although no objective differences between CSD and TMD patients were found. Subgroups of TMD patients reported joint sounds, and pain on palpation and joint play tests of the temporomandibular joint (TMJ) more frequently than CSD patients. Joint sounds on active movements, pain on palpation of the TMJ, and pain on joint play tests correctly classified 82% of the patients with TMD and 72% of the patients with CSD. In spite of the biomechanical and anatomical relationship between the neck and the stomatognathic system, the results of the study show that CSD patients have signs and symptoms of TMD comparable with those of the adult Dutch population. It was concluded that the function of the masticatory system should be evaluated in patients with neck complaints in order to rule out a possible involvement of the masticatory system.

ISSN:0305-182X    

DOI:10.1046/j.1365-2842.1996.00427.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

This study was performed to assess the prevalence of signs and symptoms related to cervical spine disorders (CSD) in subgroups of patients with temporomandibular disorders (TMD) and to compare TMD patients and CSD patients with regard to the results of orthopaedic cervical spine tests. One hundred and eleven consecutive patients with TMD and 103 consecutive patients with signs and symptoms of CSD were examined. The results indicated that there is a considerable overlap in the signs and symptoms of patients with TMD and patients with CSD. Signs and symptoms on neck extension occurred more often in CSD patients than in subgroups of TMD patients. No significant differences in upper cervical extension, neck flexion, and shoulder girdle function were found between CSD patients and subgroups of patients with TMD. Patients with CSD reported neck pain during active and passive movements of the neck more often than the subgroups of patients with TMD. TMD patients and CSD patients did not differ with regard to pain on shoulder girdle function and palpation of the shoulder girdle. Logistic regression analyses showed that orthopaedic tests of the cervical spine are of minor importance in discriminating between patients with TMD and patients with CSD. It is concluded that TMD with a myogenous involvement in contrast to TMD with only an arthrogenous involvement should no longer be viewed as a local disorder of the stomatognathic system. The upper quarter, including the stomatognathic system, cervical spine, and shoulder girdle, should be evaluated in patients with more complex or persistent symptoms in the head and neck region.

ISSN:0305-182X    

DOI:10.1046/j.1365-2842.1996.d01-187.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

A filler for a urethanedimethacrylate composite was silanated with mixtures of fluoroalkyl‐, aminoalkyl‐, phenyl‐, vinyl‐, bis silyl ethane‐ and 3‐methacryloxypropyltrimethoxysilane (MAOP) in an attempt to increase the hydrophobicity of the coupling agent layer. Diametral tensile strength was used to evaluate composites stored for (1) 24 h in 23°C (RT) air; (2) 24 h in RT air plus 24 h in 100°C air; (3) 24 h in RT air plus 24 h in 100°C water; and (4) 24 h in RT air plus 24 h in 100°C air plus 24 h in 100°C water. Water sorption and solubility of composites was also determined on samples stored for 24 h in RT air. Heating composites for 24 h in 100°C air increased the tensile strength in eight of 13 silane treatments, while heating in 100°C water for 24 h caused decreases for five silane treatments, no change for six and increases in tensile strength for two silane treatments. When composites that had been stored for 24 h at RT plus heated for 24 h in 100°C air were then heated for 24 h in 100°C water, only one silane treatment, the vinyltriethoxysilane at 25% (25% V), showed no significant decrease in tensile strength. Also, the composite silanated with 25% V had the highest value for tensile strength after storing for 24 h at RT air plus 24 h in 100°C air plus 24 h in 100°C water. These data indicate that the use of vinyltriethoxysilane increases the hydrolytic stability of the composite. Water sorption and solubility of the silanated composites were not satisfactory tests for evaluating hydrolytic s

ISSN:0305-182X    

DOI:10.1046/j.1365-2842.1996.d01-194.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

The design of dental superstructures influences the loading on dental implants and the deformation of the anterior interforaminal bone in an edentulous mandible. This deformation causes stress in the bone around the implants and may lead to bone resorption and loss of the implant. The stress distribution around dental implants in an edentulous mandible was calculated by means of a three‐dimensional, finite‐element model of the anterior part of the jaw. This model was built from data obtained from slices of a single human mandible and was provided with four endosseous implants in the interforaminal region. The implants were either connected with a bar or remained solitary. The solitary implants or the bars were loaded either uniformly or non‐uniformly. In case of a non‐uniform distribution, either the central bar or the central implants were loaded or the lateral bars or the lateral implants were loaded. The most extreme stresses in the bone were always located around the neck of the implant. In the case of the uniform distribution of the loading there were more or less equal extreme principal stresses around the central and lateral implants. If the load was not uniformly distributed on the superstructure then the implant that was nearest to the place of loading showed the highest stress concentration; with connected implants there was a reduction in the magnitude of the extreme principal stresses compared to solitary i

ISSN:0305-182X    

DOI:10.1046/j.1365-2842.1996.d01-185.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Rehabilitation of the oral cancer patient should aim to achieve not only morphological restoration but also post‐operative functions. However, there are few reports describing quantitative evaluation of the latter. The authors have attempted quantitative evaluation of post‐operative articulatory function after glossectomy, and report the evaluation of it by speech intelligibility, electropalatography (EPG), and acoustical analysis. Subjects were five directly sutured patients and five patients reconstructed with forearm flap, all after glossectomy. The target syllable was /ta/ from among speech intelligibility test samples. The speech intelligibility and acoustical analysis were investigated pre‐operation, and 1, 6 and 12 months post‐operation. EPG data were collected by DP‐01(RION) at 6 months post‐operation. Acoustical analyses were carried out by consonant frequency characteristics and formant variance from consonant to vowel transitions. As a result, subjects reconstructed with a forearm flap showed higher restorative tendency than directly sutured subjects. Articulatory characteristics expected from acoustical analysis were more in agreement with the results of EPG than with the results of the speech intelligibility test. From the results, it was suggested that the acoustical analysis used for this research could reveal changes in articulatory movement and will be useful for quantitatively evaluating post‐operative articulat

ISSN:0305-182X    

DOI:10.1046/j.1365-2842.1996.d01-186.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Several papers have recently appeared in the literature questioning the usefulness of surface EMG in the management of temporomandibular dysfunction (TMD) patients. One of the concerns is the stability of EMG over time in any one patient. This study was undertaken on normal subjects to determine the level of surface EMG stability over time using a variety of spectral analysis parameters. Four male and seven female subjects, ranging from 24 to 38 years of age, were selected for the study. All subjects had class I occlusions, intact dentition and no history of TMD. Oral and perioral hard and soft tissues were within normal limits. EMG data from the bilateral masseter muscles were obtained during four states of jaw activity: rest, right‐sided chewing, left‐sided chewing, and 50% maximal clench. Three sets of recordings were obtained in each study session. Three 10‐min study sessions were obtained for each subject. Six measures, which included SP‐50, central frequency, band width, effective band width, zero crossings and power spectrum, were analysed to assess their reliability and sensitivity over time during the several states of jaw activity. The conclusion of the study was that bilateral masseter EMG band width, effective band width, and power spectrum in normal humans are all reliable enough to be stable over a 6 week period, and sensitive enough to differentiate among jaw rest, right chewing, left chewing and 50% clench; power spectra being the most se

ISSN:0305-182X    

DOI:10.1046/j.1365-2842.1996.d01-192.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

The aim of this study was to determine peak temperatures of some prosthetic acrylic resins at the time of polymerization. The acrylic resins included two temporary restoration resins, three autopolymerizing resins for different applications and one heat‐cured denture base resin. The peak temperatures were measured with a ferro‐constantan thermocouple from test specimens of three different volumes at different temperatures. The results revealed that with increasing volume of polymerizing acrylic resin the peak temperature also increased. In general, acrylic resins for temporary restorations had lower peak temperatures than other acrylic resins. However, despite the lower peak temperatures, the temperature of temporary restoration resins during polymerization can be as high as 82°C. Therefore, to minimize thermal injuries of the tissues of vital tooth, dentists must be aware of the heat formation of the acrylic resins used in the oral ca

ISSN:0305-182X    

DOI:10.1046/j.1365-2842.1996.00430.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY