摘要:

SUMMARYThe purpose of the present study was to compare the vertical change in the incisor and molar areas caused by insertion of a bite opening appliance and to analyse the occurrence of rotation and eruption during the following treatment period (mean 4.3 months). Eight patients between 15 and 24 years of age with vertical overlaps ≥ 4mm were treated by means of a maxillary fixed lingual arch appliance with an anterior bite plane. The retruded mandibular position was recorded with cold cure acrylic before treatment, immediately after insertion of the fixed appliance, and after removal of it. Vertical overlap and separation between the first molars was measured at each of these occasions. Finally, tooth movements during eruption were measured on the indices in the area of the second molar. The results showed that, independent of the amount of bite raise, the relation between frontal and molar area bite raise was approximately 2:1 for six and 5:3 for two patients. There was a significant difference in thickness of indices from registrations I and III in the second molar area indication not only eruption during bite opening therapy but also buccolingual rotatio

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00081.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SUMMARYThe alveolar bone height in a total of 713 15–16‐year‐old children consisting of 364 males and 349 females was assessed using posterior bitewing radiographs. The distance between the alveolar crest (AC) and amelo‐cemental junction (ACJ) on all molar and premolar teeth was determined from magnified images of the radiographs. Analyses of variance models were fitted in order to assess the dependence of the overall ACJ to AC distance on the inter‐subject variables of gender and social class and the intra‐subject variables of site, missing adjacent tooth, condition of the approximal tooth surface, and for mesial surfaces, gingivitis and pocket depth. The overall geometric mean for bone height for the whole population was 0.542mm. The ACJ to AC distance for the vast majority of sites was below 2 mm. Site had a highly significant effect on bone height (P≤ 0.001): ACJ to AC distances were greater in the maxilla compared to the mandible (P≤ 0.001), greater for distal sites compared to mesial (P≤ 0.001) and significantly affected by tooth type (P≤ 0.001). Sites with missing adjacent teeth also had significantly increased distances (P≤ 0.001). The condition of the approximal tooth surface and the presence of pocketing or gingivitis did not have a significant association with bone height. The geometric mean AC to ACJ distance, adjusted for subject, site and social class was 0.577mm for males and 0.506mm for females (P≤ 0.001), but the main effect of social cl

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00082.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SUMMARYThe aim of this study was to establish (i) the causes and effects of void space formation in acrylic‐glass fibre composite material; and (ii) to clarify the effect of polymerization time of acrylic resin on the transverse strength of heat‐cured acrylic resin test specimens. In study I, three transverse sections of the continuous glass fibre reinforced test specimens (n= 48) were studied by a scanning electron microscope (SEM) and the SEM‐micrographs were analysed by a computerized picture analyser. The results suggested that the void space inside the test specimens is caused by a lack of the adsorbed monomer liquid in the fibre bundle before polymerization. The correlation coefficient between these two factors was –0.633 (P≥ 0.001). No correlation was found between the void space of the acrylic‐glass fibre composite and the transverse strength of the test specimens (r= 0.000,P= 1.000). The results of study 2 showed that the transverse strengths of test specimens (n= 240, total) subjected to polymerization of different time spans did not vary significant

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00083.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SUMMARYThe maximal interincisal distance added to the vertical overlap is generally used as a measure for temporomandibular joint mobility. However, the length of the mandible also has an influence on this measure. The angle of mouth opening as a measure of temporomandibular joint mobility is independent of the length of the mandible. The aim of the study was to develop a mandibular goniometer to measure the angle of mouth opening and to test its realiability. Ten subjects, two males and eight females (mean age 28.1 years) participated in the study. The measurements were performed during four independent sessions of three measurements each. The results were analysed with ANOVA. Intraobserver variability was found to be 2–0° when the result of all the measurements were analysed, and were found to be 1–2° when the mean value of the sessions were used for analysis. Based on the results of this study it can be concluded that the angle of mouth opening canbe measured rel

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00084.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SUMMARYRadiographic signs in the temporomandibular joints (TMJs) and finger joints were investigated in a series of 139 residents of elderly people's homes using panoramic tomographs and dorso‐volar radiographs. Radiographic signs in TMJs were found in 14% of the subjects, whereas all subjects had signs in at least one finger joint. The TMJs of men and women were equally affected, whereas signs in finger joints were more severe in women. No correlation was found between radiographic signs in TMJs and finger joints, suggesting that most signs in TMJs are probably due to local factor

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00085.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SUMMARYAbrasive wear testing of five restorative materials was carried otu with human enamel as the opposing surface using a wear machine specifically designed to simulate the masticatory cycle. The results showed that enamel demonstrated good abrasion resistance against amalgam and microfine composite and moderate abrasion resistance against gold. Conventional composite produced marked destruction of enamel and the greatest amount of enamel wear was produced by porcelain. The ranking order compared favourably with results fromin vivostudies.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00086.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SUMMARYAnin vivoanimal (goat) mandibular bone model has been evaluated for the cortical and trabecular bone response to biomaterials with different elastic modulus and/or different surfaces. The effect of the elastic modulus on the bone formation was also studied. The difficulties encountered in orientation of the implants probably could have been surmounted if pre‐operative radiographs has been available. It was also established that there is a large variance in the amount of trabecular and cortical bone in the mandible of the goat‘one mod

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00087.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SUMMARYAn epidemiological study was conducted to investigate the relationship between craniomandibular dysfunction and oral parafunctions in 386 children aged 6–10 years with and without unpleasant life events. The results showed statistically significant correlations between grinding, clenching, lip/cheek biting and muscle tenderness or pain, and clicking in subjects without unpleasant life events. Also, significant correlations were found in the same group between these parafunctions and difficulties in opening wide and pain on movements. When the definitional symptoms of craniomandibular dysfunction were aggregated, the chi‐square test revealed significant correlations between them and the same oral parafunctions. The correlations in subjects with unpleasant life events between grinding, clenching, lip/cheek biting and each sign and symptom of craniomandibular dysfunction were close to the significance level. No significant correlations were detected between the definitional symptoms and these parafunctions in this group. The present study suggests that in patients without unpleasant life events grinding, clenching, and lip/ cheek biting cannot be considered ‘necessary’ but can be ‘sufficient’ cause for the development of craniomandibular dysfunction. In subjects with unpleasant life events the origin of signs/symptoms of the dysfunction can be attributed to muscle tension or to another unknown aetiolog

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00088.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SUMMARYWe examined the influence on temporal aspects of three consonants, /k/, /c/ and /s/, of alterations in the oral environment produced by either palatal augmentation or by an increase in the vertical dimension of occlusion. Voice onset time (V.O.T.) for /k/ and /c/ was influenced more than aspiration time by the palatal augmentation. Consonant duration for /s/ was also influenced by palatal augmentation. Significant influence of an increase in vertical dimension on the timing was not recognized. Speech disorder caused by the malformation of palate seems to be more frequent than that caused by vertical dimension. Adaptation to prostheses would seem to be definitely concerned with orosensory feedback.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00089.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SUMMARYA mechanical model (link quadrilateral bell crank) is used to demonstrate the equilibrium of normal force vectors transmitted to the masticatory system and maxillary occlusal biteplane splints with different designs. Occlusal contacts were imposed on the proposed models under the action of a masticatory force vector with an arbitrary value of 40 kgf. The consequence of this force action created different responses within the joint and at the level of the dentition. When compared to the intercuspal position in centric occlusion, intra‐oral appliances with either smooth contacting surfaces or indentations, both with increased vertical dimension, forced the mandible to assume an anterior position with a con‐ current increase of joint forces. The bite‐splint that produced the least amount of joint force was the stabilization type with minimal increase of vertical dime

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1995.tb00090.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY