摘要:

The size of maximal active movements of the mandible were studied in children in two age groups. The younger group consisted of 33 children, aged 1-2 years, in whom mouth opening was recorded using an indirect method. Highly significant differences were found between 3 recordings with the third recording having the largest mean, 38.4 mm.The older group consisted of 75 boys and 75 girls, aged 6 years. None of them had pain or severe symptoms of dysfunction of the masticatory system. The mean maximal opening was 44.8 mm. The means found for maximal lateral movement to the right and to the left and for maximal protrusion were each about 8 mm. No differences in vertical or horizontal movements were found between the sexes. The mobility of the mandible varied greatly inter-individually, but as the various movements were highly significantly correlated in both boys and girls, the value found for one movement must be evaluated in relation to the sizes of the other movements.The ranges within which a pair of observations of maximal mandibular movements in a healthy 6-year old child may be expected to fall with 95% probability were calculated and presented graphically. Repeated recordings of maximal opening are recommended for children.

ISSN:0001-6357    

DOI:10.3109/00016357409002543

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor

摘要:

Thermal percolation has been considered a cause of a number of the flaws occurring in connection with resin fillings. However, in fillings expanded against the cavity walls by water absorption, elastic stresses counteract the formation of marginal gaps. The purpose of the present work was 1) to study the relationship between temperature reduction and size of marginal gaps and 2) to investigate the effect of a rise in temperature on the gaps formed under subsequent cooling. Fillings made in extracted human teeth were studied. The brands investigated were Adaptic, Blendant, Concise, Opotow, Sevriton Simplified, and Swedon. After closure of the initial gaps by water absorption expansion the fillings were polished and examined microscopically under water. Marginal gaps between filling and tooth were measured between 37 and 2°C. The effect of a rise in temperature was investigated by heating the fillings to SO or 60°C, with subsequent measurement of gap size at 2°C. It was found that the fillings could be cooled through a certain temperature range without marginal gaps being formed. The size of the gaps at 2°C was but little affected by previous heating to 50°C. Heating to 60°C increased the gap size at 2°C only in unfilled resins.

ISSN:0001-6357    

DOI:10.3109/00016357409002544

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor

摘要:

Guinea pigs were immunized with autologous serum exposed to chlorhexidine gluconate. Injections were given every second day for one week. After four weeks the animals were given a booster-dose and were tested for antibodies using the cutaneous anaphylaxis test. The titre of chlorhexidine-treated serum showing a positive reaction was 1: 1000 in immunized animals. Control animals showed positive reaction in a dilution of 1: 10 but negative in 1: 100.

ISSN:0001-6357    

DOI:10.3109/00016357409002545

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor

摘要:

A twin investigation was carried out to elucidate the influence of heredity in the development of bruxism. The material consisted of 117 pairs of twins of four age classes, average age 12.1 years, in the county of Västerbotten. Zygosity was determined using blood group serological methods. Bruxism was diagnosed by recording bruxo facets. Occlusal interferences and palpation tenderness in certain masticatory muscles were also recorded.The results show that monozygotic twins have a statistically significant higher frequency of the same facet pattern than do dizygotic twins. It was not established that heredity influences the occurrence of occlusal interferences or muscle tenderness. The study supports the hypothesis that hereditary factors are important to the genesis and pattern of bruxism.

ISSN:0001-6357    

DOI:10.3109/00016357409002546

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor

摘要:

Prosthodontic appliances, especially two types of fixed bridge-work, were simulated by means of 7 series of bar elements, cast in a gold alloy. Elastic deformation studies were made in a bench installation. Double exposure holographic interferometry was performed using a continuous helium-neon laser in which forces applied to the bar elements were increased between exposures. The effect of force increases up to 1.5 N could be determined by analyzing the resulting interference fringe patterns. In all, 170 double exposed holograms were evaluated and photographically documented. Differences in the deflection characteristics of the bars were studied with the aid of two composite histograms. Variations in the elastic deformation could be traced to technical reasons, such as the casting technique and the presence of soldered and screw-locked joints. The stiffening effect of internal ivory cylinders simulating teeth prepared as full-crown abutments was proved. The sensitivity of the method as well as the measuring range depend on the wave-length of helium-neon laser light (0.6328μml).

ISSN:0001-6357    

DOI:10.3109/00016357409002547

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor

摘要:

This study describes the frequency of hypodontia among all the children of the same age group in a Norwegian municipality and reports variations of some dimensions of the dentition associated with hypodontia. Congenitally missing permanent teeth, not including third molars, were found in 7.1 per cent of the material at age seven, and in 6.6 per cent at age nine. The difference seemed to be due to insufficient mineralization of the second lower premolars in boys at age seven. The frequency of hypodontia per se was a little higher in girls than in boys, and the girls were missing more teeth per individual. Neither the dental arch width nor the mesiodistal diameter of the teeth were significantly different in the hypodontia group compared to a control group without hypodontia.

ISSN:0001-6357    

DOI:10.3109/00016357409002548

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor

ISSN:0001-6357    

DOI:10.3109/00016357409002549

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor