摘要:

Some physico‐chemical properties of the enamel of deciduous and permanent (young and old) teeth were investigated and compared using x‐ray diffraction, infrared absorption spectroscopy, scanning electron microscopy and chemical analyses. Results demonstrated the following: all enamel samples gave x‐ray diffraction patterns of only apatite; all enamel samples gave IR absorption spectra of carbonate‐containing apatite; the α‐axis of deciduous enamel apatite was larger than that of permanent (both young and old) enamel apatite (mean values, deciduous = 9.458 ± 0.003A; permanent =9 443 ± 0.003A); apatite crystallite dimensions increased with age especially along thec‐axis; when compared to permanent, deciduous enamel contained slightly more carbonate, magnesium and HPO42‐; the prism (enamel rods) dimensions were slightly smaller, and the extent of acid‐etching was more extensive in deciduous enamel than in permanent enamel. These observations combined with other factors such as the difference in the orientation of and crystal density in prism rods and the difference in conditions of the oral environment between deciduous and permanent enamel may account for the reported observations of a decrease in caries p

ISSN:0734-0664    

DOI:10.1111/j.1741-2358.1983.tb00341.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

The present study describes the age changes to the microvasculature and connective tissue interstitium of the osteons and periosteums of aged human mandibles and maxillae. The mandibles and maxillae obtained from 14 and 19 year old males, respectively, were also studied. In the nutrient canals of the aged osteons, the walls of the arterioles and venules stained intensely PAS positive, and alcian blue negative. The walls of the blood capillaries were thick and strongly PAS positive. There was a deposition of PAS positive material in the connective tissue stroma of the nutrient canals which progressed to the obliteration of the canal space. Many of the nutrient canals exhibited diffuse calcification within the connective tissue interstitium localized around the blood vessels. The lacunae and canaliculi of those osteons in which the nutrient canals were partially or completely obliterated were filled with PAS material. None of these histochemical changes were seen in the osteons of young individuals. The microvasculature of the aged periosteum showed similar changes. The periosteal tissue consisted of thick collagenous bundles and few osteogenic cells. There was a thin darkly stained amorphous calcified layer forming the bone surface.

ISSN:0734-0664    

DOI:10.1111/j.1741-2358.1983.tb00342.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Lysyl oxidase activity and the extractability of recently synthesized collagen were measured in gingiva and skin, two tissues which exhibit altered pathophysiologic responses during diabetes. Both tissues showed a reduced content and extractability of newly synthesized,14C‐Hydroxyproline labeled, collagen after induction of streptozotocin‐induced diabetes. Diabetes increased lysyl oxidase activity in skin and gingiva but the effect on gingiva was much less dramatic. The altered characteristics of interstitial collagen in the diabetic rat, including aging‐like changes, appear to reflect multiple alterations in collagen metab

ISSN:0734-0664    

DOI:10.1111/j.1741-2358.1983.tb00343.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

A method of analyzing facial proportions in evaluating occlusal vertical dimension was used in a test on 71 complete denture wearers aiming to find a way to rank denture wearers with different stages of reduced vertical dimension and development an instruction for patients' self judgment. By use of face drawings on a proforma the patients ranked themselves into one of four classes. The investigator also ranked the patients into these classes. There was a significant correlation (p<0.01) between the ranking by patient and investigator. The face proportions were also measured with an instrument. The distances nasion‐rima oris and subnasale‐gnathion were established. When ranking into classes, there was a significant (p<0.0001) correlation between the ranking by the investigator and the measurements. The results show that it may be possible to use information of facial proportions to give complete denture wearers a way of assessment of face height and thus a reason to consult a dentist in case of suspicion of reduced vertical dimens

ISSN:0734-0664    

DOI:10.1111/j.1741-2358.1983.tb00344.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

ISSN:0734-0664    

DOI:10.1111/j.1741-2358.1983.tb00345.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

ISSN:0734-0664    

DOI:10.1111/j.1741-2358.1983.tb00346.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY