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Biomedical subjects

A Wenzel

Publications and source records attributed to A Wenzel.

216 records · Page 12Linked to original sources
PubMed1982

The relationship between water-borne fluoride, dental fluorosis and skeletal development in 11-15 year old Tanzanian girls.

Dental fluorosis was evaluated by a classification system, previously shown to be sensitive, and skeletal changes evaluated by bone maturity and structure. Dental fluorosis was more severe in posterior than in anterior teeth in both jaws irrespective of fluoride concentration of the drinking water. There appeared to be no dependence between fluoride content of the water and skeletal maturity or structure, but there was a definite relationship between the degree of dental fluorosis and skeletal maturity within the high fluoride area. Fluoride concentrations in the drinking water above 3 parts/10(6) seemed to affect all mineralizing tissues under formation. The unique pattern of enamel formation and mineralization renders it the only hard tissue which permits an early diagnosis of the biological effect of even low fluoride doses on the human body.

Adolescent↗
PubMed1982

Skeletal development and dental fluorosis in 12--14-year-old Danish girls from a fluoride and a non-fluoride community.

The present study has examined the relationship between waterborne fluoride, dental fluorosis and skeletal maturity in two Danish areas containing less than 0.2 and 2.4 parts/10(6) F- in the drinking water. 12--14-year-old girls, 113 from the non-F- area and 122 from the F- area, born and raised in the areas, were examined. No relationship could be found between skeletal maturity and fluoride content of the drinking water. The association between the severity of dental fluorosis and skeletal maturity in the girls from the F- area was not statistically significant, but the tendency followed the same pattern as observed in tropical high and low fluoride areas.

Adolescent↗
PubMedDate not supplied

[Transcatheter occlusion of the persisting arterial duct].

BACKGROUND: Transcatheter occlusion of the persisting arterial duct (PDA) is feasible using different techniques like coil-embolization (CE), Rashkind PDA occluder (Rash), Amplatzer Duct Occluder (ADO). Comparative studies with this devices in relation to the size of the PDA and the device are missing. Aim of this study was to evaluate the different systems at the own patient population. PATIENTS AND METHODS: From 1993 to 12/2001 transcatheter occlusion was attempted in 92 patients aged 4,13 years (range 0,07 to 14,39 years) using CE, Rash or ADO. All patients received echocardiographic examinations 24 hours before and after intervention, after 3, 6, and 12 months and than yearly. RESULTS: 91/92 PDAs could be successfully closed by 97 interventions. There were 63 CE, 25 Rash and 9 ADO performed. Primary closure rate was 75 % for Rash, 80 % for ADO and 80,8 % for CE (n. s.) and after 6 months 88 % for Rash, 92,3 % for CE and 100 % for ADO (p < 0,001), although the size of the PDA increased significantly from CE (2,14 + 1,1 min) to Rash (3,2 +/- 1,3 min) to ADO (4,9 +/- 1,9 min) (p < 0.05). In 6/7 pts with residual shunts complete occlusion could be achieved by second intervention. CONCLUSION: In dependency of the size of the PDA and the right choice of the occluder almost all PDAs are closable with transcatheter techniques.

Cardiac Catheterization↗
PubMedDate not supplied

Skeletal maturity in 6-16-year-old Danish children assessed by the Tanner-Whitehouse-2 method.

A study of skeletal maturity was conducted in 1100 healthy Danish children at ages 6-16 years. The children were selected in a random manner reflecting a cross-section of socio-economic levels in Denmark. Skeletal maturity was assessed according to the method of Tanner and co-workers (TW-2, 1975). The results confirmed that the TW-2 method is well suited for the evaluation of skeletal maturity in Danish children. The RUS-score, however, was about six months advanced in Danish boys aged 14-15 and girls aged 12-15. A similar pattern has been reported for other groups of Danish children by Helm (1979). The present results revealed no relationship between skeletal maturity and socio-economic class.

Adolescent↗
PubMedDate not supplied

Skeletal maturity in Austrian children assessed by the GP and the TW-2 methods.

Skeletal maturity was assessed in 637 Austrian children from 7 to 16 years of age. The Greulich - Pyle and the Tanner- Whitehouse -2 ( RUS and TW 20-bone) methods were used. The GP ages showed some major deviations at and after puberty, especially in boys. The RUS and 20-bone ages conformed more closely to the standards although a general advancement in RUS ages was seen in girls after the age of 10 1/2. A similar pattern in RUS ages has been reported for other populations and may indicate a secular trend.

Adolescent↗
PubMedDate not supplied

Dental and skeletal maturity in adoptive children: assessments at arrival and after one year in the admitting country.

Seventy-one adoptive children from Asian countries, mainly Korea, were adopted by Danish parents. Height and weight were measured and dental and skeletal maturity assessed immediately after arrival and one year later. Increase in dental age was in complete concordance with the time interval between the two examinations. With regard to skeletal age, the majority of children showed an increased maturation rate although some of the youngest children seemed to be further retarded in maturation rate during their first year in Denmark. Comparison between two methods for assessing skeletal maturity revealed that the 'catch up' observed for children above one year of age was significantly more pronounced when assessed by the TW-2 method than when applying the G-P method. For the Korean children height and weight measurements increased more than the average values for the Danish population.

Adoption↗
PubMedDate not supplied

A two-film versus a four-film bite-wing examination for caries diagnosis in adults.

The aim of this study was to compare the caries diagnostic outcome of a two-film and a four-film routine bite-wing examination undertaken in an adult population. A digital bite-wing examination using two and four films, respectively, was performed in 174 patients. The radiographs from the two examinations were assessed jointly by 2 observers for the number of imaged surfaces in the area from the distal surface of the canine to the distal surface of the third molar and for the detection of carious lesions. Significantly more surfaces were available for examination by the four-film than by the two-film examination. Overlapping surfaces were recorded in 14 and 10%, respectively, of the surfaces imaged by the two-film and four-film set. The prevalence of primary enamel and dentinal caries was 6.8% with the two-film and 5.6% with the four-film method. In 1, 684 surfaces only imaged by the four-film method caries was detected in 20 surfaces. If these extra lesions were added to the number of lesions found by the two-film method the total disease prevalence using the last-mentioned method would increase by 2 per thousand. The majority (92-99%) of all recorded lesions were detected in surfaces located between the occlusal surface of the first premolar and the mesial surface of the third molar. The little additional diagnostic outcome obtained by the use of four instead of two films did not seem to match the extra resources (double patient charge and radiation dose, and extended scan/developing and recording time for the dentist) connected to the four-film method. Thus, it may be recommended that a routine bite-wing examination undertaken in young adults should be performed with only two films: one in each side of the mouth, placed behind the premolars and the first and second molars.

Adult↗
PubMedDate not supplied

Behaviour of approximal carious lesions assessed by clinical examination after tooth separation and radiography: a 2.5-year longitudinal study in young adults.

This study aimed to record and monitor over a 2.5-year period the occurrence of cavitation and lesion depth progression in approximal surfaces with radiographic caries at baseline. In total, 66 approximal sites (in 29 students), where at least one of the contacting surfaces had radiographic caries, were selected to take part in the study. A clinical examination undertaken before and after tooth separation in order to assess the presence/absence of cavitation was repeated every sixth month. To monitor lesion progression bite-wing radiographs were taken every sixth month, too. After each series of examinations, surfaces judged to be prone for disease progression were referred to operative caries treatment. In surfaces with radiographic dentinal caries at baseline the cavitation prevalence following tooth separation found at the various recall examinations ranged from 20 to 44%. In surfaces with radiographic enamel caries at baseline this prevalence ranged from 4 to 8% at the various recall examinations. In dentinal lesions found with an intact surface at baseline, the risk of cavitation development during the first 1.5-year period was assessed to be up to 22%. After this period no new cavitations were found in previously intact dentinal lesions. In intact enamel lesions the risk of cavitation formation was found to be 3% during the first 1-year period. After this period no new cavitations developed in previously intact enamel lesions. Three of 7 lesions, which showed radiographic caries progression from the outer one third to the inner two thirds of the dentine during the observation period, had intact surfaces at baseline. On the basis of these results it is recommended to re-examine carefully intact, dentinal lesions by repeated clinical examination after tooth separation and by radiography about 1-1.5 years after baseline.

Adult↗
PubMedDate not supplied

Reproducibility in the assessment of caries lesion behaviour: a comparison between conventional film and subtraction radiography.

The purpose of this study was to compare reproducibility in the assessment of caries lesion behaviour in digital subtraction images and conventional radiographs. Ninety-seven pairs of conventional film bite-wings were included. The radiographs had been taken with a Kwik-Bite filmholder without further standardisation. The selection criterion was that at least one surface imaged in a bite-wing pair should show progresssion of a caries lesion from the first exposure to the second. The time interval between the bite-wings was 1-2 years. The radiographs were scanned into a personal computer and the two images from the same patient subtracted. Seven observers scored the subtraction images and the conventional films. The scale was based on no change/ change in surface appearance scored in the following categories: 0 = no change; 1 = development of a new caries lesion in enamel; 2 = development of caries lesion in enamel and dentine/progression of an existing enamel lesion into dentine/progression of a dentinal lesion further into dentine; 3 = development of secondary caries; 4 = new filling/change of filling/extension of filling. Cohen's kappa coefficients were calculated for intra- and inter-observer agreement for the two radiographic methods separately. The kappa value served as the statistical sampling unit for testing differences between the two methods (Wilcoxon's test for ranked pairs). The average intra-observer kappa value was 0.875 (range 0.775-0.958) for the subtraction images and 0.758 (range 0.560-0.890) for the conventional radiographs. The difference was statistically significant (p<0.05). For inter-observer agreement, the kappa values were lower than for intra-observer agreement. The average value was 0.678 (range 0.485-0.754) for the subtraction images and 0.701 (range 0.497-0.817) for the conventional radiographs (p>0.1). This study suggests a new way of comparing reproducibility in terms of kappa values between diagnostic methods in clinical studies where accuracy cannot be evaluated. The subtraction method may be useful in the assessment of caries lesion behaviour in the clinic.

Dental Caries↗
PubMedDate not supplied

Computer-automated caries detection in digital bitewings: consistency of a program and its influence on observer agreement.

The aim of this study was to evaluate a decision-support, caries detection program and its influence on observer agreement in caries diagnosis. 130 patients were examined by digital bitewing radiography (RVG XL sensor, Trophy Radiologie Inc.). Fifty-four approximal surfaces (27 in premolars and 27 in molars) were selected by the author: 24 surfaces (9 in molars and 15 in premolars) scored as sound, 16 surfaces (9 in molars and 7 in premolars) scored as carious in enamel, and 14 surfaces (9 in molars and 5 in premolars) scored as carious in dentine. The Logicon Caries Detector (LCD) program (Logicon Inc., USA) was assessed by repeating the automated analysis ten times for each surface. The two most varying outcomes for lesion probability (Lp(min) and Lp(max)) were saved. Five observers scored the 54 surfaces independently as sound, caries in enamel or caries in dentine before and after the use of LCD. In more than one third of all surfaces the program indicated different lesion probability, from sound at Lp(min) to the presence of a carious lesion at Lp(max). The 5 observers changed their caries score after the use of LCD in a total of 31 surfaces (only 2 of these were in the same surface). Mean kappa value for inter-observer agreement for caries scores before the use of LCD was 0.47 (range 0. 39-0.61) and after LCD 0.48 (range 0.37-0.69). It was concluded that the automated caries detection program was not very consistent and provided different opinions on the caries status in a surface. Inter-observer agreement in caries diagnosis did not improve using the program.

Decision Support Systems, Clinical↗
PubMedDate not supplied

Immunobiochemical characterization of the NMDA-receptor subunit NR1 in the developing and adult rat brain.

To investigate the developmental and regional expression of the NR1-subunit of the NMDA-receptor on the protein level, two polyclonal antisera [NR1(N) and NR1(C)] were raised against fusion proteins derived from the N- and C-terminal domain of the NR1-subunit, respectively. In Western blots of rat brain membranes, both antisera specifically recognized a single protein band with an apparent molecular size of 115 kDa. The regional distribution of the NR1-subunit immunoreactivity was analyzed in the developing and adult rat brain using sections blotted onto nitrocellulose membranes for immunostaining. With the NR1(N)-antiserum, strongest signals were detected in hippocampus, followed by cortex, striatum and thalamus, and weaker staining was observed in tectum, brainstem and cerebellum of adult brain. The NR1(C)-immunoreactivity exhibited a similar distribution, except that the staining in thalamus, tectum, brainstem and cerebellum was faint or virtually absent. The distinct pattern of NR1(N)- and NR1(C)-immunoreactivity arose during postnatal development. At birth, moderate staining with both NR1-subunit antisera was observed throughout the brain increasing strongly in most brain regions until postnatal day 21. In some brain areas, however, the NR1(C)-, in contrast to the NR1(N)-staining, decreased postnatally e.g. in thalamus, tectum and brainstem. The restricted staining intensity of the NR1(C)-antiserum in particular areas of adult and developing brain appears to reflect the emergence of C-terminal splice variants of the NR1-subunit which are not recognized by the NR1(C)-antiserum.

Animals↗
PubMedDate not supplied

Accuracy of clinical diagnosis for the detection of dentoalveolar anomalies with panoramic radiography as validating criterion.

It is noteworthy that little attention has been paid to the balance between economy, discomfort, and risk to the patient (costs) and the clinical significance (benefit) of panoramic radiography as a routine screening procedure. This study used orthopantomographs to validate clinical detection of dentoalveolar anomalies in young children. It appears that 439 children (67 percent) were exposed without benefit from the radiography.

Child↗