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Biomedical subjects

K Stoltze

Publications and source records attributed to K Stoltze.

64 records · Page 4Linked to original sources
PubMed1977

Long-term changes in the perception of comfortable mandibular occlusal positions.

The aim of this study was to disclose, whether use of a screw jack device to set the distance between the jaws, would contribute towards a stabilization of the magnitude and position of a comfortable zone of mandibular positions or even eliminate it. Thirteen subjects participated in each of fifteen experimental sessions distributed over a 3-week period. Throughout the investigation the zone prevailed at an average width of 1-3 mm. The gap shrank 0-08 mm on average per experimental session. Although this latter value was found to be significant statistically, it can hardly be of clinical importance, considering the time needed for a total contraction of 0-8 mm to develop.

Aged↗
PubMed1977

Short-term changes in the perception of comfortable mandibular occlusal positions.

In search of a new clinical method for determining the occlusal height of full dentures, the perception of the comfortable zone was studied in fifteen edentulous patients. In each experimental session perceptual changes were recorded from forty-four consecutive applications of a screw jack per subject. Two stages in perceptual acuity were found. An initial stage, in which only minor variations occurred among the final screw adjustments which the subjects made when they assessed the borders of the comfortable zone. In the ensuing stage greater variations emerged, indicating a deterioration in the ability of the subjects to discriminate.

Aged↗
PubMed1977

A new intra-oral screw jack.

A new pattern of screwjack for assessing the vertical dimension for occlusion utilizing an edentulous patient's proprioceptive sensation is described. It provides a greater range of movement than other, giving infinitely variable heights between 9 and 21 mm. The elements being captive, it cannot come to pieces in use. Laboratory experiments were contrived to define the magnitude of reading errors and the play in the screw threads. It was found that, only in instances where a graduation related closely to the datum mark, did errors of interpretation arise. These were found to exceed the height set for test purposes by 0-1 mm consistently. An error of this order is of no practical significance clinically and is no impediment to such an application of the device. Mean play in the new pattern jacks was 0-01 mm compared to 0-05 mm in the Timmer versions. In a clinical experiment the performance of the screw was compared to that of Timmer. Statistical evidence was found which suggested a functional difference between the two, the new pattern being significantly more accurate.

Aged↗
PubMed1977

A comparative study of three different approaches to the comfortable zone.

By means of a screw jack device, applied to thirteen edentulous subjects, the comfortable zone was approached in three different ways, by the central, the internal and the external approaches. Correspondingly, the zonal borders behaved differently. Applying the central approach it was found that the initial height of the screw jack had a lingering effect upon subsequent adjustments of the screw. Moreover, lower border data collected by the external approach distinguished themselves from other zonal border data by showing a significantly lower susceptibility to successive adjustments. The study suggests that muscle activity is a factor on which the perceptual mechanism relies, when a zonal border is assessed subjectively by a patient.

Aged↗
PubMed1977

Juvenile periodontitis: skeletal bone mineral content.

No analysis of the skeletal bone mineral content in patients with juvenile periodontitis seems to be available. The purpose of the present analysis, therefore, was to determine, on the basis of estimation of the skeletal bone mineral content (BMC), if an osteopenia is present in patients with juvenile periodontitis. The material consisted of 30 subjects without known systemic diseases: one group of 15 patients with juvenile periodontitis and a control group of 15 subjects with normal periodontal conditions. Test- and control subjects were paired according to sex, age, height, and weight. Each group comprised four men and 11 women aged 18-31 years. The bone mineral content (BMC) was estimated by gamma-ray photon absorptiometry of both forearms, expressed (in arbitrary units) as the mean value of 6 scans of each forearm. No significant differences were found between the total average of the 6 scans from right and left forearms or between the total and mean value for BMC in the test- and in the control group. Conclusively, the analysis shows that the BMC values lie within normal limits in patients with juvenile periodontitis. Therefore, a generalized osteopenia does not seem to be a contributory factor in this disease.

Adult↗
PubMed1976

The linear model: a statistical tool applied to psychophysical research in dental prosthetics.

The construction of a linear model is described, and its function in analysing variations in the perception of comfortable mandibular occlusal positions is explained. In principle, the model combines analyses of variance and regression in a number of simple computer operations. Data from a clinical study were used to demonstrate the analytical capacity of a specific model, designed to estimate the effect of factors, which were supposed to influence the perception of comfortable mandibular positions.

Adult↗
PubMed1976

In vivo uptake of fluoride by surface enamel of cleaned and plaque-covered teeth.

Utilizing a newly developed biopsy method, the F uptake in the outer 3 mum of enamel from a single topical application of neutral NaF or amine F solution was tested on cleaned and plaque-covered premolars in 12- to 14-year-old children. Cleaned teeth treated with neutral NaF acquired only insignificant amounts of F. The presence of plaque seemed to enhance the deposition of F in surface enamel. The findings were discussed in relation to the possible mechanisms of action of topically applied fluorides. Topical treatments with amine F increased surface enamel F considerably more than the NaF. The F uptake was similar in cleaned and plaque-covered teeth. It was suggested that the usually performed plaque-removing procedures prior to topical F applications are superfluous and may even be disadvantageous.

Adolescent↗
PubMed1975

A field biopsy method for fluoride determinations in human surface enamel.

An enamel biopsy method was developed that is especially intended for use under primitive clinical conditions in field studies. Three successive enamel layers, each of 1 mum or less, were etched off the same delimited area of 3 mm2 by means of perchloric acid, using a microsampler with disposable tips. The biopsy technique was applicable to the vestibular surface of almost all teeth, causing no perceptible damage to the enamel surface. Based on cumulated data from the successive enamel layers, curves were drawn from which F levels at various depths in the outer 3 mum of the enamel could be interpolated. F levels in surface enamel of maxillary first premolars in 40 12-13-year-old children in a locale with 0.5 mg F/l in the drinking water were found to be 3,800, 2,400 and 2,000 parts/10(6) in three successive enamel layers of 0.6, 1.0 and 1.1 mum, respectively, demonstrating a decrease in F concentration of about 1,800 parts/10(6) within this depth interval. Identical F concentrations were found in bilateral premolars.

Adolescent↗
PubMedDate not supplied

Histological and histomorphometrical evaluation of tissue reactions adjacent to endosteal implants in monkeys.

A qualitative and quantitative histological study of the initial healing response adjacent to 24 submerged and non-submerged implants placed in the lower jaws of 6 monkeys is presented. The histomorphometric analysis showed no significant differences in mineralized bone-implant contact length between submerged and non-loaded non-submerged titanium implants. The infrabony defects around some of the implants on the radiographs were significantly correlated to the histological measurements. Qualitatively, a greater number of gingival inflammation cells and a longer junctional epithelium were seen adjacent to non-submerged implants without oral hygiene than were seen adjacent to non-submerged implants with oral hygiene in the initial healing period.

Animals↗