PubMed Health⌕ Search

Biomedical subjects

A P Muchitsch

Publications and source records attributed to A P Muchitsch.

8 recordsLinked to original sources
PubMed1992

[A new method for the quantitative and qualitative measurement of tooth movements].

A new method for the in vivo measurement of the movements of teeth is described. Measuring blocks are attached to brackets and tubes. Calibrated holes are drilled in each side of the blocks. Using an electronic sliding caliper, measurements are made in all three dimensions between moving teeth and blocks of anchored segments. With the aid of a computer programme, these measurements can be used to construct pictures of various teeth. By taking measurements at different stages of treatment, the movements of the teeth can be shown in three-dimensional images.

Adolescent↗
PubMed1991

[The tooth transplant in orthodontic treatment planning].

The analysis of all examined transplant cases combined treated with orthodontics shows a success rate of 76%. It must be underlined that the germ development at the time of the transplantation is of utmost importance. The best possible time proved to be at a root development of 2/3 to 3/4. Exact indication position, a careful atraumatic operation method and a short time of operation are also important factors of a successful transplantation. If all these preconditions are met, this method can be recommended.

Adolescent↗
PubMed1990

[The effect of the vertical bracket position on the orthodontic finish].

As during orthodontic treatment and in particular during the phase of the precise adjustment of occlusion by applying the "straight-wire technique" problems arise as far as the vertical dimensions are concerned, the usual distances between the bracket slots and the edges of the incisors respectively the top of the cusps have been verified. Measurements were done on models at the end of treatment of ten patients treated with fixed attachments who may represent ideal occlusion as far as profile radiographs and gnathology were concerned. After regulation of the plane of occlusion the vertical distances between the slot base plane (parallel to the plane of occlusion) and the edge of the incisors respectively tops of cusps were measured by means of a modified parallelometer in connection with a special slot and tube support as well as a specially developed dial test indicator, while a maximum fit between bracket base and buccal crown surface was given. In case of the upper front brackets (torque + 22 degrees) large vertical measurement to the edge of the incisors were recorded, 8.25 respectively 8.33 mm). This may be attributable to excessive torque of the applied brackets. Only approximate figures for the vertical positioning for other teeth could be given, as anatomical variations have to be considered.

Adolescent↗
PubMed1989

[The positioner--a possibility for the fine adjustment of the occlusion objectively assessed by condylar measurements of the discrepancy between the ICP and RCP].

A group of ten adolescents was treated with fixed appliances at the Department of Stomatology and Oral and Maxillofacial Surgery, Graz. Subsequently the patients were fitted with a gnathological positioner. On the day of band removal ten sets of models were made and subsequently two, four and twelve weeks later. They were mounted on an articulator and cephalometric measurements were taken three times by each of the examiners. These records served to provide evidence of discrepancies of the condylar position between ICP and RCP in all three planes. In the second part of the examination, the patients were instructed to wear the appliance at night for another year. Casting of models, mounting in articulators and condymetric measurements were repeated as above. After wearing the positioner for three months, we observed a definite improvement of the occlusion and a wide conformity of the RCP and ICP measurements. After one year of night-time retention there was a slight increase of the mean values. In addition, we could establish statistically that condymetric model measurements are independent of the examiner and the method employed.

Adolescent↗
PubMed1989

[Adhesive strength and bonding behavior in graphite-marked bracket positioning].

During a one-year observation period eleven patients treated with fixed appliances and 164 brackets which had been bonded in pairs, were checked at periodic intervals. Every patient had brackets positioned on the teeth in the first and fourth quadrant without graphite marking and in the second and third quadrant with graphite marking. In a parallel in-vitro study with eight pairs of teeth the above described conditions were applied. These specimens were examined in an universal testing machine in order to determine the magnitude of the shear forces. In the in-vivo as well as in the in-vitro study no statistically significant correlations were revealed between the graphite marking and the durability of adhesion as well as the required shear force of the examined brackets. Utilising light microscopy studies, the penetration of adhesive was determined in relation to the position of the graphite marking in etched enamel; at was harmlessness of the reference medium.

Acid Etching, Dental↗
PubMed1989

[Fixed appliances current state of the art].

Recent advances in fixed appliances are reviewed and discussed. These include cosmetically more appealing brackets (ceramic, lingual); new wires (nickel-titanium and titanium-molybdenum alloys); new biomechanical approaches (accurate computation of forces and torques according to Burstone resulting in the use of new mechanical concepts); experiences in the treatment of transplanted teeth made in the past 15 years; new approaches to the orthodontic finish (implementation of Andrews' "six keys to normal occlusion" with straight wires, accurate positioning of brackets, and gnathological positioners). Cases will be demonstrated.

Adolescent↗