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The purpose of the study was to analyse and compare deep overbite correction in adult patients carried out by a straight wire appliance and the segmented arch technique as recommended by Burstone. The sample comprised 50 adult, deep bite patients, 25 each treated with straight wire appliance and segmented arch technique. Plaster casts and lateral cephalograms made before and immediately after finishing treatment were analysed. Both techniques were successful in overbite correction; overbite reduction amounted to 3 to 3.5 mm. The straight wire appliance group demonstrated predominantly molar extrusion and as a result posterior mandibular rotation. A slight intrusion of 1 mm was seen in the lower incisor area. The segmented arch technique resulted in an incisor intrusion of 1.5 mm in the upper and 1.7 mm in the lower jaw. No substantiate extrusion in the molar area was found. The advantages of this technique are discussed.

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.

Burstone's intrusion mechanics has been found to be effective in the treatment of a deep bite due to intrusion of the anterior teeth. The pre-activation of the intrusion arch by a tip-back bending shows a shortening in the activation. Measurements objectified the extent of the shortening and the resulting horizontal forces for TMA arches of a dimension of 0.017 x 0.025 inch relating to different distances between molars and anterior teeth and pre-activation by means of tip-back bending or curvature. The change of the vertical force in connection with a simulated intrusion of 5 mm was also registered. Clinical consequences of the therapy are discussed.

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.

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.

The aim of this research was to examine the effect of the chin cap on mandibular prognathism (Angle class III) with or without a Fränkel appliance. 30 class III patients were examined. Head plates and casts made before and after active treatment were evaluated. The patients were divided into group I (initial X-ray incisivi decidui ID) and group II (initial X-ray incisivi permanentes IP). Group I (ID) showed a stronger skeletal response. Group II (IP) already showed more severe prognathic values in the initial X-rays. In group I (ID) a decrease of the gonial angle, SNB- and SNPog angle as well as an increase of both the ANB- and articulare angle were observed, however not in group II (IP) or at least not to the same extend. Overbite and overjet values reached the ideal values. In both groups dental compensation was observed.

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.

The normal development of the periodontal structures was confirmed histologically on young beagle dogs following tooth germ transplants. In humans, clinical and radiographic examinations revealed no pathology of the periodontium following transplantation of tooth germs. The grafted teeth could be moved orthodontically in the same way as any other teeth. No precautions need to be taken. This paper describes the most common indications for transplanting the tooth germs of canines, bicuspids and molars.

Levelling arches made of stainless-steel wires were compared with nickel-titanium wires of the new generation which are distinguished by their shape memory, superelasticity and their excellent spring-back. The data received from a bending test have been analysed statistically and revealed a linear unloading curve of the twisted stainless-steel wires. The nickel-titanium wires, however, showed a clear deviation form the linearity with a curviform course. Besides the unusual unloading curve with a constant force mechanism in the middle range of deactivation the wires give off the same amount of force irrespective of the degree of activation (that is to say, regardless whether the level difference between the brackets amounts to 1 or to 4 mm). The diagram shows that the greater the activity between the brackets, the longer the period of superelasticity. Therefore the nickel-titanium wires are suited for large level differences or deflections. At a low activation rate the characteristic line takes a very steep and almost linear deactivation curve. In these cases twisted stainless steal wires should be preferred because of their lower load deflection rate and flexibility.

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.