Proliferative response of cells of the dentogingival junction to mechanical stimulation.

The aim of this research was to study the proliferative response of junctional epithelium (JE) and gingival connective tissue (GCT) to mechanical stimulation in vivo with regard to the potential occurrence of apical migration of JE and loss of GCT attachment during orthodontic tooth movement. Elastic bands were inserted between the maxillary first and second molars of male rats aged 8 weeks, which were pulse-labelled with 3H-thymidine and subsequently killed in groups, together with labelled control animals (a total of 98 rats) after periods of 1-168 hours. Autoradiographs were prepared from plastic mesiodistal sections, and parameters of cell proliferation for JE and GCT of the papilla between the second and third molars were determined.

Functional and social discomfort during orthodontic treatment--effects on compliance and prediction of patients' adaptation by personality variables.

During the course of treatment orthodontic patients frequently endure a number of functional complaints and are anxious about their appearance. The aims of this longitudinal study were to follow the progress of patients' adaptation to discomfort, to elucidate the putative relationship between the type of appliance worn and functional and social discomfort experienced, to study potential predictability by their attitude to treatment and to evaluate the effects of discomfort as predictors of patients' compliance. Eighty-four patients undergoing either removable, functional, or fixed appliance treatment monitored their complaints during the first 7 days of treatment and rated them retrospectively 14 days, and 3 and 6 months after appliance insertion.

Efficacy of protection by latex gloves during orthodontic therapy.

The wearing of gloves during orthodontic or dental treatment is generally indicated for reasons of hygiene and protection against infection. This study was aimed at determining the extent and localization of perforations caused by the various orthodontic treatment techniques and interrupting the infection barrier. The impermeability was tested by means of a water retention test according to European standard EN 455, Part 1, performed on 1600 Centramed (Centramed, Koblenz), Tekmedic and SafeEx non-sterile disposable latex gloves (both by Safe Med, Switzerland) and Safe Gan latex gloves with an additional acrylate coating (also by Safe Med).

Relationship between patient discomfort, appliance acceptance and compliance in orthodontic therapy.

Orthodontic treatment is occasionally a discomfort to patients, due to pain or functional restrictions. In this context, several retrospectively planned studies were performed in the 1980s, but correlations between different aspects of patient discomfort were not investigated. The present study aimed at examining and structuring the psychogenic dimensions of patient discomfort.

Pain and discomfort during orthodontic treatment: causative factors and effects on compliance.

Orthodontic patients experience pain and discomfort to a varying degree during the course of treatment. The aims of the present investigation were to follow the progress of adaptation after insertion of new appliances and to study the relationships between the type of appliance worn and pain or discomfort experienced, between pain sensations and attitude toward the treatment and their effects on patients' compliance. Pain and discomfort experienced by 84 patients undergoing orthodontic treatment, their attitude toward the treatment, and compliance were assessed 7 days, 14 days, 6 weeks, 3 months, and 6 months after appliance insertion, using specially designed protocols, questionnaires, and rating scales.

A comparative assessment of acceptance of different types of functional appliances.

Patients' acceptance of an orthodontic appliance may influence compliance and thus contribute to a successful outcome of treatment. The aim of this study was to assess the influence of shape and design of different types of functional appliances on their acceptance by patients. For each of 10 adult volunteer subjects employed in the study eight different functional appliances were fabricated which had a varying extension of the resin base and amount of interocclusal opening.

An experimental study of the esthetic effect of facial profiles.

In this study good-looking "male" and "female" as well as ugly facial profiles were shaped by 104 lay persons using an especially constructed device according to specific instructions. These profiles were photographed and subsequently evaluated using a series of parameters from soft tissue profile analyses. Although some significant mean value differences were found between the good-looking and ugly profile variants, they were not substantial.

Study of psychosocial aspects of adult orthodontic treatment.

A semistandardized questionnaire was administered to adult orthodontic patients to gain insight into their motives for seeking treatment and their experience during treatment. The data collected from 60 patients aged 18 to 52 years were used for descriptive statistics and calculation of correlations. The results indicate that apart from objective and immediately comprehensible reasons for certain behavioral patterns, ideas influencing emotional life may have an important effect on attitudes toward treatment.

A method of measuring the apical base.

The maxillary and mandibular apical base areas were measured, using a gnathograph, on the study casts of 156 adults and children representing Class II division 1, Class II division 2 and Class III malocclusions. There were significant differences between the groups at each age. The maxillary apical base areas tended to be smaller for the adults than for the children in all three occlusal classes.

A holographic study of variations in bone deformations resulting from different headgear forces in a macerated human skull.

The effects of headgear on maxillary displacement and the resulting growth modifications are not completely understood, especially regarding the complex relationships between initial and secondary skeletal reactions on one hand and the influence of the direction and magnitude of the applied force on the other. The aim of the present investigation was to study, by means of holographic interferometry, the initial bone displacement occurring in response to headgear traction applied at different force magnitudes and in different directions. Orthopedic forces of 560 grams and orthodontic forces of 354 grams were stimulated on a macerated human skull.

[A holographic study to demonstrate the initial displacements of a macerated human skull under the influence of the orthodontic force from headgear with traction in different directions].

The phenomena of maxillary displacement and the subsequent growth modifications which result from the application of orthopedic headgear traction are very complex and not yet completely understood. The aim of this study was to investigate with the help of holographic interferometry the influence of the headgear's differing traction directions on the initial bone displacement in the maxillary complex. 560 g high, straight, and low pull headgear traction exerted above, through, and below the center of resistance of the upper first permanent molars was simulated on a macerated human skull and skeletal changes were recorded by laser holography as they occurred.

[An in-vitro study of 2 resins used in orthodontics for their cell toxicity].

The aim of this study was to examine in vitro cell compatibility of the orthodontic base resins Orthocryl (Dentaurum) and Wil-o-dont (Wilde) using the method described by Heidemann and Lampert (1980). The acute local nonspecific cytotoxicity of these materials and that of their individual components were evaluated. Used were both a qualitative microscopic assessment of cytopathological changes occurring in human gingival fibroblasts cultured along side the specimens and a semiquantitative assessment of the zones of inhibited cell growth around the specimens.

Theoretical approaches to behavior change in myofunctional therapy.

The effectiveness of myofunctional therapy depends not only on the quality of the individual exercises but also considerably on the patient's compliance. In this paper, factors are described which may decisively influence patients motivation to cooperate during treatment. Based on experience in dealing with patients, clinical studies and psychological knowledge, theoretical approaches to patient motivation are discussed, namely aspects of verbal communication, control, reward, behavior agreement as well as verbal self-control and self-reward.

[A dental arch index related to tooth size and facial breadth].

Taking as its starting point the often postulated criticism of Pont's Index, the intent of the study was to develop a diagnostic procedure which took into consideration the objection that the Pont Index doesn't take the shape of the patient's skull into consideration. On the basis of the data obtained from the models and anthropological measurements of 50 adult subjects with fairly eugnathic dentition, the first step was to follow Pont and study which skull size exhibited the highest correlation to the posterior dental arch. Of all the relevant sizes the zygomatic arch width exhibited the highest correlation.

On the prediction of dentist-evaluated patient compliance in orthodontics.

The aim of the present study was to determine to what degree social and psychological patient variables can predict orthodontic co-operation evaluated by dentists 3 and 6 months after the beginning of treatment. The subjects were 94 patients from seven orthodontic practices. They received a questionnaire with four subscales: impulsiveness, dominance, anxiety, and orthodontic attitudes.

Relations between verbal behavior of the orthodontist and communicative cooperation of the patient in regular orthodontic visits.

A study of interrelationships between orthodontist and patient communication characteristics on the basis of audiotape recordings is reported. The subjects were 66 patients from an orthodontic outpatient clinic who were treated by seven orthodontists. Strong relationships (partial correlations) were found between clinicians encouraging behavior (listener signals and symmetrical answering) and patient communicative cooperation (speech volume, detailed answering, questions, initiatives); whereas orthodontists guiding behavior showed lower correlations, only the clinicians' direct questions were significantly related to patient participation.

[Elemental analytical and quantitative morphometric determination of the synthetic resin residues and enamel avulsion after the removal of metal brackets].

A number of clinical and experimental studies were performed to assess the quality of the enamel-adhesive-bracket bond. The aim was to present a combined method that enables the investigator both to examine the surface of metal brackets quantitative-morphometrically and to detect the presence of enamel particles. To this end, 38 metal brackets were examined in the scanning electron microscope.

[The demonstration of cellular reactions in the temporomandibular condylar cartilage by NMR microscopy. The basic research for high-resolution NMR tomography of the temporomandibular joint].

The regional resolution of modern imaging methods is not good enough to clinically objectify changes to the cartilage of the temporomandibular joint, for example in functional orthodontic treatment. NMR microscopic studies of an intact temporomandibular joint preparation were done experimentally in the domestic pig on the basis of 1H-NMR relaxometric measurements in specimens of condylar cartilage. We succeeded in representing the cartilage of the temporomandibular joint down to the cellular level, and in demonstrating regeneration processes as a late sequela of surgery on the temporomandibular joint.

[A comparative study of the possibility of reducing the dosage in lateral teleradiographs].

Thanks to their capability for post-processing of image data, the digital radiological techniques introduced from 1970 onwards permit dose reduction with no loss of clinical information. The aim of this study was to establish the extent of possible dose reduction in orthodontic lateral cephalography. For this purpose, lateral cephalograms of a head phantom taken with varying radiation doses (5 to 150 mAs, constant 70 kV) were evaluated.

Disfigurement and psychosocial handicap of adults with extreme mandibular prognathism.

Questionnaires and psychological tests were used to assess the psychosocial impact of mandibular prognathism. Patients with mandibular prognathism were asked to assess the impediments caused by their dentofacial deformity. In addition, they were asked to rate their appearance and to report the effect that it had on their social contacts.

Morphological cephalometric differences between two European populations.

Earlier research in craniofacial morphology of the inhabitants of Mainz (Germany) and Zagreb (Croatia), who represent the populations of wider areas, have shown some roentgen-cephalometric differences. The aim of this study is to determine the craniofacial morphologic differences of these populations in three dimensions. The sample consists of 200 adult examinees, male and female respectively, inhabiting the mentioned areas.

[The morphological results of the use of a pulsed krypton fluoride excimer laser for enamel conditioning].

Although there have been many advances in the field of acid etching, major problems still present. For the most part, these are the unpredictability of the effects of etching, the lack of control of the depth of etching over the long term, and the development of enamel fractures occurring on debonding. The aim of this study was to investigate the morphological effects of enamel conditioning using a pulsed krypton fluoride excimer laser (wavelength 248 nm).

[Comparative study of the accuracy of localizing cephalometric reference points in using digital and conventional imaging technique].

The purpose of this study was to present possible advantages of digital luminescence radiography for cephalometry. Conventional and digitalized lateral headfilms were compared and evaluated. The first impression of an improved simultaneous presentation of bony structures and soft tissue profile in digital x-rays was statistically verified.

[Perceptibility of details in conventional and digital teleradiography--a comparative study].

By introduction of rare earth film-screen combinations instead of classical screens dose reduction has already been possible. By this study the extent of dose reduction without loss of clinical information was to be examined by comparing conventional radiographic rare earth film-screen combinations to digital radiography. Statistical analysis proves for conventional lateral cephalograms that soft tissue reference points can better be localized if small radiation doses are used.