[The influence of major connectors of partial dentures of phonation: an instrumental analysis of speech]. / Der Einfluss der grossen Verbinder von zahnärztlichen Teilprothesen auf die Lautbildung. Eine instrumentalphonetische Untersuchung

After the insertion of removable dentures for restoring partially edentulous arches, phonation is affected by many factors, of which many influences are not completely understood. The aim of this study was to investigate the influence of various construction elements of maxillary and mandibular partial dentures on the formations of plosives, nasals, lateral approximates and fricatives. Twenty-four patients were included in the study. For each patient five different test dentures were constructed. Over a period of 24 h, six digital tape records were made for each patient. By this time, the patient had worn the dentures maximally 6 h. With the help of a computer-supported frequency analysis based on the principle of fast Fourier transformation (FFT), it was possible to demonstrate the differences in phonation in regard to denture design. During the test period, the patients were asked to fill in a questionnaire on denture comfort and phonation. This study also quantifies the influence of the sublingual bar on phonation. It can be assumed that the speaker tries to retain his habitual way of articulation despite the inserted test denture. Therefore, a phonation test immediately after insertion of a new constructed partial denture should be interpreted with caution because of the assumed compensation process. The results of this study could have consequences for dental therapy plans.

Long-term experience with telescopically retained overdentures (double crown technique).

To evaluate the long term results of telescopically retained overdentures, 92 patients with a total of 106 overdentures on 236 teeth were examined after two to eleven years. Thirty-three teeth were lost during the follow-up period. A higher tooth survival rate of the double-crowned teeth was found under mandibular overdentures (92%) than under maxillary overdentures (86%) after five years. The palladium-silver-alloy used seemed to be more suitable for telescopic crowns than the use of precious gold-copper-alloys because of tarnishing the latter alloys.

Long-term electromyography as a possible diagnostic aid for detecting craniomandibular dysfunctions.

As there is a positive correlation between oral parafunctional habits and craniomandibular disorders, objective electromyographic findings on parafunctional jaw activities could be very interesting for the diagnosis and management of craniomandibular disorders. The described pocket-sized and battery-operated electromyographic measuring device fulfils the essential requirements for monitoring and recording parafunctional activity in a chosen time period. It is easy to handle and can therefore be operated by a trained patient. At the end of the registration the collected data are transferred to a computer for statistical or graphical analysis. With this device, long-term electromyography on patients in their usual environment is possible. Further studies on parafunctional behaviours applying long-term electromyography could increase the understanding of craniomandibular disorders.

[Operative correction of dysgnathism as preprosthetic management]. / Operative Dysgnathie-Korrektur als präprothetische Massnahme.

The prosthetic management of edentulous patients with skeletal dysgnatism is difficult. Surgical treatment as Le-Fort-I-osteotomy or sagittal split and rigid fixation with plates can be helpful. Technique, indications and additional procedures are introduced in two clinical cases.

[Functional craniomandibular disorders and ENT-symptoms]. / Funktionsstörungen des Kauorgans und Hals-Nasen-Ohren-Symptome.

Complaints in the otolaryngologic region, that cannot be referred to an otolaryngological pathologic process, are often caused by or combined with craniomandibular dysfunctions. As a rule these complaints are not the result of direct mechanical irritation of the articular tissues, but the effect of neuromuscular incoordination and spasms. Consequently the term "Costen's syndrome" is obsolete and should be used no more. In many cases the interaction of otolaryngological symptoms and craniomandibular disorders can only be proved ex iuvantibus. Occlusal equilibration combined with physical and physiotherapeutic treatment are approved methods to normalize neuromuscular function and eliminate muscle tension and pain.

[Influence of registration plate placement on axiographic tracings of mandibular movement in transverse plane mandible]. / Der Einfluss der Registrierplattenstellung auf die achsiographische Erfassung der Unterkieferbewegungen in der Transversal-Sagittalebene.

In all achsiographic techniques a non perpendicular alignment and adjustment of the sagittal-vertical registration plates to the centric positioned hinge axis leads to an incorrect recording of mandibular movements. Among other things the dimension of the registration error decisively depends on the quality and quantity of the angle of hinge axis inclination. The achsiographies of 234 patients were analysed. In most cases incorrect measurements of the individual Bennett angle of only 1-2 degrees were found. These deviations are not relevant and have therefore not to be taken into account. On the other hand differences of the correct and incorrect recorded Bennett angle between 3 degrees and 8 degrees could be registrated in more than 25%. These errors have to be considered in diagnostics and treatment procedures. Correcting methods and techniques are described and discussed.

[Influence of occlusion on head posture, during periods of continuous intermaxillary pressure]. / A influência da oclusão na postura da cabeça, durante fases de pressão intermaxilar contínua.

The influence of divergent splint-adjusted maximum intercuspation on head posture during prolonged phases of clenching was studied in five subjects. During clenching in maximum intercuspation profound changes of head posture were observed, if intercuspation was not harmonized with an upright posture of head and body. Since the interrelation between occlusion and head posture is established a comprehensive approach of orthopedic, physiotherapeutic, and dental measures, in particular for the therapy of myoarthropathy patients with cervical spine symptoms seems appropriate. Occlusal corrections and determination of occlusal relations must always be made or at least checked in the upright relaxed patient with the head straight.

[Results of incorrectly positioned hinge axis on axiographic tracings of mandibular movement]. / Die Auswirkungen einer fehllokalisierten Scharnierachse auf die achsiographische Erfassung der mandibularen Kinematik.

This article deals with the different influences of an incorrectly located or arbitrary hinge axis upon axiographic tracings of mandibular movements. Unless the recorded curvatures of the three-dimensional pathways of the condyles start from true hinge axis points, paraxial distortions of the tracings will be the result. These recording errors can be so outstanding, that essential advantages of the modern electronical registration systems like the possibility of high-resolution measurement will become uncertain. Within the scope of instrumental analysis of stomatognathic disturbances distorted tracings can lead to false diagnosis easily.

[Considerations of precision and consistance of mandibular transverse hinge axis]. / Betrachtungen zur Präzision und Konstanz der transversalen Scharnierachse des Unterkiefers.

This paper deals with the nature of mandibular hinge axis and the consequences for its application in diagnostics and treatment. The transversal hinge axis of the mandible can be characterized as an exact and true axis of pure mandibular rotation or a more or less exactly located axis as a result of a combined rotation and translation of the condyles. During opening movements of about 8 mm already an insignificant gliding of the condyles of 0.5 mm displaces the individual located hinge axis of more than 6 mm in its relation to the lower jaw. The true hinge axis as it is needed for achsiographic or pantographic registration techniques has inevitably not to be identical with the transferred axis for mounting casts in an adjustable articulator.

[Determination of transverse resilience of human temporomandibular joint]. / Zur Erfassung der transversalen Resilienz des menschlichen Kiefergelenkes.

Transversal TMJ-resiliency is defined as a possible movement of the condyles exclusively in the lateromedial direction. The extent of this individual and variable shifting of the condyles can be recorded and reproduced using high-resolution electronic axiography and a special manipulating technique by the dentist. A study on 52 patients showed an average value of 0.3 mm for the transversal resiliency, which can be considered as physiological range. The results were discussed along with the question for the relevance of transversal TMJ-resiliency measuring regarding TMJ-disorders.

[The neuromuscular effect of anterior guidance on the protrusive movement pattern of the mandible. Observations in the horizontal plane]. / Neuromuskulärer Einfluss der anterioren Führung auf das protrusive Bewegungs-Muster der Mandibula. Betrachtungen in der Horizontalebene.

The influence of a temporarily altered anterior guidance on mandibular movement patterns of tooth-guided and non-guided protrusion was examined in a clinical study on 20 patients, all with complete sets of teeth. Registration and recordings of movements were done with the computer-aided ultrasonic measuring system MT 1602. Based on an average measuring time of 40 min for each patient the main results were as follows: 1. The shape of the anterior guidance strongly influences the horizontal tracings of tooth-guided and non-guided protrusion. In most cases these tracings show a deviation from the mid-sagittal path due to neuromuscular coordination. 2. Insertion of an idealized, symmetrical anterior guidance or a horizontal plateau lessens the mandibular deviation and harmonizes the tooth-guided and non-guided paths. However, the old neuromuscular engrams are not completely erased. 3. Newly formed engrams can be erased much easier than old ones.

[Evaluation and classification of dysfunction patients]. / Evaluation und Klassifikation von Dysfunktions-Patienten.

The "Stomatognathic-Dysfunction-Index" (SDI) comprises anamnestic and clinical information regarding occlusion, TMJ, head- and neck muscles. The different SDI parameters were chosen in a way that enables them to lead to a firm statement regarding the individual dysfunction. The examination results are easily reproduceable in the sense of a "intra- and inter-examiner reliability" and the scores can be reattributed to individual combinations of symptoms. The patients can be sorted into classes of dysfunction according to their total SDI-Score. This makes the SDI especially suitable for epidemiologic studies, but the easy handling of the SDI allows its use in private practice as well. Here it enables the dentist to classify patients with stomatognathic dysfunctions according to the necessity of treatment and sometimes to determine such necessity as well. The SDI is not meant to replace the extensive standard methods of clinical and instrumental analysis. It is meant to provide a maximum of diagnostic and therapeutic economic value from an affordable input of time in the everyday routine. It fulfills all requirements of an index for epidemiological studies.

[Bactericidal effects of antiseptic gypsum]. / Zur bakteriziden Wirksamkeit Antiseptischer Gipse.

In tests with plaster models we inspected the antibacterial effect of the dental plasters Dento-rock and Dento-dur. The results show, that models consisting of plaster that contains Chloramin T 80 were free of bacteria, even when produced from bacterial contaminated alginate impressions. After separation of the plaster models from the alginate impressions, a bactericide effect could be traced to a layer of 220 microns below the surface of the alginate. By using dental plaster of the tested types, it is therefore possible to eliminate the risk of a bacterial infection through plaster models, without any extra investing in time or labor. There is no sign of a negative influence of chloramin on physical parameters of the tested plasters.

[Comparative analytic occlusal study of clinical use of T-scan systems]. / Vergleichende okklusionsanalytische Studie zur klinischen Anwendbarkeit des T-Scan Systems.

Occlusal corrections are dependent on a precise registration. The T-Scan system has recently been presented to the market as an innovative, computer-aided device, capable of providing exact information regarding position, strength and frequency of occlusal contacts. The diagnostic validity of this technique was tested in a comparing study on 16 patients. The occlusal situation of these patients was analyzed by use of the T-Scan system and the markings compared with those obtained from UV-sensitive articulation foil. The results show that the diagnostic possibilities of the T-Scan system are very much limited. The use oft he T-Scan system as the only means of occlusal analysis cannot be recommended. The main reason for this is an often misleading reproduction of occlusal contacts, caused by the T-Scan-sensor-foil being too thick and too inflexible and therefore creating an uncontrollable shift of the mandibula when closing the bite. However, the T-Scan system seems to be a valuable tool for education of both students and patients, as the on-screen coulour display of occlusal mechanisms are really impressive.

[Is the T-scan system a relevant diagnostic method for occlusal control?]. / Ist das T-Scan-System eine diagnostisch relevante Methode zur Okklusionskontrolle?

The T-Scan system has recently been introduced to the market as a computer-aided device for direct monitoring and documentation of individual occlusal patterns. To receive first assessments of diagnostic relevance of this method, sensitivity and planar resolution capacities of the T-Scan system was tested in an in-vitro study, that showed a lack in the resolution capacity and an excessive variation in sensor sensitivity. Therefore the clinical use of the system is very limited.

[Influence of occlusion on head posture during prolonged phases of clenching]. / Der Einfluss der Okklusion auf die Kopfhaltung während anhaltender Pressphasen.

The influence of divergent splint-adjusted maximum intercuspation on head posture during prolonged phases of clenching was studied in five subjects. During clenching in maximum intercuspation profound changes of head posture were observed, if intercuspation was not harmonized with an upright posture of head and body. Since the interrelation between occlusion and head posture is established a comprehensive approach of orthopedic, physiotherapeutic, and dental measures, in particular for the therapy of myoarthropathy patients with cervical spine symptoms seems appropriate. Occlusal corrections and determination of occlusal relations must always be made or at least checked in the upright relaxed patient with the head straight.