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Biomedical subjects

B B Welsch

Publications and source records attributed to B B Welsch.

11 recordsLinked to original sources

A preliminary study of the effects of tooth guidance on working-side condylar movement.

Clinical observations have indicated that lateral working-side tooth contacts can produce a posterior shift of the working-side condyle, resulting in pain in the temporomandibular joint. This study examined the influence of lateral retrusive and lateral protrusive tooth guidance on the movements of working condyles of the lateral pole. Four patients with lateral retrusive natural tooth contacts and four patients with lateral protrusive natural tooth contacts were studied. Movement of the lateral pole of the working condyle was recorded under the following conditions: (1) natural teeth in contact, (2) wearing of a mandibular acrylic resin splint that created lateral protrusive or lateral retrusive tooth guidance, and (3) a central bearing screw and bearing plate separating the teeth. The results indicated that the condition of the patient's temporomandibular joints was a crucial factor in consistency of condylar tracings. Condylar tracings from patients with temporomandibular joint condyle-disk lacking coordination were inconsistent and unreproducible. Consistent, reproducible tracings for patients without condyle-disk disorders indicated that lateral retrusive guidance can cause a more posterior pathway of the lateral pole of the working condyle than lateral protrusive guidance. Future studies are necessary to establish the relationship between lateral tooth guidance and temporomandibular disorders.

Adult↗

Temporomandibular joint disk position as determined by a simple recorder.

A method that will determine the condyle position necessary to keep the disk in place during splint fabrication has been described. The equipment used is simple and relatively inexpensive, and the entire procedure can be accomplished chairside in a matter of minutes. In those instances in which splint therapy does not result in significant improvement in symptoms, the Quick Set recorder can be used to repeat the initial condyle path recordings. A comparison of these sets of recordings can be used to determine whether the disk is in place. If doubt exists about the diagnosis, arthrography can be done to determine whether a closed locked disk position exists.

Cartilage, Articular↗

Analysis of disagreement in the evaluation of clinical products.

This paper reports an analysis of factors that reduce agreement in clinical evaluation. Four instructors representing different restorative departments met regularly over a four-month period to study the evaluation process. Each participant selected a task from his discipline, identified critical errors made in performing the task, produced these errors in models and extracted teeth, and developed criteria and checklists to aid in categorizing and counting the errors. In weekly sessions the models were evaluated, and judgments were compared. Factors that reduced agreement were identified, discussed, and listed. In some sessions ongoing evaluation was reported orally, tape-recorded, and analyzed to elucidate the underlying mental processes. Analysis indicated that agreement was reduced by 16 factors, including unclear rules, the faculty member's memory, unstandardized aids to judgment, inconsistent observational methods, differences in ability, and differing tendencies to leniency.

Clinical Competence↗

Simplifying the bead-brush technique.

This article describes a method of controlling monomer addition using the bead-brush technique. With the addition of a cotton pellet to the monomer, incorporation of liquid can adequately be controlled.

Acrylic Resins↗

Stable matrix for amalgam build-up.

A method is proposed of making amalgam build-ups for coronally debilitated teeth through the use of a stable matrix consisting of a disposable tray and polyvinylsiloxane occlusal registration material. For teeth with minimal remaining coronal tooth structure and/or the absence of adjacent teeth, this technique provides proper stabilization of the matrix band to permit adequate condensation of amalgam.

Dental Amalgam↗