Path Of Placement Research Articles

Prosthodontic treatment for the Applegate-Kennedy class V partially edentulous patient

Concomitant loss of a canine and adjacent teeth usually occurs in the maxilla as a result of trauma in youngsters with well-preserved dentition or as an outcome of surgical excision of a localized pathosis in that area. It is postulated that in Applegate-Kennedy class V partially edentulous situations, the remaining anterior teeth in the maxilla should not be used as abutments for removable partial dentures. The stability of the prosthesis is maintained by counterresisting the occlusal forces exerted on the restored arch-curve by use of a posteriorly directed path of placement for the prosthesis.

Rotational path partial denture design: A 10-year clinical follow-up—Part I

A conventional removable partial denture that uses a straight path of placement requires that all rests and clasps be seated simultaneously. The incorporation of a dual, curved, or rotational path of placement permits one portion of the framework to be seated first, followed by the remainder of the framework. This procedure usually permits a reduction in the number of clasps in the framework without compromising the biomechanical properties of the prosthesis. Rotational path designs that eliminate clasps reduce tooth coverage by components and often enhance esthetics, thereby contributing to improved patient acceptance.

Ｏｂｔｕｒａｔｏｒの維持装置の動態と維持力に関する研究

The purpose of this study was to investigate the movement of the obturator framework and abutment tooth and to find a method to improve its retention, support and stability. The model and framework in this experimental study simulated the posterior portion of the resected maxilla and obturator framework. The movement of the framework and abutment tooth under loading on the resected side were observed. And the retentive force under loading or pulling on the resected side was measured on each retainer designed by the three different paths of placement. The findings were as follows: 1. The typical movement of the framework and abutment tooth was seen under loading on the resected side. The framework rotated with a movement of the center of rotation from the middle of the residual palate to the resected and occlusal direction. And sliding on the palate to abutment direction was observed. 2. The abutment tooth inclined to the resected side, and also the mesio-distal and axial movements were observed. 3. The path of placement in designing affected the retentive force under loading or pulling force. 4. The optimum path of placement in designing the obturator and the method of finding it were discussed from the standpoint of retention and stability.

A Study on Image Analysis of distribution of Retentive Area on Abutment Teeth in Partial Denture

The purpose of this study was to propose the image analysis of the retentive area in removable partial denture by personal computer instead of surveyor.1. The image through CCD TV camera was processed on personal computer to recognized the shadow as the undercut area on the abutment teeth in removable partial denture. The binary processed image was reversed and added to the original one. The threshold level of digital processing was determined by density histogram of primary colors.2. The lines drawn by Laplacian emphasis corresponded to survey lines.3. The light was directed toward perpendicular to occlusal plane of the cast by the reflection of the mirror. The path of placement and removal was alternated by changing the inclination of the mirror. The distribution of undercut area on abutment teeth could be found repeatedly at different angles and the retentive areas in common to mesial and distal directions could be found by image calculating.

The hinged-clasp assembly removable partial denture

Severe undercuts and malpositioning of teeth can create problems with the path of insertion of removable partial dentures. Prostheses that have conventional clasp designs are not well-suited for these situations because a common path of placement must exist for all clasps. A technique that incorporates a hinged-clasp assembly to overcome this problem is described.