Abstract

The relative merits of laminagraphic and panographic radiographic images of the temporomandibular joint area have been compared.

Serial temporomandibular joint area radiographs were taken with a panographic unit. A dried human skull was used as the study subject. Wire grids were placed over the temporomandibular joint areas. The linear and angular distortion of the wire grids was measured with the plane of occlusion being serially tipped horizontally from minus fifteen degrees to plus fifteen degrees.

Lateral laminagraphs were then taken of the same skull with the wire grids still in place to determine the accuracy of the laminagraphic technique as compared to the panographic technique.

A second study was done with five dried human skulls. Each was radiographed laminagraphically and panographically, The results were then compared by measuring the differences linearly between the two images of the same condyle head.

The third part involved a clinical study of fifty temporomandibular joint areas which had been panographically and laminagraphically radiographed as part of an orthodontic screening program at Loma Linda University.

The results were as follows:

Magnification, angular and linear distortion of the temporomandibular joint area was present in all panographic radiographs. The least being when the occlusal plane of the study skull was positioned at zero degrees, as the chin is raised or lowered, the linear and angular distortion is in creased proportionally.

The lateral laminagraph of the same skull with the wire grids still in place, showed the grid image to be visually distortion-free.

The comparison study using the five skulls which were panographically and laminagraphically radiographed showed an overall magnification of sixteen to seventeen percent of the condyle heads in the panographs. General morphologic similarities of the same condyle head were noted between the laminagraphic and panographic techniques.

The clinical comparison study of the fifty temporomandibular joint areas showed many morphological dissimilarities in the condyle heads between the two techniques. This was felt to be caused by the laminagraph operators failing to take a deep enough "'cut" or section through the condyle head, therefore; the laminagraphic image of the condyle head was more narrow and shorter than the panographic image of the same condyle head as it failed, in many cases, to show the true anterior and posterior borders of the condyle head.

Both the laminagraphic and panographic techniques have their merits and drawbacks. The value of each technique de pends on the knowledge, skill and care that the operator exercises when obtaining either kind of radiographic survey of the temporomandibular joint area.

Because of the ease of reproducibility and standardization, the laminagraph appears to be superior for measuring the position of the condyle in the fossa, i.e. for ascertaining anterior, superior or posterior displacement.

Alien one considers the amount of standard deviation present in the clinical comparison study of both laminagraphic and panographic surveys, it is evident that in only a few cases is it possible to correlate a panographic survey of the same area with a laminagraphic survey of the same area on a one to one basis. At best, one could predict that the panographic survey will be magnified when compared to the laminagraphic survey and that morphologically, the shapes of the same condylar head will likely be dissimilar comparatively and no correlation is likely to be made between the two different methods.

However; if proper care is exercised, both types of radiographs may be of diagnostic value. From the findings obtained in this study, the writer thinks that the panographic technique is the most valuable for screening for temporomandibular joint pathology due to its ease of use, its readily availability and low patient dosage of radiation. When more definition is required of the temporomandibular joint area, a laminagraphic survey, using the proper techniques, is indicated.

LLU Discipline

Orthodontics

Department

Dentistry

School

Graduate School

First Advisor

J. Milford Anholm

Second Advisor

Lawrence W. Will

Third Advisor

James R. Wise

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

1980

Date (Title Page)

8-1980

Language

English

Library of Congress/MESH Subject Headings

Temporomandibular Joint

Type

Thesis

Page Count

vii; 43

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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