Abstract

The articulator as we know it has evolved since the late 1700's, however, it has not changed much in function since the 1970's. Our methods of determining contact information i.e., centric stops and pre-maturities also has not changed much beyond that of "carbon paper". With the advent of new computer technologies, dental models are now being placed into the virtual world through variations of image slicing and laser scanning. The purpose of this paper is to determine if the Occlusogram developed by OrthoCad is as accurate as common methods currently used to determine occlusal contacts.

Twenty dental students volunteered to have upper and lower polyvinylsiloxane impressions taken along with facebow recordings and bite registrations including CO and CR. One set of models was prepared and mounted using the Sam II articulator. Another identical set of models, poured from the same impressions and trimmed by the same investigator using the same CO and CR bite registrations were sent to OrthoCad for computer entry.

The mounted articulated models were checked with articulating paper in both CO and CR. The models, with marked occlusal contacts, were scanned into a computer using a 1200 dpi scanner by Umax. The scanned images were superimposed, using Adobe Photoshop 6.0, onto the digital images of the virtual models provided by OrthoCad. The virtual contact markings were compared to the contact markings of the articulated models determined by three experienced dentists to be valid markings. The investigator performed statistical analyses including descriptive statistics and the Wilcoxon signed rank test at α= .05. Results showed that there was a statistically significant difference between the methods for determining contact similarity. The standard articulated models displayed more contacts that were verified by the 3 evaluators than the OrthoCad models. The OrthoCad occlusogram for contacts, did show that the occlusogram had at least 64% of the contacts also recognized on the articulated models for the sum in CO. Though this is not currently at a stage to displace the accuracy of articulated models for the purpose of occlusal contact determination, the method does show promise.

LLU Discipline

Orthodontics and Dentofacial Orthopedics

Department

Orthodontics and Dentofacial Orthopedics

School

Graduate School

First Advisor

Joseph M. Caruso

Second Advisor

Craig A. Andreiko

Third Advisor

Mike J. Fitzpatrick

Fourth Advisor

Jay S. Kim

Fifth Advisor

V. Leroy Leggitt

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

2001

Date (Title Page)

6-2001

Language

English

Library of Congress/MESH Subject Headings

Orthodontics Appliances; Dental Articulators; Centric Relations

Type

Thesis

Page Count

viii; 31

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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