Abstract

The magnitude, and manner of application of forces effects the whole complex picture of tooth movement. Proper mechanical management in terms of the individual tooth as well as the entire arch, must be kept in mind. When applying forces for producing individual tooth movement as desired in cuspid retraction, we must consider the nature of the biological resistance in terms of the force distribution in the periodontal membrane as well as the force magnitudes necessary for efficient tissue response.

Since the alteration of wire configuration offers the greatest potential in changing the physical properties of a unit of wire, the ability of different wire configurations to meet the clinical demands as well as biological requirements of cuspid retraction should be given consideration.

An instrument was designed and utilized for carrying out a two dimensional analysis of force distribution produced by various wire configurations at the two points in the periodontal membrane which offer the greatest resistance to tipping.

It was found that at force levels which have been established as being efficient and yet safe for cuspid retraction, a force distribution exists which would not promote bodily tooth movement during the initial stages of cuspid retraction. Force levels are recommended which develop a distribution tending to minimize the amount of tipping, yet being at levels which are considered to be safe and effective.

If loop springs are utilized, the stiffer configurations (consisting of less wire length) supply a more uniform force distribution but allow less activation distance within physiologic limits. Loops offer the advantage that root torque may be incorporated into the design, favoring a more uniform distribution. Straight wire offers the greatest potential of stiffness but has the disadvantage that root torque is not developed until the cuspid has been allowed to tip.

The tipping property of loops is effective in attaining a uniform force distribution by aiding in the development of a greater force at the apex when the loop is activated.

The findings of this investigation lend support to the following conclusions:

  1. Production of a force distribution which would theoretically result in pure bodily movement during cuspid retraction, is not a practical reality with the mechanisms tested.

  2. The relatively higher retraction forces will more likely produce distal crown tipping.

  3. Resiliency and force control, are incompatible factors in orthodontic mechanics.

  4. The use of loops offers a great potential in altering force distribution.

  5. Further studies should be undertaken involving three dimensional analysis of force distribution produced by these and other wire configurations. Further clinical experimentation would be of value in determining the correlation of theoretical measurements with experimental clinical findings.

LLU Discipline

Orthodontics

Department

Dentistry

School

Graduate School

First Advisor

Thomas J. Zwemer

Second Advisor

Melvin R. Lund

Third Advisor

Robert L. Nutter

Fourth Advisor

Robert W. Woods

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

1963

Date (Title Page)

6-1963

Language

English

Library of Congress/MESH Subject Headings

Dental Instruments; Cuspid

Type

Thesis

Page Count

vii; 40

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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