Abstract

In a clinical study, polyurethane-type plastic modules were evaluated for use in retracting cuspids and incisors in Class I extraction cases.

Seven patients were selected to be treated with a technique utilizing these plastic modules. All cases were in Class I molar relationship and were either bimaxillary, protrusive or had tooth-size, arch-length discrepancies.

Evaluation was based on rate of cuspid and incisor retraction and the control of molar anchorage during the retraction phase.

At four-week intervals data were collected on space closure. At the same time, such subjective data as amount and duration of pain, difficulty of appliance adjustment and length of appointment, were recorded.

A basic philosophy of this technique was to establish a rigid template along which the cuspids could be retracted. Heavy forces were applied which caused tipping of the cuspids until the bracket bound on the arch wire and the movement stopped. Apparently occlusion then helped to upright the teeth and movement was again allowed to proceed.

The mean rate of cuspid retraction was .96 mm. per month with .16 mm. per month of forward molar movement. The combined per cent of cuspid retraction was found to be 83 per cent. Mean skeletal growth was 1 3/8 inches during the study with a mean change in the length of S - N of .6 mm. The principle cephalometric changes were an opening of the mandibular plane angle of 3.8 degrees, extrusion of the molars, and forward positioning of the mandibular incisor roots.

Forces were heavy and intermittent with an initial force of 24 to 28 ounces. From the data it appears the technique, as described, provides an excellent method of preserving anchorage.

The rate of retraction was greater in the maxilla than in the mandible; however, from a clinical point of view, the rate in both appeared quite rapid.

From this data, it could be concluded that the amount of pain was negligible. Considering the simplicity of the appliance adjustments and average length of each appointment, the technique was considered practical to use and would appear to be efficient from a clinical point of view.

LLU Discipline

Orthodontics

Department

Dentistry

School

Graduate School

First Advisor

Roland D. Walters

Second Advisor

John P. DeVincenzo

Third Advisor

Jack L. Tomlinson

Fourth Advisor

John K. Pearson

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

1972

Date (Title Page)

5-1972

Language

English

Library of Congress/MESH Subject Headings

Orthodontic Appliances; Cuspid; Incisor

Type

Thesis

Page Count

vi; 32

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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