Abstract

A controlled clinical study of cuspid and incisor retraction using the mechanics advocated by Charles H. Tweed on class I four first bicuspid extraction cases was conducted. A carefully restricted sample of seven patients, three boys and four girls, was treated by seven graduate orthodontic students at Loma Linda University.

Measurements were made at monthly intervals to assess cuspid, incisor, and molar movements. Data were collected at each appliance adjustment to evaluate pain, difficulty, length of appointment, and the observations and impressions of each clinician regarding the technique.

The mean rates of cuspid movement during the cuspid retraction phase of treatment were -.65 ± .09 mm. per month in the maxilla, -.53 ± .07 mm. per month in the mandible, and -.59 ± .07 mm. per month combined. During the cuspid retraction phase of treatment the mesial molar movement were found to be .34 ± .06 mm. per month in the maxilla, .40 ± .06 mm. per month in the mandible, with a combined rate of .37 ± .06 mm. per month. Cuspid retraction was found to be translatory in both arches.

Incisor retraction rates were -1.00 mm. per month in the maxilla, -.54 mm. per month in the mandible and -.77 mm. per month combined. Anchorage loss was .27 mm. per month in the maxilla, .66 mm. per month in the mandible, with a combined rate of .44 mm. per month.

The average increase in skeletal height (1.0 inches) occurring during treatment and the average increase in the length of S-N (1 mm.) were shown to be statistically insignificant. Therefore growth apparently had little effect on the results.

The various cephalometric measurements were generally nearer accepted normal values at the end of the study than at the beginning. Of particular interest are: FMA 30.4° - 31.0°, IMPA 96.7° - 91.1°, FMIA 52.9° - 57.9°, and ANB 4.9° - 4.2°.

Subjective measurements indicated that pain intensity (1.6 + .2 on a scale of 0-5) and duration (1.3 ± .2 days) were very low. Use of the appliance was judged average in difficulty (2.4 ± .1 on a scale of 1-5) and the length of the appointments was found to be 63 ± 4 minutes. There was no apparent root resorption and oral irritation as a result of the appliance was minimal and the patients showed good oral hygiene.

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

Joseph Jacobs

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

Cuspid; Incisor; Dental Instruments

Type

Thesis

Page Count

vi; 33

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

Download

Share

COinS