Abstract

The purpose of this study was to determine the effects of midpalatal suture separation on the craniofacial complex by quantitative roentgenographic analysis.

Ten female Macaca mulatta monkeys were randomly grouped for experimentation. Six animals were paired in groups for two months of treatment, four months of treatment followed by two months of post retention, and six months of treatment. The four remaining monkeys were paired and served as control animals for two and six month periods. Total activation of the expansion appliances in the treated animals was completed over a three week period.

The findings of this study were based on tracing measurements obtained from occlusal, cross sectional cephalometric, and frontal and lateral cephalometric roentgenograms.

The findings were as follows:

  1. Increases of up to 6.0 mm. were recorded in alveolar arch width and 7.0 mm. in dental arch width.
  2. The beginning normal occlusion was forced into a bilateral buccal cross-bite malocclusion in the treated animals.
  3. Changes in dental arch length were minor, inconsistent, and unpredictable in both the treated and control group animals.
  4. The palatal processes were rotated in an upward and outward direction about the midpalatal region. The midpalatal region moved downward resulting in a lowering of the palatal vault.
  5. The separated midpalatal suture was rapidly filled with new bone and remained stable thereafter.
  6. The teeth were carried bodily rather than being tipped later ally as shown by biometric analysis.
  7. The laterally displaced teeth tended to revert back to a more vertical position following removal of the appliance while the palatal processes remained unchanged in position.
  8. Adjacent sutural adjustment areas seem to govern the amount and direction of movement of the affected facial bones.
  9. Greatest changes in the lateral dimension were shown to occur in the lower levels of the vertical plane, decreasing superiorly to the fulcrum of movement located in the fronto-maxillary suture.
  10. Separation of the midpalatal suture was shown to cause a decrease in the mandibular and palatal plane angles, and to increase the occlusal plane angle. The premaxilla, represented by prosthion, remained relatively stable anteroposteriorly during the expansion procedure.

The findings of this study clearly illustrate the changing spatial relationship of the craniofacial complex during the expansion procedure. Treatment planning of cases selected for maxillary expansion in clinical practice demands a thorough understanding of the overall effects of orthopedic movement and should not be limited solely to correction of occlusal relationships.

LLU Discipline

Orthodontics

Department

Dentistry

School

Graduate School

First Advisor

Howard W. Conley

Second Advisor

Alden B. Chase

Third Advisor

Edwin H. Collins

Fourth Advisor

Karl K. Nishimura

Fifth Advisor

Roland D. Walters

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

1968

Date (Title Page)

6-1968

Language

English

Library of Congress/MESH Subject Headings

Facial Bones; Palate

Type

Thesis

Page Count

viii; 77

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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