Abstract

Modification of cephalometric roentgenographic procedures provided a means to identify the anterior borders of the right and left masseter muscles and relate them to surrounding dentoskeletal elements. Attachment of short, stiff, wires to the cheeks in a position superficial to the anterior borders of the muscles, subsequent to palpation and prior to exposure of the roentgenographic film, was the procedure used. The bi-lateral images projected on the film were averaged and traced along with dentoskeletal elements including those associated with skeletal type. This line representing the anterior border of the musculature was used to assess muscle position in the vertical and anterior-posterior dimensions of space.

Five measurements indicative of skeletal type were employed for the purpose of dividing a sample of 80 subjects into three groups. The statistic of one standard deviation from the mean was used to divide the sample into groups representative of skeletal open bite, closed bite and "normal." The values obtained from the cephalometric tracings were subjected to statistical procedures, including student "t" tests and correlation analysis to compare muscle position between the two extreme groups.

Comparison of the skeletal open bite and closed bite groups revealed a more horizontally placed masseter musculature, relative to S-N, Frankfort and palatal planes, in the open bite group. The skeletal open bite group had a more vertically inclined musculature than did the closed bite group when relating it to the mandibular plane. Masseter muscle attachment sites, per se, revealed no apparent difference between the two groups. Masseter muscle inclination, relative to occlusal plane, was the same in skeletal open bite and closed bite individuals.

LLU Discipline

Orthodontics

Department

Dentistry

School

Graduate School

First Advisor

Howard W. Conley

Second Advisor

Charles T. Smith

Third Advisor

Karl K. Nishimura

Fourth Advisor

Steve N. Asahino

Fifth Advisor

John P. DeVincenzo

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

Masticatory Muscles

Type

Thesis

Page Count

v; 60

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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