Abstract

A study of the pattern of malocclusion of the six lower permanent anterior teeth in subjects with malocclusion and no history of orthodontic treatment was undertaken to determine if the malocclusion of these teeth occurred in a random manner or followed a definite regular pattern.

The problem was approached epidemiologically by studying the positions assumed by the teeth in 408 males and females age 12 to 23. The subjects of this investigation were enrolled as students in the grammar school, academy, college and university system of the Pacific Union Conference of Seventh-day Adventists.

The method of visual assessment of malocclusion as advocated by Massler and Frankel was employed to determine the type of malocclusion of the individual tooth.

The relationship of the mesial and distal halves of each of the teeth to the contact line was determined as being on line, buccally displaced, lingually displaced or combinations of buccal and lingual displacement. The relationship was determined for each age group, for developmental age groups and for the total sample.

The relationship of the seven contact areas adjacent to the teeth was determined as being normal, spaced or crowded. The number of subjects presenting each of the spacing conditions for each of the seven spaces considered were obtained for individual age groups, for developmental age groups and for the total sample. The relationships and frequencies observed were also related to the sex of the subject.

Other measures obtained included the number of subjects presenting Angle Class I, II, III and mixed malocclusions and the mean overbite for each age group, for developmental age groups and for the total sample.

Teeth, teeth positions, contact areas, contact area relationships, age, sex, Angle Classification and overbite were assigned identification numbers and coded for processing by the IMB 082 Sorter at Loma Linda University.

The following is a brief summary of the more significant findings of this investigation.

1. The malocclusion of the lower permanent anterior teeth seems within broad limits to follow a definite pattern.

2. The most frequently maloccluded teeth in descending order are the left lateral incisor, right lateral incisor, right cuspid, left central incisor, left cuspid and right central incisor. The positions most frequently assumed by these teeth when maloccluded are:

A. Left and right cuspids - mesial one-half displaced buccally - distal one-half displaced lingually.

B. Left and right lateral incisors - lingually displaced.

C. Left and right central incisors - mesial one-half displaced lingually - distal one-half displaced buccally.

3. The deviation from normal of the contacts adjacent to the teeth seems within broad limits to follow a definite pattern.

4. The contacts most often spaced in descending order are located between right cuspid and first bicuspid, right cuspid and lateral incisor, left cupid and first bicuspid, left cupid and lateral incisor, right central and lateral incisors, left and right central incisors and left lateral central incisors.

5. The contacts most often crowded in descending order are located between left cuspid and lateral incisor, right cuspid and lateral incisor, right lateral and central incisor, left lateral and central incisors, left and right central incisors, right cuspid and first bicuspid and cuspid and first bicuspid.

6. Class I, II and III malocclusions occur in males in the ratio of 12:2:1 and in females of the ratio of 29:6:1.

7. The mean overbite decreases with age and for the total sample measures 3.51 millimeters (approximately 40.3 per cent of the crown height of the lower central incisors).

LLU Discipline

Orthodontics

Department

Dentistry

School

Graduate Studies

First Advisor

Thomas J. Zwemer

Second Advisor

Kenneth R. Lutz

Third Advisor

Saleem Assad Farag

Fourth Advisor

Ralph R. Steinman

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

Malocclusion

Type

Thesis

Page Count

ix; 104

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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