Abstract

Gnathologists have suggested that in order to prevent excessive wear on posterior teeth, alveolar bone loss due to traumatic occlusion, and temporomandibular Joint (TMJ) disturbances, the mandibular incisors should disclude the posterior teeth by moving along the lingual surfaces of the maxillary incisors as the condyles move down the articular eminence in protrusion. It is suggested that in order for this to occur, the lingual surface of the maxillary incisors should be steeper than the eminence.

A cephalometric technique was developed to accurately determine the anatomical form of the articular eminence. A regular orthodontic tracing of the head was done including the articular eminence and the lingual surface of the maxillary incisor. A line was drawn that best fit the downward slope of the articular eminence, to intersect S-N plane. Next a line was drawn from the inferior lingual surface of the maxillary central to the point where the mandibular centrals met the maxillary centrals in centric, to intersect S-N plane. The angulation of these lines to S-N plane from 11 ideal occlusions were compared.

On five of these 11 patients who had traceable occlusal tooth surface, their functional condylar path was transferred to the tracing. The mandible was moved down its functional path with the mandibular incisors in contact with the lingual surface of the maxillary incisors. The effect on the posterior occlusal table was noted. The mandible was then moved down its functional path, with its molar inclined planes in contact with the maxillary molar inclined planes, showing the effects if no anterior disclusion were present.

On each patient, the path of lingual surface of the maxillary incisors was more vertical than the eminence and each of the patients exhibited anterior disclusion. On each of the five patients, the inclined plane of the mandibular molars were in contact with the inclined planes of the maxillary molars when anterior disclusion was absent. Conversely in the presence of anterior disclusion the molar inclined planes were immediately released from centric relation in the protrusive movement of the mandible.

LLU Discipline

Orthodontics

Department

Dentistry

School

Graduate School

First Advisor

Roland D. Walters

Second Advisor

Llyod Baum

Third Advisor

Alden B. Chase

Fourth Advisor

John P. DeVincenzo

Fifth Advisor

Edwin F. Shryock

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

1970

Date (Title Page)

6-1970

Language

English

Library of Congress/MESH Subject Headings

Mandible; Incisor

Type

Thesis

Page Count

vii; 58

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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