Abstract

Utilizing an extra-oral approach and sterile technique, left mandibular ostectomy was performed on five miniature pigs. The segment removed was 3 cm long and included the inferior border, mandibular canal and, in some cases, apices of a molar tooth.

Bone and plaster grafts (one solid and one canalized of each) were used to fill these defects. The fifth was left with no graft.

The objective was to learn the effect of each of these procedures on regeneration of the mandibular nerve across the defect. It was hypothesized that canals through the grafts would facilitate regeneration.

X-rays were taken periodically. The animals were sacrificed approximately four months postoperatively and the mandibles fixed in formalin. Pig "Baker" was sacrificed one month postoperatively due to bilateral fractures of the mandible. Cross sections of hard and soft mandibular tissues were prepared for microscopic examination.

In Baker with the fracture, which occurred through the solid plaster graft, some plaster remained unresorbed. A fibrous connective tissue "capsule" surrounded it and obstructed the mandibular canal. Just proximal to this obstruction early nerve regeneration in the pattern of an amputation neuroma had occurred. Some new bone had formed between the periosteum and the remaining plaster.

In the other four animals the ostectomy site was completely replaced by osseous and fibrous tissue with no demonstrable continuous canal. Proximal to the surgical site in each case there was a nerve configuration consistent with amputation neuroma.

In several animals there was dense fibrous connective tissue occupying the canal at the proximal or distal ends of the surgical sites. In all cases the proximal portion of the nerve appeared more vital than the distal nerve tissue. In Baker the distal portion looked better than in the others--probably because it had less time to degenerate.

Conclusion: Canals through bone and plaster grafts, as used in this study, did not appear to significantly promote nerve regeneration across a defect. This was presumably due to fibrosis of canal ends before the nerve had regenerated across these areas.

School

Graduate School

First Advisor

Bernard C. Byrd

Second Advisor

Irving I. Rappaport

Third Advisor

Guy M. Hunt

Fourth Advisor

Elmer E. Kelln

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

1969

Date (Title Page)

8-1969

Language

English

Library of Congress/MESH Subject Headings

Mandibular Nerve

Type

Dissertation

Page Count

iv; 45

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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