Journal of Dental Research, Vol 72, 1356-1359, Copyright © 1993 by International & American Associations for Dental Research Online Journals
Increased condylar growth after experimental relocation of the glenoid fossa
P. Pirttiniemi, T. Kantomaa and M. Tuominen
Department of Orthodontics, University of Oulu, Finland.
Attempts to increase mandibular growth by the stimulation of condylar
proliferative activity, either experimentally or with functional appliances
in humans, have led to controversial results. The aim of this study was to
measure changes in proliferative activity in the mandibular condyle after
steady experimental posterior relocation of the glenoid fossa in the rabbit
without actively interfering with normal masticatory action. The method
differed from most previous experimental procedures, which force the
mandible anteriorly to stimulate functional appliance therapy. Twelve
5-day-old rabbits underwent gluing of the interparietal, temporoparietal,
and lambdoidal sutures. Three experimental and three control rabbits were
injected with tritiated thymidine at 10, 15, 20, and 30 days and were
killed after 2 h for histological and autoradiographic examination. The
total number of labeled cells in the prechondroblastic layer was higher in
the experimental group, the difference being greatest in the 20-day-old
rabbits. The highest proliferative activity in the experimental group was
found in the area immediately posterior to the articular contact surface.
There was a tendency for the cartilage layers to be thicker in the
experimental group, especially in the extreme anterior segments of the
condyle.
