Journal of Dental Research, Vol 69, 1551-1554, Copyright © 1990 by International & American Associations for Dental Research Online Journals
Periostomy and growth of the mandibular condyle in the rat
D. M. Killiany
Department of Orthodontics, St. Louis University Medical Center, Missouri 63104.
It has been shown that a release of periosteal tension may augment the
growth of a long bone; however, similar experiments in the mandible have
produced equivocal results. For further definition of the role of
periosteal tension in the growth of the mandibular condyle, 80 young female
Sprague-Dawley rats were randomly assigned to four equal groups: (1) sham,
(2) condylotomy, (3) narrow periostomy, and (4) wide periostomy. All
procedures were performed unilaterally. Lateral cephalograms, transcranial
condylar radiographs, and metallic implants made possible the measurement
of the actual increment of condylar growth over three post-operative
periods: 0 to 14 days, 14 to 28 days, and 0 to 28 days. Analysis of
covariance was performed (weight gain as the covariate) and, where overall
significance was found, Turkey's HSD test was used for determination of
individual group differences. Conservative, circumferential periostomy of
the condylar neck as well as condylotomy failed to alter the condylar
growth rate, whereas removal of a wide band of periosteum led to a small
decrease. These findings suggest that, at least in the rat, periosteal
tension plays only a minor role-if any-in the control of
condylar/mandibular growth. Furthermore, a subsequent increase or decrease
in condylar growth, in experiments that use a condylotomy model, cannot be
attributed solely to a disturbance in periosteal integrity caused by the
condylotomy.
