Journal of Dental Research, Vol 80, 2085-2088, Copyright © 2001 by International & American Associations for Dental Research Online Journals
Collagen fiber orientation affects osteoclastic resorption
V. J. Kingsmill and A. Boyde
Department of Adult Oral Health, Barts & the London Queen Mary's School of Medicine and Dentistry, UK. V.J.Kingsmill @qumul.ac.uk
The bone surrounding the teeth is constantly remodeled throughout life,
particularly during tooth movement and following tooth loss. Alveolar bone
proper contains many highly oriented extrinsic fibers, but whether their
orientation affects resorption is unknown. To determine if it does, we
selected sperm whale cementum to provide large anisotropic substrates
resembling extrinsic fiber bone. Slices cut either perpendicular or
parallel to the extrinsic fiber axis were cultured for 24 hours with
pre-hatched chick osteoclasts. Resorption pit areas and volumes were
measured by video-rate reflection confocal microscopic mapping. Pits in the
perpendicular group were smaller in area and were deeper than those in the
parallel group (median values, 402 micron2 and 572 micron2, n > 950, p
< 0.0001; volume/area 5.37 microm and 4.58 microm); volume differences
only just reached significance (2,137 micron3 and 2,554 micron3, p <
0.05). These results show that the fiber orientation within a substrate can
profoundly influence the shape of resorption lacunae. This pattern of
resorption may help in the maintenance of an optimally functioning
attachment of periodontal ligament fibers to alveolar bone.
