The effect that a reduction of alveolar height has on
stress in the tooth and the alveolar bone induced by
a labio-radicular torque on an inferior canine has
been analized using the Finite Element Method
(FEM). The torque was produced by a couple of 50
g mm applied in the centre of the labial side of the
crown; then the stress in the tooth and the alveolar
bone were calculated on a three-dimensional model.
Successive computations were performed after
reducing the heigth of the alveolar bone by 2, 4, 6
and 8 mm. With 4 mm of loss, an important compression
zone arises on the labial side of the alveolar
bone in the apical region of the model. The same
behavior was seen after 6 or 8 mm of bone loss.
From this results we conclude that the possibility of
undesirable effects of an orthodontic treatment increases
considerably in patients who have suffered
periodontal disease with loss of bone support.
(Rev Esp Ortod. 1999;29(1):027-031)