Biomedical Engineering Reference
In-Depth Information
1
1
1
1
1.5
1.5
2
3
2
3
4
4
5
5
6
8
6
8
Z
Z
XY
XY
(a)
(b)
1
1
1
1
1.5
1.5
2
2
3
4
3
4
5
5
6
Z
6
Z
XY
8
8
XY
(c)
(d)
FIgure 20.5
(See color insert.)
Simulated distribution of apparent bone density (g/cm
3
) under the differ-
ent actions of orthodontic loading. (a) Tipping; (b) rotation; (c) extrusion; and (d) intrusion. The cross-section
of the model is shown in each case.
the affected region was smaller than that of case (a). For case (d), the direction of orthodontic load-
ing was opposite to case (c). When the tooth was intruded into the alveolar bone, the cortical bone
undertook most of the mechanical loadings, thus the cancellous bone densification was less than
that of other three kinds of orthodontic treatment (Figure 20.5d).
20.3.2 S
imulation
of
a
lVeolar
B
one
r
emodelinG
i
nduced
By
i
implant
-S
upported
f
fixed
p
artial
d
enture
WitH
or
WitHout
c
antileVer
e
xtenSion
Figure 20.6 shows changes in bone density, which varied from 0.20 to 2.0 g/cm
3
, from the beginning
to the end of the 18-month simulation. The relative variation in Model A (a single implant-supported
two-unit cantilever FPD) was small and stable under loading, and the highest value was concen-
trated in the area closer to the alveolar margin. In contrast, the maximum density in Model B (a dou-
ble implant-supported two-unit non-cantilever FPD) was evidently adjacent to the root of the dental
implant and the minimum value was located around the cortical neck area. The blue color around
the neck of the implant represents regions with very low density caused by overloading resorption.
20.3.3 S
imulation
of
tHe
B
one
r
emodelinG
p
roceSS
of
tHe
i
internal
B
one
a
rcHitecture
around
tHe
d
ental
i
implant
Figure 20.7 shows the complete history of the simulated remodeling process of the internal bone
architecture around the threaded cylinder implant during iterations. As demonstrated in this figure,
the morphology of the trabecular architecture changes gradually from an initial uniform state to a
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