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FIGURE 33.17 Craniofacial reconstruction from a cone-beam CT scan of a type III OI patient following orthodontic and prosthetic treat-
ment.
Treatment of Malocclusions Affecting OI
Patients
The most important limiting factor for tooth move-
ment is the underlying condition of the bone. 72 OI type I
patients can receive orthodontic treatment as their treat-
ment response to orthodontic forces is fairly similar to
a normal population, 48 and the extent of their malocclu-
sion is also manageable in private orthodontic offices.73 73
Types III and IV present much more complicated
challenges. Their craniofacial deformities are much
more severe, especially the Class III lateral open-bite
malocclusions found in a great proportion of these
patients. Closure of the lateral open-bites would be of
great benefit to these patients in order to restore their
masticatory function.
Orthodontic tooth movement should be expected to be
markedly slowed due to the lack of bone resorption caused
by the bisphosphonates. 48 Clinically, the effect on the rate
of tooth movement is variable, and may be most extreme in
the posterior dentition of OI type IV or III patients.
Figure 33.19 shows the lower incisors of an OI type III
patient treated with fixed appliances for 18 months. No
root resorption was evident and anterior teeth moved
slowly but normally while posterior teeth proved to be a
challenge, and showed minimal movement. Despite con-
stant wear of orthodontic elastics, they never showed any
signs of mobility. More research is actually being conducted
on mice in our laboratory to hopefully elucidate some of
the questions related to tooth movement in OI patients.
FIGURE 33.18 Lateral cephalometric radiograph and tracing of
an OI type III patient presenting with severe lateral open-bite and
retrusive maxilla. Cephalometric measurements are markedly abnor-
mal horizontally and vertically.
malocclusion, the facial balance is almost normal at this
age (10 years old).
The OI type III patient in Figure 33.18 , while
older (14 years old), presents a marked delay in
tooth eruption. Impacted teeth are clearly visible.
Cephalometrically, SNA of 65 degrees shows a marked
reduction of the maxillary projection (norm is 81
degrees). SNB angle is almost normal at 75 degrees
(norm is 78 degrees). Mandibular projection is increased
by the clockwise rotation of the mandible as illustrated
by the Y-axis of 53 degrees (norm is 64 degrees) result-
ing in a reduced lower face height and mandibular
anterior position.
CONCLUSION
Dental defects associated with OI have been
reviewed.
 
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