what-when-how
In Depth Tutorials and Information
teeth are lost. There are no studies that compare bone
loss under dentures in people with OI to people with-
out OI. The bone loss that occurs when teeth are lost is
a resorption of the bone, not a fracture process, so it is
not known if bone loss would be more rapid in people
with OI. Complete dentures in children and adolescents
who are still growing will need to be adjusted and/or
remade on a routine basis to compensate for growth in
the jaw.
Removable partial dentures are used when some
teeth remain in one or both jaws. A denture, typically
made with a metal framework for strength and reten-
tion, is constructed to replace missing teeth.
13
of non-OI patients on bisphosphonates who receive den-
tal implants. In a group of 115 patients over the age of
40 years who were taking oral bisphosphonates (mean
duration 38 months) before (89/115) or after (26/115)
the placement of a total of 468 implants, the overall
success rate was the same as those not on oral bisphos-
phonates.
44
There was no osteonecrosis reported in
this group. As stated by Grant et al.
44
“There is insuffi-
cient evidence to suggest that implant placement, tooth
extraction, and other surgical treatments should be rou-
tinely avoided for patients receiving oral bisphosphonate
therapy. Instead, evidence suggests that frequent clinical
and radiological examinations with prompt treatment
of problems will minimize potential risks.” A distinc-
tion is made between the risk in older patients based
upon using oral versus intravenous bisphosphonates,
and other factors.
45,46
It has been recommended that
“Placement of dental implants should be avoided in the
oncology patient exposed to the more potent IV bisphos-
phonate medications (zoledronic acid and pamidronate)
on a frequent dosing schedule (4 to 12 times annually).”
47
Dental Implants
Dental implants are used to replace missing teeth.
Theoretically it is possible to do this successfully for
a person with OI and there is anecdotal evidence that
this has been accomplished. However, there are no con-
trolled studies on the use of dental implants in people
with OI and only a few case reports (two with sinus
augmentation and two with alveolar augmentation to
increase bone to place implants) in the literature.
37-42
A study of retrospective and prospective data on
implant survival in OI and non-OI individuals showed
the long-term failure rate in OI patients was essentially
that of non-OI patients from the literature.
43
It should
be noted that the OI cohort consisted of ten type I, two
type VI and two type III subjects that received a total
of 46 implants. None of the subjects were using or had
used bisphosphonates.
Dental implants are somewhat like screws that go
into the alveolar (jaw) bone. Since the implants osseo-
integrate, they cannot grow with the increasing verti-
cal dimension of a growing patient like natural teeth
with a periodontal ligament. Thus they are generally
contraindicated in patients until they have completed
their facial growth. In order to function, there must be
enough bone in the jaw for the implant to be securely
placed. After healing, a “post” is placed in the implant
and an artificial tooth is attached.
Good, strong healing around the implant is criti-
cal, as is continued healing of small microfractures
of the bone around an implant that occur over time
as the individual chews. The body normally does this
through bone remodeling. However, it is expected that
this physiologic process will be diminished in indi-
viduals taking bisphosphonates. While this typically
decreases the incidence of fractures in individuals with
OI, it could also increase the long-term failure of dental
implants.
While there are no reports on the long-term survival
of dental implants in OI patients who are using or have
used bisphosphonates, there are reports on the outcome
Orthognathic (Jaw) Surgery
As will be discussed in the next sections, individu-
als with OI (especially types IV and III) often have the
upper jaw, or maxilla, not grow as much as the lower jaw,
or mandible. Sometimes the way that both jaws grow
makes it difficult, if not impossible, to bring the teeth
together properly, even after orthodontic braces. If the
malocclusion is due to a problem with the growth of one
or both jaws, then a combination of orthodontic braces
and orthognathic surgery may be used to align the teeth.
Some period of orthodontic braces is also usually needed
after the jaw surgery. There are a few published reports
about these surgeries indicating good post-operative
healing of the jaws. The same concerns that one would
have with any surgery in people with OI, such as
potential bleeding problems and reaction to general
anesthesia, still apply. Furthermore, the recent use of
bisphosphonates to treat different bone disorders triggers
many additional questions regarding jaw surgeries.
13,48
CRA
NIOFACIAL FEATURES OF
OI
The collagen abnormality has a variable second-
ary effect on craniofacial development that approxi-
mates the severity of the effect on the long bones as
expressed by a diminished height Z-score. There is also
a trend that cranial base anomalies are more common in
patients who also have DI. The base of the skull shows
platybasia (11%), basilar impression and basilar invagi-
nation (26%), and multiple Wormian bones have been
described, especially in types IV and III patients.
3,49-51
