Bisphosphenate
Induced Osteonecrosis
Osteonecrosis
of the jaws in patients with bone metastasis from a variety of
solid tumors, breast cancer, and multiple myeloma has been reported
in the literature. In the last two years the number of reports
of this type has increased significantly. The patients are invariably
on an intravenous bisphosphenate regimen. Bisphosphenates have
a primary function of inhibiting bone resorption and maintaining
bone density. Common names for these medications are: Zometa,
Aredia, Fosamax, Bonvia, Actonel, Skelid, Bonefos, and Didronel.
Also any generic drugs ending in the suffix - “dronate”
are included. There have been multiple case reports in the medical
literature, however, none have appeared earlier than 2003 and
the drug company Novartis Pharmaceuticals did not alert dentists
to possible oral problems with the drug until May of 2005.
The mechanism is thought to be inhibition of osteoclastic function
which results in the suppression of normal bone metabolism and
inhibited vascularity. In the oral cavity, the maxilla and mandible
are subjected to constant stress from masticatory forces. This
combined with the bacterial flora of the oral environment make
bisphosphenate related osteonecrosis more common in the mouth
than other parts of the body.
The initial clinical clinical presentation may be seen as a boney
sequestrum protruding through the mucosa. Some sequestra occur
spontaneously or can be associated with trauma from sharp food
items.
Bisphosphenate associated osteonecrosis has significant clinical
implications because many patients fail to heal after dental surgical
procedures.
CLINICAL CONSIDERATIONS
Routine restorative treatment with local aesthesia can be provided.
The mucosa should be as trauma free as possible, especially during
scaling and prophylaxis.
Teeth that are extensively carious should be considered for endodontic
treatment, extraction should be avoided whenever possible.
Orthodontic extrusion until the root tip is free of the alveolar
bone is an alternative for extraction.
The exposed bone can only be treated minimally with superficial
debridement. Antibiotic and chlorhexidine rinses are recommended.
** Patients may not remember to inform their dentist that they
have received an intravenous drug because it may only be administered
once per month in a hospital oncology unit.
** The oral medication Fosamax is more likely to be reported on
the medical history because it is taken daily or weekly. Fosamax
is sometimes used with intravenous bisphosphenates.
** Written medical histories can be used to query the patient
for specific drug use, for example, past use of the diet drug
Phen-Fen. A recommendation for managing potential problems with
bisphosphenates is to specifically ask about use of Fosamax or
“other osteoporosis type medications” in the medical
history.
The
December 2005 issue of the Journal of the American Dental Association
has devoted the cover story and three clinically significant articles
to this important topic
ESCONDIDO
ENDODONTICS 488 EAST VALLEY PARKWAY SUITE 307 ESCONDIDO, CA 92025
(760) 739-1400
FAX (760) 739-1100 www.escoendo.com
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