Is bone turnover of jawbone and its possible over suppression by bisphosphonates of etiologic importance in pathogenesis of bisphosphonate-related osteonecrosis?
OBJECTIVE
The pathogenesis of bisphosphonate-related osteonecrosis of the jaw (BRONJ) is not completely understood. The most popular hypothesis has suggested that the bone turnover (BT) in the jawbone is greater than that in other sites and that this turnover will be overly suppressed by bisphosphonates. Using bone scintigraphy, a simple tool for the quantitative evaluation of bone metabolism and blood flow, the goals of the present study were to determine whether the rate of bone remodeling is greater in the jaw and whether the bone BT in the jaw is differentially altered after bisphosphonate intake compared with that in other skeletal sites.


METHODS
The bone scintigraphies of 90 female patients with breast cancer were retrospectively analyzed (n = 45 with bisphosphonate intake; n = 45 without bisphosphonate intake [control group]). All patients in the study group had undergone bone scintigraphy before therapy and during the treatment (course after 12 and 24 months). The data were quantitatively analyzed using 6 predetermined regions of interest.


RESULTS
The bone BT of the mandible was similar to that of the femur and significantly reduced compared with that of the maxilla (P < .01). None of the investigated bone regions (including the mandible and maxilla) were significantly altered after bisphosphonate administration (P > .05).


CONCLUSIONS
The finding that the mandible had significantly lower bone BT than that of the maxilla and that two thirds of BRONJ cases occur in the mandible were inconsistent with the investigated hypothesis. Furthermore, the bone BT in the jawbone was not overly suppressed by bisphosphonates. Thus, it is unlikely that over suppression of bone BT is the exclusive causation playing a role in the pathomechanism of BRONJ.
Resident, Medizin and Ästhetik, Clinic for Oral and Maxillofacial and Plastic Surgery, Munich, Germany; and Dental Medical Student, University of Munich, Munich, Germany. Electronic address: ristow@aesthetik-muenchen.de.
Oliver
O
Ristow
Resident, Department of Nuclear Medicine, Technische Universität München, Munich, Germany.
Carlos
C
Gerngroß
Head, Department of Nuclear Medicine, Technische Universität München, Munich, Germany.
Markus
M
Schwaiger
Senior Consultant, Department of Oral and Maxillofacial Surgery, Technische Universität Munich, Munich, Germany; and Partner, Medizin and Ästhetik, Clinic for Oral and Maxillofacial and Plastic Surgery, Munich, Germany.
Bettina
B
Hohlweg-Majert
Statsistician, Institute of Medical Statistics and Epidemiology, Technische Universität München, Munich, Germany.
Victoria
V
Kehl
Resident, Department of Obstetrics and Gynecology, Technische Universität München, Munich, Germany.
Heike
H
Jansen
Dental Medical Student, University of Munich, Munich, Germany; and Resident, Medizin and Ästhetik, Clinic for Oral and Maxillofacial and Plastic Surgery, Munich, Germany.
Lilian
L
Hahnefeld
Senior Consultant, Department of Oral and Maxillofacial Surgery, Ludwig-Maximilians Universität München, Munich, Germany.
Sven
S
Otto
Senior Consultant, Department of Oral and Maxillofacial Surgery, University of Munich, Munich, Germany; and Partner, Medizin and Ästhetik, Clinic for Oral and Maxillofacial and Plastic Surgery, Munich, Germany.
Christoph
C
Pautke
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059266:Bisphosphonate-Associated Osteonecrosis of the Jaw / Q000000981:diagnostic imaging / Q000209:etiology*; D050071:Bone Density Conservation Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000188:drug therapy / Q000556:secondary; D016723:Bone Remodeling / Q000187:drug effects*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D004164:Diphosphonates / Q000009:adverse effects* / Q000627:therapeutic use; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000187:drug effects; D005500:Follow-Up Studies; D005624:Frontal Bone / Q000000981:diagnostic imaging / Q000187:drug effects; D006801:Humans; D007093:Imidazoles / Q000009:adverse effects / Q000627:therapeutic use; D007568:Jaw / Q000000981:diagnostic imaging / Q000187:drug effects*; D008334:Mandible / Q000000981:diagnostic imaging / Q000187:drug effects; D008437:Maxilla / Q000000981:diagnostic imaging / Q000187:drug effects; D008875:Middle Aged; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D017556:Technetium Compounds; D051598:Whole Body Imaging; D000077211:Zoledronic Acid
D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D007093:Imidazoles; D019275:Radiopharmaceuticals; D017556:Technetium Compounds; D000077211:Zoledronic Acid; C029045:technetium Tc 99m diphosphonate