Histomorphologic characteristics of bisphosphonate-related osteonecrosis of the jaw.
BACKGROUND
Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a known side effect of the therapy with bisphosphonates. No specific pathologic aspects or histological features are included in the most current definition. This study investigates characteristics of BRONJ with a special emphasis on histomorphologic aspects, evaluating the role of Actinomyces spp. as well as other disease-promoting factors in a formal pathogenetic context.


METHODS
We investigated 23 patients (14 female, nine male; mean age: 66 ± 11.8 years) who received bisphosphonates with a gender- /age-matched control group. Tissue specimens were treated according to local standards and analyzed histologically.


RESULTS
In 18 (78.3%) BRONJ cases, we found Actinomyces spp. colonies. Bone remodeling could be found in three specimens (13%). Eight specimens (34.8%) showed signs of epithelial proliferation. Analysis of dental treatment before the onset of BRONJ did not reveal significant differences (P > 0.20). In 10 patients (83%; P > 0.05) of the reported cases a relationship between dental treatment and the occurrence of a purulent bone necrosis could be observed. Statistically significant differences in thickness of trabeculae were detected between the two study groups (P = 0.04).


CONCLUSIONS
This study demonstrates the important influence of the osteoblast-osteoclast balance in a histomorphologic analysis. Together with cofactors, which are able to trigger the onset of BRONJ, a new pathogenesis model was developed.
Department of Oral and Maxillofacial Plastic Surgery, University of Wuerzburg, Wuerzburg, Germany.
Steffen
S
Koerdt
Svenja
S
Dax
Hannes
H
Grimaldi
Oliver
O
Ristow
Alexander C
AC
Kuebler
Tobias
T
Reuther
D000196:Actinomycosis / Q000382:microbiology; D000368:Aged; D000369:Aged, 80 and over; D058491:Bacterial Load; D059266:Bisphosphonate-Associated Osteonecrosis of the Jaw / Q000382:microbiology / Q000473:pathology*; D050071:Bone Density Conservation Agents / Q000009:adverse effects; D016723:Bone Remodeling / Q000502:physiology; D016022:Case-Control Studies; D049109:Cell Proliferation; D003729:Dental Care; D004847:Epithelial Cells / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010006:Osteoblasts / Q000473:pathology; D010010:Osteoclasts / Q000473:pathology; D010019:Osteomyelitis / Q000382:microbiology / Q000473:pathology; D010020:Osteonecrosis / Q000473:pathology; D012307:Risk Factors; D013492:Suppuration
D050071:Bone Density Conservation Agents
Actinomyces; bisphosphonate; infected osteonecrosis; osteoblast; osteoclast; osteonecrosis