The main causes for the occurrence of bisphosphonate-related osteonecrosis of the jaws (BRONJ) are the application of aminobisphosphonates and the extraction of teeth. However, the question which factors in dental and oral health are relevant has not been answered completely.
Materials and methods
In a retrospective study, 50 patients who were treated with BRONJ between 2000 and 2009 were analyzed. As underlying diseases, they suffered from breast cancer (n = 24), multiple myeloma (n = 16), prostate cancer (n = 5), osteoporosis (n = 4), and kidney cancer (n = 1). The data were collected from the patient charts of the treating dentists, oral and maxillofacial surgeons, general practitioners, and oncologists. The time of occurrence of BRONJ after treatment onset with bisphosphonates (BP) was examined with Kaplan–Meier estimator and logrank test (level of significance 0.05).
At the time of BP treatment, onset the decayed, missing, and filled teeth (DMFT) index was 20.5 ± 4.2. Patients with a DMFT value less than 20 showed a significantly longer BRONJ-free time interval after BP treatment onset with 39.7 ± 1.1 months compared to patients with a DMFT value higher than 20, in whom BRONJ appeared after 14.4 ± 2.8 months (p < 0.001). However, the DMFT value had no influence on the success rate of BRONJ treatment.
As a pre-existing oral disease, 60 % of the patients (n = 30) had marginal periodontitis; 38 % (n = 19), apical periodontitis; and 22 % (n = 11), a pressure lesion from their dentures.
In patients with marginal periodontitis, BRONJ occurred after 26.3 months (range 20.9–31.3) and in patients without marginal periodontitis, after 27.4 months (range 14.6–40.1) (p = 0.58). Only 20 % of the patients with marginal periodontitis received adequate treatment. Without parodontal treatment, BRONJ occurred 15 months earlier compared to patients with parodontal treatment (p = 0.12). The state of the periodontium did not influence the healing rate of BRONJ (p > 0.999).
The present study highlights the great benefit of good dental and oral health in the prevention of BRONJ; but it also shows that after the appearance of BRONJ, these factors do no longer seem to play a relevant role in the disease course.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.