Prevalence Of Osteonecrosis Of The Jaw Research Articles

Preventing or controlling periodontitis reduces the occurrence of osteonecrosis of the jaw (ONJ) in rice rats (Oryzomys palustris).

Osteonecrosis of the jaw (ONJ) is an adverse event that requires association of both systemic risk factors, such as powerful anti-resorptives (pARs; e.g. zoledronic acid [ZOL]), and local oral risk factors (e.g. tooth extraction, periodontitis). Whereas optimal oral health prior to initiate pARs is recognized as critically important for minimizing ONJ risk, the efficacy of preventive/maintenance measures in patients who are taking pARs is understudied. Rice rats fed a standard diet (STD), rich in insoluble fiber, develop localized periodontitis. STD-rats with localized periodontitis treated with ZOL for 18-24 wk develop ONJ. Hence, we hypothesized that controlling/preventing localized periodontitis in the ZOL-treated rats, reduces ONJ occurrence. We used two approaches to attempt reducing periodontitis prevalence: 1) periodontal cleaning (PC); and 2) replacing the STD-diet with a nutritionally-equivalent diet high in soluble fiber (SF). 75 four-week-old male rats were weight-randomized into five groups (n=15) in a 24-week experiment. Three groups ate the STD-diet and two the high SF-diet. STD-diet groups received intravenous (IV) vehicle (VEH) q4wks (STD+VEH), 80μg/kg ZOL q4wks IV (STD+ZOL), or ZOL plus PC q2wks (STD+ZOL+PC). The SF-diet groups received VEH (SF+VEH) or ZOL (SF+ZOL). Jaws were processed for histopathology and evaluated for ONJ prevalence and tissue-level periodontitis. 1) 40% of STD+VEH rats developed maxillary localized periodontitis with no ONJ; 2) 50% of STD+ZOL rats developed ONJ; 3) 7% of STD+ZOL+PC rats developed ONJ (p<0.01 vs. STD+ZOL); and 4) one SF+ZOL rat developed localized periodontitis, and no SF+VEH or SF+ZOL rats developed ONJ (p<0.001 vs. STD+ZOL). 1) Periodontal cleaning in ZOL-treated rats decreases localized periodontitis severity and reduces ONJ prevalence; and 2) feeding a SF-diet to ZOL-treated rats reduces both incidence of localized periodontitis and ONJ. Our data indicates strong oral microbial community shifts according to oral health condition and trends in the shifts associated with diet.

Factors associated with osteonecrosis of the jaw in women with breast cancer receiving high-dose bisphosphonates to prevent breast cancer metastases as part of the SWOG 0307 trial.

552 Background: Bisphosphonates reduce the risk of bone metastases in postmenopausal women with early-stage breast cancer but carry the risk of osteonecrosis of the jaw (ONJ). We used the data collected in the S0307 trial to describe factors associated with provoked and unprovoked ONJ. Methods: In S0307, 6097 patients with Stage I-III breast cancer who had surgery were randomized to receive zoledronic acid (ZA) 4mg IV monthly for 6 months, then every 3 months, clodronate (CL) 1600mg daily, or ibandronate (IB) 50mg daily for three years, with no difference in bone metastases or disease-free survival. Patients completed dental procedures prior to and had a dental exam at enrollment. Pearson’s Chi-squared and Student’s T-test were used to test differences in categorical and continuous variables, respectively; logistic regression was used test independent association. Results: Of 5836 evaluable women, 48 developed ONJ, which was associated with bisphosphonate type (28/2124 (1.26%) for ZA, 8/2185 (0.36%) for CL and 12/1527 (0.77%) for IB (p = 0.002). Median time to onset of ONJ was 24.9 (1.4-66.6) for ZA, 41.2 months (range 33.8-67.4) for CL, 23.9 (2.1-75.3) for IB (p = 0.0447). Infection was present in 21 (43.8%) and absent in 20. ONJ was considered unprovoked in 20 (41.7%) and provoked by dental extraction in 20 (41.7%), periodontal disease in 14 (29.2%), denture trauma in 6 (12.5%), other dental surgery in 3 (6.3%). ONJ was associated with dental calculus (OR 2.03 (95% CI: 1.08-3.81), gingivitis (OR 2.11, 95% CI: 1.12-3.98), and periodontal disease (OR 2.87, 95% CI 1.45-5.53) that were moderate/severe and &gt; 4mm periodontitis (OR 2.20, 95% CI 1.18-4.08). Patients with provoked and unprovoked ONJ had similar amounts of dental disease and lesion location. ONJ was not associated with dentures, plaque, chemotherapy, corticosteroids or renal adverse events. In multivariate analysis (limited by small sample), only bisphosphonate type was associated with ONJ. Conclusions: ONJ prevalence was low, likely due to patients completing dental procedures before enrollment. ZA carried a higher risk of ONJ (though current adjuvant dosing interval recommendations are less frequent), with time to onset similar to IB. Oral CL and IB (not currently available in the United States) are thus likely more appropriate for patients with poor dental health. Clinical trial information: NCT00127205.

Vasculature submucosal changes at early stages of osteonecrosis of the jaw (ONJ).

Osteonecrosis of the jaw (ONJ), a rare, but potentially severe side effect of anti-resorptive medications, presents as exposed bone in the maxillofacial region lasting for at least 8 weeks. While clinical experience and animal models concur in finding that systemic antiresorptive treatment in conjunction with local risk factors, such as tooth extraction or dental disease may lead to ONJ development, the subclinical molecular changes that precede bone exposure remain poorly understood. The identification of these changes is not only important in understanding disease pathophysiology, but could provide potential for treatment development. Here, we evaluated the early stages of ONJ utilizing a model of experimental periodontitis (EP) in mice treated with two different types of antiresorptives, targeting potential changes in vasculature, hypoxia, oxidative stress, and apoptosis. Antiresorptive treatment in animals with EP increased levels of empty osteocytic lacunae and increased ONJ prevalence compared to Veh animals. The arteriole and venule network seen around EP areas was diminished in animals treated with antiresorptives. Higher levels of vascular endothelial growth factor A (VEGF-A) and vascular cell adhesion protein-1 (VCAM-1) were observed 1-week following EP in treated animals. Finally, levels of hypoxia, oxidative stress, and apoptosis remained high in antiresorptive treated animals with EP through the duration of the experiment. Together, our data point to subclinical vasculature organizational disturbances that subsequently affect levels of hypoxia, oxidative stress, and apoptosis in the area of developing ONJ.

Zoledronate treatment duration is linked to bisphosphonate-related osteonecrosis of the jaw prevalence in rice rats with generalized periodontitis.

ObjectivesTo determine the extent that zoledronate (ZOL) dose and duration is associated with bisphosphonate‐related osteonecrosis of the jaw (BRONJ) prevalence in rice rats with generalized periodontitis (PD), characterize structural and tissue‐level features of BRONJ‐like lesions in this model, and examine the specific anti‐resorptive role of ZOL in BRONJ.Materials and MethodsRice rats (n = 228) consumed high sucrose‐casein diet to enhance generalized PD. Groups of rats received 0, 8, 20, 50 or 125 µg/kg IV ZOL/4 weeks encompassing osteoporosis and oncology ZOL doses. Rats from each dose group (n = 9–16) were necropsied after 12, 18, 24 and 30 weeks of treatment. BRONJ‐like lesion prevalence and tissue‐level features were assessed grossly, histopathologically and by MicroCT. ZOL bone turnover effects were assessed by femoral peripheral quantitative computed tomography, serum bone turnover marker ELISAs and osteoclast immunolabelling.ResultsPrevalence of BRONJ‐like lesions was significantly associated with (a) ZOL treatment duration, but plateaued at the lowest oncologic dose, and (b) there was a similar dose‐related plateau in the systemic anti‐resorptive effect of ZOL. ZOL and BRONJ‐like lesions also altered the structural and tissue‐level features of the jaw.ConclusionThe relationship between BRONJ‐like lesion prevalence and ZOL dose and duration varies depending on the co‐ or pre‐existing oral risk factor. At clinically relevant doses of ZOL, BRONJ‐like lesions are associated with anti‐resorptive activity.

The influence of alendronate and tooth extraction on the incidence of osteonecrosis of the jaw among osteoporotic subjects.

BackgroundAlthough bisphosphonate-related osteonecrosis of the jaw (ONJ) develops mainly after tooth extractions (TEs), the strength of the association between them and how the existence of the disease among bisphosphonate (BP)-treated osteoporotic patients exposed to TE remain uncertain.MethodsA nationwide retrospective cohort study investigated the influence of alendronate and TE on the development of ONJ.ResultsIncidence of ONJ following long-term alendronate therapy was 262/100,000 person-years, while no event developed in the control group on raloxifene. Overall prevalence of ONJ in osteoporotic subjects receiving alendronate was estimated at 0.34% which rose to 2.16% after TE. Multiple logistic regression analysis, adjusted for the potential confounders, showed TE (adjusted odds ratio, 9.60 [4.33–21.29]), drug duration exceeding 3 years (3.00 [1.33–6.76]), and concomitant rheumatoid arthritis (4.94 [1.64–14.90]) were independent predictors of ONJ.ConclusionsThis article strengthens the relationship between ONJ and BPs. Among osteoporotic patients exposed to alendronate, TE confers a 9.6-fold increased risk for ONJ and it should be performed with caution irrespective of drug duration.

Denosumab-related osteonecrosis of the jaw in a patient with bone metastases of prostate cancer: A case report and literature review.

Denosumab, a human monoclonal antibody directed against the receptor activator of nuclear factor-κβ ligand (RANKL), is used for the treatment of patients with metastatic cancer of the bone or osteoporosis. Recent reports have demonstrated that denosumab can induce osteonecrosis of the jaw (ONJ), but reported cases of this are uncommon. The present study reports the case of an 86-year-old male with prostate cancer patient exhibiting bone metastases who developed ONJ whilst receiving denosumab. To elucidate the influence of denosumab on the development of ONJ, the present study also reviewed the literature, including clinical trials and case reports. In the clinical trials, the prevalence of denosumab-related ONJ was higher in patients with cancer compared with those with osteoporosis. The high risk of ONJ in patients with cancer was thought to be associated with the differing dose and frequency of denosumab administration. The prevalence of ONJ was not significantly different between patients receiving denosumab and bisphoshonate (BP). In the reported cases, denosumab-related ONJ had a similar clinical presentation to BP-related ONJ. There was also a tendency for denosumab-related ONJ to develop in the mandible of elderly patients. Previous invasive dental treatment was a commonly shared characteristic of patients with denosumab-related ONJ. A complex medical history was also suspected to affect the prevalence. No clear association between the dose or duration of denosumab treatment and the development of ONJ was observed. Although conservative treatments are given for denosumab-related ONJ, non-improving cases were managed surgically with primarily positive results. Because denosumab may offer superior results compared with BP for the treatment of metastatic cancer of the bone or osteoporosis, the use of denosumab is expected to increase in the near future. Clinicians should also be aware of the risk factors for denosumab-related ONJ, in order to aid in its diagnosis. In addition, patients treated with denosumab should receive prophylactic treatment to maintain their oral health prior to, during and after denosumab treatment.

Dental treatments, tooth extractions, and osteonecrosis of the jaw in Japanese patients with rheumatoid arthritis: results from the IORRA cohort study.

This study aimed to evaluate dental treatments, tooth extractions, and osteonecrosis of the jaw (ONJ) in Japanese patients with rheumatoid arthritis (RA). Patients with RA enrolled in our cohort completed self-administered questionnaires, which included questions regarding their dental treatments, tooth extractions by dentists during the past 6months, and past history of ONJ. The history of ONJ was validated with the patients' medical records. Logistic regression was used to determine the association of variables with dental treatments and tooth extractions during the past 6months. Among 5695 Japanese patients with RA who responded to the questionnaires (mean age, 61.0years; 85.6% female), 2323 patients (40.8%) and 378 patients (6.6%) reported having had dental treatments and tooth extractions performed by a dentist within the past 6months, respectively. In multivariate models, advanced age was significantly (P<0.0001) associated with both dental treatments and tooth extractions during the prior 6-month period, and ever smoking was significantly (P=0.023) correlated with tooth extractions during that time. Among patients who reported a history of ONJ, we confirmed five cases of ONJ with patient medical records. The prevalence of ONJ was 0.094% among all RA patients and 0.26% among female RA patients ≥65years of age (n=1888). Our data suggest that more than a few Japanese patients with RA have dental complications that require care by dentists, and that Japanese rheumatologists and dentists should cooperate to improve dental health in patients with RA.

Animal model for medication-related osteonecrosis of the jaw with precedent metabolic bone disease

Despite the fact that the medications used to treat abnormal bone conditions often induce osteonecrosis of the jaw (ONJ), previous attempts to establish an animal model for ONJ have shown insufficient consideration for this important prerequisite for the development of the disease. The purpose of this study was to establish an animal model with the most common metabolic bone disease, osteoporosis.Ninty-six rats were randomly divided into ovariectomy (Ov) group (n=48) and sham-operated group (n=48). Six weeks after Ov or sham surgery, rats in each group were subdivided into bisphosphonate group (n=36 each) and control group (n=12 each) and injected with zoledronic acid and normal saline, respectively, once a week. After additional 6weeks, surgical intervention was performed, and the injections were continued for 8 more weeks. The animals were then sacrificed for further macroscopic, histological, histomorphometric, radiological, and bone biomarker investigations.As histologically determined, the Ov group (77.8%) showed higher ONJ prevalence compared to the sham group (47.2%; P<0.05). Micro-structural and histomorphometric assessments revealed that rats with ONJ (ONJ group) presented with deteriorated bone architectures with higher necrotic bone fraction and lower number of osteoclasts (P<0.05). Compared to the sham-operated ONJ group, the Ov ONJ group showed significantly lower values of Tb.N, Tb.Sp, Conn.D, N.Oc/T.Ar, and TRACP 5b and CTX/TRACP (P<0.05).The ovariectomized rat model in this study successfully mimicked human ONJ lesions with an underlying bone disease and showed different bone characteristics than that of the previous ONJ model. Based on the differences, further researches for investigating pathophysiology of ONJ, including various pharmacological responses for deteriorated bone environment, are required.

Osteonecrosis of the jaws in 194 patients who have undergone intravenous bisphosphonate therapy in Spain.

BackgroundOsteonecrosis of the jaw (ONJ) is a destructive bone process in patients undergoing bisphosphonate therapy and it is modulated by local and systemic factors. The purpose of this article is to determine the prevalence of ONJ in patients who have undergone intravenous bisphosphonate therapy, and relate the risk factors described to establish a protocol to reduce the risk of developing ONJ.Material and MethodsWe performed a retrospective study on 194 patients treated with IV bisphosponates, analyzing clinical and pathological variables.ResultsThe prevalence of ONJ was 12.9 %. The most remarkable complication was pain, which was reported by 80% of patients. The average age of the patients undergoing bisphosphonate therapy was 68.91 years. Most of non-diabetic patients did not develop ONJ (92.3%) (p=0.048). During bisphosphonate therapy, 3.1% of patients underwent extractions in the same percentage in the maxilla and in the mandible; all of which, except for one patient, developed ONJ (p<0.001). In regards to the periodontal state, 94.3% of patients without periodontal problems did not develop ONJ (p=0.001). Almost 50% of the necrosis were located unifocally on the mandible (p<0.001). The number of affected patients and the aggressiveness of the disease increased significantly three years after starting treatment (p<0.001).ConclusionsEtiology still is a controversial issue and we should focus on known risk factors, such as the development of surgical procedures in patients undergoing bisphosphonate therapy, especially in patients who have already started their treatment, a group in which ONJ prevalence increases. Moreover, a bad periodontal state in these patients is also an important risk factor, and the control of diabetes reduces it. Due to the above, all patients should be diagnosed and educated in oral hygiene prior to treatment, performing periodical maintenance, to detect possible traumatisms and periodontal infection as soon as possible. Key words:Osteonecrosis of the jaws, intravenous bisphosphonate therapy.

Incidence of serious side effects with intravenous bisphosphonate: a clinical audit

Bisphosphonates (BP) have been associated with osteonecrosis of the jaw (ONJ) and atypical femoral fractures (AFF). The prevalence of these side effects in intravenous (IV) BP-treated subjects is not well understood. This audit aimed to delineate the prevalence of ONJ, thigh pain and AFF in patients having regular IV BP and its effect on bone mineral density (BMD). Design and Patients attending for IV BP over a 3-month period completed a questionnaire about thigh pain and dental health. Data concerning BMD, treatment indication and treatment history were obtained from medical records. There were 201 patients between 28 and 94 years (74.1% female) mostly on zoledronate (ZOL) (102) or pamidronate (PAM) (97). Osteoporosis (75.6%) and Paget's disease (16.5%) were the main indications for treatment; median length of IV BP was 4 years (range 0.25-25). One patient had ONJ (0.5%) while oral pain was reported by 6.5% and 12.7% noted tooth loosening. Twenty-seven subjects (13.4%) complained of current thigh pain. AFF occurred in four patients (2%), none of whom had idiopathic osteoporosis. At time of AFF, only one patient had a femoral neck T-score less than -2.5. All four had received pamidronate treatment; median 12.5 years (range 7-22). IV BP treatment significantly increased lumbar spine BMD but not femoral neck BMD. Classical ONJ was rare (0.5%), although tooth loss was more frequent. Thigh pain was frequent while AFF occurred in 2.0% of subjects and was associated with long treatment periods and non-osteoporotic bone.

Osteonecrosis of the Jaw in Patients with Metastatic Breast Cancer: Ethnic and Socio-Economic Aspects

Bisphosphonate therapy is an important adjunct to the treatment of patients with bone metastasis. Osteonecrosis of the jaw (ONJ), a complication related to bisphosphonate therapy, is reported in up to 7% of patients with metastatic breast cancer. The objective of this study was to define the prevalence and to identify risk factors associated with development of ONJ in a predominantly low socio-economic population. Medical records of patients with a diagnosis of metastatic breast cancer with bone metastasis seen between 2002 and 2007 were reviewed. All patients received a minimum of four infusions of zolendronic acid. Data on demographics, insurance status, tobacco use, concurrent therapy, body mass index, and number of zolendronic acid infusions were analyzed. Of the 110 patient analyzed, 10 developed ONJ (9%) with the mean number of zolendronic acid infusions in patients with ONJ of 22.9 ± 17. ONJ was seen more frequently in Caucasian than in African Americans patients (15% versus 2%; p = 0.019). ONJ was associated with older age at diagnosis of metastatic breast cancer (p = 0.02), tobacco use (p = 0.049), but was not associated with SES or duration of therapy. After adjusting for SES, Caucasian patients were 9.1 times more likely to have ONJ when compared with African American patients. (95% CI 1.03-81.7). Our results suggest an increase prevalence of ONJ in Caucasian breast cancer patients. However, as our study population is small, additional studies to confirm this finding are needed.

The Incidence of Osteonecrosis of the Jaw in Patients Receiving 5 Milligrams of Zoledronic Acid: Data from the Health Outcomes and Reduced Incidence With Zoledronic Acid Once Yearly clinical trials program

The Health Outcomes and Reduced Incidence with Zoledronic Acid Once Yearly-Pivotal Fracture Trial found one case of osteonecrosis of the jaw (ONJ) in a patient with postmenopausal osteoporosis (OP) treated with 5 milligrams of zoledronic acid (ZOL) once yearly and one case in a patient receiving a placebo. The authors examined ONJ incidence in four additional clinical trials involving patients with osteopenia or OP who were treated with ZOL, and they analyzed levels of the bone resorption marker serum β C-telopeptide (S-CTx) to assess its usefulness in predicting the risk of developing ONJ. To determine ONJ prevalence, an independent committee conducted a masked review of the clinical trials' adverse events databases for cases meeting predefined criteria for ONJ. The committee collected S-CTx level data for subsets of patients from these trials. The results of the four additional clinical trials revealed no further cases of ONJ. The S-CTx levels commonly were lower than 0.15 nanograms per milliliter, with no correlation to the incidence of ONJ. In the clinically diverse group of 5,903 patients who received ZOL in five clinical trials, ONJ incidence was less than one in 14,200 patient treatment-years. Data from four clinical trials indicated that S-CTx levels lower than 0.15 ng/mL were common among patients receiving ZOL for treatment of OP and were not associated with ONJ. Occurrences of ONJ have been rare in patients with OP who are receiving ZOL. Whereas low S-CTx values may be common in patients receiving bisphosphonates for OP therapy, they are not associated necessarily with an increased risk of developing ONJ.

Increased prevalence of bisphosphonate-related osteonecrosis of the jaw with vitamin D deficiency in rats

Necrotic bone exposure in the oral cavity has recently been reported in patients treated with nitrogen-containing bisphosphonates as part of their therapeutic regimen for multiple myeloma or metastatic cancers to bone. It has been postulated that systemic conditions associated with cancer patients combined with tooth extraction may increase the risk of osteonecrosis of the jaw (ONJ). The objective of this study was to establish an animal model of bisphosphonate-related ONJ by testing the combination of these risk factors. The generation of ONJ lesions in rats resembling human disease was achieved under the confluence of intravenous injection of zoledronate (ZOL; 35 µg/kg every 2 weeks), maxillary molar extraction, and vitamin D deficiency [VitD(−)]. The prevalence of ONJ in the VitD(−)/ZOL group was 66.7%, which was significantly higher (p < .05, Fisher exact test) than the control (0%), VitD(−) (0%), and ZOL alone (14.3%) groups. Similar to human patients, rat ONJ lesions prolonged the oral exposure of necrotic bone sequestra and were uniquely associated with pseudoepitheliomatous hyperplasia. The number of terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate–biotin nick-end label–positive (TUNEL+) osteoclasts significantly increased on the surface of post–tooth extraction alveolar bone of the VitD(−)/ZOL group, where sustained inflammation was depicted by [18F]fluorodeoxyglucose micro-positron emission tomography (µPET). ONJ lesions were found to be associated with dense accumulation of mixed inflammatory/immune cells. These cells, composed of neutrophils and lymphocytes, appeared to juxtapose apoptotic osteoclasts. It is suggested that the pathophysiologic mechanism(s) underpinning ONJ may involve the interaction between bisphosphonates and compromised vitamin D functions in the realm of skeletal homeostasis and innate immunity. © 2010 American Society for Bone and Mineral Research.

Prevalence of Osteonecrosis of the Jaw in Patients With Oral Bisphosphonate Exposure

Osteonecrosis of the jaw (ONJ) is a serious complication associated with bisphosphonate therapy, but its epidemiology in the setting of oral bisphosphonate therapy is poorly understood. The present study examined the prevalence of ONJ in patients receiving chronic oral bisphosphonate therapy. We mailed a survey to 13,946 members who had received chronic oral bisphosphonate therapy as of 2006 within a large integrated health care delivery system in Northern California. Respondents who reported ONJ, exposed bone or gingival sores, moderate periodontal disease, persistent symptoms, or complications after dental procedures were invited for examination or to have their dental records reviewed. ONJ was defined as exposed bone (of >8 weeks' duration) in the maxillofacial region in the absence of previous radiotherapy. Of the 8,572 survey respondents (71 +/- 9 years, 93% women), 2,159 (25%) reported pertinent dental symptoms. Of these 2,159 patients, 1,005 were examined and an additional 536 provided dental records. Nine ONJ cases were identified, representing a prevalence of 0.10% (95% confidence interval 0.05% to 0.20%) among the survey respondents. Of the 9 cases, 5 had occurred spontaneously (3 in palatal tori) and 4 occurred in previous extraction sites. An additional 3 patients had mandibular osteomyelitis (2 after extraction and 1 with implant failure) but without exposed bone. Finally, 7 other patients had bone exposure that did not fulfill the criteria for ONJ. ONJ occurred in 1 of 952 survey respondents with oral bisphosphonate exposure (minimum prevalence of 1 in 1,537 of the entire mailed cohort). A similar number had select features concerning for ONJ that did not meet the criteria. The results of the present study provide important data on the spectrum of jaw complications among patients with oral bisphosphonate exposure.

O.134 Bisphosphonates, extractions & ONJ: some good news at last!

A potential side effect associated with bisphosphonates, a class of drugs used in the treatment of osteoporosis, Paget's disease and metastatic bone disease, is osteonecrosis of the jaw (ONJ). The incidence of ONJ in the general population is unknown; this rare condition also may occur in patients not receiving bisphosphonates. Case reports have discussed ONJ development in patients with multiple myeloma or metastatic breast cancer receiving bisphosphonates as palliation for bone metastases. These patients are also receiving chemotherapeutic agents that might impair the immune system and affect angiogenesis. The incidence or prevalence of ONJ in patients taking bisphosphonates for osteoporosis seems to be very rare. No causative relationship has been unequivocally demonstrated between ONJ and bisphosphonate therapy. A majority of ONJ occurs after tooth extraction. Furthermore, the underlying risk of developing ONJ may be increased in osteoporotic patients by comorbid diseases. Treatment for ONJ is generally conservative.

A Review of the Literature on Osteonecrosis of the Jaw in Patients with Osteoporosis Treated with Oral Bisphosphonates: Prevalence, Risk Factors, and Clinical Characteristics

Objective: This literature review was performed to elucidate the relationship between bisphosphonate use and development of osteonecrosis of the jaw (ONJ) in patients receiving oral bisphosphonates for the treatment of osteoporosis. Methods: MEDLINE, the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, and EMBASE were searched for English-language articles published from 1966 to September 2006 whose titles included the term osteonecrosis of the jaw in conjunction with bisphosphonates, alendronate, risedronate, ibandronate, etidronate, clodronate, zoledronic acid, or pamidronate. Articles were included in the review if the population consisted of adults with ONJ; patients received bisphosphonates for the treatment of osteoporosis only; the reported data included baseline characteristics of the study population (age; sex; comorbidities; concomitant medications; history of dental surgery, trauma, or infection), characteristics of bisphosphohate treatment (specific bisphosphonate, dose, duration of treatment, mode of administration), clinical features of ONJ (signs, symptoms, site), the treatment protocol used to manage ONJ, or the prevalence of ONJ in patients with osteoporosis treated with bisphosphonates; and the publication involved a case report, case series, or observational study. Results: After application of the search strategy and the inclusion/exclusion criteria, 11 publications reporting 26 cases of ONJ in patients receiving bisphosphonates for the treatment of osteoporosis were included in the review. The most commonly affected site was the mandible (16 patients), followed by the maxilla (6 patients). Among the 23 patients whose age was reported, 18 (78%) were aged ≥60 years. Among the 23 patients whose sex was reported, only 3 (13%) were men. Of 15 patients with a history of invasive dental treatment, 12 (80%) had undergone dental surgery or experienced dental trauma at the site of ONJ. Among the 10 patients for whom the duration of bisphosphonate treatment was reported, no clear relationship between the duration of bisphosphonate treatment and the development of ONJ was observed. Conclusions: Considering that millions of patients have been prescribed bisphosphonates for the treatment of osteoporosis, the relative prevalence of ONJ in these patients was low. Age ≥60 years, female sex, and previous invasive dental treatment were the most common characteristics of those who developed ONJ. However, it is not possible to draw further conclusions about the potential association between oral bisphosphonate use and ONJ in the identified studies because of incomplete reporting and the presence of confounding factors.

Bisphosphonates and Osteonecrosis of the Jaw: A Retrospective Study

To assess the prevalence of osteonecrosis of the jaw (ONJ) in patients receiving bisphosphonate therapy and in those who were bisphosphonate naïve. We undertook a retrospective review of medical records of patients at the New York Harbor Health Care System from 1999 through 2004. Charts were selected for review if patients had a Current Procedural Terminology (CPT) code suggestive of ONJ or if they had ever received bisphosphonate therapy. Among 1,951 medical records reviewed, we identified 2 patients with ONJ who had received bisphosphonates and 2 patients with ONJ who were bisphosphonate naïve. Both patients treated with bisphosphonates had multiple myeloma and were receiving monthly infusions. They had initially received pamidronate before treatment was changed to zoledronic acid. In each case, ONJ was precipitated by a routine dental extraction. The prevalence of ONJ in our patient population receiving intravenously administered bisphosphonates was 1 in 71.5. Of the 2 cases of ONJ in bisphosphonate-naïve patients, osteoradionecrosis was clearly incriminated in 1 patient and potentially the causative factor in the other patient as well. No patients receiving orally administered bisphosphonates had ONJ, nor did this complication occur in any patients receiving parenteral bisphosphonate therapy for disorders such as osteoporosis or Paget's disease of bone. Bisphosphonates remain an important option for management of metabolic bone disease and complications of malignant disease. The overall prevalence of ONJ in patients receiving bisphosphonates seems to be very low; however, patients receiving intense parenteral therapy for an underlying malignant condition appear to have a uniquely elevated risk for the development of this complication. A causal relationship between bisphosphonates and ONJ remains to be proved and merits further investigation.