Incidence of osteonecrosis of the jaw in Japanese osteoporosis patients taking minodronic acid

Reliability of early stage symptoms/clinical findings of osteonecrosis of the jaw: Japanese Osteoporosis Intervention Trial-05 (JOINT-05)

INTRODUCTION

To investigate the differences in the incidence rates of suspected stage 0/1 osteonecrosis of the jaw (ONJ) and incidence risk of relevant clinical findings of suspected stage 0 ONJ between patients treated with sequential therapy comprising weekly teriparatide for 72 weeks followed by alendronate for 48 weeks vs. those who received monotherapy with alendronate for 120 weeks.

MATERIALS AND METHODS

Suspected stage 0/1 ONJ was defined by non-specific symptoms. Tooth mobility and periodontal symptoms (gingival bleeding, swelling, and/or pain) were selected as clinical findings of suspected stage 0 ONJ. Poisson regression models were applied to calculate the incidence rate ratios of suspected stage 0/1 between the teriparatide group (TG) and alendronate group (AG). Generalized linear models were used to calculate the risk ratios of clinical findings between groups.

RESULTS

Two hundred and sixty-one participants in the TG and 344 in the AG answered a structured questionnaire on oral health and were included in this study. There were no significant differences between the groups in the incidence rate of suspected stage 0/1 ONJ at both 72 and 120 weeks. The risk ratio of the TG to AG for tooth mobility was 0.34 (95% confidence interval [CI] 0.13-0.88, p = 0.02) at 72 weeks and 0.90 (95% CI 0.40-2.03, p = 0.83) at 120 weeks. The incidence rate of tooth mobility related to periodontal symptoms decreased in the TG and increased in the AG during the study.

CONCLUSION

Tooth mobility accompanied by clinical periodontal symptoms may be a useful early sign of stage 0 ONJ.

Osteonecrosis of the jaws in patients under osteoporosis treatment: a nine-year experience report

Objective

This study aimed to report the experience of medication-related osteonecrosis of the jaws (MRONJ) in osteoporotic patients for nine years, and their associated initiating factors.

Materials and methods

The numbers of invasive oral procedures (IOP) (tooth extraction, dental implant placement, and periodontal procedures) and removable prostheses performed from January 2012 to January 2021 were obtained from the digital records of a large public dental center. There were an estimated 6,742 procedures performed in patients under osteoporosis treatment.

Results

Two cases (0.03%) of MRONJ were registered in nine years amongst patients with osteoporosis who had dental treatment at the center. From the 1,568 tooth extractions, one patient (0.06%) developed MRONJ. There was also one case from the 2,139 removable prostheses delivered (0.05%).

Conclusion

The prevalence of MRONJ associated with osteoporosis treatment was very low. The protocols adopted seem to be adequate for the prevention of this complication. The findings of this study reinforce the rare frequency of MRONJ associated with dental procedures in patients submitted to the pharmacological management of osteoporosis. An integral analysis of systemic risk factors and oral preventive strategies may be considered regularly in the dental treatment of these patients.

Low concentrations of grape seed extract maintain osteoblast morphology, cell adhesion, and mineralization

The increase in life expectancy has led to a higher incidence of osteoporosis, characterized by an imbalance in bone remodeling. Several drugs are used for its treatment, but most promote undesirable side effects. The present investigation evaluated the effects of two low concentrations of grape seed extract (GSE) rich in proanthocyanidins on MC3T3-E1 osteoblastic cells. The cells were cultured in an osteogenic medium and divided into control (C), 0.1 µg/mL GSE (GSE0.1), and 1.0 µg/mL GSE (GSE1.0) groups to evaluate cell morphology, adhesion, and proliferation, in situ alkaline phosphatase (ALP) detection, mineralization and immunolocalization of osteopontin (OPN). The data obtained were analyzed by statistical tests for a significance of 5%. Cell morphology was maintained with both GSE concentrations, whereas cell adhesion significantly increased within three days in all groups. Cell proliferation increased significantly at seven days of culture, followed by a significant decrease in all experimental periods, with no statistical difference among them. In situ detection of ALP and mineralization increased with time, but within each period, no statistical differences among groups were observed. The expression of osteopontin was distributed regularly with more intensity after 24 hours in the GSE0.1 group. After three days, OPN expression was more intense in the control group, followed by GSE0.1 and GSE1.0 groups. Data obtained suggest that low concentrations of GSE do not affect the morphology and may stimulate the functional activity of osteoblastic cells.

Management of Tooth Extraction in Patients Taking Antiresorptive Drugs: An Evidence Mapping Review and Meta-Analysis

BACKGROUND

Medication-related osteonecrosis of the jaw (MRONJ) is a well-known severe adverse reaction of antiresorptive, antiangiogenic or targeted therapies, and usually occurs after tooth extraction. This review is aimed at determining the efficacy of any intervention of tooth extraction to reduce the risk of MRONJ in patients taking antiresorptive drugs, and present the distribution of evidence in these clinical questions.

METHODS

Primary studies and reviews were searched from nine databases (Medline, EMBase, Cochrane Library, Scopus, WOSCC, Inspec, KCI-KJD, SciELO and GIM) and two registers (ICTRP and ClinicalTrials.gov) to 30 November 2022. The risk of bias was assessed with the ROBIS tool in reviews, and the RoB 2 tool and ROBINS-I tool in primary studies. Data were extracted and then a meta-analysis was undertaken between primary studies where appropriate.

RESULTS

Fifteen primary studies and five reviews were included in this evidence mapping. One review was at low risk of bias, and one randomized controlled trial was at moderate risk, while the other eighteen studies were at high, serious or critical risk. Results of syntheses: (1) there was no significant risk difference found between drug holiday and drug continuation except for a subgroup in which drug continuation was supported in the reduced incidence proportion of MRONJ for over a 3-month follow-up; (2) the efficacy of the application of autologous platelet concentrates in tooth extraction was uncertain; (3) there was no significant difference found between different surgical techniques in any subgroup analysis; and (4) the risk difference with antibacterial prophylaxis versus control was -0.57, 95% CI -0.85 to -0.29.

CONCLUSIONS

There is limited evidence to demonstrate that a drug holiday is unnecessary (and may in fact be potentially harmful) in dental practice. Primary closure and antibacterial prophylaxis are recommended despite limited evidences. All evidence have been graded as either of a low or very low quality, and thus further high-quality randomized controlled trials are needed to answer this clinical question.

Clinical Observations of Osteoporosis in Japanese Patients with Rheumatoid Arthritis

Osteoporosis is the one of the major adverse outcomes in patients with rheumatoid arthritis (RA). Recently, we and others have been reported many clinical observations related to osteoporosis in Japanese RA patients. In this article, I reviewed these findings. Japanese patients with RA have a two-fold risk of fractures compared with those without RA. Among the fractures in Japanese RA patients, three quarters of the fractures were non-vertebral fractures. The incidence of non-vertebral fractures did not change, despite an improvement in RA disease activity. Older age, female gender, history of fractures, history of total knee replacements, disease activity scores in 28 joints (DAS28), health assessment questionnaire disability index (HAQ-DI), low bone mineral density, glucocorticoid dose, and vitamin D deficiency were significantly associated with fractures. Older age, high body mass index (BMI), HAQ-DI, and polypharmacy were significantly associated with falls. BMI (both overweight and underweight), DAS28, and HAQ-DI were significantly associated with frailty. Half and three quarters of Japanese men and women with RA had vitamin D deficiency, respectively. The incidence of osteonecrosis of the jaw may be higher in Japanese RA patients than those without RA. Undertreatment of osteoporosis appears to exist in Japanese patients with RA.

Influence of symptomatic periodontal disease on changes in skeletal bone density during medication therapy for osteoporosis in postmenopausal women: the Japanese Osteoporosis Intervention Trial (JOINT)-04 and JOINT-05

Japanese postmenopausal women with symptomatic periodontal disease had a significantly smaller increase in the T-score for total hip bone density than those without periodontal disease during medication therapy for osteoporosis. Intervention to treat symptomatic periodontal disease before and/or during osteoporosis therapy could maintain the effect of osteoporosis medications.

PURPOSE

Women with periodontal disease may be more likely to develop osteoporosis. We evaluated whether the presence of symptomatic periodontal disease can influence changes in skeletal bone mineral density (BMD) during medication therapy for osteoporosis in Japanese postmenopausal women.

METHODS

A total of 4,258 postmenopausal women participated in the Japanese Osteoporosis Intervention Trial protocol number 4 (JOINT-04 trial) and number 5 (JOINT-05 trial), which were multi-center, open-label, randomized controlled trials in Japan. Of these, 3,670 non-edentulous subjects participated in the study. Subjects who had self-reported symptoms of periodontal disease at baseline were defined as having periodontal disease. The study outcome was the difference in BMD changes during the study between subjects with and without periodontal disease. Mixed models for repeated measures after adjusting for covariates were used to investigate the difference in the BMD changes during the study between subjects with and without periodontal disease.

RESULTS

Subjects with periodontal disease had significantly lower T-scores for total hip (p = 0.035) and metacarpal (p = 0.048) BMD than those without periodontal disease at baseline. During medication therapy for osteoporosis, subjects with periodontal disease had a significantly smaller increase in T-score for total hip BMD than those without periodontal disease (p = 0.021), although no significant differences were observed in the changes in T-scores for other skeletal BMD measurements between subjects with and without periodontal disease.

CONCLUSIONS

The presence of self-reported symptoms of periodontal disease may be associated with a decrease in the effect of osteoporosis medications in Japanese postmenopausal women.

Bisphosphonates, Old Friends of Bones and New Trends in Clinics

Bisphosphonates, used for a long time in osteoporosis management, are currently the target of intensive research, from pre-formulation studies to more advanced stages of clinical practice. This review presents an overview of the contributions of this family of compounds to human health, starting with the chemistry and clinical uses of bisphosphonates. Following this, their pharmacology is described, highlighting administration-borne handicaps and undesirable effects. The last three sections of the review describe the research efforts that seek to curb delivery-related issues and expand bisphosphonate use. Innovative routes and strategies of administration, such as nano-encapsulation for oral intake or injectable cements for local or in-bone delivery are presented, as well as the latest results of case studies or preclinical studies proposing new therapeutic indications for the clinically approved bisphosphonates. Finally, a selection of anti-infectious bisphosphonate new drug candidates is shown, with focus on the molecules reported in the last two decades.

The Effect of Teriparatide for the Treatment of Multiple Spontaneous Clinical Vertebral Fractures after Discontinuation of Denosumab in a Female Patient with Rheumatoid Arthritis: A Case Report

Discontinuation of denosumab is associated with the risk of rebound in bone turnover and rebound-associated spontaneous clinical vertebral fractures. This case report presents an 86-year-old woman with rheumatoid arthritis who experienced rebound-associated spontaneous clinical vertebral fractures at 9 months after denosumab discontinuation. Following 5-year bisphosphonate treatment, the patient had 9 injections of 60-mg denosumab every 6 months. Because of tooth extraction, denosumab treatment was discontinued, and raloxifene was administered. At 9 months after the last denosumab injection, the patient experienced severe low back pain. Magnetic resonance imaging (MRI) and radiograph demonstrated clinical fracture at the fourth lumbar vertebra. MRI performed at 3 months after first fracture showed two additional fractures at the second and third lumbar vertebrae. Teriparatide was administered for management of rebound-associated spontaneous clinical, multiple vertebral fractures. Teriparatide was effective for accelerating the fracture healing and suppressing the occurrence of new fractures. However, 2-year treatment of teriparatide did not have suppressive effect of rebound in bone turnover and general bone loss. This case suggested that teriparatide was effective for suppression of new rebound-associated spontaneous clinical vertebral fractures, but not effective in prevention of general bone loss after denosumab discontinuation.

Randomized head-to-head comparison of minodronic acid and raloxifene for fracture incidence in postmenopausal Japanese women: the Japanese Osteoporosis Intervention Trial (JOINT)-04

AIMS

We conducted a head-to-head randomized trial of minodronate, a bisphosphonate, and raloxifene, a selective estrogen receptor modulator, to obtain clinical evidence and information about their efficacy and safety.

METHODS

The Japanese Osteoporosis Intervention Trial protocol number 4 (JOINT-04) trial is a multi-center, open-labeled, blinded endpoints, head-to-head randomized trial of minodronate and raloxifene. Ambulatory elderly women with osteoporosis (age, >60 years) were randomly allocated to the raloxifene or minodronate group by central registration. The co-primary endpoints included any one of osteoporotic fractures (vertebral, humeral, femoral, and radial fractures), vertebral fractures, and major osteoporotic fractures (clinical vertebral, humeral, femoral, and radial fractures). The biological effects of each drug, patients' quality of life, and drug safety were assessed based on the secondary outcomes. This study was registered at the University Hospital Medical Information Network-Clinical Trials Registry (UMIN-CTR) under trial identification number UMIN000005433.

RESULTS

A total of 3896 patients were randomized to the minodronate and raloxifene groups, and drug efficacy assessments were performed for 3247 patients (1623 and 1624 patients, respectively). Among these patients, 1176 and 1187 patients received allocated treatment for 2 years. The incidence rate ratios for osteoporotic, vertebral, and major osteoporotic fractures in the minodronate group were 0.94 (95% CI: 0.78-1.13, p = .494), 0.86 (95% CI: 0.70-1.05, p = .147), and 1.22 (95% CI: 0.86-1.74, p = .274), respectively. Compared to the raloxifene group, the minodronate group showed significantly increased bone mineral density of the lumbar spine for each visit (6 months: p = .007, 12 months: p = .0003, 24 months: p<.0001). Also, serious adverse reactions were observed for four and six patients in the minodronate and raloxifene groups, respectively.

CONCLUSIONS

Overall, there were no statistical differences in the incidence rates of osteoporotic, vertebral, or major osteoporotic fractures between the two groups. Serious adverse reactions were rare in both groups.

Morphological and immunohistochemical features of tooth extraction sites in rats treated with alendronate, raloxifene, or strontium ranelate

OBJECTIVE

The aim of this study was to evaluate morphological and immunohistochemical features of tooth extraction sites in rats subjected to different antiresorptive drugs.

MATERIALS AND METHODS

Wistar rats were allocated into 4 groups according to the treatment: (1) alendronate, (2) raloxifene, (3) strontium ranelate, and (4) control. The animals underwent tooth extraction (60th day of treatment) and afterwards were euthanized (90th day of treatment). Tooth extraction sites were analyzed by means of scanning electron microscopy (SEM), hematoxylin-eosin staining (H&E), and immunohistochemical staining (RANKL and OPG).

RESULTS

On H&E analysis, the alendronate group showed greater amounts of non-vital bone, biofilm, inflammatory infiltrate and root fragment, and smaller amount of vital bone. The strontium ranelate group showed great amount of non-vital bone. This group also had lower levels of OPG, while the alendronate group showed lower OPG and RANKL than the other groups. On SEM analysis, the alendronate group showed a considerable number of microcracks on the alveolar bone surface and few Howship lacunae and lack of bone cells as well. The raloxifene, strontium ranelate, and control groups showed a large number of bone cells and Howship lacunae on the bone surface and few microcracks.

CONCLUSION

Alendronate therapy is associated with macro- and microscopic features of medication-related osteonecrosis of the jaw at tooth extraction sites, whereas raloxifene therapy is not, and strontium ranelate therapy is associated with non-vital bone.

CLINICAL RELEVANCE

Osteonecrosis of the jaws is a serious side effect of alendronate therapy, where tooth extraction is a major risk factor. Considering the significant number of patients undergoing antiresorptive therapies worldwide, the present study investigated whether raloxifene and strontium ranelate interfere with bone repair after tooth extraction in a similar way to bisphosphonates.

Parity and Number of Teeth in Japanese Women: Results from the Japan Nurses' Health Study

Background: Parity is thought to be associated with a decreased number of teeth present in women. However, educational level and social status, which are particularly significant risk factors for loss of teeth, have been heterogeneous in previous observations. This cross-sectional survey aimed to clarify the associations of parity with the risk of having <20 teeth in Japanese female nurses participating in the Japan Nurses' Health Study (JNHS). Methods: In the third follow-up questionnaire of the JNHS, 11,299 women aged 27-82 years participated in this study. The number of participants according to age range was 7,225 (63.9%) aged <50 years and 4,074 (36.1%) aged ≥50 years. Information on parity and risk factors for loss of teeth was collected through a baseline questionnaire and then a follow-up questionnaire. Multivariate logistic regression analysis was used to calculate the adjusted odds ratio (OR) and 95% confidence interval (CI) of having <20 teeth according to parity category. Results: Participants ≥50 years who had experienced three or more deliveries had a significantly higher risk of having <20 teeth than those who had not experienced delivery (OR = 1.59, 95% CI = 1.14-2.20), although this finding was not observed in participants <50 years. In addition to parity, age and current smoking may be independent risk factors for having <20 teeth in Japanese nurses. Conclusions: Higher-parity female nurses ≥50 years may be more likely to lose teeth than those who have not experienced delivery.

Minodronate

Minodronate is a heterocyclic nitrogen-containing bisphosphonate with high potency in inhibiting bone resorption, and is developed for clinical use in Japan. Minodronate has very high potency in inhibiting farnesyl pyrophosphate synthase, and shows lower affinity for bone matrix hydroxyapatite at both neutral and acidic pH. As a result, small amount of minodronate is deposited in bone but can exert strong anti-resorptive activity in vivo. In this review on minodronate, we summarize the mechanism of action, physico-chemical properties, effects on bone quality in animals, and effects on bone turnover, bone mineral density and fracture prevention, as well as safety in the treatment of patients with osteoporosis.

Rescue bisphosphonate treatment of alveolar bone improves extraction socket healing and reduces osteonecrosis in zoledronate-treated mice

Bisphosphonate (BP)-related osteonecrosis of the jaw, previously known as BRONJ, now referred to more broadly as medication-related osteonecrosis of the jaw (MRONJ), is a morbid condition that represents a significant risk for oncology patients who have received high dose intravenous (IV) infusion of a potent nitrogen containing BP (N-BP) drug. At present, no clinical procedure is available to prevent or effectively treat MRONJ. Although the pathophysiological basis is not yet fully understood, legacy adsorbed N-BP in jawbone has been proposed to be associated with BRONJ by one or more mechanisms. We hypothesized that removal of the pre-adsorbed N-BP drug common to these pathological mechanisms from alveolar bone could be an effective preventative/therapeutic strategy. This study demonstrates that fluorescently labeled BP pre-adsorbed on the surface of murine maxillo-cranial bone in vivo can be displaced by subsequent application of other BPs. We previously described rodent BRONJ models involving the combination of N-BP treatment such as zoledronate (ZOL) and dental initiating factors such as tooth extraction. We further refined our mouse model by using gel food during the first 7 days of the tooth extraction wound healing period, which decreased confounding food pellet impaction problems in the open boney socket. This refined mouse model does not manifest BRONJ-like severe jawbone exposure, but development of osteonecrosis around the extraction socket and chronic gingival inflammation are clearly exhibited. In this study, we examined the effect of benign BP displacement of legacy N-BP on tooth extraction wound healing in the in vivo model. Systemic IV administration of a low potency BP (lpBP: defined as inactive at 100 μM in a standard protein anti-prenylation assay) did not significantly attenuate jawbone osteonecrosis. We then developed an intra-oral formulation of lpBP, which when injected into the gingiva adjacent to the tooth prior to extraction, dramatically reduced the osteocyte necrosis area. Furthermore, the tooth extraction wound healing pattern was normalized, as evidenced by timely closure of oral soft tissue without epithelial hyperplasia, significantly reduced gingival inflammation and increased new bone filling in the extraction socket. Our results are consistent with the hypothesis that local application of a rescue BP prior to dental surgery can decrease the amount of a legacy N-BP drug in proximate jawbone surfaces below the threshold that promotes osteocyte necrosis. This observation should provide a conceptual basis for a novel strategy to improve socket healing in patients treated with BPs while preserving therapeutic benefit from anti-resorptive N-BP drug in vertebral and appendicular bones.