Medication-related osteonecrosis of the jaw: Clinical and practical guidelines

Dentists' knowledge about medication-related osteonecrosis of the jaw and its management

Objectives

To assess the knowledge of dentists regarding medication-related osteonecrosis of the jaw (MRONJ).

Methods

In this cross-sectional study, 74 dentists from governmental hospitals in Riyadh (Dental University Hospital in King Saud University, Military Hospital, National Guard Hospital), Jeddah (King Abdulaziz University Hospital, Ministry of Health Hospital), and the Eastern region of Saudi Arabia (Ministry of Health Hospitals in Dammam and Al-Ahsa) completed a two-part questionnaire. The first part gathered demographic data, such as sex and specialty. The second part included questions about bisphosphonate drugs and their indications; the identification of patients at risk of MRONJ; other medications associated with jaw necrosis; as well as the definition of MRONJ and its clinical features, risk factors, and preventive methods.

Results

Of the participating dentists, 60.8% knew about MRONJ, but only 35.1% were able to define it correctly. Most (79.7%) had never encountered MRONJ patients. Only 18.9% knew of the relationship between the risk of MRONJ in osteoporotic patients and long-term (>4 years) use of oral bisphosphonates or intravenous zoledronate, while 68.9% were unaware, and others answered incorrectly. Most participants did not know of MRONJ-predisposing medications, and 59.5% cited radiotherapy as the cause. Most participants identified dentoalveolar surgery as a major local factor, and the mandible as a common anatomic location.

Conclusion

Dentists at the surveyed institutions had poor knowledge of MRONJ, although their knowledge of preventive measures was good. There is an urgent need for the optimization of educational programs pertaining to MRONJ, and its related dental management considerations.

Clinical significance

Dentists in the surveyed institutions in Kingdom of Saudi Arabia have poor knowledge of MRONJ management; thus, greater effort should be taken to educate undergraduate and postgraduate students regarding this pathology.

Cytotoxicity and Gene Expression Changes of a Novel Homeopathic Antiseptic Oral Rinse in Comparison to Chlorhexidine in Gingival Fibroblasts

Most available antiseptic solutions available today have strong antibacterial effects, however most also possess major cytotoxic effects on human gingival tissues. The VEGA Oral Care Recovery Kit (StellaLife), previously evaluated in clinical studies, consists of 16 active ingredients that are monographed in the Homeopathic Pharmacopeia of United States (HPUS) and recognized for their accelerated healing properties (reduction in post-op pain). The aim of this study was to compare VEGA to chlorhexidine (CHX) in vitro on gingival fibroblast viability, survival at various concentrations, migration assay, proliferation activity, expression of both regenerative growth factors as well as inflammatory markers, and collagen synthesis. A 10-fold dilution of standard CHX (0.02%) led to cell death, whereas cell viability was significantly better in the VEGA group for all tested parameters. Furthermore, VEGA also induced significantly greater fibroblast migration and proliferation. CHX negatively impacted the cellular inflammatory response of gingival fibroblasts, and also led to a reduction in collagen synthesis (50% decrease). Findings from the present study provide support from basic laboratory experiments that validate the previous clinical studies supporting the use of the VEGA oral rinse on its superior biocompatibility and wound healing properties when compared to CHX.

Therapeutic approach and management algorithms in medication-related osteonecrosis of the jaw (MONJ): recommendations of a multidisciplinary group of experts

BACKGROUND

The justification for this consensus is the absence of local protocols on Medication-Related Osteonecrosis of the Jaws (MONJ), for prevention, evaluation, and treatment, involving physicians and dentists, leading to suspension of antiresorptive treatments, despite their benefit in the prevention of fragility fractures (40-70%). These fractures cause disability and mortality (80% and 20-30%, respectively), as opposed to the low risk associated with MONJ in osteoporotic (0.01-0.03%) and oncological patients (1.3-1.8%).

PURPOSE

To provide management recommendations through algorithms that guide health professionals to prevent, diagnose, and treat MONJ in different clinical scenarios.

METHOD

A technical multidisciplinary team composed of specialists with extensive experience in osteoporosis or osteonecrosis of the jaw from Fundación Santa Fé (Bogotá, Colombia) and the Asociación Colombiana de Osteoporosis y Metabolismo Mineral was selected. Three rounds were carried out: definition of questions, answers using Delphi methodology, and the discussion of questions in order to have an agreement. The whole group participated in two phases, and the developer group in the total number of rounds. A literature review was conducted to obtain academic support to design questions with clinical relevance.

RESULTS AND CONCLUSIONS

The consensus group generated definitions and recommendations useful for doctors and dentists, following clinical algorithms involving four scenarios: osteoporosis patient who requires dental procedures and has not received antiresorptives, osteoporosis patient who are under treatment with antiresorptives, cancer patients, and MONJ-instituted patients. The therapeutic approach in osteoporosis and cancer patients, in invasive dental procedures, must be relied on the risk-benefit treatment.

Conservative non-surgical management in medication related osteonecrosis of the jaw: A retrospective study

Objectives

To date, the best treatment for Medication Related Osteonecrosis of the jaw (MRONJ) is controversial. Recent studies suggest different therapies, considering the stage of MRONJ; however, sometimes patients, although with remarkable extension of disease, cannot undergo surgery. The purpose of present preliminary study was to evaluate the efficacy of conservative non‐surgical treatment of MRONJ lesions in a cohort of patients ineligible for surgery or refusing any surgical treatment for stage II and III of MRONJ.

Materials and methods

Patients with MRONJ (staging II or III) ineligible for surgical treatment were selected for a retrospective study. A conservative non‐surgical therapy (antibiotics and antiseptic) was administered for 1 year. Five scheduled checks were performed to assess changes in signs and symptoms during the observational period.

Results

Our observation was carried out on 12 patients. Improvement of signs and symptoms of disease were observed in population.

Conclusion

This study suggests that non‐surgical treatment may be a valid therapeutic option in patients ineligible for surgery. The sample size is small, further studies should be carried out to satisfy the aim of a conservative non‐surgical treatment protocol establishment.

Endothelial progenitors increase vascularization and improve fibroblasts function that prevent medication-related osteonecrosis of the jaw

OBJECTIVES

In a previous rat model, MRONJ occurrence was 50%. Our aim was to investigate the potential of endothelial progenitor cells (EPCs) to improve fibroblasts function and prevent MRONJ.

METHODS

Human gingival fibroblasts were cultured with EPC-conditioned media (EPC-CM); endothelial growth media (EGM-2) or DMEM followed by incubation with 10 µM zoledronic (ZOL) and dexamethasone (DEX). Cell proliferation and migration were assessed by XTT and scratch wound healing assays. In vivo, ten Lewis rats were treated weekly with ZOL and DEX for 11 weeks. After a week, EPCs or EGM-2 were injected to the gingiva around the molars. At 3 weeks, bilateral molars were extracted. After 8 weeks, wound healing was assessed, and serum VEGF and blood vessels were quantified.

RESULTS

ZOL/DEX significantly reduced fibroblasts proliferation and wound healing. Treatment with EPC-CM before ZOL/DEX improved cell proliferation, and scratch healing (p = .007, p = .023). In vivo, local EPC injection before tooth extraction increased serum VEGF (p = .01) and soft tissue vascularization (p = .05). Normal healing was similar (80%) in EPCs and EGM-2 groups.

CONCLUSION

EPC rescued fibroblasts from the cytotoxic effect of ZOL/DEX and elevated serum VEGF and vessel density that might reduce MRONJ occurrence to 20% compared to 50% in a similar model.

Does Medication-Related Osteonecrosis of the Jaw Influence the Quality of Life of Cancer Patients?

The aim of this study is to observe the influence of Medication-Related Osteonecrosis of the Jaw (MRONJ) on the physical and mental conditions of cancer patients using a Quality of Life (QoL) questionnaire during regular dental practice measures. Twenty cancer patients (8 males and 12 females) with established MRONJ were enrolled in the “MoMax” (Oral Medicine and Maxillofacial) project of the Department of Oral Sciences and Maxillofacial Surgery at “Sapienza” University of Rome, and were included in the study. The 12-item Short Form Survey was used to evaluate the QoL. Statistical analysis revealed a significant difference for Mental Component Summary (MCS) scores based on age (p = 0.018). The regression analysis revealed that the Physical Component Summary (PCS) scores were negatively influenced by the anti-resorptive medication duration (p = 0.031 and β = −1.137). No significant differences were observed with the other variables considered. The QoL of cancer patients is generally deteriorated and MRONJ may cause a further negative impact. This study highlights the possible need to include psychosocial and physical evaluations in the management process of MRONJ in cancer patients.

Evaluation of SPECT/CT in the assessment of inflammatory jaw pathologies

PURPOSE

Since accurate diagnosis of inflammatory jaw diseases is still challenging, this study investigated the performance of three phase bone scintigraphy including SPECT/CT in the assessment of correct diagnosis and size of the affected bone tissue.

METHOD

This retrospective study contained 31 patients with suspected jaw-related osteoradionecrosis, osteomyelitis or medication-related osteonecrosis of the jaw, which underwent 3-phase bone scintigraphy including SPECT/CT. Results were reviewed by two nuclear medicine physicians. Positive cases received surgery; negative ones were followed-up for six months. Both served as reference standard. Inflamed bone length was measured in the SPECT/CT images and postoperatively by a pathologist.

RESULTS

19 out of 20 positive cases and 10 out of 11 negative ones were classified correctly by SPECT/CT (sensitivity 95 %, specificity 91 %, accuracy 94 %, positive predictive value 95 %, negative predictive value 91 %). Regarding the length of affected bone, no significant difference (p = 0.23) could be observed between SPECT/CT and postoperative obtained values. Both correlated significantly (r = 0.86, p = 0.0001).

CONCLUSION

SPECT/CT can safely detect different kinds of inflammatory jaw pathologies compared to other conventional imaging modalities. Lack of specificity of conventional scintigraphy ranging from 17 % to 71 % in earlier studies could be improved by adding CT-analysis. Additionally, SPECT/CT assists the surgeon in determining the expansion of the process (with focus on the length) preoperatively and thereby optimizing surgery planning.

Medication-related Osteonecrosis of the Jaw: A Review

Medication-related osteonecrosis of the jaw (MRONJ) is a rare, severe debilitating condition from unknown causes. It is characterized by nonhealing exposed bone in a patient with a history of antiresorptive or antiangiogenic agents in the absence of radiation exposure to the head and neck region. The first case of MRONJ was reported in the early 2000s. Diagnostic criteria for MRONJ was developed by the American Association of Oral and Maxillofacial Surgeons (AAOMS) based on pharmacological history as well as clinical and radiographic features. Antiresorptive medications such as bisphosphonate and denosumab are currently considered the treatment of choice in patients with osteoclastic bone disease. These reduce bone turnover and improve bone density, thereby improving bone quality. These agents have also been shown to reduce the risk of osteoporotic fractures due to their potent effect in suppressing osteoclastic activity by slowing the remodeling process and increasing bone density, thereby improving quality of life for most of the patients. Despite the great benefits of bisphosphonates and other antiresorptive medications, osteonecrosis of the jaw (ONJ) due to the effects of these medications in the presence of a local risk factor is a significant drawback. Moreover, antiangiogenic drugs play a major role in developing bone necrosis. They are prescribed in cancer cases to prevent metastasis through the blood and lymph nodes. These drugs interfere with the formation of new blood vessels, resulting in ischemia and eventually ONJ. This risk can be managed by evaluating the route and the duration of administration as such a risk can be considered dose-time dependent. As a preventive measure, dental screening before initiating any type of ONJ-related medications can significantly lower the risk of ONJ. Treatment goals can be achieved through pain and infection control, in addition to the management of bone necrosis and resorption. The aim of this review is to identify all causative agents and summarize the preventive measures, diagnostic criteria, and treatment strategies related to MRONJ.

Cloud-Based Multicenter Data Collection and Epidemiologic Analysis of Bisphosphonate-Related Osteonecrosis of the Jaws in a Central European Population

Objective: Bisphosphonate-related osteonecrosis of the jaws is considered to be a rare but severe complication of bisphosphonate therapy. To understand this condition better, data collection is essential. Although the number of scientific papers about this subject is large, to date only a few multicenter reports have been published. Study design: We present a novel cloud-based data collection system for the evaluation of the risk factors of bisphosphonate-related osteonecrosis of the jaws. Web-based questionnaire and database have been set up and made available to voluntary researchers and clinicians in oral and maxillofacial surgery in Hungary and Slovakia. Results: To date, fifteen colleagues from eight maxillofacial units have joined the study. Data of 180 patients have been recorded. Collected data were statistically analysed and evaluated from an epidemiological point of view. Conclusions: Authors consider cloud-based multicenter data collection a useful tool that allows for real-time collaboration between users, facilitates fast data entry and analysis, and thus considerably contributes to widening our knowledge of bisphosphonate-related osteonecrosis of the jaws.

Cloud-Based Multicenter Data Collection and Epidemiologic Analysis of Bisphosphonate-Related Osteonecrosis of the Jaws in a Central European Population

Objective: Bisphosphonate-related osteonecrosis of the jaws is considered to be a rare but severe complication of bisphosphonate therapy. To understand this condition better, data collection is essential. Although the number of scientific papers about this subject is large, to date only a few multicenter reports have been published. Study design: We present a novel cloud-based data collection system for the evaluation of the risk factors of bisphosphonate-related osteonecrosis of the jaws. Web-based questionnaire and database have been set up and made available to voluntary researchers and clinicians in oral and maxillofacial surgery in Hungary and Slovakia. Results: To date, fifteen colleagues from eight maxillofacial units have joined the study. Data of 180 patients have been recorded. Collected data were statistically analysed and evaluated from an epidemiological point of view. Conclusions: Authors consider cloud-based multicenter data collection a useful tool that allows for real-time collaboration between users, facilitates fast data entry and analysis, and thus considerably contributes to widening our knowledge of bisphosphonate-related osteonecrosis of the jaws.

Mathematical modelling of the role of Endo180 network in the development of metastatic bone disease in prostate cancer

Metastatic bone disease (MBD) is a common complication of advanced cancer and recent research suggests that Endo180 expression is dysregulated through the TGFβ-TGFβR-SMAD2/3 signalling pathway during the invasion of tumour cells in the development of MBD. We here provide a model for the dysregulation of the Endo180 network to demonstrate its vital contribution to bone destruction as well as tumour cell growth. The model consisted of a set of ordinary differential equations and reconstructed variations in the bone cells, resultant bone volume, and biochemical factors involved in the TGFβ-TGFβR-SMAD2/3 signalling pathway over time. The model also investigated the underlying mechanism in which the change of TGFβ affects the TGFβ-TGFβR-SMAD2/3 signalling pathway and the resultant Endo180 expression in osteoblastic and tumour cells. The model links the appearance of tumour cells with the inhibition of TGFβ binding to its receptors on osteoblastic cells, to affect TGFβ-TGFβR-SMAD2/3 signalling and Endo180 expression. Temporal variation in bone cells, bone volume, and the biochemical factors involved in the TGFβ-TGFβR-SMAD2/3 pathway as demonstrated in the model simulations agree with published experimental data. The model can be refined based on further discoveries but allows the influence of Endo180 network dysregulation on bone remodelling in MBD to be established. This model could aid in the development of Endo180 targeted therapies for MBD in the future.

Role of dendritic cell-mediated immune response in oral homeostasis: A new mechanism of osteonecrosis of the jaw

Dendritic cells are an important link between innate and adaptive immune response. The role of dendritic cells in bone homeostasis, however, is not understood. Osteoporosis medications that inhibit osteoclasts have been associated with osteonecrosis, a condition limited to the jawbone, thus called medication-related osteonecrosis of the jaw. We propose that disruption of the local immune response renders the oral microenvironment conducive to osteonecrosis. We tested whether zoledronate (Zol) treatment impaired dendritic cell (DC) functions and increased bacterial load in alveolar bone in vivo and whether DC inhibition alone predisposed the animals to osteonecrosis. We also analyzed the role of Zol in impairment of differentiation and function of migratory and tissue-resident DCs, promoting disruption of T-cell activation in vitro. Results demonstrated a Zol induced impairment in DC functions and an increased bacterial load in the oral cavity. DC-deficient mice were predisposed to osteonecrosis following dental extraction. Zol treatment of DCs in vitro caused an impairment in immune functions including differentiation, maturation, migration, antigen presentation, and T-cell activation. We conclude that the mechanism of Zol-induced osteonecrosis of the jaw involves disruption of DC immune functions required to clear bacterial infection and activate T cell effector response.

Dental care for patients taking antiresorptive drugs: a literature review

Antiresorptive drugs (ARDs), such as bisphosphonates or denosumab, that prevent bone resorption are widely used in patients with osteoporosis or with cancer that has metastasized to the bones. Although osteonecrosis of the jaw (ONJ) is a well-documented complication of ARD use, the benefits ARDs outweigh the complication. Thus, research has focused on finding ways to prevent or reduce the risk of developing ONJ. Dentists, as part of a multi-professional team, have a critical role in preventing ONJ. However, many dentists tend to hesitate to provide dental care to patients with ONJ, or tend to think that it is a problem to be dealt with by oral surgeons. This review gives an overview of ARD-related ONJ and provides the guidelines for dental care in patients taking ARDs to lower the risk of developing ONJ.

Dental students' knowledge of medication-related osteonecrosis of the jaw

Objectives:

The aim of this study was to evaluate and assess knowledge and attitude of dental students about medication-related osteonecrosis of the jaw (MRONJ), to optimize future training programs in this field.

Materials and Methods:

A cross-sectional study was administrated. Ninety-eight participants agreed to complete an anonymous questionnaire. It was divided into two sections: the first section was about general information such as interviewer's gender and date of birth; the second section included questions about bisphosphonates (BPs), others medication associated to osteonecrosis of the jaw (ONJ), risk factors, and prevention of osteonecrosis. Descriptive statistics were computed and the odds ratio was used to compare the odds for the groups.

Results:

Ninety-nine percent of participants declared to know BPs, but only 26.9% of 4^th year and 34.8% of 6^th year students knew the correct definition of MRONJ. Almost all of students identified the importance to report, in anamnesis, the use of BPs, as well as to check-up patients before the beginning of treatment; on the other hand, the knowledge about how invasive dental treatment might be carried out in patients under therapy was not adequate. In addition, half of the students did not recognize any active principle or commercial name of BPs. The situation was even worse regarding alternative drugs involved in ONJ.

Conclusions:

These findings are alarming and the lack of knowledge about MRONJ suggests that greater educational efforts should be performed about this pathology at undergraduate level.

Pharmacogenomics of osteonecrosis of the jaw

Osteonecrosis of the jaw (ONJ) is a rare but serious drug induced adverse event, mainly associated with the use of antiresorptive medications, such as intravenous (IV) bisphosphonates (BPs) in cancer patients. In this review, we evaluated all the pharmacogenomic association studies for ONJ published up to December 2018. To date, two SNPs (CYP2C8 rs1934951 and RBMS3 rs17024608) were identified to be associated with ONJ by two genome-wide association studies (GWAS). However, all six subsequent candidate gene studies failed to replicate these results. In addition, six discovery candidate gene studies tried to identify the genetic markers in several genes associated with bone remodeling, bone mineral density, or osteoporosis. After evaluating the results of these 6 studies, none of the SNPs was significantly associated with ONJ. Recently, two whole-exome sequencing (WES) analysis (including one from our group) were performed to identify variants associated with ONJ. So far, only our study successfully replicated discovery result indicating SIRT1 SNP rs7896005 to be associated with ONJ. However, this SNP also did not reach genome-wide significance. The major limitations of these studies include lack of replication phases and limited sample sizes. Even though some studies had larger sample sizes, they recruited healthy individuals as controls, not subjects treated with BPs. We conclude that a GWAS with a larger sample size followed by replication phase will be needed to fully investigate the pharmacogenomic markers of ONJ.

The use of crevicular fluid to assess markers of inflammation and angiogenesis, IL-17 and VEGF, in patients with solid tumors receiving zoledronic acid and/or bevacizumab

PURPOSE

Crevicular fluid was used to assess interleukin-17 (IL-17) and vascular endothelial growth factor (VEGF) in cancer patients receiving zoledronic acid and/or bevacizumab. The markers were also assessed in the serum.

METHODS

Twenty-five patients were included and comprised three groups: patients who received zoledronic acid (n = 9), patients who received bevacizumab (n = 9), and patients who received zoledronic acid combined with bevacizumab (n = 5). One patient received zoledronic acid and everolimus and another received zoledronic acid, bevacizumab, and temsirolimus. IL-17 and VEGF were measured by standard quantitative ELISA kits and assessed in two study points.

RESULTS

Twenty-four patients maintained good periodontal health; one had asymptomatic osteonecrosis of the jaw. First assessment: 44 samples were collected; 21 from serum and 23 from crevicular fluid. Second assessment, 6 months later: 11 samples were collected; 6 from serum and 5 from crevicular fluid. IL-17 was detected in all samples, in serum and crevicular fluid, and remained unchanged at both time points. Serum VEGF in patients with bevacizumab alone or combined with zoledronic acid was significantly lower compared with that of patients who received zoledronic acid alone. VEGF was not detected in the crevicular fluid.

CONCLUSIONS

Crevicular fluid might be an easy, non-invasive means to assess IL-17. The stable values of IL-17 in crevicular fluid and serum and the lack of VEGF in the crevicular fluid could be related to the good periodontal health of our patients. Further studies are needed to assess IL-17 and VEGF in the crevicular fluid in patients with and without periodontal disease.

A Systematic Review of Oxygen Therapy for the Management of Medication-Related Osteonecrosis of the Jaw (MRONJ)

Background: Medication-related osteonecrosis of the jaw (MRONJ) can be a life changing iatrogenic complication of antiresorptive and antiangiogenic drug therapy. It is most often associated with high doses of these medications that are used to prevent skeletal-related events in patients with cancer and bone pathologies. Unfortunately, managing MRONJ lesions has proven difficult and remains a major challenge for clinicians. Due to the lack of efficacy in treating MRONJ by surgical modalities (local debridement and free flap reconstruction), the nonsurgical management of MRONJ is still advocated to aid healing or avoid disease progression. The aim of this systematic review is to identify, analyse and understand the published evidence related to the success of oxygen therapies such as ozone (OT) and hyperbaric oxygen (HBO) in treating MRONJ. Material and methods: A multi-database (PubMed, MEDLINE, EMBASE, CINAHL and Cochrane CENTRAL) systematic search was performed by three authors. The identified articles were independently assessed for their risk of bias. Any type of study evaluating humans treated with antiresorptive and antiangiogenic drugs were considered. The aim is primarily to evaluate the success of OT and HBO in resolving MRONJ and secondarily to identify any improvements in quality of life (QoL), rate of complications, time-to-event and severity of side effects related to these treatments. Results: In total, just 13 studies were eligible for analysis. A pooled total of 313 patients (HBO group n = 82; OT group n = 231) described in these studies have shown good tolerance for oxygen therapies. Complete resolution of MRONJ was reported in 44.58% of OT patients but only 5.17% of the HBO group. Progression of MRONJ was reported only in the HBO studies in 10.34% of cases (6 patients). The quality of evidence was low or very low in all studies. This was due to limitations in how the studies were designed, run and reported. Conclusions: Based on the limited data available, it is difficult to suggest OT is better or worse than HBO or whether it is better than a placebo. As the level of evidence available is low, this necessitates larger well-designed trials to justify these interventions for patients affected by MRONJ.

Vitamin C Prevents Hydrocortisone-Induced Injury in HMEC-1 through Promoting Bestrophin-3 Expression

OBJECTIVE

To investigate the protective effects and underlying mechanisms of Vitamin C (VC) on hydrocortisone (HC)-induced cell injury in human microvascular endothelial cells (HMEC).

METHODS

Cell viability was measured by CCK-8 assay and the expression of Best-3 was detected by Western blotting assay. The experiment was divided into normal control, HC injury group, VC treatment groups, HC + Best-3 siRNA group, HC + VC + Best-3 siRNA group, HC + pcDNA3.1 Best-3 group, and HC + VC + pcDNA3.1 Best-3 group.

RESULTS

HC inhibited HMEC-1 cell viability was balanced with lower expression of Best-3 in a dose-dependent manner. Conversely, VC promoted HMEC-1 cell viability was paralleled to higher expression of Best-3 in a dose-dependent manner. Silencing Best-3 with Best-3 siRNA inhibited HMEC-1 cell viability, however, over-expression of Best-3 with pcDNA3.1 Best-3 promoted HMEC-1 cell viability. Moreover, VC and over-expression of Best-3 prevented HC-induced HMEC-1 cell apoptosis; however, silencing Best-3 further enhanced HC-induced HMEC-1 cell apoptosis. HC reduced Best-3 expression, which was alleviated by VC treatment. HC treatment decreased Bcl-2 expression, facilitated Bax expression. Both of VC and over-expression of Best-3 promoted Bcl-2 expression and decreased Bax expression. Additionally, VC and Best-3 expression have a synergistic effect.

CONCLUSIONS

VC can efficiently attenuate HC-induced HMEC-1 cell injury, which may be related to promote Best-3 expression.

Medication-related osteonecrosis of the jaw: definition and best practice for prevention, diagnosis, and treatment

Skeletal complications caused by osteoporosis or bone metastases are associated with considerable pain, increased mortality, and reduced quality of life. Furthermore, such events place a burden on health care resources. Agents that prevent bone resorption, such as bisphosphonates or denosumab, can reduce the risk of skeletal-related events and are widely used in patients with osteoporosis or bone metastases of cancer. Medication-related osteonecrosis of the jaw (MRONJ) is a rare, but potentially serious, adverse event associated with high cumulative doses of bisphosphonates or denosumab. However, MRONJ can be treated, and the likelihood of the development of this condition can be reduced through prophylactic dental care and the maintenance of good oral hygiene. Dentists, as part of a multiprofessional team, have a critical role in preventing MRONJ. This review describes the incidence and pathophysiology of MRONJ and provides guidance for dental practitioners with regard to the screening, prophylactic treatment, diagnosis, and management of patients with this condition.

Clinical impact of bisphosphonates in root canal therapy

Bisphosphonates are stable structural analogs of pyrophosphate, which suppress the activity of osteoclasts, leading to decreased bone resorption. They are essential medications in the treatment of osteoporosis. Osteonecrosis of the jaw is a serious adverse effect of bisphosphonate therapy. The prevalence of bisphosphonate-related osteonecrosis of the jaw varies from 0% to 28%, and it can be triggered by dental extraction and trauma. Root canal therapy can delay, or even eliminate, the need for tooth extraction, and therefore, may reduce the risk of bisphosphonate-related osteonecrosis of the jaw. We suggest that this might be the best treatment for teeth with pulpal and/or periapical disease.

The Dental Management of Patients at Risk of Medication-Related Osteonecrosis of the Jaw: New Paradigm of Primary Prevention

Medication-related osteonecrosis of the jaw (MRONJ) is a serious adverse reaction of antiresorptive and antiangiogenic agents; it is a potentially painful and debilitating condition that can considerably affect the quality of life of patients. Furthermore, even if its epidemiology and pathogenesis have still not been fully clarified, several risk factors related to MRONJ have been recognized in prevention protocols. Three main risk factors are as follows: (i) the type of ONJ-related medications: antiresorptive (e.g., Bisphosphonates, Denosumab) and antiangiogenic drugs (e.g., Bevacizumab, Sunitinib); (ii) the category of patient at MRONJ risk: cancer versus non-cancer patient; (iii) the typologies and timing of dental treatments (e.g., before, during, or after the drug administration). The aim of this paper is to describe the new paradigm by the Italian Society of Oral Pathology and Medicine (SIPMO) on preventive dental management in patients at risk of MRONJ, prior to and during/after the administration of the aforementioned ONJ-related drugs. In reducing the risk of MRONJ, dentists and oral hygienists are key figures in applying a correct protocol of primary prevention for pre-treatment and in-treatment patients. However, the necessity of a multidisciplinary standardized approach, with a sustained dialogue among specialists involved, should be always adopted in order to improve the efficacy of preventive strategies and to ameliorate the patient's quality of life.

Risk-reductive dental strategies for medication related osteonecrosis of the jaw among cancer patients: A systematic review with meta-analyses

The purpose of this systematic review with meta-analysis was to assess the effectiveness of dental interventions in preventing or reducing the incidence of medication-related osteonecrosis of the jaw (MRONJ) in cancer patients receiving antiresorptive therapy, compared to similar control groups receiving no intervention. Randomized controlled trials (RCT), case-controls and cohorts on cancer patients with primary outcome being the prevalence of MRONJ were included. Four electronic databases were searched (Cochrane Library, PubMed, EMBASE and Web of Science) up to February 12, 2018. A total of 409 abstracts were assessed and one case-control, one RCT and four cohort studies with 2332 cancer patients met our inclusion criteria. Risk of bias analysis followed Cochrane's handbook. Risk of bias was unclear for the case-control study and high risk for the RCT and all cohort studies. Five studies utilized preventive measures consisting of an initial examination and performing all necessary dental treatment before patients initiated antiresorptive therapy; one study used specialized post-extraction protocols utilizing plasma-rich in growth factors (PRGF) on cancer patients receiving antiresorptive therapy. Though dental preventive measures decreased MRONJ incidence by 77.3% in six studies with 2332 cancer patients (95% CI = 47.4-90.2%; p = .001) compared to control groups, quality of the evidence was low due to high or unclear risk of bias and the observational nature of five of the included studies. In conclusion, high-quality long-term prospective large sample size studies are needed to confirm these results due to high risk of bias and heterogeneous interventions. No funding.

Zoledronic acid exacerbates inflammation through M1 macrophage polarization

Background

Zoledronic acid (Zol), one of the bisphosphonates, is frequently utilized for the treatment of osteoporosis and bone metastasis. However, the onset of medication-related osteonecrosis of the jaw (MRONJ) following dental treatments has become a serious issue. We reported previously that osteonecrosis can be induced by Zol and lipopolysaccharide (LPS) in vivo, suggesting the involvement of Zol in inflammation. Macrophages are divided into M1/M2 macrophages. M1 macrophages are involved in the induction and exacerbation of inflammation and express proinflammatory mediators including interleukin (IL)-1. On the other hand, M2 macrophages are associated with anti-inflammatory reactions through the expression of anti-inflammatory cytokines, such as IL-10. In the present study, we clarified the effects of Zol on M1/M2 macrophage polarization in vitro.

Methods

Human monocytic THP-1 cells were polarized to macrophage-like cells by phorbol 12-myristate 13-acetate (PMA), and, after culturing for an additional 24 h with or without Zol, then polarized to M1 macrophages by LPS or to M2 macrophages by IL-4. Cell viability was examined by the WST-8 assay. Gene expression was confirmed by the real-time polymerase chain reaction. Protein expression was detected by western blotting and enzyme-linked immunosorbent assays.

Results

Zol treatment upregulated the expression of IL-1β mRNA and protein through NLRP3 inflammasome activation in LPS-treated THP-1 cells. Zol treatment did not affect the expression of IL-10, IL-1ra, or CD206 in IL-4-treated THP-1 cells.

Conclusions

Zol enhanced LPS-induced M1, but not M2, macrophage polarization through the NLRP3 inflammasome-dependent pathway, resulting in the production of inflammatory cytokines in THP-1 cells.

Antiresorptive drug-related osteonecrosis of the jaws, literature review and 5 years of experience

PURPOSE

Bisphosphonate drug therapy provides benefits in the case of osteoporosis and carcinomas metastasizing to the bones, but it exposes patients to important side effects. The aim of this study was to investigate the incidence and the appropriate surgical treatment of bone lesions and fractures due to antiresorptive drug-related osteonecrosis of the jaws (ARONJ).

METHODS

Patients presenting with osteonecrosis lesions of the jaw, who were referred to the Maxillo-Facial unit of the University of L'Aquila, were considered for inclusion. Grade of the lesion and treatment choice was recorded for each patient. Descriptive statistics were calculated and the data were analysed with Chi-squared tests. A representative case of a fracture reduction with a supra-periostal approach is reported.

RESULTS

Among the 165 patients with ARONJ lesions, 112 were female and 53 were male. In total, 115 patients received intra-venous bisphosphonate therapy and 50 received oral bisphosphonate therapy. Five stage 2 lesions, three stage 2 lesions and two stage 3 lesions were not a consequence of dental procedures. Eighteen surgical bone excisions were performed and four pathological fractures were reduced. In one case (the reported one), the combined use of platelet-rich plasma and the supra-periostal approach leads to a successful 1-year follow-up.

CONCLUSIONS

ARONJ lesions are a type of pathological bone disease affecting the jawbones. The pathology pathway remains a controversial and frequently discussed topic. A surgically conservative strategy seems to be the best way to assure a comfortable quality of life to those patients negatively affected by this condition.

Microsurgical Reconstruction of the Jaws Using Vascularised Free Flap Technique in Patients with Medication-Related Osteonecrosis: A Systematic Review

Background

Osteonecrosis of the jaw (ONJ) has been reported to be associated with patients receiving primarily bisphosphonate (BP) therapies. However, lately it has been documented that other medications, such as RANK ligand inhibitor (denosumab) and antiangiogenic drug, can cause ONJ. Micro-osseous-vascular reconstruction of the jaws in patients affected by medication-related osteonecrosis of the jaw represents a viable option of treatment for patients affected by stage III of the disease. However, there are still considerable doubts about the success of this procedure in the short, medium, and long term.

Material and Methods

A multidatabase (PubMed/MEDLINE, EMBASE, and CENTRAL) systematic search was performed. Any type of studies considering human patients treated with antiresorptive and antiangiogenic drugs was considered. The aim of the research is to primarily understand the success rate of micro-osseous-vascular reconstruction in the short, medium, and long period of time. This review has also the goal of better understanding any perioperative and postoperative complications resulting from the use of the reconstruction techniques.

Results

Eighteen studies resulted eligible for the study. Fibula free flap is the most commonly utilised vascularised free flap reconstruction technique (80.76%). Ten out of eighteen studies reported no complications. Recurrence of osteonecrosis was registered in five cases (6.41%) after free flap reconstruction. The overall free flap success rate was 96.16%.

Conclusions

Based on the limited data available in literature (Level 4 of the Oxford Evidence-based medicine scale), micro-osseous-vascular reconstruction of the jaws represents a valid treatment in patients with bisphosphonate-related osteonecrosis at stage III of the disease. However, additional data based on a larger cohort of patients are necessary to justify this type of intervention in patient affected by MRONJ.

What is the Current Evidence on Vertebral Body Osteonecrosis?: A Systematic Review of the Literature

Osteonecrosis (ON) is a clinical entity characterized by a pattern of cell death and complex process of bone resorption and formation. Studies related to ON have largely focused on certain anatomical sites; however, the evidence on vertebral body ON (VBON) is largely inconsistent and fragmented. The aim of this study was to clarify the pathophysiology, risk factors, imaging findings, and available treatment modalities for VBON. A systematic review of the relevant articles published in English was performed using PubMed, Embase, Medline, Google Scholar, Cochrane Central Register of Controlled Trials (CENTRAL), and CINAHL databases. A total of 81 articles were included in this study. Three main topics about VBON were identified: (1) pathophysiology and risk factors, (2) diagnosis, and (3) treatment. Forty-five studies were based on the pathophysiology, 52 on diagnosis, and 38 on the treatment options for VBON. The literature on VBON was limited and mainly focused on post-traumatic cases with a considerable overlap with nonunion and pseudoarthrosis.

Could the Combined Administration of Bone Antiresorptive Drug, Taxanes, and Corticosteroids Worsen Medication Related Osteonecrosis of the Jaws in Cancer Patients?

The study presents a report of 58 metastatic cancer patients who developed osteonecrosis of the jaws after being treated with zoledronic acid and taxanes, plus corticosteroids. A retrospective analysis of data registered in the archives of two Italian osteonecrosis of the jaws treatment centers, who are based at the University of Messina and at the University of Palermo, was performed in order to study, in these patients, demographic data and characteristics such as frequency of cancer location, lines of therapy, frequency of cancer drugs, presence/absence of oral trigger, number, location, and stage of jaw osteonecrosis. It was found that the majority of patients developed advanced stages of osteonecrosis, frequently complicated with infection. It was hypothesized that the concurrent administration of chemotherapeutic agents could be eventually considered as a factor able to allow a faster worsening of the clinical manifestation through the exacerbation of soft tissue defects, due to chemotherapy drugs.

Changes in dimension of neurovascular canals in the mandible and maxilla: A radiographic finding in patients diagnosed with MRONJ

Background

The aim of this retrospective study was to compare the morphological features of neurovascular canals and foramina of patients with medication-related osteonecrosis of the jaws (MRONJ) and healthy individuals by using cone beam computed tomography (CBCT).

Material and Methods

The CBCT images of 58 patients under bisphosphonate therapy diagnosed with MRONJ and age gender- matched controls were retrospectively evaluated. The diameter of mandibular and nasopalatine canal and mandibular, mental and lingual foramina were measured on several sections of CBCT. The value of mental index (MI) and panoramic mandibular index (PMI) were also assessed.

Results

The mean value of diametric measurements for all neurovascular canals and foramina in MRONJ patients were narrower than controls. Left mandibular foramen was the most affected area (p<0.001). There were significantly difference in all measurements of mental foramen, lingual foramen and mandibular incisive canal between two groups (p<0.05). PMI of MRONJ subjects were also significantly differences in both sides (p<0.05).

Conclusions

In MRONJ patient, neurovascular canals and foramina are affected due to the alterations in bone remodeling. Therefore, the diametric measurement of neurovascular canals and assessment of MI and PMI on CBCT, is a potentially useful method for detection of early changes associated with bisphosphonate therapy and for predict areas where new necrosis may occur.

Key words:Bisphosphonate, MRONJ, CBCT, neurovascular canals, PMI.

Osteonecrosis of the Jaw among Patients Receiving Antiresorptive Medication: A 4-year Retrospective Study at a Tertiary Cancer Center, Kerala, India

Purpose:

Osteonecrosis of the jaw (ONJ) is a rare but complicated side effect of antiresorptive medications. The aim of the study is to evaluate the dental and drug-related factors related to ONJ among patients on these drugs at a tertiary cancer center, India.

Methodology:

A retrospective record review of patients who received antiresorptive medication at our center from 2011 to 2014 was done. The demographic factors, type, dosage, and duration of the medication and dental history were collected, and the data were entered an analyzed using Epidata software.

Results:

A higher incidence of ONJ (8.1%) was noted in our sample (n = 183). Dental intervention after zoledronic acid (ZA) administration showed a statistical significance (P < 0.001). No significance (P value) was noted with respect to sex (0.78), age (0.28), median duration (0.9), and median dosage (0.9) of ZA.

Conclusion:

Oro-dental screening and dental monitoring shall reduce the incidence of ONJ. Within the limitations of our study, no significant relation could be pointed toward the dosage and duration of the drug and development of ONJ.

Orofacial manifestations of adverse drug reactions: a review study

Background

Adverse reaction to medication is common and may have a variety of clinical manifestations in the oral cavity. The present review paper aimed to describe adverse drug reactions (ADRs) which might be encountered by dental practitioners in every discipline.

Methods

In this narrative review article, the specialized databases such as PubMed, PubMed Central, MEDLINE, EBSCO, Science Direct, Scopus, and reference books from the years 2000-2016 were used to find relevant documents by using MeSH terms: Adverse Drug Reaction, Drug induced, Medication Related, Mouth, Oral Manifestation, Tooth, Hard Tissue, Soft Tissue.

Results

The data were categorized in 4 groups as follows: saliva and salivary glands involvement, soft tissue (mucosal) involvement, hard tissue involvement, and non specific conditions (taste disorders, halitosis, neuropathies, movement disturbances, and infection). Most articles were about the adverse effect of drugs on the function of salivary glands, which often cause a decrease in saliva secretion. Other reactions were less common; meanwhile, the side effect of bisphosphonate was increasing in the alveolar bone, because of its unlimited prescription.

Conclusion

Oral health care providers should be familiar with such events, as they will be confronted with them in their practice.

A multicenter case registry study on medication-related osteonecrosis of the jaw in patients with advanced cancer

Purpose

This observational case registry study was designed to describe the natural history of cancer patients with medication-related osteonecrosis of the jaw (ONJ) and evaluate the ONJ resolution rate.

Methods

Adults with a diagnosis of cancer and with a new diagnosis of ONJ were enrolled and evaluated by a dental specialist at baseline and every 3 months for 2 years and then every 6 months for 3 years until death, consent withdrawal, or loss to follow-up. The primary endpoint was the rate and time course of ONJ resolution. Secondary endpoints included frequency of incident ONJ risk factors, ONJ treatment patterns, and treatment patterns of antiresorptive agents for subsequent ONJ.

Results

Overall, 327 patients were enrolled; 207 (63%) were continuing on study at data cutoff. Up to 69% of evaluable patients with ONJ had resolution or improvement during the study. ONJ resolution (AAOMS ONJ staging criteria) was observed in 114 patients (35%); median (interquartile range) time from ONJ onset to resolution was 7.3 (4.5–11.4) months. Most patients (97%) had received antiresorptive medication before ONJ development, 9 patients (3%) had not; 68% had received zoledronic acid, 38% had received denosumab, and 10% had received pamidronate (56% had received bisphosphonates only, 18% had received denosumab only, and 21% had exposure to both).

Conclusions

These results are consistent with those observed in clinical trials evaluating skeletal-related events in patients with advanced malignancy involving bone. Longer follow-up will provide further information on ONJ recurrence and resolution rates between medically and surgically managed patients.

Selective Percutaneous Controlled Radiofrequency Thermocoagulation of the Gasserian Ganglion To Control Facial Pain Due to Medication-Related Osteonecrosis of the Jaw

BACKGROUND

Medication-related osteonecrosis of the jaw (MRONJ) is an important complication in patients treated with antiresorptive agents such as bisphosphonates and the receptor activator of nuclear factor κB ligand inhibitor (denosumab). Treatment of MRONJ is extremely difficult, which makes it a distressing long-term complication.

OBJECTIVES

We report a case of intractable facial pain due to MRONJ that was successfully controlled with selective percutaneous controlled radiofrequency thermocoagulation of the Gasserian ganglion.

SETTING

A 68-year-old woman with breast cancer was diagnosed as having MRONJ. She was very distressed because of jaw pain and infections secondary to MRONJ. Her quality of life (QOL) was severely decreased. Since alleviation of the MRONJ could not be expected within the patient's life expectancy, it was decided to investigate the usefulness of selective percutaneous controlled radiofrequency thermocoagulation of the Gasserian ganglion to control the pain.

RESULTS

After the procedure, the anesthesia was obtained in the distribution of the third branch of the trigeminal nerve, and the pain completely disappeared. Although hypoesthesia was provoked as a complication, it was tolerated by the patient and she was very satisfied. Up to the time of death, there was no recurrence of pain or worsening of the MRONJ.

DISCUSSION

This procedure is a common technique for treating trigeminal neuralgia. Its effect is immediate and long lasting, although it provokes hypoesthesia in treated division, and it is also suited for cancer patients in terminal stage. This case suggests that the procedure was useful for improving the patient's QOL.

Acquired heterotopic ossification of the temporomandibular joint

Although the risk factors and diagnosis of heterotopic ossification (HO) are discussed in the orthopedics literature, the etiology of HO, as well as its prevention and management, remain theoretical. Furthermore, there is a lack of information in the literature regarding HO in temporomandibular joint replacement (TMJR). This article provides a qualitative review of information relative to the etiology, diagnosis, and management of HO to inform and encourage further investigation in TMJR. The orthopedic HO literature considered for this qualitative review was drawn from a comprehensive examination of the subject published previously by one of the authors. Using the key words "heterotopic ossification" or "heterotopic bone", citations in the PubMed database from both the dental and oral and maxillofacial surgery literature were reviewed. Based on this, it appears that the etiology, diagnosis, imaging, laboratory testing, risk factors, prophylaxis, and non-surgical and surgical options available for the management of TMJR-related HO are similar to those for orthopedic HO, but further elucidation is required for TMJR. There is a lack of published information in the literature on TMJR. Therefore, using the literature from this review as a foundation, studies should be developed and reported so that alloplastic TMJ surgeons have evidence-based protocols that will lead to the early detection and potential prevention of HO.

Dental Implants Placed in Patients with Mechanical Risk Factors: A Long-term Follow-up Retrospective Study

Objectives:

Risk factors in oral implantology are defined as local or systemic conditions that increase failure rates. The purpose of this paper is to evaluate the long-term survival rate of dental implants placed in patients presenting mechanical risk factors.

Materials and Methods:

This retrospective study was conducted only with patients presenting at least one of the following risk factors were included: Bruxism; crown-to-implant (C/I) ratio <0.8; abutment angulation. The overall implant survival was estimated using Kaplan–Meier analyses. Risk factors for implant failure were identified using the Cox proportional hazard regression models.

Results:

Eighty-nine eligible patients were enrolled in this study: They were both male (n = 56, 62.92%) and female (n = 33, 37.08%), with an average age of 53.24 (23–76 years), with 227 dental implants inserted. The mean follow-up was 13.6 years (range: 10–16 years). The overall 10-year Kaplan–Meier survival estimate with associated 95% confidence intervals was 86.34% (82.8, 87.1). Bruxism was the only variable that showed a statistically significant association with implant failure (P < 0.05) and a hazard ratio of 2.9, while both Crown to-implant and abutment angulations reported lower values of failure (P > 0.05).

Conclusions:

Within the limitations of this study, can be concluded that data suggested an evident relationship between bruxism and dental implant failure but further studies, with a larger sample and a different design are required to assess this relationship.

Otorhinolaryngological Toxicities of New Drugs in Oncology

Many new or relatively new cancer drugs-personalized anticancer agents-have been approved for use in various clinical settings in oncology or are still under evaluation in clinical trials. Targeted therapies as well as new immune checkpoint blockers have toxicity profiles that differ from conventional cytotoxic chemotherapy, and many can cause adverse effects that affect the mouth and pharynx, the nasal cavities, and the larynx. This review aims to provide an overview of current knowledge concerning these side effects and contemporary management. Adverse effects of the mouth/pharynx, nasal cavities, larynx, and cochlear-vestibular system are generally low grade (according to the Common Terminology Criteria for Adverse Events) and generally present non-life-threatening symptoms. However, the impact on patients' quality of life could be important. The incidence and severity vary according to the drug, its target(s), and dose, but there are currently no known predictive factors, and each patient has an individual toxicity profile. Management guidelines are based on expert opinion. These ear, nose, and throat adverse effects are not frequently mentioned in the literature because of the often non-specific nature of the symptoms and their mildness, but also the absence of specific treatment. These symptoms can contribute to decreased quality of life and lead to drug compliance issues if not diagnosed and managed appropriately.

[Evaluation of healing time of osteochemonecrosis of the jaw after surgery: Single-center retrospective study and review of the literature]

INTRODUCTION

Osteochemonecrosis of the jaw (ONJ) is a chronic ischemic bone exposure. It has an increasing incidence. ONJ is mainly related to bisphosphonate and denosumab therapies in oncologic settings. Healing is considered uncertain ad as occurring slowly. International recommendations suggest to treat ONJ symptomatically in a first attempt. A surgical procedure, potentially aggressive, should be carefully weight up in patients in poor condition and whose life expectancy is often limited. However, surgical treatment seems to allow for a high rate of clinical remission. Postoperative remission periods, when mentioned in the studies, are disparate. The aim of our study was to clarify the remission period of ONJ after surgical management.

METHOD

A retrospective study was conducted on all patients operated for an ONJ at stage 2 and 3 in the Department for Oral and Maxillofacial Surgery - University Hospital of Besançon (France) from January 2006 to September 2015. Healing was defined as complete mucosal closure and asymptomatic site. Stage of the disease, the number and the type of surgery and the time between the last operation and the healing was noticed. These data were compared to an exhaustive review of the literature on PubMed with the following key-words: "osteonecrosis" AND "jaw" AND "surgery" AND "management". Only the articles giving the healing period were included.

RESULTS

Regarding the single-center retrospective study, the files of 23 patients could be included. Fifteen percent of the patients benefited from several procedures under general anesthesia. Twenty percent had a stage 3 ONJ and 80 % had a stage 2 ONJ. Twenty-five interventions were performed on 23 sites in 20 patients. Immediate healing after surgery occurred in 35 % of the patients. At 6 months after surgery, 57 % of the treated areas were healed. Twenty percent of the patients had died. The healing rate did not improve further after 6 months postoperatively. Regarding the review of the literature, 7 articles could be included. The mean postoperative healing period was 60.7 % at 6 months, 71.1 % at 12 months and 69.5 % at 18 months.

DISCUSSION

Our study shows that the postoperative healing rate of ONJ lies between 57 and 66.7 % at 6 months and that this rate was optimized in the order of 10 % to 12months and stable at 18months postoperatively. The ONJ of our series were partially or fully linked to other drugs than bisphosphonates in 70 % of the cases: 50 % were related to denosumab, alone or in combination and 35 % were related to an association with antiangiogenics, bevacizumab mainly.

"English Disease": Historical Notes on Rickets, the Bone-Lung Link and Child Neglect Issues

Nutritional or classical rickets (here labeled as "rickets") is a worldwide disease involving mostly infants and young children having inadequate sunlight exposure, often associated with a low dietary intake of Vitamin D. Rickets targets all layers of society independently of economic status with historical information spanning more than two millennia. Vitamin D is critical for the absorption of calcium and prevention of rickets in children as well as osteomalacia in adults. The initial and misleading paradigm of the 19th and 20th centuries that rickets may have been the consequence of infection has been, indeed, reversed following the identification of the Vitamin D molecule's important role in the function of the immune system. Although traditionally considered limited to osteopathology, Vitamin D deficiency is now known to be linked to infection, inflammation, and carcinogenesis. In this review, we consider the key historical (Whistler, pre-Whistler and post-Whistler descriptors) and social facts around rickets; highlight the osteo-pathological features of rickets and the pathology of the upper and lower respiratory tract, stressing the fact that lungs remain the main secondary organ affected by Vitamin D deficiency; and emphasize the public health role in identifying the cases of child neglect or abuse based on the evaluation of the costochondral region.

Impact of Soft Tissue Pathophysiology in the Development and Maintenance of Bisphosphonate-Related Osteonecrosis of the Jaw (BRONJ)

Since the first description of bisphosphonate-related osteonecrosis of the jaw (BRONJ), numerous research groups have focused on possible pathological mechanisms including the suppression of the bone turnover of the jaw, antiangiogenic effects and soft tissue toxicity. In our review we focused on summarizing the role of the soft tissues in the development and progression of BRONJ. The biological behavior of fibroblasts can be significantly influenced by bisphosphonates (BP) such as a concentration dependent reduction of cell viability. High concentrations of BP can induce apoptosis and necrosis of the cells. Comparable effects could be detected for keratinocytes. Compared to non-nitrogen containing bisphosphonates, nitrogen-containing BP have worse effects on cell biology by blocking the mevalonate pathway. Further, the cell architecture and expression levels of several genes and proteins are significantly disturbed by BP. These inhibitory effects of BP are in accordance with BP-related reduced angiogenesis and neovascularization and could underline the hypothesis that inhibition of fibroblasts and keratinocytes results in delayed wound healing and can induce and trigger BRONJ.