Quantitation and distribution of metallic elements in sequestra of medication-related osteonecrosis of jaw (MRONJ) using inductively coupled plasma atomic emission spectroscopy and synchrotron radiation X-ray fluorescence analysis

Development of Cu application using dual-energy computed tomography for detecting medication-related osteonecrosis of the jaw

INTRODUCTION

The present study developed an application using dual-energy computed tomography (DECT) focused on Cu for detecting medication-related osteonecrosis of the jaw (MRONJ).

MATERIALS AND METHODS

First, we performed two types of phantom studies using a Cu wire syringe and pig mandible with Cu wire to detect Cu on DECT. Second, DECT examinations of 44 patients with MRONJ were performed to compare lesion and normal bone sites using single-energy CT, DECT-virtual non-calcium (VNCa), and DECT-Cu applications. Quantitative analyses of VNCa CT and CT values were performed, and a cut-off value was calculated using receiver operating characteristic analysis. Third, we compared the Cu content in the MRONJ and normal bone groups using inductively coupled plasma atomic emission spectroscopy (ICP-AES).

RESULTS

The material-specific differences in attenuation between the two different energies enabled the accurate separation of Cu from Ca in phantom studies. The sensitivity and specificity for single-energy CT, DECT-VNCa, and DECT-Cu applications were 97.7% and 2.3%, 86.4% and 81.8%, and 88.6% and 97.7%, respectively. Thus, VNCa CT values obtained on DECT-Cu application images showed the highest area under the curve value and maximal diagnostic efficacy in differentiating lesion sites from normal bone sites. On ICP-AES analyses, the Cu content was significantly higher in the MRONJ group than in the normal bone group.

CONCLUSION

DECT-Cu application demonstrated better diagnostic performance in detecting MRONJ compared with single-energy CT or DECT-VNCa.

Nickel particles are present in Crohn's disease tissue and exacerbate intestinal inflammation in IBD susceptible mice

Crohn's disease is an inflammatory disease of the gut caused by a complex interplay among genetic, microbial, and environmental factors. The intestinal tract is constantly exposed to metals and other trace elements ingested as food. Synchrotron radiation-induced X-ray fluorescence spectroscopy and X-ray absorption fine structure analysis revealed the deposition of nickel particles within Crohn's disease tissue specimens. After nickel particle stimulation, THP-1 cells showed filopodia formation and autophagic vacuoles containing lipid bodies. Nickel particles precipitated colitis in mice bearing mutations of the IBD susceptibility protein A20/TNFAIP3. Nickel particles also exacerbated dextran sulfate sodium-induced colitis in mice harboring myeloid cell-specific Atg5 deficiency. These findings illustrate that nickel particle ingestion may worsen Crohn's disease by perturbing autophagic processes in the intestine, providing new insights into environmental factors in Crohn's disease pathogenesis.

Pathophysiology of Demineralization, Part I: Attrition, Erosion, Abfraction, and Noncarious Cervical Lesions

PURPOSE OF THE REVIEW

Compare pathophysiology for infectious and noninfectious demineralization disease relative to mineral maintenance, physiologic fluoride levels, and mechanical degradation.

RECENT FINDINGS

Environmental acidity, biomechanics, and intercrystalline percolation of endemic fluoride regulate resistance to demineralization relative to osteopenia, noncarious cervical lesions, and dental caries. Demineralization is the most prevalent chronic disease in the world: osteoporosis (OP) >10%, dental caries ~100%. OP is severely debilitating while caries is potentially fatal. Mineralized tissues have a common physiology: cell-mediated apposition, protein matrix, fluid logistics (blood, saliva), intercrystalline ion percolation, cyclic demineralization/remineralization, and acid-based degradation (microbes, clastic cells). Etiology of demineralization involves fluid percolation, metabolism, homeostasis, biomechanics, mechanical wear (attrition or abrasion), and biofilm-related infections. Bone mineral density measurement assesses skeletal mass. Attrition, abrasion, erosion, and abfraction are diagnosed visually, but invisible subsurface caries <400μm cannot be detected. Controlling demineralization at all levels is an important horizon for cost-effective wellness worldwide.

Pathophysiology of Demineralization, Part II: Enamel White Spots, Cavitated Caries, and Bone Infection

PURPOSE OF REVIEW

Compare noninfectious (part I) to infectious (part II) demineralization of bones and teeth. Evaluate similarities and differences in the expression of hard tissue degradation for the two most common chronic demineralization diseases: osteoporosis and dental caries.

RECENT FINDINGS

The physiology of demineralization is similar for the sterile skeleton compared to the septic dentition. Superimposing the pathologic variable of infection reveals a unique pathophysiology for dental caries. Mineralized tissues are compromised by microdamage, demineralization, and infection. Osseous tissues remodel (turnover) to maintain structural integrity, but the heavily loaded dentition does not turnover so it is ultimately at risk of collapse. A carious tooth is a potential vector for periapical infection that may be life-threatening. Insipient caries is initiated as a subsurface decalcification in enamel that is not detectable until a depth of ~400μm when it becomes visible as a white spot. Reliable detection and remineralization of invisible caries would advance cost-effective wellness worldwide.

Bone single-photon emission computed tomography-CT peak standardized uptake value for chronic osteomyelitis, osteoradionecrosis and medication-related osteonecrosis of the jaw

INTRODUCTION

Recently, standardized uptake value (SUV) has been applied for the evaluation of SPECT-CT. This study was performed to investigate the bone SPECT-CT peak SUV for chronic osteomyelitis, osteoradionecrosis and medication-related osteonecrosis of the jaw (MRONJ).

METHODS

Sixty-five patients with jaw lesions (12 chronic osteomyelitis, 12 osteoradionecrosis and 41 MRONJ) underwent SPECT-CT after injection of technetium-99m hydroxymethylene diphosphonate. The peak SUV was compared for the chronic osteomyelitis with osteoradionecrosis and MRONJ using GI-BONE software. Statistical analyses for the peak SUV were performed by one-way repeated measures analysis of variance with Tukey's HSD test. A P-value lower than 0.05 was considered as statistically significant.

RESULTS

Peak SUV for chronic osteomyelitis (15.6 ± 4.4) was significantly higher than those for osteoradionecrosis (6.7 ± 2.1, P = 0.000) and MRONJ (10.7 ± 6.1, P = 0.019).

CONCLUSION

The SPECT-CT peak SUV using GI-BONE software can be useful for the evaluation of jaw lesions, such as chronic osteomyelitis, osteoradionecrosis and MRONJ.