Using Salivary MMP-9 to Successfully Quantify Periodontal Inflammation during Orthodontic Treatment

Treatment of Class II Malocclusion With Orthodontic Microimplant Anchorage

INTRODUCTION

The objective of the study was to compare the effects of orthodontic microimplant anchorage (MIA) and conventional extraoral arch anchorage (EAA) on tooth structure and oral inflammatory response in patients with Class II Division I malocclusion.

METHODS

A total of 104 patients with Class II malocclusion were enrolled and were randomly assigned to receive MIA or EAA treatments. Clinical efficacy was assessed at 6 months after treatment by measuring molar shift, convex distance, and hinge angle difference between maxillary and mandibular incisors. X-ray was performed for tissue evaluations. The levels of cell adhesion molecule-1 (CAM-1), matrix metalloproteinase-2 (MMP-2), and proinflammatory cytokines in gingival sulcus fluid were measured using enzyme-linked immunosorbent assay to assess inflammatory responses to the implants.

RESULTS

Our study demonstrated superior efficacy of MIA compared to EAA in terms of overall efficacy, molar shift, convex distance between upper and middle incisors, as well as hinge angle difference between upper and middle incisors. MIA also showed greater efficacy in reducing tissue fix-point measurements, including saddle point-nasal root point-superior alveolar seat point (SNA), alveolar seat point-nasal root point-inferior alveolar seat point (ANB), overlying (OJ), and overbite (OB).

CONCLUSIONS

MIA is a novel orthodontic treatment that showed stronger efficacy in inducing molar shift and correcting soft/hard tissue positions, whilst generating suppressed inflammatory responses. Our study could have significant implications for practice in the orthodontic treatment of Class II malocclusion.

New Approaches and Technologies in Orthodontics

In recent years, new diagnostic and treatment approaches in orthodontics have arisen, and there is thus a need for researchers and practitioners to stay up to date with these innovations [...].

Intelligent salivary biosensors for periodontitis: in vitro simulation of oral oxidative stress conditions

ASTRACT

One of the most common oral diseases affecting millions of people worldwide is periodontitis. Usually, proteins in body fluids are used as biomarkers of diseases. This study focused on hydrogen peroxide, lipopolysaccharide (LPS), and lactic acid as salivary non-protein biomarkers for oxidative stress conditions of periodontitis. Electrochemical analysis of artificial saliva was done using Gamry with increasing hydrogen peroxide, bLPS, and lactic acid concentrations. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were conducted. From EIS data, change in capacitance and CV plot area were calculated for each test condition. Hydrogen peroxide groups had a decrease in CV area and an increase in percentage change in capacitance, lipopolysaccharide groups had a decrease in CV area and a decrease in percentage change in capacitance, and lactic acid groups had an increase of CV area and an increase in percentage change in capacitance with increasing concentrations. These data showed a unique combination of electrochemical properties for the three biomarkers. Scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) employed to observe the change in the electrode surface and elemental composition data present on the sensor surface also showed a unique trend of elemental weight percentages. Machine learning models using hydrogen peroxide, LPS, and lactic acid electrochemical data were applied for the prediction of risk levels of periodontitis. The detection of hydrogen peroxide, LPS, and lactic acid by electrochemical biosensors indicates the potential to use these molecules as electrochemical biomarkers and use the data for ML-driven prediction tool for the periodontitis risk levels.

Matrix Metalloproteinases in the Periodontium-Vital in Tissue Turnover and Unfortunate in Periodontitis

The extracellular matrix (ECM) is a complex non-cellular three-dimensional macromolecular network present within all tissues and organs, forming the foundation on which cells sit, and composed of proteins (such as collagen), glycosaminoglycans, proteoglycans, minerals, and water. The ECM provides a fundamental framework for the cellular constituents of tissue and biochemical support to surrounding cells. The ECM is a highly dynamic structure that is constantly being remodeled. Matrix metalloproteinases (MMPs) are among the most important proteolytic enzymes of the ECM and are capable of degrading all ECM molecules. MMPs play a relevant role in physiological as well as pathological processes; MMPs participate in embryogenesis, morphogenesis, wound healing, and tissue remodeling, and therefore, their impaired activity may result in several problems. MMP activity is also associated with chronic inflammation, tissue breakdown, fibrosis, and cancer invasion and metastasis. The periodontium is a unique anatomical site, composed of a variety of connective tissues, created by the ECM. During periodontitis, a chronic inflammation affecting the periodontium, increased presence and activity of MMPs is observed, resulting in irreversible losses of periodontal tissues. MMP expression and activity may be controlled in various ways, one of which is the inhibition of their activity by an endogenous group of tissue inhibitors of metalloproteinases (TIMPs), as well as reversion-inducing cysteine-rich protein with Kazal motifs (RECK).

Inflammatory Responses in Periodontitis with or Without Rheumatoid Arthritis Alter Salivary Metallothionein and Zinc

Periodontitis (PD) and rheumatoid arthritis (RA) are causally linked by their common inflammatory responses, yet it is largely unknown if these inflammatory responses might have an impact on salivary metallothionein (MT), zinc (Zn), and calcium (Ca) content. In this study, we analysed salivary concentrations of pro-inflammatory (IFN-γ, IL-6, and IL-17) and anti-inflammatory (IL-4 and IL-10) cytokines, as well as MT, Zn, and Ca in four groups of participants, namely control (without PD or RA, n = 21), PD (n = 21), RA (n = 21), or RAPD (n = 19). As expected, an increased amount of salivary pro-inflammatory cytokines were observed in the PD, RA, and RAPD groups. While Ca concentration was not significantly different between the groups, Zn concentration was lower in the PD, RA, and RAPD groups compared to the control group (p < 0.05). These groups also expressed higher MT/Zn ratios compared to the control group (p < 0.05). Unlike the control group, concentrations of inflammatory cytokines, MT, Zn, and Ca correlated with each other in the PD, RA, and RAPD groups (p < 0.05). Additionally, comorbidity of PD and RA appears to have a cumulative immuno-pathological impact that warrants further investigation. This study suggests that, in addition to inflammatory cytokines, salivary MT and Zn could reflect the severity of PD with or without RA, hence providing an important biomarker for diagnosis.

Host mRNA Analysis of Periodontal Disease Patients Positive for Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans and Tannerella forsythia

Periodontal disease is a frequent pathology worldwide, with a constantly increasing prevalence. For the optimal management of periodontal disease, there is a need to take advantage of actual technology to understand the bacterial etiology correlated with the pathogenic mechanisms, risk factors and treatment protocols. We analyzed the scientific literature published in the last 5 years regarding the recent applications of mRNA analysis in periodontal disease for the main known bacterial species considered to be the etiological agents: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans and Tannerella forsythia. We identified new pathogenic mechanisms, therapeutic target genes and possible pathways to prevent periodontal disease. The mRNA analysis, as well as the important technological progress in recent years, supports its implementation in the routine management of periodontal disease patients.

Mechanical Compression by Simulating Orthodontic Tooth Movement in an In Vitro Model Modulates Phosphorylation of AKT and MAPKs via TLR4 in Human Periodontal Ligament Cells

Mechanical compression simulating orthodontic tooth movement in in vitro models induces pro-inflammatory cytokine expression in periodontal ligament (PDL) cells. Our previous work shows that TLR4 is involved in this process. Here, primary PDL cells are isolated and characterized to better understand the cell signaling downstream of key molecules involved in the process of sterile inflammation via TLR4. The TLR4 monoclonal blocking antibody significantly reverses the upregulation of phospho-AKT, caused by compressive force, to levels comparable to controls by inhibition of TLR4. Phospho-ERK and phospho-p38 are also modulated in the short term via TLR4. Additionally, moderate compressive forces of 2 g/cm², a gold standard for static compressive mechanical stimulation, are not able to induce translocation of Nf-kB and phospho-ERK into the nucleus. Accordingly, we demonstrated for the first time that TLR4 is also one of the triggers for signal transduction under compressive force. The TLR4, one of the pattern recognition receptors, is involved through its specific molecular structures on damaged cells during mechanical stress. Our findings provide the basis for further research on TLR4 in the modulation of sterile inflammation during orthodontic therapy and periodontal remodeling.

Fluorescence-aided removal of orthodontic composites: an in vivo comparative study

Background

To compare the fluorescent properties of 6 different orthodontic adhesives and provide useful information for clinicians in the adhesion choice, in order to remove it easily at the end of orthodontic treatment by using the Fluorescence-aided Identification Technique (FIT).

Methods

Six orthodontic adhesives were included: Ortho Connect, Gradia LoFlo A3.5, Greengloo, Transbond XT, KommonBase Pink, and KommonBase Clear. The same thermoformed template with 1 mm shell thickness on the six anterior teeth was used for adhesive positioning; furthermore, an ultraviolet light-emitting diode flashlight was used for the FIT. The brightness of adhesive area and tooth area (L* color coordinate) were measured on the photographs by using the “color picker” tool of Photoshop software.

Results

GC Ortho Connect, Gradia Direct LoFlo and KommonBase Clear showed the highest differences of brightness (15.5, 16.3 and 13.5, respectively), while Greengloo, Transbond XT and KommonBase Pink registered similar values between resin area and tooth area with FIT (− 0.5, − 0.8 and − 1.0, respectively). The high viscosity adhesive resins, as Greengloo and Transbond XT, showed a similar performance in terms of fluorescence to the KommonBase Pink, the lowest viscous resin adhesive considered.

Conclusions

The most used orthodontic adhesives showed different fluorescence properties. Some resins were brighter with the FIT, facilitating identification and subsequent removal. Other orthodontic adhesives presented no difference between adhesive and tooth. The viscosity of orthodontic adhesives did not influence the brightness emitted with FIT.

Dento-Skeletal Class III Treatment with Mixed Anchored Palatal Expander: A Systematic Review

Bone-anchored appliances for the treatment of Class III malocclusions have recently been found to reduce the dentoalveolar effects caused by conventional tooth-borne devices while also improving orthopaedic outcomes in growing patients. The goal of this systematic review was to compare the outcomes of skeletal Class III interceptive treatment with dental anchoring devices to those achieved with mixed anchored palatal expanders. The inclusion criteria were as follows: patients who were treated with hybrid anchored palatal expanders and different maxillary advancement appliances. Study quality was estimated using the Newcastle–Ottawa scale. A search on the Pubmed, Scopus, Embase and Cochrane Library databases yielded 350 papers. Following the initial abstract selection, 65 potentially acceptable papers were thoroughly examined, resulting in a final selection of 9 articles. The results in the short-term showed that combined tooth-borne and bone-borne appliances for rapid maxillary expansion might be recommended in protocols of skeletal Class III treatment to obtain more skeletal effects and reduce side effects on the upper teeth.

The Impact of the COVID-19 Pandemic on Dentistry and Dental Education: A Narrative Review

Dentists and dental staff have an increased risk of airborne infection with pathogens such as SARS-CoV-2 since they are exposed to high levels of droplets and aerosols produced during specific dental procedures. Hence, new guidelines such as patient screening and temperature control, air purification, space, surface and hand sanitizing and the use of protective equipment and physical barriers have been successfully implemented. In addition, the use of teledentistry has expanded considerably in pediatric dentistry, orthodontics, oral medicine and periodontics in order to address oral and dental health issues during the COVID-19 pandemic while minimizing virus transmission. Thus, teleconsultation, telediagnosis, teletriage, teletreatment and telemonitoring have emerged as valuable tools not only in the delivery of care, but also in the academic and research training of dental health professionals. This narrative review summarizes the current literature on the impact of the pandemic on dental care, dental staff and dental education, with an emphasis on how newly emerging protocols and technologies can be successfully utilized as integral parts of various branches of the dental practice and their future implications without compromising patient care.

The Role of Matrix Metalloproteinases (MMP-8, MMP-9, MMP-13) in Periodontal and Peri-Implant Pathological Processes

Severe periodontitis, a destructive inflammatory disease of the supporting tissues of the teeth, ranks sixth in terms of global spread, affecting about 11% of the population. Metalloproteinases (MMPs) are extracellular matrix (ECM) macromolecules that are important in cellular development and morphogenesis, and they are capable of activating growth factors in their proximity, cell surface receptors, and adhesion molecules. MMPs are part of a major family of zinc-dependent endopeptidases, and their activity is modulated and regulated by certain inhibitors known as tissue metalloproteinase inhibitors (TIMPs). Because type I collagen is the major component of the periodontal extracellular matrix, special attention has been paid to the role of collagenases, especially MMP-8 and MMP-13 and gelatinases, MMP-2 and MMP-9, in periodontal diseases. In fact, MMP-8 (or collagenase 2) is currently one of the most promising biomarkers for periodontitis in oral fluids. Among them, salivary MMP-9 has been shown to be a more sensitive marker for periodontal inflammation during orthodontic treatment, which opens new perspectives in reducing periodontal hazards during such treatments. Both MMP-8 and MMP-9 are extremely valuable diagnostic tools in treating periodontitis, and future studies and healthcare policies should focus on implementing more accessible methods of chairside testing in order to reduce the prevalence of this disease.

Metformin for Cardiovascular Protection, Inflammatory Bowel Disease, Osteoporosis, Periodontitis, Polycystic Ovarian Syndrome, Neurodegeneration, Cancer, Inflammation and Senescence: What Is Next?

Diabetes is accompanied by several complications. Higher prevalence of cancers, cardiovascular diseases, chronic kidney disease (CKD), obesity, osteoporosis, and neurodegenerative diseases has been reported among patients with diabetes. Metformin is the oldest oral antidiabetic drug and can improve coexisting complications of diabetes. Clinical trials and observational studies uncovered that metformin can remarkably prevent or alleviate cardiovascular diseases, obesity, polycystic ovarian syndrome (PCOS), osteoporosis, cancer, periodontitis, neuronal damage and neurodegenerative diseases, inflammation, inflammatory bowel disease (IBD), tuberculosis, and COVID-19. In addition, metformin has been proposed as an antiaging agent. Numerous mechanisms were shown to be involved in the protective effects of metformin. Metformin activates the LKB1/AMPK pathway to interact with several intracellular signaling pathways and molecular mechanisms. The drug modifies the biologic function of NF-κB, PI3K/AKT/mTOR, SIRT1/PGC-1α, NLRP3, ERK, P38 MAPK, Wnt/β-catenin, Nrf2, JNK, and other major molecules in the intracellular signaling network. It also regulates the expression of noncoding RNAs. Thereby, metformin can regulate metabolism, growth, proliferation, inflammation, tumorigenesis, and senescence. Additionally, metformin modulates immune response, autophagy, mitophagy, endoplasmic reticulum (ER) stress, and apoptosis and exerts epigenetic effects. Furthermore, metformin protects against oxidative stress and genomic instability, preserves telomere length, and prevents stem cell exhaustion. In this review, the protective effects of metformin on each disease will be discussed using the results of recent meta-analyses, clinical trials, and observational studies. Thereafter, it will be meticulously explained how metformin reprograms intracellular signaling pathways and alters molecular and cellular interactions to modify the clinical presentations of several diseases.

Salivary Oxidative Stress Markers' Relation to Oral Diseases in Children and Adolescents

Current evidence suggests that salivary markers of oxidative stress are indicative of clinical disease indices such as the papillary bleeding index (PBI) and the caries index (CI). The aim of this study was to assess the relation of oxidative stress markers with oral dental caries and periodontal problems in a pediatric population. In our case-control study, unstimulated whole saliva was collected from individuals aged 3–18 years (n = 177); 14 individuals were excluded. Study subjects were divided into those with caries (CI = 2, n = 78) and those who were caries-free (n = 85). These groups were then divided into another subset consisting of children (mean age 7.3 years, n = 121) and adolescents (mean age 16.1 years, n = 42). The PBI was determined in all groups. We then assessed salivary levels of oxidative stress markers. Our results showed that, the total antioxidant capacity (TAC) level increased in patients with more gingival bleeding (p < 0.05) in the study group aged 3–18 years. In addition, TAC showed a significant decrease in samples with caries when compared to the caries-free group in adolescents (p = 0.008). In conclusion, TAC levels may be a marker of both gingival bleeding and dental caries in young adult populations. We hope that in the near future, prophylaxis, control, follow up and even possible therapeutic use of oxidative stress markers in a chairside way will become possible as antioxidants have been shown to be effective against oral diseases.

Diagnostic potential and future directions of matrix metalloproteinases as biomarkers in gingival crevicular fluid of oral and systemic diseases

Gingival crevicular fluid (GCF) is a physiological fluid and an inflammatory serum exudate derived from the gingival plexus of blood vessels and mixed with host tissues and subgingival plaque flows. In addition to proteins, GCF contains a diverse population of cells, including desquamated epithelial cells, cytokines, electrolytes, and bacteria from adjacent plaques. Recently, matrix metalloproteinases(MMPs), which are endopeptidases that are active against extracellular macromolecules, in GCF have been revealed as potential utility biomarkers for the diagnosis and follow-up of oral and systemic diseases, thereby facilitating the early evaluation of malignancy risk and the monitoring of disease progression and treatment response. Tissue inhibitors of metalloproteinases (TIMPs) are specific inhibitors of matrixins that participate in the regulation of local activities of MMPs in tissues. This review provides an overview of the latest findings on the diagnostic and prognostic values of MMPs and TIMPs in GCF of oral and systemic diseases, including periodontal disease, pulpitis, peri-implantitis and cardiovascular disease as well as the extraction, detection and analytical methods for GCF.