Microbiome in Early Childhood Caries: Caries Severity-Dependent Insights.

Introduction: Children with early childhood caries (ECC) show different caries severities and susceptibility in different tooth types and location in the oral cavity. The study aimed to investigate differences in the oral microbiome in ECC subjects stratified according to the severity of caries and between more and less caries prone teeth within the same subjects.

Methods: Supragingival plaque from the upper and lower anterior regions in the oral cavity of subjects were collected in 3 groups of increasing caries severity, G1 - Molar (M) caries only; G2 - Molar and Upper Anterior (UA) caries; and G3 - M + UA + lower anterior (LA) caries were obtained followed by microbiome analysis.

Decoding Adenine DNA Methylation Effects in Streptococcus Mutans: Insights Into Self-DNA Protection and Autoaggregation.

Streptococcus mutans, a key player in dental caries, faces multiple environmental challenges within the oral cavity, including oxidative stress, nutrient scarcity, and acidic pH. To survive and thrive, S. mutans has evolved intricate mechanisms, including the CSP-ComDE quorum sensing system, which coordinates responses to environmental cues.

Dosage-dependent effects of FGFR2 mutation on craniofacial shape and cellular dynamics of the basicranial synchondroses.

Craniosynostosis is a common yet complex birth defect, characterized by premature fusion of the cranial sutures that can be syndromic or nonsyndromic. With over 180 syndromic associations, reaching genetic diagnoses and understanding variations in underlying cellular mechanisms remains a challenge. Variants of FGFR2 are highly associated with craniosynostosis and warrant further investigation.

Transcriptome Analysis of Quorum Sensing-Mediated Persisters Reveals an Enrichment in Genes Related to Stress Defense Mechanisms.

Persisters are a small fraction of growth-arrested phenotypic variants that can survive lethal concentrations of antibiotics but are able to resume growth once antibiotics are stopped. Their formation can be a stochastic process or one triggered by environmental cues. In the human pathogen , the canonical peptide-based quorum-sensing system is an inducible DNA repair system that is pivotal for bacterial survival.

Antimicrobial activity of probiotic Streptococcus salivarius LAB813 on in vitro cariogenic biofilms.

Objective: To investigate the antimicrobial activity of a novel commensal strain of Streptococcus salivarius, LAB813, against Streptococcus mutans biofilms.

Methods: The inhibitory activity of LAB813 towards S. mutans was tested using mono-, dual-, and multi-species cariogenic biofilms formed on three types of orthodontic appliances (metal, ceramic, aligner).

Microencapsulation of Probiotic LAB813.

Probiotics are living microorganisms that confer a health benefit on the host when administered in adequate amounts. , a commensal bacterium found in the oral cavity, has been shown to secrete antimicrobial peptides and can be used as probiotics. This study aimed to develop a delivery system for the probiotic LAB813, a novel strain first identified in the laboratory.

A DNA-Damage Inducible Gene Promotes the Formation of Antibiotic Persisters in Response to the Quorum Sensing Signaling Peptide in .

Bacteria use quorum sensing (QS) to communicate with each other via secreted small autoinducers produced by individuals. QS allows bacteria to display a unified response that benefits the species during adaptation to environment, colonization, and defense against competitors. In oral streptococci, the CSP-ComDE QS is an inducible DNA damage repair system that is pivotal for bacterial survival.

Effectiveness of the Lorodent Probiotic Lozenge in Reducing Plaque and Levels in Orthodontic Patients: A Double-Blind Randomized Control Trial.

Orthodontic patients are at a significant risk for oral diseases due to increased plaque accumulation and oral bacterial dysbiosis. We aimed to determine the efficacy of the commercially available Lorodent Probiotic Complex at reducing plaque accumulation and bacterial levels in adolescent orthodontic patients. Sixty adolescents undergoing fixed orthodontic treatment for a minimum of 6 months were recruited in a randomized, double-blind, parallel-group, placebo-controlled trial.

Rapid Isolation and Purification of Secreted Bacteriocins from and Other Lactic Acid Bacteria.

Bacteriocins are small ribosomally synthesized antimicrobial peptides produced by some microorganisms including lactic acid bacteria (LAB), a group of Gram-positive bacteria (cocci, rods) expressing high tolerance for low pH. Bacteriocins kill bacteria rapidly and are biologically active at very low concentrations. Bacteriocins produced by LAB are primarily active against closely related bacterial species.

Toll-Like Receptor 4 in the Rat Caudal Medulla Mediates Tooth Pulp Inflammatory Pain.

The aims of this study were to investigate if Toll-like receptor 4 (TLR4) is expressed in the medullary dorsal horn (MDH) and if medullary application of a TLR4 antagonist (lipopolysaccharides from , LPS-RS) can attenuate changes in nociceptive sensorimotor responses or TLR4 expression that might be evoked by mustard oil (MO) application to the right maxillary first molar tooth pulp. Of 41 adult male Sprague-Dawley rats used in the study, 23 received intrathecal application of the TLR4 antagonist LPS-RS (25 μg/10 μl; LPS-RS group) or isotonic saline (10 μl; vehicle control group) 10 min before pulpal application of MO (95%; 0.2 μl).

Genetic Analysis of Mutacin B-Ny266, a Lantibiotic Active against Caries Pathogens.

Bacteriocins are ribosomally synthesized proteinaceous antibacterial peptides. They selectively interfere with the growth of other bacteria. The production and secretion of bacteriocins confer a distinct ecological advantage to the producer in competing against other bacteria that are present in the same ecological niche.

Bond Strength of Universal Self-Etch 1-Step Adhesive Systems for Orthodontic Brackets.

Objective: The objective of this study was to assess the shear bond strength (SBS) of orthodontic brackets bonded to uncut enamel with universal self-etch 1-step adhesive systems.

Methods: Extracted uncut premolars (n = 160) were randomly divided into 4 groups for treatment with Scotchbond Universal Adhesive (SU), All-Bond Universal (BU), Clearfil Universal Bond (CU) or the control, Adper Scotchbond Multi-Purpose Adhesive. Following bonding of brackets on tooth surfaces, teeth were stored in distilled water for 24 h and 6 months, and brackets were tested for SBS.

Short-term effects of fixed orthodontic appliance on concentrations of mutans streptococci and persister cells in adolescents.

Introduction: Orthodontic patients are at an increased risk for developing caries. Dental caries is a biofilm-mediated disease, with mutans streptococci (MS) as the primary etiologic bacterial group. It has been suggested that persister cells (PCs), a subset of cells within the biofilm, contribute to the chronic infectious nature of dental caries.

Association of Streptococcus mutans collagen binding genes with severe childhood caries.

Objective: An important factor in the assessment of caries risk is the presence of specific oral microflora, especially Streptococcus mutans. Some S. mutans strains possess proteins capable of binding collagen, such as the Cnm and Cbm proteins.

Streptococcus mutans isolated from children with severe-early childhood caries form higher levels of persisters.

Objectives: Dental caries is the most common chronic infectious disease in children. Streptococcus mutans, the main cariogenic bacterial species, produces persisters, nongrowing dormant variants of regular cells associated with chronicity of diseases. We hypothesized that the recurrent nature of caries, particularly within populations with high-caries risk, is due partly to specific phenotypic features of S.

Complete Genome Sequence of Megaplasmid-Bearing Streptococcus salivarius Strain LAB813, Isolated from the Dental Plaque of a Caries-Free Child.

strain LAB813 was isolated from the dental plaque biofilm of a caries-free child with healthy oral tissues. We report here the complete genome sequence of strain LAB813. This genome consists of a chromosome of 2.

Complete Genome Sequence of Streptococcus mutans Strain LAB761, Which Harbors Several Bacteriocin Loci, Isolated from a Caries-Active Child in Canada.

Streptococcus mutans LAB761 has been isolated from dental plaque collected from a child with severe caries. We report here the complete genome sequence of S. mutans strain LAB761, which has a chromosome of 2.

A tripartite toxin-antitoxin module induced by quorum sensing is associated with the persistence phenotype in Streptococcus mutans.

The oral pathogen Streptococcus mutans communicates using a canonical Gram-positive quorum sensing system, CSP-ComDE. The CSP pheromone already known to be involved in the development of genetic competence positively influences the formation of persisters, dormant variants of regular cells that are highly tolerant to antimicrobial therapy. It is now believed that the persistence phenotype is the end result of a stochastic switch in the expression of toxin-antitoxin (TA) modules.

Conservative orthodontic fixed appliance management of pediatric mandibular bilateral condylar fracture.

Introduction: Management of mandibular condylar fractures is difficult in children with their inherently dynamic and unstable deciduous and mixed dentitions. We present a variation of the conservative fixed orthodontic approach that was used as an adjunct to aid in the reduction of a bilateral condylar fracture in a pediatric patient.

Methods: A boy, aged 10 years 9 months, came with clinical signs and symptoms of mandibular fracture after being involved in a motor vehicle accident.

The effect of light emitting diode phototherapy on rate of orthodontic tooth movement: a split mouth, controlled clinical trial.

Objective: Increasing the rate of orthodontic tooth movement (OTM) can reduce risks such as periodontal disease and caries.

Trial Design: This split-mouth randomized controlled clinical trial investigated whether light emitting diode (LED) phototherapy could accelerate the rate of OTM.

Setting: The study was conducted at the Graduate Orthodontics Clinic at the University of Toronto, Faculty of Dentistry.

Isoforms of receptors of fibroblast growth factors.

The breadth and scope of Fibroblast Growth Factor signaling is immense, with documentation of its role in almost every organism and system studied so far. FGF ligands signal through a family of four distinct tyrosine kinase receptors, the FGF receptors (FGFRs). One contribution to the diversity of function and signaling of FGFs and their receptors arises from the numerous alternative splicing variants that have been documented in the FGFR literature.

Cranial neural crest: migratory cell behavior and regulatory networks.

Defects of the head and neck region account for a substantial portion of all human birth disorders. The high incidence of malformations in this region may be attributed in part to the intricate means by which the facial region is assembled during embryonic development. The starting constituent for the majority of skeletal and connective tissues in the face is a pluripotent population of cells, the cranial neural crest (CNC) cells.

FLRT2 interacts with fibronectin in the ATDC5 chondroprogenitor cells.

Expression studies have implicated FLRT2 in cranial neural crest cell migration and prechondrogenic cell condensation during craniofacial skeletogenesis. We aimed to determine whether FLRT2 was involved in mediating cell-matrix interactions in the ATDC5 chondroprogenitor cell line. Immunolocalization experiments of ATDC5 cells revealed that FLRT2 was present on the cell membrane as well as extracellularly, where it colocalized with Fibronectin (Fn).