Papers by Natalia I Chalmers DDS, MHSc, PhD
American journal of public health, Jan 17, 2017
To assess the relation between Medicaid reimbursement rates and access to dental care services in... more To assess the relation between Medicaid reimbursement rates and access to dental care services in the context of dentist density and dentist participation in Medicaid in each state. Data were from Early and Periodic Screening, Diagnostic, and Treatment reports for 2014, Medicaid reimbursement rate in 2013, dentist density in 2014, and dentist participation in Medicaid in 2014. We assessed patterns of mediation or moderation. Reimbursement rates and access to dental care were directly related at the state level, but no evidence indicated that higher reimbursement rates resulted in overuse of dental services for those who had access. The relation between reimbursement rates and access to care was moderated by dentist density and dentist participation in Medicaid. We estimate that more than 1.8 million additional children would have had access to dental care if reimbursement rates were higher in states with low rates. Children who access the dental care system receive care, but reimbur...
Dentistry, Oct 10, 2013
He has been teaching and practicing Orthodontics. Currently, also serves as a director in the MEM... more He has been teaching and practicing Orthodontics. Currently, also serves as a director in the MEM Dental Technology Co. Ltd, Taiwan. His research involves the matrix-mediated bio-mineralization mechanism in bone and dentin, mechanical loading to the bone cells, and orthodontics. The works were reported in Journal of Dental Research, Journal of Biological Chemistry, and others. He also reviewed for Journal of Orthopedic Research, Bone, etc. and orthodontic related journals. Biology of the orthodontic tooth movement-using collagenase 3 (MMP-13, matrix metalloprotease 13) as a working model
Early Well Child Visits Associated with Higher Dental Utilization
Pediatrics, 2019
Objective: This study evaluated the impact of well-child visits (WCV) on promoting preventive vis... more Objective: This study evaluated the impact of well-child visits (WCV) on promoting preventive visits to the dentist. Effects by age, race, gender, procedure and diagnosis were investigated. Methods: Administrative claims data for 1.85 million Medicaid enrolled children aged 4 or less in 13 states for 2013 were identified from the Truven MarketScan Medicaid Database. Using Streamline’s Clinical LookingGlass, a cohort for all children who had a well-child visit in 2013 was generated and followed for 365 days to identify the date …
American Journal of Preventive Medicine, 2019
Introduction: This study investigated opioid prescription patterns for acute and chronic pain man... more Introduction: This study investigated opioid prescription patterns for acute and chronic pain management among U.S. Medicaid patients. Methods: This study used medical and pharmacy claims data obtained from the multistate Truven MarketScan Medicaid Database© from 2013 to 2015 for Medicaid patients receiving health care. Medicaid beneficiaries who utilized an outpatient healthcare facility for back pain, neck pain (cervicalgia), joint pain (osteoarthritis and rheumatoid arthritis), orthopedics (simple/ closed fractures and muscle strains/sprains), headache (cluster headaches and migraines), dental conditions, or otorhinolaryngologic (otalgia) diagnoses, based on ICD-9-CM diagnosis codes, and received an opioid prescription within 14 days of diagnosis were included in this study. Results: There were 5,051,288 patients with one of the seven diagnostic groupings; 18.8% had an opioid prescription filled within 14 days of diagnosis. Orthopedic pain (34.8%) was the primary reason for an opioid prescription, followed by dental (17.3%), back pain (14.0%), and headache (12.9%). Patients receiving an opioid for conditions associated with acute pain management, like otorhinolaryngologic (OR=1.93, 95% CI=1.85, 2.0), dental (OR=1.50, 95% CI=1.48, 1.53), or orthopedic (OR=1.31, 95% CI=1.29, 1.32), were more likely to receive the prescription from an emergency department provider versus a general practitioner. However, other providers were more likely to prescribe opioids for conditions associated with chronic pain management compared with general practitioners.
BMC Oral Health, 2018
Background: To achieve optimal health and oral health, the system of care must place a person and... more Background: To achieve optimal health and oral health, the system of care must place a person and their social well-being at the center of decision making and understand factors spent outside the clinical settings, including individual behavior, context and lifestyle. Main text: Person-centered care offers a unique and compelling opportunity for dentistry, and its practitioners, to improve quality of care and overall health outcomes. For decades, the dominant treatment modalities within dentistry primarily focused on a surgical, treatment-oriented approach as opposed to health promotion and improvement. However, new business and care models are disrupting the dental care system, and transforming it into one that is focused on disease management and prevention-oriented primary care that considers overall health and well-being. We proposed a person-centered care model to improve oral health as an integral part of overall health. The model identified three key players who act as change agents with their respective roles and responsibilities: Person, provider, and health care system designer. Conclusions: While previous person-centered models in dentistry focused on the role of providers within the clinical setting, this work emphasizes the role of the care designer in creating an environment where both person and provider are able to communicate effectively and achieve improved health outcomes.
Journal of the American Dental Association (1939), 2018
The objective of this study was to identify specific factors (sex, race or ethnicity, and health ... more The objective of this study was to identify specific factors (sex, race or ethnicity, and health care provider type) associated with patient receipt of an opioid prescription after a dental diagnosis. The authors used Medicaid claims dated from January 1, 2013, through September 30, 2015, for 13 US states in this study. The authors identified oral health-related conditions by using International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes 520.0 through 529.9. During the 2013-2015 study period, among the more than 890,000 Medicaid patients with a dental diagnosis, 23% received an opioid within 14 days of diagnosis. Female patients were 50% more likely to receive an opioid for pain management of a dental condition than were men (odds ratio [OR], 1.53; 95% confidence interval [CI], 1.52 to 1.55). Non-Hispanic whites and African Americans were approximately twice as likely to receive opioids than were Hispanics (OR, 2.11; 95% CI, 2.05 to 2.17 and OR...
Updated caries risk assessments model incorporating Scardovia wiggsiae
Dentistry, 2013
Improving Quality in Dentistry: An Imperative for the Profession
Pediatric dentistry, 2016
Development of an Analysis Pipeline Characterizing Multiple Hypervariable Regions of 16S rRNA Using Mock Samples
PLOS ONE, 2016
There is much speculation on which hypervariable region provides the highest bacterial specificit... more There is much speculation on which hypervariable region provides the highest bacterial specificity in 16S rRNA sequencing. The optimum solution to prevent bias and to obtain a comprehensive view of complex bacterial communities would be to sequence the entire 16S rRNA gene; however, this is not possible with second generation standard library design and short-read next-generation sequencing technology. This paper examines a new process using seven hypervariable or V regions of the 16S rRNA (six amplicons: V2, V3, V4, V6-7, V8, and V9) processed simultaneously on the Ion Torrent Personal Genome Machine (Life Technologies, Grand Island, NY). Four mock samples were amplified using the 16S Ion Metagenomics Kit™ (Life Technologies) and their sequencing data is subjected to a novel analytical pipeline. Results are presented at family and genus level. The Kullback-Leibler divergence (DKL), a measure of the departure of the computed from the nominal bacterial distribution in the mock samples, was used to infer which region performed best at the family and genus levels. Three different hypervariable regions, V2, V4, and V6-7, produced the lowest divergence compared to the known mock sample. The V9 region gave the highest (worst) average DKL while the V4 gave the lowest (best) average DKL. In addition to having a high DKL, the V9 region in both the forward and reverse directions performed the worst finding only 17% and 53% of the known family level and 12% and 47% of the genus level bacteria, while results from the forward and reverse V4 region identified all 17 family level bacteria. The results of our analysis have shown that our sequencing methods using 6 hypervariable regions of the 16S rRNA and subsequent analysis is valid. This method also allowed for the assessment of how well each of the variable regions might perform simultaneously. Our findings will provide the basis for future work intended to assess microbial abundance at different time points throughout a clinical protocol.
Possibly the first biofilm samples ever examined from a microbiological perspective were obtained... more Possibly the first biofilm samples ever examined from a microbiological perspective were obtained from the oral cavity: Antonie van Leeuwenhoek's tooth scrapings. Since that time, oral microbiologists have made major contributions to microbial taxonomy, physiology, and ecology. The oral cavity distinguishes itself from other environments by having over 700 phylotypes (taxonomic units), nearly half of which have culturable representatives. Aerobic, facultatively anaerobic, and obligately anaerobic physiologies are present. Members of the microbial kingdoms Archaea, Bacteria and Fungi are present. What generates and maintains this diversity? Why are these communities attractive targets for study? How does commu- nity analysis using modern molecular methods differ from that using classical bacteriologi- cal approaches? We strive to answer these questions in the following contribution and, as far as possible, we rely on knowledge obtained from studies of plaque in situ. The oral cav...
Periodontal Biofilm Microbiota of Patients with Leukocyte Adhesion Deficiency
Objective: Leukocyte Adhesion Deficiency Type 1 (LAD-1) is a rare autosomal recessive condition c... more Objective: Leukocyte Adhesion Deficiency Type 1 (LAD-1) is a rare autosomal recessive condition caused by a mutation in the beta-2 integrin chain (ITGβ2-CD18), a cell membrane glycoprotein. Neutrophils of LAD-1 patients present with heterogeneous molecular defects in the CD18 subunit and functional defects in adhesion. Clinically, the hallmark of LAD-1 is recurrence of bacterial infections, including severe periodontitis. In this pilot study, we characterized the microbial diversity in subgingival biofilms of patients with LAD-1 periodontitis and compared them to that of health and chronic periodontitis. Method: Patients diagnosed with LAD-1 were clinically evaluated and subgingival biofilm samples were collected from three patients. 16S rRNA genes were amplified by PCR from DNA extracted from biofilms. DNA-DNA hybridization was performed using the Human Oral Microbe Identification Microarray (HOMIM) for over 300 bacterial species or groups. Microbial profiles with relative abundanc...
Neutrophil Recruitment Deficiencies Result in Distinctive Periodontal Biofilm Microbiota
Objective: In this pilot study, we characterized the microbial diversity in subgingival biofilms ... more Objective: In this pilot study, we characterized the microbial diversity in subgingival biofilms of patient populations with distinct immunodeficiencies linked to defective leukocyte recruitment, Hyperimmunoglobulin E syndrome (HIES) and Leukocyte Adhesion Deficiency Type 1 (LAD-1), and compared them to that of health, and chronic periodontitis. HIES is attributed to a mutation in STAT3, essential for cell growth/differentiation, cytokine signaling and developmentof TH17 helper cells. HIES patients lack TH17 cells and display defects in leukocyte chemotaxis. LAD-1 is a rare autosomal recessive condition caused by a mutation in the beta-2 integrin chain. Neutrophils of LAD-1 patients present with functional defects in adhesion. Clinically, the hallmark of LAD-1 is recurrence of bacterial infections, including severe periodontitis. Method: Patients diagnosed with HIES and LAD-1 were periodontally evaluated and subgingival biofilm samples were collected. 16S rRNA genes were amplified b...
Mutualism in in vitro Streptococcus - Veillonella spp. Oral Biofilms
Objectives: Oral biofilms are complex multi-species communities that can consist of over 70 bacte... more Objectives: Oral biofilms are complex multi-species communities that can consist of over 70 bacterial species within an individual. Spatial relationships between species are important for the biofilm development. Early childhood caries is a virulent polymicrobial infection that affects the primary dentition. In addition to Streptococcus mutans, species such as non-mutans streptococci and Veillonella spp. have been linked with the disease. Here we present evidence for metabolic synergism among Streptococcus spp. and Veillonella sp. as part of multi-species biofilms grown with saliva as the sole nutrient source. Methods: Using a high throughput assay mono- and dual-species biofilms were developed on transferable solid phase lids with pegs. Biofilms were studied with three parallel approaches: crystal violet for total biomass quantification; species-specific Real-Time Polymerase Chain Reaction (RT-PCR) for species quantification and confocal microscopy with primary immunofluorescence f...
Scardovia Species and Childhood Caries
Cluster analysis of cultural microbiota from early childhood caries
Objective: Anaerobic culture of plaque samples from children with severe-early childhood caries (... more Objective: Anaerobic culture of plaque samples from children with severe-early childhood caries (S-ECC) detected a diverse microbiota (Tanner et al. 2011) comparable to that from molecular clonal analyses. This study sought microbial complexes from samples cultured on acidic and blood agars from caries-free and S-ECC children. Method: The study population comprised 42 S-ECC and 40 caries-free children (2-6 years old). Over 5,000 isolates from plaque cultured anaerobically on blood (pH 7), and acid (pH 5) agars were identified by comparing partial 16S rRNA sequences with taxa/species in the Forsyth Human Oral Microbiome Database. The microbiotas in samples were clustered by disease category and isolation medium using principal component analysis and two-way cluster analysis. Result: The microbiotas of blood and acidic agars grouped separately by cluster analysis. There was some overlap in the microbiotas of S-ECC and caries-free samples isolated on blood. In contrast, samples culture...
A New Scardovia Species Associated with Severe Early Childhood Caries
Objectives: Severe early childhood caries (S-ECC) is an aggressive infection affecting preschool ... more Objectives: Severe early childhood caries (S-ECC) is an aggressive infection affecting preschool children, particularly in disadvantaged populations. We have cultured a caries-associated unnamed Scardovia (Bifidobacterium) species, previously recognized from molecular cloning and sequence analysis. This study aimed to evaluate the association of this new species with S-ECC, evaluate its taxonomic status, and determine acid production as a measure of cariogenicity. Methods: Strains from S-ECC and caries-free (CF) children (2-5 years) were isolated on an acid (pH5) and blood agars. Isolates were characterized using 16S rRNA partial sequencing to identify Forsyth Human Oral Microbiome Database Oral Taxon (HOT) 195, an unnamed Scardovia species, in addition to Parascardovia denticolens. Isolates were compared between 28 S-ECC and 35 caries-free (CF) children, characterized biochemically and compared in DNA-DNA homology experiments with closely related species. Results: The unidentified ...
Pulp and Carious Lesion Microbiota in Severe Early Childhood Caries
Objectives: Pulp infection is a frequent complication of severe early childhood caries (S-ECC) wh... more Objectives: Pulp infection is a frequent complication of severe early childhood caries (S-ECC) which disproportionately affects children with oral health disparities. We recently detected a new Bifidobacteriaceae species, Scardovia wiggsiae significantly associated with S-ECC. This pilot study compared the pulp and carious lesion microbiota seeking species, including Bifidobacteriaceae, that might important in pulpal pathology. Methods: Samples were taken under general anesthesia from carious lesions and carious exposures of pulps of affected primary teeth affected with S-ECC. Samples were cultured anaerobically on enriched blood agar and an acid agar pH5. Isolates were identified by comparing partial 16S rRNA sequences with taxa (species) in the Forsyth Human Oral Microbiome Database (HOT taxa). Results: Ten children 2-6 yrs old were included in the study. Over 800 isolates were characterized. 64 different taxa were identified, 20% only in infected pulps, 26% only in caries and 54%...
Insights into Genus Veillonella in the Genomics Era
Oral Microbial Communities, 2011
PLOS Pathogens, 2015
Leukocyte Adhesion Deficiency I (LAD-I) is a primary immunodeficiency caused by single gene mutat... more Leukocyte Adhesion Deficiency I (LAD-I) is a primary immunodeficiency caused by single gene mutations in the CD18 subunit of β2 integrins which result in defective transmigration of neutrophils into the tissues. Affected patients suffer from recurrent life threatening infections and severe oral disease (periodontitis). Microbial communities in the local environment (subgingival plaque) are thought to be the triggers for inflammatory periodontitis, yet little is known regarding the microbial communities associated with LAD-I periodontitis. Here we present the first comprehensive characterization of the subgingival communities in LAD-I, using a 16S rRNA gene-based microarray, and investigate the relationship of this tooth adherent microbiome to the local immunopathology of periodontitis. We show that the LAD subgingival microbiome is distinct from that of health and Localized Aggressive Periodontitits. Select periodontitis-associated species in the LAD microbiome included Parvimonas micra, Porphyromonas endodontalis, Eubacterium brachy and Treponema species. Pseudomonas aeruginosa, a bacterium not typically found in subgingival plaque is detected in LAD-I. We suggest that microbial products from LAD-associated communities may have a role in stimulating the local inflammatory response. We demonstrate that bacterial LPS translocates into the lesions of LAD-periodontitis potentially triggering immunopathology. We also show in in vitro assays with human macrophages and in vivo in animal models that microbial products from LAD-associated subgingival plaque trigger IL-23-related immune responses, which have been shown to dominate in patient lesions. In conclusion, our current study characterizes the subgingival microbial communities in LAD-periodontitis and supports their role as triggers of disease pathogenesis.
OTU Analysis of Clonal and Cultural Microbiota of Childhood Caries
Objectives: Severe early childhood caries is an aggressive bacterial infection, which recent mole... more Objectives: Severe early childhood caries is an aggressive bacterial infection, which recent molecular analyses have indicated is characterized by a wide diversity of species or taxa. The purpose of this study was to analyze the microbial diversity obtained by clonal and cultural analyses, based on operational taxonomic unit (OTU) analysis in libraries of 16S rRNA gene sequences from severe early childhood caries (S-ECC) and caries-free bacterial populations. Methods: S-ECC and caries-free (CF) children (2-6 years) were recruited and plaque samples obtained. Samples underwent clonal analysis and were cultured anaerobically on blood (pH 7), and acid (pH 5) agars. All clones, and isolates from blood and acid agars, were characterized using 16S rRNA partial sequencing. Six 16S rRNA libraries were constructed clones S-ECC and CF, blood isolates S-ECC and CF, and acid isolates S-ECC and CF. OTU analysis was performed using the mother software and phylogenetic assignment of OTU done at fo...
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Papers by Natalia I Chalmers DDS, MHSc, PhD