Streptococcus mutans harbors collagen-binding protein genes, namely cnm and cbm, which are implicated in its virulence and pathogenicity in both oral and extraoral infections. Although both genes were initially identified in S. mutans isolated from Japanese populations, their geographical prevalence, distribution, and genetic relatedness within Japan remain largely unexplored. This study investigates the prevalence of S. mutans strains carrying cnm and cbm genes across Japan, correlates these findings with clinical data, and analyzes the genetic relatedness of cnm-positive and cnm-negative strains using multilocus sequence typing (MLST). Dental plaque specimens were collected from 1248 individuals from eight Japanese cities (Hiroshima, Fukuoka, Nagasaki, Niigata, Okayama, Osaka, Tokushima, and Tokyo) and plated on selective medium for S. mutans isolation. S. mutans was confirmed in 523 subjects by colony morphology and PCR using species-specific primers, and the presence of the cnm and cbm genes was determined by PCR with gene-specific primers. Demographic (age, sex) and oral examination (caries prevalence, caries experience, number of teeth) data were recorded. MLST was employed to genotype selected cnm-positive and cnm-negative S. mutans strains to assess their clonal relationships. Among 523 subjects possessing S. mutans (aged 3-90 years), we detected cnm-positive strains in all cities; specifically, the prevalence ranged from 5.5% in Okayama to 25.0% in Tokushima. In contrast, cbm-positive strains were less common and undetectable in some regions. Furthermore, subjects harboring cnm-positive S. mutans were significantly older (p = 0.002) and had higher caries prevalence and experience (p < 0.001). MLST revealed evolutionary relationships among cnm-positive strains across the cities but no discernible region-specific clustering. Clonal relationships partially reflected cnm gene distribution, particularly for exclusively cnm-positive or cnm-negative clonal complexes, but inconsistencies involving serotypes and cnm presence within some clonal complexes and sequence types were also noted. The cnm-positive S. mutans strains are widely distributed throughout Japan and are associated with increased age and caries burden. Although core genome analysis revealed some clonal patterns, the non-uniform distribution of the non-core cnm gene is likely influenced by horizontal gene transfer, providing S. mutans with adaptive advantages irrespective of its core genetic background or serotype.

BackgroundChlorhexidine is widely used as a chemical antibacterial mouthwash, but its potential side effects have spurred interest in safer natural alternatives.PurposeThis study aimed to evaluate the anticariogenic efficacy and inhibitory effects of a functional mouthwash containing Clematis chinensis Osbeck (C. chinensis Osbeck) extract in a randomized controlled clinical trial.Study design and methodsIn this randomized, double-blind, controlled clinical trial conducted at Busan M Dental Clinic, 69 participants were randomly assigned to three groups: saline gargle (n = 23), chlorhexidine gargle (n = 23), and C. chinensis Osbeck extract gargle (n = 23). Participants used 15 mL of the assigned mouthwash four times daily for 2 weeks. The oral environment was standardized with professional scaling and a 1-week recovery period before the intervention. Clinical outcomes were evaluated using the O’Leary index and the Cariview™ test kit (AIOBIO Co. Ltd., Seoul, South Korea) at baseline, 1 week, and 2 weeks, respectively, to evaluate dental plaque acidogenicity and user satisfaction. Saliva tests (including cariogenic bacterial counts, acidogenicity, and buffering capacity) were performed using the SillHa Oral Wellness System (ARKRAY Inc., Kyoto, Japan). Subgingival plaque samples were analyzed by quantitative real-time polymerase chain reaction (PCR) analysis to detect cariogenic bacteria (Streptococcus mutans [S. mutans] and Gram-positive cariogenic bacteria [GS group], comprising S. mitis, S. sobrinus, and Lactobacillus casei). Statistical analyses were performed using analysis of variance (ANOVA) and Duncan’s post hoc test, with significance set at P < 0.05.ResultsThe C. chinensis Osbeck extract gargle group showed reductions in the O’Leary index score and cariogenic activity, alongside a progressive increase in user satisfaction. Saliva analysis revealed significant decreases in caries-causing bacterial numbers and acid production and improved buffering capacity, enhancing salivary defense. Only the C. chinensis Osbeck extract gargle group showed a significant reduction in S. mutans and the GS group. Compared with the saline and chlorhexidine groups, this group demonstrated a continuous decrease in caries risk over the 2 weeks.ConclusionC. chinensis Osbeck extract significantly improved clinical parameters related to dental caries, suggesting its potential as a safe and effective natural alternative to chemical antibacterial agents for caries prevention and oral health maintenance.Trials registrationClinicalTrials.gov, KCT0008539. Registered on June 21, 2023, https://cris.nih.go.kr/cris/search/detailSearch.do/23816).Supplementary InformationThe online version contains supplementary material available at 10.1186/s13020-025-01258-z.

Dental plaque is a complex oral biofilm responsible for periodontal diseases. Bacterial biofilms are often regulated by Quorum Sensing (QS) mediated by N-acyl homoserine lactones (AHLs). While their presence and roles in oral microbiota have been debated, emerging evidence suggests AHLs influence oral biofilm development. AHLs are detectable in a microbial community derived from human dental plaque cultured under 5% CO2 but not under anaerobic conditions. Manipulating QS in this community via AHL lactonases enriched commensals and pioneer colonizers under 5% CO₂, whereas in anaerobic conditions exogenous AHLs promoted late colonizers. QS disruption reduced biofilm formation, enhanced sucrose fermentation to lactate, and altered metabolic profiles of the community depending on the lactonase substrate specificity. Our findings highlight the importance of AHL-mediated QS in oral biofilm development and suggest its differential roles under aerobic versus anaerobic conditions. Targeting QS may offer a novel strategy for managing oral biofilms and preventing periodontal disease.

Dental caries remains among the most common oral health problems globally, with Streptococcus mutans being a key etiological agent. Understanding the prevalence of this bacterium among symptomatic patients is crucial for developing targeted preventive and therapeutic strategies. This study aimed to determine the prevalence of Streptococcus mutans among patients presenting with tooth decay symptoms at Murtala Muhammed Specialist Hospital, Kano State, Nigeria. A cross-sectional study was conducted involving 400 patients. Oral dental plaque samples were aseptically collected from patients with dental caries at Murtala Muhammed Specialist Hospital, Kano's dental clinic, and transported in sterile peptone water for microbiological analysis. The samples were cultured on chocolate agar and incubated in a candle jar at 37°C for 24 hours. Bacterial identification involved colony morphology, Gram staining, catalase, optochin sensitivity tests, and confirmation using the API 20 Strep system. Antibiotic susceptibility testing was performed using the disk diffusion method with five antibiotics and interpreted based on CLSI 2020 guidelines. Out of 400 samples processed, 351 (87.8%) yielded positive cultures, all of which were Gram-positive cocci. Among the 116 suspected Viridans streptococci, 87 (75.0%) were confirmed as Streptococcus mutans. Antibiotic susceptibility testing showed the highest resistance to tetracycline (67.8%), followed by erythromycin (28.7%) and ciprofloxacin (27.6%). The study found a high prevalence of Streptococcus mutans (75.0%) among patients with dental caries, with significant resistance observed to tetracycline (67.8%). These findings underscore the need for targeted oral health interventions and prudent antibiotic use in dental practice.

Periodontal disease is a chronic inflammatory condition that affects the supporting tissues of teeth and represents the main cause of tooth loss in adults. Consequently, many patients seeking rehabilitation with dental implants have a history of periodontitis. Recent studies indicate that this condition may increase the risk of periimplant complications, such as marginal bone loss and peri-implantitis. Objective: To review the scientific literature of the last five years about the influence of previous periodontal disease on dental implant success, considering clinical, microbiological and behavioral parameters. Methodology: This is an integrative literature review, conducted in the PubMed, SciELO, LILACS, Cochrane and Science Direct databases, including articles published between 2020 and 2025. The descriptors “Periodontal Diseases” and “Dental Implants” were used. After screening and exclusion of duplicates, seven studies were selected for analysis. Results: The studies analyzed showed that patients with periodontitis history have a higher rate of implant failure, greater marginal bone loss and greater incidence of peri-implantitis. Recent studies (Annunziata et al., 2024; Serroni et al., 2024) have shown up to four times higher risk of peri-implantitis in previously affected individuals, as well as a reduction in the survival rate of implants (Young et al., 2021). Adherence to supportive periodontal therapy and professional control of bacterial plaque was essential for the stability of peri-implant tissues (Gissler et al., 2025; Cimões et al., 2021). Conclusion: Previous periodontal disease is a significant risk factor for the failure of dental implants. Even after periodontal treatment and stabilization, these patientsremain predisposed to peri-implant inflammation and marginal bone loss. Individual risk assessment, strict infection control and adherence to periodic maintenance programs are key to ensuring long-term rehabilitator success.

Considering the high prevalence of dental caries in children and the diversity of children’s toothpaste formulations, there is a need to critically evaluate active components and their effects on dental plaque, caries, and salivary pH. This study aims to review and synthesize scientific evidence on the main ingredients of pediatric toothpastes — including fluorides (NaF, MFP, SnF₂), hydroxyapatite, calcium-phosphate complexes (CPP-ACP), xylitol, detergents, and abrasives — describing their mechanisms of action and clinical implications in pediatric dentistry. To this end, an integrative literature review was conducted across PubMed, PMC, and SciELO, prioritizing systematic reviews, clinical guidelines, and randomized controlled trials published up to 2025. It was observed that fluoride-containing toothpastes show robust efficacy in caries prevention and remineralization of initial lesions; alternatives such as hydroxyapatite and CPP-ACP demonstrate promising remineralizing potential; xylitol contributes as an adjunct anticariogenic agent; and detergents and abrasives enhance mechanical plaque removal, with safety dependent on formulation. These findings allow the conclusion that the selection of children’s toothpaste should consider caries risk, age, ability to expectorate, possible allergies, and sensory acceptability, highlighting evidence-based formulations as a central tool for caries prevention in pediatric dentistry.

BackgroundAccumulation of dental plaque can lead to gingival problems. A fluoride toothpaste containing naturally occurring enzymes and proteins has been shown to improve gingival health and reduce supragingival plaque in European populations. The objective of the current study was to evaluate the ability of this toothpaste to improve gingival condition and reduce supragingival plaque in an alternative study population.MethodsThis was a double-blind (participant, examiner, investigator, statistician), randomised, parallel group, efficacy study conducted at a Chinese university dental hospital. Participants (age 18-70) with a mean Gingival Index (GI) ≥ 1.0 and mean Modified Quigley and Hein Plaque Index (MQHPI) ≥ 1.5 were randomised at baseline using sex stratification to twice-daily brushing with either test toothpaste (n=127) or control fluoride toothpaste (n=124) for 26 weeks. Assessments of GI (primary outcome) and MQHPI were conducted at baseline and after 4, 13 and 26 weeks of product use. Results were analysed using ANCOVA model for between product comparison (α= 0.05).ResultsOne hundred and six participants using test toothpaste and 92 using control toothpaste completed the study. The test toothpaste showed significantly greater improvements in gingival health than the control toothpaste. The estimated differences in GI between groups were –0.18 (95% CI: –0.23 to –0.12) at week 4, –0.16 (95% CI: –0.20 to –0.11) at week 13, and –0.53 (95% CI: –0.60 to –0.46) at week 26 (all p < 0.0001). Similarly, reductions in supragingival plaque were greater in the test group, with differences in MQHPI of –0.29 (95% CI: –0.38 to –0.21) at week 4, –0.35 (95% CI: –0.45 to –0.25) at week 13, and –0.96 (95% CI: –1.06 to –0.85) at week 26 (all p < 0.0001).ConclusionsThe study demonstrated that a toothpaste containing naturally occurring enzymes and proteins significantly improved gingival health and reduced supragingival plaque compared to a control toothpaste, after 4, 13, and 26 weeks of use.Clinical trial registrationNCT06932211 (retrospectively registered on April 17, 2025).

Objective The objective of this study was to isolate and characterize oral aerobic, facultative anaerobic, and microaerophilic bacterial species from supragingival plaque and to evaluate the association of different demographic, phenotypic, and biochemical characteristics with the identified organisms. Material and Methods This prospective cross-sectional study enrolled 101 bacterial isolates sampled from the supragingival plaque, using sterile swab. Oral bacterial species were identified through biochemical and phenotypic analysis using standardized methods. The inclusion criteria were participants of Karachi, residents of both genders, being at least eighteen years old, having a Loe and Silness plaque index. Participants with severe systemic illnesses, such as immunodeficiency disorders, on chemotherapeutic drugs, antibiotic therapy twelve weeks before sampling persistent systemic infections, or known communicable diseases, were excluded. All details were recorded on proforma and data was analyzed by using SPSS version 22.0. p-value of &lt; 0.05 was considered significant. Results and Discussion Multiple bacterial Species were identified, with Gram-positive species predominating. Statistically significant variables included gender, age, occupation, hemolysis on blood agar, bile esculin hydrolysis, catalase, oxidase, ONPG, CIT, MALO, ODC, UREA, VP, GEL, nitrate, sucrose, mannitol, melibiose, and raffinose. It was found that considerable variation in the oral bacterial species exists influenced by multiple factors. Conclusion It has been concluded that multiple and variable Gram-positive and negative bacterial species have been isolated from supragingival dental plaque of local isolates. The demographic, phenotypic, and biochemical characteristics demonstrated statistically significant associations with the identified organisms. BJMS, Vol. 24 No. 04 October’25 Page : 1153-1166

Hybrid-designed metal-phenolic nanoparticles for synergistic nano-gene periodontal therapy.

Cystic Fibrosis (CF) and Modulators Based Therapy (CFTR) in oral and salivary perspectives: A single center cross-sectional study.

Near-infrared laser-activated PLGA-PDA core-shell nanohybrids for synergistic photothermal antibacterial therapy and sustained ion release in orthodontic white spot lesions prevention.

Background & aim Parental awareness of oral hygiene plays a crucial role in safeguarding children's oral health. This study sought to evaluate the oral health status, habits, and dietary patterns of primary schoolchildren in rural Armenia while investigating the influence of parental oral health knowledge on their children's oral health, as assessed by child's dental plaque index. Design The study involved primary schoolchildren and their parents from two rural communities in Armavir province. It was comprised of two key components: (1) a cross-sectional telephone survey conducted with parents to evaluate their knowledge of oral health, their children's oral hygiene practices, dietary habits, and socio-demographic background, and (2) a clinical assessment of the children's oral health, which included measuring plaque index and recording the Decayed, Missing, and Filled Teeth (DMFT/dmft) index. To determine the relationship between parental oral health knowledge and children's plaque index, multivariable linear regression analysis was performed. Results A total of 400 parents participated. Children had a mean plaque index of 3.1 (SD 0.7) and a mean DMFT/dmft index of 7.3 (SD 3.3). The score indicating oral health behavior averaged 3.0 out of 6.0. The mean dietary habits score was 4.5 out of 9.0. The mean score indicating oral health knowledge of parents was 6.9 out of 9.0. After adjusting for potential confounders, each one-point increase in parental oral health knowledge score was associated with a 0.05-point reduction in the child's dental plaque index (95% CI: -0.10; -0.002). Conclusions The findings emphasize the need for comprehensive strategies to improve children's oral health, including parental education, behavioral support, caries-prevention efforts, and better access to dental care.

The article presents the rationale for using fluorescence diagnostics to objectively assess the hygienic condition of patients' oral cavities in a dental clinic. The relationship between various methods of its assessment is shown: classical subjective, as measured by the OHI-S, and digital fluorescence. Subject. The subject of this study is fluorescence diagnostics of the hygienic condition of the oral cavity of patients, carried out in a dental clinic. Objectives. To determine the efficiency of fluorescence diagnostics based on the bio-response of dental hard tissues and oral fluid samples to optimize personal oral hygiene methods. Methodology. The quantitative assessment of dental plaque was evaluated by calculating the OHI-S index. Fluorescence diagnostics were performed by the hardware and software complex (HSC) "InSpectrM" using a contact-stable measurement method, using a light guide with an individual attachment of the HSC "InSpectrM" with a laser radiation wavelength of 405 nm at a radiation power of 15 mW at the end of the light guide (with a signal recording time of 10-20 seconds). The results were evaluated using the automated HSC program by determining the integral value of fluorescence intensity, which is the area under the fluorescence curve in relative units (rel. units). Results. As a result of quantitative determination of the degree of plaque coverage of the tooth surface experienced a decrease in fluorescence intensity by 23% (p &lt; 0.05), and in patients with a satisfactory hygiene indicator (group 2) - by 39% (p &lt; 0.05) compared to the initial indicators (Figs. 1 and 2).

Biocompatible hydroxyapatite (HA) is a biomaterial widely used in the regeneration and replacement of dental and bone tissue. On these HA surfaces, complex multicellular communities known as biofilms are established by pathogenic microorganisms, contributing to 75% of all bacterial infections and presenting a significant public health concern. Among the various charged polymers, zwitterionic polymers are commonly used for antifouling applications due to their ability to form a strong hydration layer. In contrast, charged polymers like polyampholytes with both positively and negatively charged groups remain largely unexplored for this application. Polyampholytes can be modified to be neutral, cationic, or anionic, as they are composed of two monomers with opposite charges. In this study, we aim to investigate the preparation of polyampholytes with different charges through Reversible Addition-Fragmentation chain Transfer (RAFT) polymerization, coating these polymers onto HA discs and evaluating their antifouling capabilities using bacterial adhesion experiments. We synthesized charged polyampholytes using [2-(methacryloyloxy)ethyl]trimethylammonium chloride (MAETMA) and sodium-p-vinylbenzenesulfonate (VBS), which are cationic and anionic monomers, respectively, in a DI water/dioxane medium via RAFT polymerization. Next, HA discs were coated with a series of synthesized charged polymers, resulting in surfaces with systematically tuned net charges ranging from fully positive to fully negative, labeled as HAP1-HAP5. Cytotoxicity assessments using NIH-3T3 fibroblast cells confirmed the biocompatibility of the polymer-coated HA surfaces. To confirm the antifouling property, adherence studies of Streptococcus mutans (S. mutans), a bacterium that causes dental caries (tooth decay) and dental plaque, were analyzed using a scanning electron microscope (SEM). Among all samples, HAP3 exhibited the minimum bacterial adhesion and the most effective resistance to protein adsorption, significantly outperforming the uncoated HA control.

Background: Children are considered as the future leaders of a nation. But, in developing countries like Bangladesh, school-age children often face a specific burden of preventable health issues that are aggravated by poor living conditions, inadequate hygiene, and health knowledge. Objective: The study aimed to assess the common health problems among school-going children in a sub-urban area of Chattogram city, Bangladesh. Methodology This was a descriptive cross-sectional study conducted among 181 school children going to a sub-urban school in Chattogram city on April 9, 2025. A semi-structured questionnaire was used for data collection. Sociodemographic information, health practices and problems related data were recorded and analyzed. Descriptive statistics were performed using Microsoft Excel. Results: Age of the participants ranged from 5 to 16 years, with a mean age of 9.43 (±2.76). Majority of them were boys (62.43%). Deworming and immunization status were 70.17% and 33.15% respectively. Common health complaints included dental caries (46.41%), undernutrition (39.78%), dental plaque (34.81%), scabies (30.39%), and anemia (27.07%). Conclusion: Dental health problems are the commonest complaints among school-age children. The study also addressed a high burden of other preventable health conditions such as undernutrition, scabies and anemia. These findings underscore the need for regular school health screening programs and large-scale studies to improve health promotion initiatives in school level. Journal of Paediatric Surgeons of Bangladesh (2021) Vol. 12 (1 &amp; 2):10-16

Traditional Chinese medicine Pudilan synergizes with smc gene to impair cell growth and exopolysaccharides synthesis of Streptococcus mutans.

Introduction: Microbial plaque is the primary cause of dental caries, gingivitis, and periodontal disease, necessitating effective strategies for its reduction. Mechanical removal methods may be challenging for some individuals, highlighting the need for alternative approaches. Curcumin, a natural compound with antimicrobial and anti-inflammatory properties, shows promise for oral health. This study evaluates the anti-inflammatory and antibacterial effects of a 20% curcumin mouthwash compared to a 0.2% chlorhexidine mouthwash on dental plaque and gingivitis. Materials and methods: In this randomized clinical trial, 39 patients aged 20 and older with gingivitis participated, randomly assigned to three groups of 13. All participants initially received scaling treatment. Group 1 utilized chlorhexidine mouthwash (SRP/CHX Gr-1), while Group 2 used curcumin mouthwash (SRP/CUR Gr-2). Group 3 received only scaling (SRP Gr-3) with the placebo mouthwash (distilled water). Gingival bleeding and plaque indices were recorded on Day 0 (before treatment) and Day 14, and the differences among the groups were statistically analyzed using repeated measure ANOVA and paired t-tests. Results: Clinical parameters improved in all three groups compared to baseline. Both the curcumin and chlorhexidine groups exhibited statistically significant improvements in the gingival bleeding index compared to the control group (Gr-3) (P &lt; 0.05), while no significant difference was observed in the dental plaque index (P &gt; 0.05). Additionally, there were no statistically significant differences in the modified sulcular bleeding index and plaque index (Turesky) between the curcumin and chlorhexidine groups (P &gt; 0.05). Conclusion: The results of this study indicate that curcumin is comparable to chlorhexidine as an anti-inflammatory mouthwash and can serve as an effective adjunct in periodontal treatments.

BackgroundSilver diamine fluoride (SDF) is a simple and non-invasive agent used to arrest early childhood caries (ECC). This study aimed to investigate potential changes to the oral microbiome in children with ECC who were treated with SDF and sodium fluoride (NaF) varnish at three different frequency regimens.MethodsForty-five children (n = 15 per group) with ECC were recruited from community-based dental clinics in Winnipeg, Canada into an open-label, parallel-group, randomized clinical trial testing three different treatment frequency regimens of SDF. A total of 195 carious lesions were treated with two applications of 38% SDF and 5% NaF varnish (and assessed over three study visits one month, four months, or six months apart. Dental plaque samples were collected at each visit. Sequencing of the V4-16 S rRNA and ITS1 rRNA genes were used to study the supragingival plaque microbiome.ResultsMicrobial diversity analyses showed no significant differences in the overall microbiome after SDF treatment. However, significant changes in the abundance of specific bacteria and fungi, particularly Lactobacillus spp., Bifidobacterium spp., and Candida spp., were observed after treatment. Furthermore, overabundance of Streptococcus mutans and Candida dubliniensis at baseline was observed in children who had at least one caries lesion not arrested after one SDF application, compared to those who had 100% arrest rates. The overall arrest rates for treated carious lesions were 75.9% at the second visit and 92.8% at the third visit. Arrest rates were higher for all lesions after two applications of SDF with NaF varnish, and applications one month and four months apart had higher arrest rates (95.9% and 98.5%) than six months (81.1%) apart.ConclusionsApplications of SDF with NaF varnish were an effective modality for arresting ECC, with higher arrest rates after two SDF applications. No loss of diversity but changes in the abundance of specific bacteria and fungi were observed after SDF treatment.Trial registrationClinicalTrials.gove NCT04054635 (first registered 13/08/2019).Supplementary InformationThe online version contains supplementary material available at 10.1186/s12903-025-06986-0.

Background: This study aimed to evaluate the effectiveness of xylitol- and fluoride-containing chewing gum in reducing dental plaque using a novel 3D colorimetric analysis, and to compare results with the Plaque Control Record (PCR). Methods: An acute intervention study was conducted on 34 healthy adults (18–45 years). A plaque-disclosing solution was applied, and intraoral scans were taken before and after 15 min of gum mastication. Plaque was quantified with PCR and the Placca Read software, which analyzes colorimetric patterns of scanned images. Statistical analyses (Shapiro–Wilk test, paired t-test) were performed with Jamovi Software version 1.6.14. Results: A significant reduction in plaque scores was observed after chewing gum (p < 0.05). Mean reduction reached −14.8% in the experimental group versus −3.9% in controls, where natural saliva flow and pigment washout may explain the modest decline. The 3D analysis provided precise measurements across all dental surfaces and showed strong correlation with PCR, supporting its validity. Conclusions: These findings indicate that functional chewing gum can significantly reduce plaque accumulation even after a single use, and that 3D colorimetric analysis offers a reliable, comprehensive alternative to conventional indices.

Sex differences in oral health behaviours and function during childhood may affect long-term oral and general health. However, large-scale studies of Japanese children are limited. To clarify sex differences in oral hygiene, masticatory performance, and chewing habits of Japanese schoolchildren. This cross-sectional study included 1400 fourth-grade children (686 boys and 714 girls) from public elementary schools in Osaka City. Oral examinations assessed dental plaque, gingival inflammation, and caries experience (DMFT/dmft indices). Masticatory performance was evaluated using a colour-changeable chewing gum test. Chewing and toothbrushing habits were assessed by questionnaires. Logistic regression analyses were conducted to examine associations between sex and oral health outcomes, adjusting for dental development stage and caries indices. Boys had higher prevalences of dental plaque and gingival inflammation, higher masticatory performance scores, and were more likely to eat fast and eat with the mouth full than girls. On multivariate analyses, boys were more likely to have dental plaque (odds ratio (OR) = 1.31, 95% confidence interval (CI): 1.02-1.68), gingival inflammation (OR = 1.49, 95% CI: 1.04-2.13), eat fast (OR = 3.11, 95% CI: 2.48-3.91), and eat with the mouth full (OR = 2.43, 95% CI: 1.93-3.07), and less likely to have lower masticatory performance (OR = 0.70, 95% CI: 0.55-0.90). Significant sex differences were observed in oral hygiene, masticatory function, and chewing behaviour of Japanese schoolchildren. These findings highlight the need for sex-specific strategies in oral health, particularly targeting boys with poorer oral hygiene and chewing habits.