Incidence, mortality and survival rates of lip, oral cavity and salivary glands cancers in Singapore: A half-century time trend analysis (1968-2017)

OBJECTIVES

To examine trends in incidence and mortality and evaluate overall survival (OS) of oral cancer in Singapore between 1968 and 2017.

METHODS

All diagnosed oral cancers by anatomical sites and population size were extracted from the Singapore Cancer Registry and the Department of Statistics Singapore. The trend of age-standardized incidence rate (ASIR) and mortality rate (ASMR) (per 100 000 person-years) of the lip, oral cavity and salivary gland cancers were evaluated by Prais-Winsten regressions for each ethnicity and gender. Kaplan-Meier curves were performed to evaluate the OS by anatomical sites in each age group by ethnicity and sex.

RESULTS

Overall, 49, 3494 and 1066 people were diagnosed, and 28, 2310 and 476 died from lip, oral cavity and salivary gland cancers, respectively. The oral cavity cancer ASIR and ASMR reduced from 3.07 (1968-1972) to 2.01(2008-2012) and from 2.06 (1978-1982) to 1.21 (2013-2017) per 100 000 person-years, respectively, with both highest in Indians throughout the whole period. Male:Female ratio ranged from 3.43 (1973-1977) to 1.75 (2013-2017) and from 3.41 (1978-1982) to 2.40 (2013-2017) for ASIR and ASMR, respectively. However, both salivary gland cancer ASIR and ASMR increased from 0.50 (1968-1972) to 0.80 (2008-2012) and from 0.18 (1968-1982) to 0.42 (1988-1992) per 100 000 person-years, respectively, with both higher in males since 1993. Oral cavity cancer ASIR decreased for males aged ≥60, and Indian females ≥25, but increased among Chinese females aged ≥60. Oral cavity cancer ASMR decreased among Chinese aged 25-59, and among Malay males and Indian females. Salivary gland cancer ASIR increased among Chinese males aged ≥60 and Malay males aged 25-59; while ASMR increased among Chinese males aged ≥60. The median OS for oral cavity, lip and salivary gland cancers were 3.0, 9.3 and 18.1 years, respectively, with females surviving longer than males.

CONCLUSIONS

Singapore has experienced a decline in the incidence and mortality of lip, oral cancer, an increase in in the incidence and mortality of salivary gland cancer, with an increase in the median overall survival rate. Monitoring the magnitude of oral cancer burden and the demographic, and temporal variations is necessary for tailoring health planning and setting priorities for future clinical care and research.

Oral and systemic health in Singapore: Revisiting the past to define the future

OBJECTIVES

This study aimed to identify studies exploring oral and systemic conditions using Singapore data.

METHODS

Studies were searched using the databases PubMed, Embase and Web of Science, with no publication date or language restrictions. Studies analysing Singaporean data were included in this review.

RESULTS

Six domains were identified: pregnancy and gingivitis; tooth eruption, dental caries and early-life factors; Crohn's disease and oral microbiome; diabetes and periodontal diseases; number of teeth, chewing ability and cognitive status; and oral health and pneumonia. Using data from Singapore, oral-systemic studies have prompted reflections on the aetiopathogenesis of oral disorders, such as common causes connecting oral and systemic chronic conditions. Moreover, it is speculated whether oral conditions could be used as a marker to predict future systemic diseases or whether early-life factors could affect the development of oral and systemic immune responses.

CONCLUSIONS

While Singapore provides opportunities to explore challenges connected to healthy ageing, it also explores health development in many stages of life. Singapore has been prioritizing investigations on a healthier life, and new initiatives are paving the way for oral health research across the lifespan.

Co-occurrence of Periodontitis and Diabetes-Related Complications

Periodontitis is a common finding among people with diabetes mellitus (DM) and has been cited as a DM complication. Whether and how periodontitis relates to other diabetes-related complications has yet to be explored. This study aims to examine the clustering of periodontitis with other diabetes-related complications and explore pathways linking diabetes-related complications with common risk factors. Using data from participants with DM across 3 cycles of the National Health and Nutrition Examination Survey (NHANES) (n = 2,429), we modeled direct and indirect pathways from risk factors to diabetes-related complications, a latent construct comprising periodontitis, cardiovascular diseases, proteinuria, and hypertension. Covariates included age, sex, socioeconomic status (SES), smoking, physical activity, healthy diet, alcohol consumption, hemoglobin A1c (HbA1c), dyslipidemia, and body mass index (BMI). Sensitivity analyses were performed considering participants with overweight/obesity and restricting the sample to individuals without DM. Periodontitis clustered with other diabetes complications, forming a latent construct dubbed diabetes-related complications. In NHANES III, higher HbA1c levels and BMI, older age, healthy diet, and regular physical activity were directly associated with the latent variable diabetes-related complications. In addition, a healthy diet and BMI had a total effect on diabetes-related complications. Although sex, smoking, dyslipidemia, and SES demonstrated no direct effect on diabetes-related complications in NHANES III, a direct effect was observed using NHANES 2011-2014 cycles. Sensitivity analysis considering participants with overweight/obesity and without DM showed consistent results. Periodontal tissue breakdown seems to co-occur with multiple diabetes-related complications and may therefore serve as a valuable screening tool for other well-known diabetes-related complications.

Effect of Smoking Exposure on Nonsurgical Periodontal Therapy: 1-Year Follow-up

This study investigated the influence of different levels of exposure to smoking on periodontal healing for 12 mo after nonsurgical periodontal therapy and supportive periodontal care every third month. Eighty smokers willing to quit smoking and with periodontitis were included. Participants were offered an individualized voluntary smoking cessation program. Data collection included questionnaires and a full-mouth periodontal examination. Group-based trajectory modeling was used to model smoking trajectories over the follow-up. The effect of smoking trajectory on periodontal parameters over time was estimated with mixed effects modeling. Three smoking patterns were identified: light smokers/quitters (n = 46), moderate smokers (n = 17), and heavy smokers (n = 17). For the periodontal data, the first factor, moderate periodontitis, included the number of sites with clinical attachment levels (CALs) of 4, 5, 6, and 7 mm; periodontal pocket depths (PPDs) of 4, 5, and 6 mm; and bleeding on probing. The second factor, severe periodontitis, consisted of the number of sites with a CAL ≥8 mm and PPD ≥7 mm. Heavy smokers commenced with a higher average CAL of 1.1 mm and 10 more sites with severe periodontitis than light smokers/quitters. While light smokers/quitters and moderate smokers obtained an average improvement of 0.6-mm PPD and 0.7-mm CAL, respectively, heavy smokers experienced 0.5-mm attachment loss. Heavy smokers had only a 50% reduction in the number of sites with moderate periodontitis when compared with light smokers/quitters and moderate smokers. While most participants benefited from nonsurgical periodontal therapy with results affected in a dose-response manner, the therapy had no effect on severe periodontitis among heavy smokers. Smoking cessation should be part of periodontal therapy; otherwise, limited benefits would be observed among heavy smokers, hindering the effect of treatment.

Role of occlusal factors on probable bruxism and orofacial pain: Data from the 1982 Pelotas birth cohort study

OBJECTIVES

This study aimed to explore the association between occlusal features and temporomandibular disorder (TMD) pain complaints and probable awake or sleep bruxism METHODS: Path analysis was used to estimate direct, indirect and total effects of occlusal features on probable bruxism and pain-related TMD in adults aged 31 years from the 1982 Pelotas Birth Cohort. A total of 539 cohort members had an oral examination in 2013. Occlusal features were assessed through the Dental Aesthetic Index (DAI), orofacial pain complaints through the TMD pain screener and probable bruxism based on self-reports in combination with clinical findings.

RESULTS

Malocclusions were found in 28.8% of the participants, while awake bruxism was reported in 35.2%, sleep bruxism in 15.2%, and pain-related TMD in 52.5% of the sample. Occlusion had no direct effect on either awake bruxism [standardized coefficient (SC) -0.002; p = 0.995] or pain-related TMD (SC -0.06; p = 0.115). Conversely, probable awake bruxism was associated with pain-related TMD (SC 0.35; p < 0.001). Similar results were found when sleep bruxism was set as the mediator of interest, as malocclusion did not directly affect sleep bruxism (SC 0.05; p= 0.220) nor pain-related TMD (SC -0.06; p = 0.167). A direct effect of sleep bruxism on pain-related TMD was observed with an SC of 0.16 (p < 0.001).

CONCLUSION

Our findings suggested that malocclusion during adulthood did not directly influence probable awake or sleep bruxism nor TMD pain complaints. Instead, probable awake and sleep bruxism was associated with TMD pain complaints.

CLINICAL SIGNIFICANCE

Malocclusion did not impact the presence of bruxism nor TMD complaints in adulthood, but awake and sleep bruxism were associated with TMD pain complaints. The significance of malocclusion should be reconsidered in contemporary dentistry and oral rehabilitation.

Influence of Bacterial Profiles in Cytokine and Clinical Features of Endodontic Disease

INTRODUCTION

We verified the association between selected bacterial profiles and levels of cytokines, chemokines, and the expression of signs and symptoms of primary endodontic infection with apical periodontitis.

METHODS

Samples were collected from 21 root canals, and macrophages were stimulated for 24 hours. Tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, IL-10, IL-12p70, interferon gamma, and chemokine (C-C motif) ligand 2 (CCL2) were measured using cytometric bead array. We investigated the overlapping networks between cytokines and chemokines with regression analysis. Checkerboard DNA-DNA hybridization was used to assess 40 target bacteria species. Using factor analysis, bacterial species aggregated in 2 factors. The association of bacteria species-based factors on cytokine and chemokine levels and clinical features was estimated with regression analysis.

RESULTS

A negative relationship between IL-10 (anti-inflammatory cytokine) and CCL2, TNF-α, and IFN-γ (proinflammatory cytokines) (all P < .05) was observed. CCL2 was positively correlated with TNF-α (P < .01). Thirty-eight bacteria species were detected in primary endodontic infection with apical periodontitis. The first bacteria species-based factor was associated with the size of the radiolucent area (coefficient = 15.42) and tenderness to percussion/pain on palpation (coefficient = 20.79). The second factor was associated with CCL2 levels (coefficient = 1.28).

CONCLUSIONS

Different bacterial profiles can be differentially related to the expression of inflammatory proteins and the experience of clinical features.

Is there a relationship between obesity and tooth loss and edentulism? A systematic review and meta-analysis

This study conducted a systematic review to assess the bi-directional association between tooth loss/edentulism and obesity. Electronic searches were performed in four different databases. Observational studies that tested associations between tooth loss/edentulism and obesity as either exposures or outcomes were included. Additionally, meta-analyses, funnel plots and sensitivity analyses were conducted to synthesize the evidence. A total of 549 articles were identified in the electronic database search. Out of which, 16 studies were included within the meta-analyses: 75% considered tooth loss/edentulism as exposure and obesity as outcome, whereas 25% alternatively considered obesity as exposure and tooth loss/edentulism as outcome. Pooled estimates showed that obese individuals had 1.49 (95%CI 1.20-1.86) and 1.25 (95%CI 1.10-1.42) times higher odds of having any tooth loss and edentulism, respectively. Alternatively, when tooth loss or edentulism were considered as exposures, individuals with any tooth loss had 1.41 (95%CI 1.11-1.79) times higher odds for obesity, while edentates had even higher odds (OR 1.60; 95%CI 1.29-2.00). The results indicate a bi-directional association between tooth loss and obesity. Considering that all selected studies were of cross-sectional study design limiting inferences on temporality, longitudinal prospective studies are required to test the causal relationship between tooth loss/edentulism and obesity or vice a versa. © 2016 World Obesity.

Antifungal activity of 3-(heteroaryl-2-ylmethyl)thiazolidinone derivatives

Thiazolidinones, synthesized from multicomponent reactions of 2-heteroarylmethylamine, arenealdehydes and mercaptoacetic acid, have been tested against six yeasts, namely Candida albicans, C. parapsilosis, C. guilliermondii, Cryptococcus laurentii, Trichosporon asahii and Rhodotorula spp. The activities were expressed as minimum inhibitory concentrations (MIC) and the minimum fungicidal concentrations (MFC). The most affected yeasts were Rhodotorula spp and T. asahii. The cytotoxicities of the thiazolidinones against the fibroblast 3T3/NIH cell line are also described. The antifungal results and the low cytotoxicity of the compounds in this work provide good guides for the further development of active compounds.

Macrophage cell activation with acute apical abscess contents determined by interleukin-1 Beta and tumor necrosis factor alpha production

INTRODUCTION

This clinical study has investigated the antigenic activity of bacterial contents from exudates of acute apical abscesses (AAAs) and their paired root canal contents regarding the stimulation capacity by levels of interleukin (IL)-1 beta and tumor necrosis factor alpha (TNF-α) throughout the root canal treatment against macrophage cells.

METHODS

Paired samples of infected root canals and exudates of AAAs were collected from 10 subjects. Endodontic contents were sampled before (root canal sample [RCS] 1) and after chemomechanical preparation (RCS2) and after 30 days of intracanal medication with calcium hydroxide + chlorhexidine gel (Ca[OH]2 + CHX gel) (RCS3). Polymerase chain reaction (16S rDNA) was used for detection of the target bacteria, whereas limulus amebocyte lysate was used to measure endotoxin levels. Raw 264.7 macrophages were stimulated with AAA exudates from endodontic contents sampled in different moments of root canal treatment. Enzyme-linked immunosorbent assays were used to measure the levels of TNF-α and IL-1 beta.

RESULTS

Parvimonas micra, Porphyromonas endodontalis, Dialister pneumosintes, and Prevotella nigrescens were the most frequently detected species. Higher levels of endotoxins were found in samples from periapical exudates at RCS1 (P < .005). In fact, samples collected from periapical exudates showed a higher stimulation capacity at RCS1 (P < .05). A positive correlation was found between endotoxins from exudates with IL-1 beta (r = 0.97) and TNF-α (r = 0.88) production (P < .01). The significant reduction of endotoxins and bacterial species achieved by chemomechanical procedures (RCS2) resulted in a lower capacity of root canal contents to stimulate the cells compared with that at RCS1 (P < .05). The use of Ca(OH)2 + CHX gel as an intracanal medication (RCS3) improved the removal of endotoxins and bacteria from infected root canals (P < .05) whose contents induced a lower stimulation capacity against macrophages cells at RCS1, RCS2, and RCS3 (P < .05).

CONCLUSIONS

AAA exudates showed higher levels of endotoxins and showed a greater capacity of macrophage stimulation than the paired root canal samples. Moreover, the use of intracanal medication improved the removal of bacteria and endotoxins from infected root canals, which may have resulted in the reduction of the inflammatory potential of the root canal content.

A double-blind randomised clinical trial of two techniques for gingival displacement

Knowledge about security and the potential damage originated by the gingival displacement techniques has not been described through randomised clinical studies. This crossover, double-blind, randomised clinical trial evaluated clinical and immunological factors related to conventional and cordless gingival displacement (GD) techniques, and patients' perceptions in 12 subjects with the employment of 2 GD techniques: conventional (gingival cord + 25% AlCl3 astringent gel) and cordless (15% AlCl3 astringent-based paste). In each subject, two anterior teeth were treated and a 10-day wash-out period separated the two treatments. Periodontal indices were evaluated before (baseline) and 1 and 10 days after GD. Interleukin 1β, interleukin 6 and tumour necrosis factor α concentrations in gingival crevicular fluid were measured before and 1 day after GD. Subjective parameters (pain, unpleasant taste and stress) were also evaluated. Data were analysed by one-way repeated-measures analysis of variance and Tukey's test (immunological factors), the Friedman test (periodontal parameters) and Fisher's exact or chi-squared test (subjective parameters), with a significance level of 95%. Gingival bleeding index, probing depth and plaque index values did not differ significantly between groups at any timepoint. Neither technique resulted in worse periodontal indices. Both techniques yielded similar results for pain and unpleasant taste, but conventional GD was significantly more stressful than cordless GD for volunteers. Both treatments significantly increased mean concentrations of the three cytokines, with the conventional technique producing the highest cytokine levels. Cordless GD is less stressful for patients and results in lower post-treatment levels of inflammatory cytokines compared with conventional GD.

Correlation between clinical/radiographic features and inflammatory cytokine networks produced by macrophages stimulated with endodontic content

INTRODUCTION

Macrophages are highly activated by endodontic contents. This study investigated the correlation between different clinical signs/symptoms and radiographic features according to the levels of interleukin (IL)-1β, tumor necrosis factor α (TNF-α), IL-6, IL-10, prostaglandin E(2) (PGE(2)), and their networks produced by endodontic content-stimulated macrophages collected from primary endodontic infection with apical periodontitis (PEIAP).

METHODS

Samples were taken from 21 root canals with PEIAP by using paper points. The presence of exudate (EX), pain on palpation (POP), tenderness to percussion (TTP), and the size of the radiographic lesion (SRL) were recorded. Polymerase chain reaction (16S rDNA) was used for bacterial detection and limulus amebocyte lysate (LAL) assay for endotoxin measurement. Raw 264.7 macrophages were stimulated with bacterial contents during 24 hs. The amounts of IL-1β, TNF-α, IL-6, IL-10 and PGE(2) were measured by enzyme-linked immunosorbent assay. Log-based data were correlated by multiple logistic regression (P < .05).

RESULTS

Bacteria and endotoxin were detected in 100% of the samples. IL-6 and TNF-α were positively correlated with SRL and EX, respectively (P < .05). Clinical signs/symptoms and radiographic findings were set as dependent variables for EX-positive correlations between PGE(2), IL-1β, and TNF-α (P < .05), whereas IL-6 and PGE(2) were positively correlated to each other in POP but negatively correlated in SRL (P < .05). When POP and TTP-POP were set as dependent variables, different cytokine networks were found.

CONCLUSIONS

Our findings suggest different roles for each cytokine in the development of apical periodontitis, whose effects of overlapping networks depend on the signs/symptoms and radiographic features found in endodontic infection.