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Objectives: To explore the association among salivary biomarkers, periodontal inflammation, and adiposity status in adolescents., Methods: This study included 180 Hong Kong adolescents aged 12-15 years. Anthropometric measurements including central obesity surrogate, waist-to-height ratio (WHtR), and dental examinations were conducted. The participants were classified into four groups as follows: with normal WHtR and less extensive periodontal inflammation (NW+LP); with high WHtR and less extensive periodontal inflammation (HW+LP); with normal WHtR and more extensive periodontal inflammation (NW+P); and with high WHtR and more extensive periodontal inflammation (HW+P). Saliva were collected to measure salivary physicochemical parameters, total bacterial load, and levels of protein biomarkers including secretory phospholipase A 2 group IIA (sPLA 2 -IIA) and interleukin-6 (IL-6). Data were analysed by Kruskal-Wallis test and Spearman correlation coefficient., Results: Salivary IL-6 levels and sPLA 2 -IIA and IL-6 output differed significantly between groups (P = 0.041, 0.027, and 0.043, respectively). The NW+P group had significantly higher salivary IL-6 output than the NW+LP group (P = 0.034) and significantly lower salivary sPLA 2 -IIA output than the HW+LP group (P = 0.038). Salivary IL-6 levels were negatively correlated with the number of sextants with healthy gingivae and positively correlated with salivary sPLA 2 -IIA levels in participants with normal WHtR. Salivary sPLA 2 -IIA levels were negatively correlated with total salivary bacterial load in participants with high WHtR., Conclusions: Salivary IL-6 levels were associated with the extent of periodontal inflammation in participants with normal WHtR but not in those with high WHtR. Adolescents with different adiposity status may have different mechanisms of periodontal inflammation., Clinical Significance: Investigating salivary biomarkers of periodontal health holds potential benefits in identifying individuals at risk and customizing oral health promotion strategies for individuals with varying levels of adiposity, even as early as adolescence., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Oral diseases are preventable through the building of good oral health behaviors. Theory-based behavior change was key to the efficacy of oral health promotion since conventional promotion strategies achieved only short-lived and limited improvements. The objective of the study was to investigate the efficacy of a peer-led oral health intervention based on the health belief model (HBM) and the social cognitive theory (SCT) on oral self-care behaviors among Hong Kong adolescents. One thousand one hundred and eighty-four adolescents in 12 schools participated and were randomly assigned to either intervention or control group, utilizing a cluster-randomized controlled trial design. Brushing/flossing frequency, HBM/SCT constructs, oral health knowledge, and dental anxiety were measured at baseline and 6-month follow-up. Changes in behaviors were assessed using mixed-effects model and the mediators of behavioral change were identified with parallel multiple mediation analysis. At 6 months, the intervention group showed a significant increase in the frequency of brushing and flossing compared with the control group. Self-efficacy was identified as mediator between treatment condition and behavioral changes of brushing and flossing. Combining theories of HBM and SCT is a promising avenue for efficacy in oral health behaviors. The effects were mediated through cognitive variables, which provided guidance for both theory and health intervention development., (© Society of Behavioral Medicine 2021. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Purpose: This study aimed to investigate the effects of a peer-led oral health intervention based on the Health Belief Model and the Social Cognitive Theory on improving oral health among Hong Kong adolescents., Methods: The study adopted a cluster-randomized controlled trial design, and 1184 students in 12 schools were randomized to intervention or control groups. After baseline assessment, the intervention group received a peer-led theory-based oral health intervention, while the control group received booklets for oral health promotion. Self-reported brushing and flossing, Health Belief Model/Social Cognitive Theory constructs, and oral health-related quality of life (OHRQoL) were measured at baseline, 6 months, and 12 months, and dental plaque accumulation and caries status were measured at baseline and 12 months. The trial was registered at https://www.clinicaltrials.gov (NCT03694496)., Results: Brushing, flossing, and OHRQoL improved more in the experimental group than in the control group at the 6-month follow-up compared with baseline (p < .001). The mean gain score difference was .81 for brushing, .47 for flossing, and -2.51 for OHRQoL. At the 12-month follow-up, the mean gain score of brushing frequency, plaque index, caries status, and OHRQoL were .18, -.28, -.32, and -2.79, respectively, which all sustained the significant difference (p < .001)., Conclusions: Our findings suggested that the Health Belief Model combined with Social Cognitive Theory in a peer-led intervention is effective to increase self-reported brushing frequency and improve oral hygiene status and OHRQoL among adolescents., (Copyright © 2021 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Background: Children with special education needs (SEN) require additional supports in education settings, as well as extra supports in healthcare services., Aim: To investigate dental visit experience and dental care barriers among Hong Kong preschoolers with SEN., Design: This was designed as a cross-sectional study. A structured questionnaire was employed to investigate dental attendance and dental care barriers among Hong Kong preschoolers with SEN. Binary logistic regression and multi-factor ANOVA were performed to identify factors associated with children's dental visit experience., Results: A total of 383 children were included in the final analysis. The average age of the recruited children was 3.87 ± 0.95 years. 72.5% parents reported that dental visits were a challenging task for their children. Among children with caries, 70.7% had never visited a dentist. Regression models indicated that (a) children over 3 years or children whose parents received tertiary education were more likely to visit a dentist; (b) the existence of dental care barriers was associated with children's primary diagnosis, practical skills, conceptual skills, and parents' education attainment; and (c) children with low conceptual skills (95%CI:0.71 to 2.40, P < .001), or children from low-income families (95%CI:1.21 to -0.06, P = .031) had more dental care barriers than their counterparts., Conclusion: Unmet dental treatment needs and dental care barriers existed among pre-schoolers with SEN. Dental care barriers were associated with children's developmental profile, parents' education attainment, and household income., (© 2020 BSPD, IAPD and John Wiley & Sons Ltd.)

Objective: To assess the association between dental anxiety and caries experience from late childhood through adolescence and into early adulthood (12, 15 and 18 years old, respectively)., Methods: A prospective cohort study was conducted among a population-representative sample of Chinese in Hong Kong. A baseline survey was conducted at age 12 and follow-up assessments were completed at ages 15 and 18. Caries experience was assessed as the number of decayed, missing and filled teeth (DMFT). Dental anxiety was assessed using the Modified Dental Anxiety Scale (MDAS). Participants' socio-economic status and oral health-related behaviours were ascertained using a self-complete questionnaire. Negative binomial regression was used to explore the association between dental anxiety and subsequent caries status, controlling for other factors., Results: At baseline, 668 children participated; 279 (41.8%, comprising 57.0% females) completed all three phases of data collection. MDAS scores at age 18 were lower than at age 12. Caries experience increased as participants aged. At age 15 and 18, females had higher MDAS and DMFT scores than males. Reported frequency of snacking between meals was associated with MDAS scores at age 18. In regression analyses, dental anxiety at age 12 was not significantly associated with dental caries experience at age 15, controlling for socio-demographic and oral-health behaviour factors at age 12. Likewise, dental anxiety at age 15 was not significantly associated with dental caries experience at age 18, controlling for the same factors at age 15., Conclusion: Dental anxiety assessed by MDAS in late childhood and adolescence appears not to predict dental caries experience later in life in this population., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: A vicious cycle exists between dental anxiety, oral health behaviors and oral health status. Based on previous research, psychological factors of the Health Belief Model (HBM) are associated with oral health behaviors and oral health, and are likely involved in this cycle. However, little is known about the relationship between HBM factors and dental anxiety of adolescents. The purpose of this cross-sectional study was to investigate the relationship between health belief factors, oral health and dental anxiety based on the constructs of the HBM., Methods: 1207 Grade 2 students from 12 secondary schools in Hong Kong were randomly selected and measured for the decayed, missing and filled permanent teeth (DMFT) index. Data for oral health behaviors, HBM constructs and dental anxiety were collected using questionnaires. The hierarchical entry of explanatory variables into logistic regression models estimating prevalence odds ratios (POR) were analyzed and 95% confidence intervals (95% CI) for DMFT and dental anxiety were generated. Path analysis was used to evaluate the appropriateness of the HBM as predictors for oral health behaviors, DMFT and dental anxiety., Results: Based on the full model analysis, individuals with higher perceived susceptibility of oral diseases (POR: 1.33, 95% CI: 1.14-1.56) or girls or whose mother received higher education level were likelier to have a DMFT≥1, while those with higher perceived severity (POR: 1.31, 95%CI: 1.09-1.57), flossing weekly, DMFT≥1 or higher general anxiety level statistically increases the possibility of dental anxiety. The results from path analysis indicated that stronger perceived susceptibility, greater severity of oral diseases, less performing of oral health behaviors and a higher score of DMFT were directly related to increased dental anxiety level. Other HBM variables, such as perceived susceptibility, self-efficacy beliefs, cues to action and perceived barriers, might influence dental anxiety through oral health behaviors and caries status., Conclusions: Clarifying the propositional structures of the HBM may help the future design of theory-based interventions in reducing dental anxiety and preventing dental caries.

Background: Oral health belief is a prerequisite of changing oral health behaviors especially during adolescence. However, there is a paucity of well-established questionnaire for use among adolescents. This study aimed to develop and validate an instrument to evaluate adolescents' beliefs about oral health behaviors using health belief model., Methods: A preliminary 43-item questionnaire was developed by an expert panel. Then the questionnaire was finalized by decreasing the number of items to 35 by analyzing the results from face validity and factor analysis from 421 Hong Kong secondary school students. The content validity were evaluated by a panel of 2 behavioral scientists, 2 dentists, 2 schoolteachers and 10 adolescents. The construct validity of the questionnaire was assessed by performing exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). The Cronbach's alpha coefficient, item-total correlation and intraclass coefficient were used to test its reliability. In addition, to confirm its applicability, multiple regression analysis and path analysis were used to evaluate the possibility of HBM as predictors for oral health behaviors and oral hygiene status., Results: The initial analysis extracted six factors that jointly accounted for 62.47% of the variance observed. Based on CFA, the final version of the questionnaire consisted of 35 items and the data of the final version fitted the model well. The Cronbach's alpha coefficient for the subscale (> 0.7), item-total correlations (0.47-0.91) and the intraclass coefficient (0.82-0.91) were all above acceptable thresholds. The results of multiple regression analysis and path analysis confirmed its ability to predict oral health behaviors and status., Conclusions: The present findings indicate satisfactory validity, reliability and applicability of the proposed Oral Health Behavior Questionnaire for Adolescents based on the Health Belief Model (OHBQAHBM) for measuring oral health beliefs of adolescents. This questionnaire can be used as an instrument to measure oral health beliefs and predict oral health behavior and oral hygiene status of adolescents.

Background: There is a lack of cohort studies on the influence factors of oral health-related quality of life (OHRQoL). This study aimed to follow subjects from age 12 to 18 to analyse the sociodemographic and clinical factors that may influence OHRQoL., Methods: This cohort study selected a representative sample from Hong Kong. Periodontal status and caries were examined according to WHO criteria. Four orthodontic indices were used to assess malocclusion. Child Perceptions Questionnaires (CPQ 11-14 ) with 8 items (CPQ 11-14 -ISF: 8) and 37 items were used to assess OHRQoL at age 12 and age 15, respectively; Oral Health Impact Profile (OHIP-14) was used to assess OHRQoL at age 18. Wilcoxon signed ranks test and Friedman's test were used to analyse the age-related change of OHRQoL and malocclusion from age 12 to 18. Generalized estimating equations were used to analyse the influence factors of OHRQoL and to calculate adjusted risk ratio (RR)., Results: Subjects recruited in this study were 589 (305 females, 284 males), 364 (186 females, 178 males) and 300 (165 females, 135 males) at age 12, 15 and 18, respectively. Among them, 331 subjects (172 females, 159 males) were followed from age 12 to 15, and 118 subjects (106 females, 82 males) were followed from age 12 to 18. Subjects had less severe malocclusion at age 12 than at ages 15 and 18 (p = 0.000, measured by Dental Aesthetic Index). Age, periodontal status, and malocclusion had an effect on OHRQoL. When compared with OHRQoL at age 12, worse OHRQoL was observed at age 15 (adjusted RR = 1.06, 95%CI = 1.01-1.12, p = 0.032), but not at age 18 (adjusted RR = 1.01, 95%CI = 0.95-1.08, p = 0.759). Unhealthy periodontal conditions had a negative effect on OHRQoL (adjusted RR = 1.14, 95%CI = 1.04-1.25, p = 0.007). Only severe malocclusions had a negative effect on OHRQoL; a more severe malocclusion was associated with a higher effect on OHRQoL (adjusted RR = 1.09, 95%CI = 1.01-1.18, p = 0.032 for severe malocclusion, and adjusted RR = 1.17, 95%CI = 1.07-1.28, p = 0.001 for very severe malocclusion measured by Dental Aesthetic Index)., Conclusion: Age, periodontal status, and malocclusion had an influence on OHRQoL from age 12 to 18. When clinicians attempt to improve subjects' OHRQoL, it is necessary to consider these factors.

This study aimed to investigate changes in types of dental arch form during adolescence and explore adolescent changes in size and form of dental arch. Hong Kong Chinese were recruited and digital dental arch models were obtained at ages 12, 15, and 18 years. Geometric morphometrics was used to investigate adolescent changes of dental arch form. There were 225 participants from whom digital models at all three age periods were available. Three types of dental arch form were identified through clustering. Significant changes (p < 0.001) in types of dental arch form were noted during age 12-18 years. During age 12-18 years, significant changes in centroid size and form of dental arch were observed (p < 0.001). No significant changes were observed during 15-18 years. Adolescent changes of dental arch form occur primarily during age 12-15 years, whereas dental arch form was relatively stable during age 15-18 years.

Objective: To assess the oral health-related quality of life among Hong Kong preschool children with severe early childhood caries., Methods: A total of 315 Hong Kong preschool children diagnosed with severe early childhood caries (S-ECC) were recruited. Their caries and plaque status were evaluated. Their parents were asked to complete the Early Childhood Oral Health Impact Scale (ECHOIS) and a sociodemographic background questionnaire., Results: There was a 98.7% response rate. The mean age was 4.7 ± 0.8 years. The mean decayed, missing and filled teeth (dmft) score was 10.2 ± 4.5. Almost all the children (98.7%) had decayed teeth. More than half of the children (61.4%) had a visible plaque index (VPI) score of above 90%. About one quarter (28.9%) were experiencing symptoms of pain. The dmft score of the child was significantly associated with the ECOHIS child impact, child function, family impact and family distress domains (P < .001). The presence of pain was significantly associated with increased ECOHIS child and family impact scores (P < .001). In the multiple regression analyses, the dmft score and presence of pain showed a significant association with the ECOHIS scores (P < .001)., Conclusion: The OHRQoL of children with S-ECC was worsened with the presence of pain and severity of the disease. More measures need to be placed to decrease the prevalence of children with S-ECC., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Thorough understanding of developmental changes of human facial shape is lacking. The present study aimed to evaluate developmental shape changes of facial morphology based on a prospective, population-representative, Chinese cohort in Hong Kong., Methods: A population-representative sample of Chinese in Hong Kong was followed. Serial facial images of over 260 participants were obtained at age 12, 15, and 18 years. Facial landmarks were digitized and the corresponding coordinates were submitted for Generalized Procrustes Analysis. The resultant Procrustes shape coordinates, which captured shape information encoded by the facial landmarks, were then used for statistical shape analyses., Results: Small but significant developmental changes in mean facial shape were observed (p < 0.0001 for all pairwise comparisons). Significant age-related changes in the magnitude of variance of facial shape were also observed (p < 0.05). Phenotypic growth trajectories representing developmental shape changes were similar in size (p > 0.05) between sexes but differed in direction (p < 0.05) in shape space and trajectory shape (p < 0.05). The magnitude of shape differences between sexes remained constant from 12 to 18 years. Results of frontal facial shape analyses after removing the effect of allometry were similar to results obtained before removal of allometry. For lateral facial configurations, allometric trajectories among the age-by-sex groups were similar in slope (p > 0.05) but varied in directions in the multidimensional shape space., Conclusions: Our findings suggested significant age-related changes in facial shape and provided a dynamic view of developmental changes in sexual dimorphism of facial shape. Allometry contributed minimally to developmental changes in frontal facial shape. In addition, the allometric trajectories for lateral facial configurations were similar in rate of shape change but differed in their directions in shape space., Competing Interests: The authors have declared that no competing interests exist.

Background: Socio-economic status, health awareness, and dietary habits have been reported as common risk factors of dental caries and obesity. The present study aimed to explore shared mediators between caries and obesity and to estimate the effects of caries-related factors on adiposity., Methods: This was a cross-sectional study among adolescents aged 18 years. The study was nested in a population-representative cohort of Chinese in Hong Kong. The number of decayed, missing, and filled permanent teeth (DMFT) was recorded during the oral examinations. Body Mass Index (BMI), Waist Circumference (WC), Waist-Hip-Ratio (WHR), Waist-Height-Ratio (WHtR), and Triceps Skinfold Thickness (TRSKF) were used as adiposity indices. Data on socio-economic status, oral health behavior (tooth brushing habit, use of fluoride toothpaste, dental flossing habit, and mouth rinse habit), and dietary record (frequency and amount of different food) were collected through self-completed questionnaires. Chi-square tests and binary logistic regressions were used for analysis., Results: Three hundred eighty-three participants were included. The mean (standard deviation, SD) of BMI, WC, WHR, WHtR, TRSKF, and DMFT were 21.26 (3.72), 69.11 (9.25), 0.77 (0.06), 0.42 (0.05), 15.72 (6.33), and 2.06 (2.43), respectively. Males were more likely to be overweight/obese than females. Various factors including gender, parental employment status, mouth rinse habit, frequency and amount of meat intake, frequency of oil intake, use of fluoride toothpaste, and DMFT were found significant (p < 0.05) in different final models of adiposity status., Conclusions: More mediators should be included in future research to elucidate mechanism of the association between caries and obesity.

Background: The development of primary dentition can be affected by oral sucking habits. Therefore, this study aims to investigate the association of nutritive and non-nutritive sucking habits with primary dentition development., Methods: One thousand one hundred and fourteen children aged 2 to 5 years old in Hong Kong were recruited in a cross-sectional study. Information on their nutritive (e.g. breastfeeding and bottle feeding) and non-nutritive sucking habits (e.g. pacifier use and thumb/digit sucking) was collected via questionnaires. The children's primary occlusions were examined in three dimensions., Results: Children who were breastfed for more than 6 months had a lower proportion of daily pacifier use (p < 0.05). Children who used pacifiers daily had a higher proportion of thumb/digit sucking (p < 0.05). Children who used pacifiers daily for more than one year had higher chances of developing an anterior open bite (p < 0.05) and a reduced overbite (p < 0.05). Those exhibiting daily thumb/digit sucking for more than one year had higher chances of developing Class II incisor and Class II canine relationships, an increased overjet and anterior open bite (p < 0.05)., Conclusion: Pure breastfeeding for more than 6 months is inversely associated with daily pacifier use and daily pacifier use is positively associated with daily thumb/digit sucking. Children with more than one year of daily pacifier use and thumb/digit sucking have higher chances of developing abnormal dental relationships in the sagittal (i.e. Class II incisor and Class II canine relationships and increased overjet) and vertical (i.e. anterior open bite) dimensions, respectively.

Background: Many countries have recently experienced a rapid increase in the demand for forensic age estimates of unaccompanied minors. Hong Kong is a major tourist and business center where there has been an increase in the number of people intercepted with false travel documents. An accurate estimation of age is only possible when a dataset for age estimation that has been derived from the corresponding ethnic population. Thus, the aim of this study was to develop and validate a Reference Data Set (RDS) for dental age estimation for southern Chinese., Materials and Methods: A total of 2306 subjects were selected from the patient archives of a large dental hospital and the chronological age for each subject was recorded. This age was assigned to each specific stage of dental development for each tooth to create a RDS. To validate this RDS, a further 484 subjects were randomly chosen from the patient archives and their dental age was assessed based on the scores from the RDS. Dental age was estimated using meta-analysis command corresponding to random effects statistical model. Chronological age (CA) and Dental Age (DA) were compared using the paired t-test., Results: The overall difference between the chronological and dental age (CA-DA) was 0.05 years (2.6 weeks) for males and 0.03 years (1.6 weeks) for females. The paired t-test indicated that there was no statistically significant difference between the chronological and dental age (p > 0.05)., Conclusion: The validated southern Chinese reference dataset based on dental maturation accurately estimated the chronological age., (Copyright © 2016 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.)

Background and Objective: Current studies on the aetiology of developmental defects of enamel (DDE) are subject to recall bias because of the retrospective collection of information. Our objective was to investigate potential risk factors associated with the occurrence of DDE through a prospective cohort study., Methods: Using a random community sample of Hong Kong children born in 1997, we performed a cohort study in which the subjects' background information, medical and dental records were prospectively collected. A clinical examination to identify DDE was conducted in 2010 when the subjects were 12 years old. The central incisor, lateral incisor and first molar in each quadrant were chosen as the index teeth and were examined 'wet' by two trained and calibrated examiners using the modified FDI (DDE) Index., Results: With a response rate of 74.9%, the 514 examined subjects had matched data for background information. Diffuse opacites were the most common type of DDE. Of the various possible aetiological factors considered, only experience of severe diseases during the period 0-3 years was associated with the occurrence of 'any defect' (p = 0.017) and diffuse opacities (p = 0.044). The children with experience of severe diseases before 3 years of age were 7.89 times more likely to be affected by 'any defect' compared with those who did not have the experience (OR 7.89; 95% CI 1.07, 58.14; p = 0.043). However, after adjusting for confounding factors, the association no longer existed., Conclusion: No variables could be identified as risk factors of DDE in this Hong Kong birth cohort.

Objective: To describe the relationship between caregivers' oral health literacy (OHL) and the oral health status of their children in an Asian population., Methods: A random sample of 301 child/caregiver dyads was recruited from kindergartens in Hong Kong. Two locally-developed and validated OHL assessment tasks were administered to caregivers with Hong Kong Rapid Estimate of Adult Literacy in Dentistry-30 (HKREALD-30) assessing word recognition and Hong Kong Oral Health Literacy Assessment Task for Paediatric Dentistry (HKOHLAT-P) assessing comprehension. Their children's oral health status was assessed [dental caries experience - decayed, missing, filled teeth index - (dmft) and oral hygiene status - Visible Plaque Index (VPI)]., Results: Caregivers' literacy was associated with children's oral health status. The HKOHLAT-P had a stronger association with children's oral health than HKREALD-30. HKOHLAT-P and HKREALD-30 remained associated with dmft in the adjusted negative binomial regression models (accounting for socio-demographics), Incidence Rate Ratio (IRR) 0.97, p=0.02, and 0.96, p=0.03, respectively. In the adjusted model, HKOHLAT-P was associated with VPI (IRR 0.90, p<0.05), but no association between HKREALD-30 and VPI was evident., Conclusion: The main conclusion of this study was that caregiver oral health literacy was associated with their child's oral health status. A comprehension instrument had a more robust association with children's oral status than a word recognition instrument., Practice Implications: This study has implications for general public health education for designing community-level interventions., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Background: To date, research on the relationship between dental caries experience and adiposity status is debated., Aim: To determine associations between dental caries experience and adiposity status among a community sample of preschool children in Hong Kong., Design: Among a random sample of 5-year-old children, clinical assessment for dental caries was conducted using WHO criteria. Anthropometric measurements for body weight, body height, waist circumference (WC), hip circumference, and triceps skinfold thickness (TRSKF) were performed to assess general adiposity, central adiposity, and peripheral adiposity. Associations between adiposity status and caries were examined in regression analyses., Results: The response rate was 83.1% (324/390). Regression analyses (adjusted for tooth brushing habits, snacking habits, and socio-demographic factors) identified that weight/height ratio z-score was associated with caries experience: prevalence of dental caries experience (dmft > 0), OR 1.41 (95% CI 1.04, 1.91), and 'very high' caries experience (dmft ≥ SiC(10) Index value), OR 1.62, (95% CI 1.05, 2.50). In addition, WC z-score was associated with 'very high' caries experience (dmft ≥ SiC(10) Index value), OR 1.72, 95% CI 1.06, 2.81., Conclusion: In a Hong Kong community sample of preschool children, dental caries experience was associated with general adiposity (as assessed by weight/height ratio) and central adiposity (as assessed by WC)., (© 2013 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: To compare the prevalence and severity of diffuse opacities among subjects whose maxillary incisors developed during periods with different concentrations of fluoride in the Hong Kong public water supply., Methods: Standardized intra-oral photographs of random samples of 12-year-old children were collected in 1983, 1991, 2001 and 2010 (n = 2658) in Hong Kong and were assessed for diffuse opacities by a calibrated and blinded examiner. The fluoride concentrations in the public water supply at the times when the enamel on their maxillary incisors developed were 1.0, 0.7, 0.5 and 0.5 ppm, respectively., Results: The mouth prevalence figures for diffuse opacities of these children (based on the maxillary incisors) were 89.3%, 48.5%, 32.4% and 42.1 in the years 1983, 1991, 2001 and 2010, respectively. Variation in the mouth and tooth prevalences of diffuse opacities was apparent among the four different year groups (P < 0.0001). Marked differences in severity of diffuse opacities, in terms of different subtypes and maximum extent of tooth affected, were also observed in association with the year of study (P < 0.001)., Conclusions: The prevalence and severity of diffuse opacities among maxillary incisor teeth of Hong Kong children decreased from 1983 and then increased in 2010; however, this change did not fully correspond to the concentration of fluoride in the drinking water during the time of enamel development., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Oral health literacy is a newly emerging field with considerable research potential., Aim: To validate an original instrument, the Hong Kong Oral Health Literacy Assessment Task (HKOHLAT-P) for paediatric dentistry., Design: A convenient sample of 200 child/parent dyads attending a dental hospital in Hong Kong was selected. Convergent validity was tested by examining the association of HKOHLAT-P scores with those derived from the Test of Functional Health Literacy in Dentistry (TOFHLiD) and Hong Kong Rapid Estimate of Adult Literacy in Dentistry (HKREALD-30). The predictive validity of HKOHLAT-P was determined by testing the association between HKOHLAT-P and children's caries experience (dmft) and the Chinese Early Childhood Oral Health Impact Scale (ECOHIS). The test-retest reliability and internal consistency of HKOHLAT-P were also evaluated., Results: HKOHLAT-P was positively correlated with TOFHLiD and HKREALD-30 (P < 0.01), and was negatively correlated with children's dmft and ECOHIS. In the regression model, HKOHLAT-P was associated with TOFHLiD, HKEALD-30, children's dmft, and ECOHIS (P < 0.05) after controlling for participants' demographic characteristics. The intra-class correlation coefficient of HKOHLAT-P was 0.63 and the Cronbach's α was 0.71., Conclusion: Initial testing of HKOHLAT-P suggested that it is a valid and reliable instrument., (© 2013 John Wiley & Sons Ltd, BSPD and IAPD.)

Aim: To develop and validate an instrument, the Hong Kong Rapid Estimate of Adult Literacy in Dentistry (HKREALD-30)., Methods: The Rapid Estimate of Adult Literacy in Dentistry (REALD-99) was translated into Chinese and modified in the pretest. A total of 200 parents of pediatric dental patients were interviewed using this modified scale and administered additional three sets of self-reported questionnaires. The 99 items of the scale were reduced to 30 (HKREALD-30). Concurrent validity was tested by comparing the HKREALD-30 scores with the participants' educational level, pattern of dental visits and reading habits. Convergent validity was tested by examining the association between HKREALD-30 and the Test of Functional Health Literacy in Dentistry (TOFHLiD). The test-retest reliability and internal consistency of HKREALD-30 were also evaluated., Results: A significant correlation (P < 0.01) was found between HKREALD-30 and participants' reading habits. HKREALD-30 was also highly correlated with TOFHLiD (Spearman's rho = 0.693, P < 0.01). In the regression model, HKREALD-30 was positively associated with TOFHLiD (P < 0.05) after controlling for participants' characteristics. The intra-class correlation coefficient of HKREALD-30 was 0.78 and the Cronbach's alpha was 0.84., Conclusion: Initial testing of HKREALD-30 suggested that it is a valid and reliable instrument for the basic screening of oral health literacy among Chinese people in Hong Kong., (© 2012 Blackwell Publishing Asia Pty Ltd.)

This paper reports the results of a four-part questionnaire survey to assess the effects of the sound of dental equipment on people's perceptions and dental anxiety levels. The convenience sample for the survey comprised 230 dental students and 230 gender and age matched non-dental university students. The subjects were requested to complete the questionnaires themselves. The results show that the sound of dental equipment has a great influence on dental anxiety. Dental students, who are more familiar with the operation of this equipment, are less prone to anxiety when they hear its sound than their non-dental counterparts.

Objectives: The early childhood oral health impact scale (ECOHIS), a proxy measure to assess the impact of oral health problems and on the quality of life of preschool children and their families, has been translated into Chinese and validated employing the classical test theory. However, some invariable problems are related to this theory. The objective of this study was to assess the metric properties of the ECOHIS by applying the item response theory., Methods: A random sample of 1296 Chinese preschool children in Hong Kong participated in the study and were subjected to an oral examination for their caries status. Their parents were asked to respond to the ECOHIS and an extra set of questions concerning their socio-demographic backgrounds. The collected data were analysed using Rasch model., Results: The obtained results support the interpretation of adequate total fit of persons and items, because the mean infit MNSQ (1.08) and outfit MNSQ (0.94) for persons, and the mean infit MNSQ (0.99) and outfit MNSQ (0.94) for items, are within the acceptable ranges (0.6-1.4). The difficulty spread of the items was between -0.81 and 1.96 logits, and the levels of respondents spanned from -5.56 to 6.72 logits on the person-item map. The spread of respondents was skewed and mistargeting, between the items and respondents, was confirmed. Combination of responses of 'often' and 'very often' was suggested because of their flat probability showing on the characteristic curves., Conclusions: Rasch model has been shown to be a feasible and practicable way of assessing the metric properties of the ECOHIS. The results allow the use of ECOHIS to be recommended for clinical research in oral health-related quality of life in young children with minor modifications., (© 2011 John Wiley & Sons A/S.)

Objective: To retrospectively study the anterior maxilla of southern Chinese children with complete cleft lip and palate (CLP) for the prevalence of different kinds of dental anomalies, position and rotation of the teeth, and the asymmetry of dental development., Patients: 195 southern Chinese children with CLP aged between 3 and 17 years., Methods and Materials: Dental records and study casts were studied as were the radiographs from which the dental development was determined., Results: The tooth prevalence of cleft side permanent lateral incisor was 19.2% in unilateral CLP (UCLP) children and 20.5% in bilateral CLP (BCLP) children. The cleft side central incisors were rotated in 78.1% and 95.9% of the teeth in UCLP and BCLP children, respectively. Of the permanent canines, 43.4% were positioned mesially on the cleft side in UCLP children, while for BCLP children 69.7% of the teeth were in a normal position. In addition, the mesially positioned canines were often associated with an absence of the permanent lateral incisor while the distally positioned canines were always associated with the presence of supernumeraries in the cleft region. The permanent teeth on the cleft side showed significantly delayed development compared with their antimeres on the noncleft side; however, the delayed permanent lateral incisors did complete their formation normally., Conclusion: This group of Chinese children with CLP demonstrated statistically significant higher prevalences of hypodontia, microdontia, and delayed dental development on the cleft side than the noncleft side.