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Objectives Subjects and Methods Results Conclusion To investigate the effect of adiposity status, salivary physicochemical parameters, and inflammatory biomarkers on the salivary abundance of the two main cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus among Hong Kong adolescents.This study included 180 adolescents aged 12–15 years from Hong Kong local secondary schools. Anthropometric measurements and oral health examinations were performed. Saliva samples were collected to measure salivary physicochemical parameters, protein biomarker levels, and salivary abundance of Streptococcus mutans, Streptococcus sobrinus, and total bacteria.Adolescents with general overweight/obesity or central obesity had significantly higher salivary Streptococcus mutans abundance and total bacterial load, lower stimulated salivary flow rate, and lower secretory phospholipase A2 group IIA levels than the lean controls. Adolescents with general overweight/obesity (OR = 3.33; 95% CI: 1.28–8.65) and those with central obesity (OR = 2.47; 95% CI: 1.02–6.00) had a significantly higher chance of having high salivary abundance of Streptococcus mutans than the lean controls after adjusting for confounders, with a similar detection rate of salivary Streptococcus sobrinus.General overweight or obesity and central obesity were associated with a high salivary abundance of Streptococcus mutans but had no significant effect on salivary Streptococcus sobrinus. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Aim: Up‐to‐date epidemiological studies on the global burden of severe periodontitis is scarce. This study aimed to present the latest estimates for prevalence of severe periodontitis from 1990 to 2019, by region, age, and level of socio‐demographic development. Materials and Methods: Estimates from the Global Burden of Disease study 2019 were used to investigate burden and trends of prevalence of severe periodontitis and its association with socio‐demographic development at global, regional, and national level. Decomposition analysis was performed to explore the contribution of demographic and epidemiological factors to the evolving burden of severe periodontitis. Results: In 2019, there were 1.1 billion (95% uncertainty interval: 0.8–1.4 billion) prevalent cases of severe periodontitis globally. From 1990 to 2019, age‐standardized prevalence rate of severe periodontitis increased by 8.44% (6.62%–10.59%) worldwide. Prevalence of severe periodontitis is higher among less developed countries/regions. Global population growth accounted for 67.9% of the increase in the number of prevalent cases of severe periodontitis from 1990 to 2019. Conclusions: The global burden of severe periodontitis has been substantial and increasing over the past three decades. Upstream policy changes are urgently needed to address the global public health challenge of severe periodontitis. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to investigate the efficacy of the social story‐based intervention in promoting the oral health status among preschool children with special healthcare needs. Methods: The 24‐month randomized controlled trial recruited 306 children from centres that provided educational training for 2‐ to 6‐year‐old children who had special healthcare needs. The participants received standardized toothbrushing training and oral health education materials. The education materials for children in the test group were validated social stories, while materials for children in the control group were standard leaflets. Those materials were introduced in each training session and used at home by parents. Children's oral health status and oral health‐related behaviours were assessed before and after interventions. Data were analysed via generalized estimating equations, negative binomial regression and binary logistic regression. Results: There was no significant difference in caries experience among children in both groups after 24 months. However, children in the test group showed better oral hygiene status and better toothbrushing performance, and they were more likely to visit a dentist (OR = 2.00, 95% CI:1.15,3.49) than their peers in the control group. Caries progression was more likely to be observed among children who had low social skills or whose parents were not working full‐time. Children from high‐income families showed better oral hygiene status than their peers (Estimate = −0.11, 95%CI: −0.20,−0.01). Conclusion: Social stories could be used to improve oral health‐related behaviours among young children with SHCN. The efficacy of the intervention might be associated with children's adaptive skills and family socio‐demographic status. [ABSTRACT FROM AUTHOR]

Toothbrushing is a routine practice for oral hygiene maintenance. It is also a challenging task for young children with special care needs. In this study, social stories were employed to teach toothbrushing skills for preschool children with special needs. Those children were recruited from the Special Child Care Centers, including 87 children with autism and 94 children without autism. A validated toothbrushing social story was used to demonstrate the toothbrushing procedure for all the recruited children. Parents were encouraged to show the stories to their children before or during their daily toothbrushing. Children's toothbrushing performance, oral hygiene status, and gingival health status were assessed at baseline and 6 months. Toothbrushing performance, oral hygiene, and gingival status of the recruited children were significantly improved after using social stories. Moreover, children with autism showed better oral hygiene status (P = 0.01) and better gingival status (P < 0.001) than their peers without autism. However, there were no significant differences in the toothbrushing performance among children with and without autism. The regression models indicated that the improvement of children's toothbrushing performance and oral health status were associated with children's intellectual functioning and parents' attitudes toward the usefulness of social story intervention. The principal findings suggested that social story intervention could be used to improve toothbrushing skills among children with or without autism, while it was more efficient in improving the oral hygiene status among children with autism. Autism Res 2020, 13: 666–674. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. Lay Summary Toothbrushing is considered as a basic self‐care practice that should be advocated in early childhood. We used social stories to train toothbrushing skills among preschoolers with special care needs. The toothbrushing skills of the recruited children were significantly improved after 6‐months intervention, and children with autism showed better oral hygiene status than their peers without autism. These findings suggested that social story‐based health promotion could be implemented among children with special needs. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: A visual‐verbal integration model (VVIM) was used to train parents and their children with intellectual and developmental disabilities (IDD) to dispense a pea‐sized amount of fluoridated toothpaste, aiming to balance the occurrence of dental caries and fluorosis. Method: Participants were 370 pairs of IDD preschool children and their parents. A two‐phase pre‐post‐intervention study was performed. The weight of toothpaste was calculated by a portable electronic compact balance. Results: A quarter of parents and <20% children dispensed the appropriate amount at baseline. Almost 85% parents and 50% children achieved the pea‐sized amount after intervention. Half of the children continued to use the recommended toothpaste amount after 6 months. Children with higher intellectual functioning and conceptual skills were more likely to dispense the pea‐sized amount of toothpaste. Conclusions: Visual‐verbal integration model training had a desired impact on parents' toothpaste‐dispensing performance. Children with higher adaptive skills may benefit from VVIM training. [ABSTRACT FROM AUTHOR]

Objective: To investigate the oral health status and associated factors among preschool children with special healthcare needs. Subjects and methods: This was designed as a cross‐sectional study. Dental examination was provided to 383 children at Special Child Care Centres. Covariates of interest included children's age, developmental profile, oral health‐related behaviours and family social‐economic status. The association between children's dental caries experiences, dental plaque deposition and gingival health status were analysed by negative binomial regression, multiple factor ANOVA and binary logistic regression when appropriate. Results: The proportion of children with caries, gingival inflammation and plaque were 30.3%, 89.6% and 95.0%, respectively. Final regression models indicated that (a) tooth decay was associated with dental visit experiences, night bottle‐feeding habit, fluoridated toothpaste and monthly income; (b) plaque deposition was associated with intellectual functioning, practical skills, night bottle‐feeding habit, use of toothpaste, initiation of toothbrushing habit, toothbrushing duration and additional cleaning habit; (c) gingival status was associated with children's intellectual functioning and toothbrushing frequency. Conclusions: Poor oral hygiene status existed among preschool children with special healthcare needs. Children's oral health status was associated with their developmental profile, oral health‐related behaviours and social‐economic status. [ABSTRACT FROM AUTHOR]

Background: People with intellectual disabilities (ID) typically have poorer oral health. Oral diseases have a microbiological origin, and thus, dental plaque control (DPC) is key to safeguard their oral health. Methods: A structured search strategy was applied to screen oral health promotion initiatives for DPC among children and adolescents with ID following PRISMA statements. Qualitative and quantitative analyses were performed. Results: From 1,455 citations, 22 studies informed this review. Seven studies related to mechanical interventions and 13 to chemical interventions. Qualitative analyses found conventional toothbrushes were less effective than modified toothbrushes but quantitative analyses were conflicting. Of the nine studies that compared chlorhexidine to placebos, seven reported chlorhexidine was more effective than placebos. Meta‐analysis favoured chlorhexidine to placebos (p < 0.0001, 95% CI 0.34–0.63). Conclusions: Both mechanical and chemical interventions are effective for DPC. It is unclear whether they are alternative means for DPC or whether they are best employed together. [ABSTRACT FROM AUTHOR]

Aim: To compare the oral health status of children and adolescents affected by intellectual disabilities with their unaffected counterparts.Method: Citations published in English were searched from electronic databases (PubMed, Embase, Web of Science, and Scopus) from their start dates to March 2017. The whole process was conducted following PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. The PICO (population, intervention/interest, comparator, outcome) principle was used to formulate the topic. Studies were synthesized through qualitative summary or, whenever possible, meta-analysis.Results: The initial search yielded 2393 records. Thirty-nine studies from 22 countries were identified for qualitative analysis; 26 studies were eligible for meta-analysis. Participants with intellectual disabilities had higher levels of dental plaque, worse gingival status, fewer decayed and filled permanent teeth, and similar caries experience between males and females. These findings were supported by both qualitative and quantitative analysis. Various patterns of caries experiences were indicated by qualitative analysis, but it was not substantiated by meta-analysis.Interpretation: There is increasing worldwide interest in oral health status of children with intellectual disabilities. Differences in dental plaque deposition, gingival inflammation, and the number of decayed and filled permanent teeth were investigated between children and adolescents with and without intellectual disabilities. Evidence remains elusive about the pattern of caries experience among those children. [ABSTRACT FROM AUTHOR]

Objectives Studies investigating influencing factors of permanent tooth eruption/emergence have primarily focused on anthropometric measurements while less attention has been paid to the effect of perinatal factors. We aimed to explore early factors associated with eruption status of permanent teeth among 12-year-olds through a population-representative prospective cohort. Methods A community sample of Hong Kong children born in 1997 was obtained by random sampling from local secondary schools. Participants' background information including birth characteristics, prenatal and early childhood exposures, family socioeconomic status and medical records was prospectively collected. Clinical examination of tooth emergence was conducted in 2010. Children were divided into complete emergence (of 28 permanent teeth) and partial emergence groups based on clinical examinations. Bivariate analyses were used to assess the association of tooth emergence status with each putative predictor. Unadjusted and adjusted logistic regression models were applied to select the best predictors for tooth emergence status at age 12. Results Complete background information and clinical data were available from 514 children (76.9% of the invited participants). Bivariate analyses showed that the average birthweight in the partial emergence group was significantly lower than the complete emergence group (mean difference 0.2 kg, P = 0.006). The finding was confirmed by logistic regression analyses. In the adjusted regression model, it was found that for every 1 kilogram increase in birthweight, the odds of having partial emergence would be lowered by 0.49 (odds ratio 0.49, P = 0.006). Conclusions Birthweight is associated with status of permanent tooth emergence at 12 years of age, as observed from a population-representative sample of Hong Kong children. [ABSTRACT FROM AUTHOR]

Objectives Epidemiological studies on developmental defects of enamel ( DDE) have focused on its potential contributory factors and prevalence while there is limited evidence on the longitudinal changes in the epidemiological profile of DDE. Thus, the objective of this longitudinal study was to investigate whether any type of DDE changes with time. Methods A total of 668 participants were initially recruited in 2010, and 432 participants were successfully followed up and examined for DDE both at the age of 12 in 2010 and 15 in 2013. The central incisor, lateral incisor and first molar in each quadrant were chosen as index teeth and were examined 'wet' by two trained and calibrated examiners using the modified FDI ( DDE) Index. Results The mouth prevalence and tooth prevalence of 'any defect' showed a significant decrease from 2010 to 2013 ( P < 0.001). This was predominantly due to the decrease in diffuse opacities ( P < 0.001). Significant difference in the distribution of the extent of DDE was also found for diffuse opacities at both the participant and tooth levels irrespective of the types of tooth ( P < 0.0001). Median extent score for diffuse opacities in 2013 was lower than those in 2010 at both participant and tooth level irrespective of the types of tooth ( P < 0.001). Conclusions Diffuse opacities, in terms of prevalence and severity, did fade out over time. The observed overall change in DDE was due to the dominating effect of diffuse opacities over demarcated opacities and hypoplasia. [ABSTRACT FROM AUTHOR]

Objectives This paper describes the development of a new literacy assessment instrument, the Hong Kong Oral Health Literacy Assessment Task for Paediatric Dentistry ( HKOHLAT- P). Its relationship to literacy theory is analyzed to establish content and face validity. Implications for construct validity are examined by analyzing cognitive demand to determine how 'comprehension' is measured. Methods Key influences from literacy assessment were identified to analyze item development. Cognitive demand was analyzed using an established taxonomy. Results The HKOHLAT- P focuses on the functional domain of health literacy assessment. Items had strong content and face validity reflecting established principles from modern literacy theory. Inclusion of new text types signified relevant developments in the area of new literacies. Analysis of cognitive demand indicated that this instrument assesses the 'comprehension' domain, specifically the areas of factual and procedural knowledge, with some assessment of conceptual knowledge. Metacognitive knowledge was not assessed. Conclusions Comprehension tasks assessing patient health literacy predominantly examine functional health literacy at the lower levels of comprehension. Item development is influenced by the fields of situated and authentic literacy. Inclusion of content regarding multiliteracies is suggested for further research. Development of functional health literacy assessment instruments requires careful consideration of the clinical context in determining construct validity. [ABSTRACT FROM AUTHOR]

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 ≥ Si C10 Index value), OR 1.62, (95% CI 1.05, 2.50). In addition, WC z-score was associated with 'very high' caries experience (dmft ≥ Si C10 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). [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 ( TOFHLi D) 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 TOFHLi D 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 TOFHLi D, 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. [ABSTRACT FROM AUTHOR]

ABSTRACT Objectives This investigation aimed to evaluate the secular trend exhibited by developing permanent teeth in 5 to 6 years old southern Chinese children. Methods Four hundred radiographs of children born in the years 1981 ( n=200) and 2001 ( n=200) were randomly selected, and then age and gender matched. Maxillary and mandibular teeth on the left side were scored. The number of tooth developmental stages (n-tds) for each stage of development and total n-tds in crown and root development was calculated. Logistic regression, X2 test for occurrence of trend and Fisher's exact test were used to evaluate the variations in n-tds between crown and root maturation and also maturation among different teeth. Dental maturation between boys and girls was also compared. Results In the maxillary dentition, children born in 2001 showed advanced dental maturation (odds ratio, 1.29; P=0.001), and girls exhibited earlier maturation than boys (odds ratio, 1.43; P=0.001). In the mandibular dentition, no significant difference between the years was observed (odds ratio, 0.97; P=0.761), however, girls showed accelerated development than boys (odds ratio, 1.26; P=0.002). Variations in maturation were also observed between individual tooth in the same arch and between the arches. Conclusions Children born in 2001 demonstrated accelerated dental development only in the maxillary dentition. Girls born in 1981 and 2001 exhibited advanced maturation than boys. Variations in development among different teeth in the year groups indicate the need for inclusion of all developing teeth to establish a secular change. Am. J. Hum. Biol. 25:329-334, 2013. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Wong HM, McGrath CPJ, King NM. Rasch validation of the early childhood oral health impact scale. Community Dent Oral Epidemiol 2011; 39: 449-457. © 2011 John Wiley & Sons A/S Abstract - 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. [ABSTRACT FROM AUTHOR]

Current studies on facial growth and development have been largely based on European populations. Less studied are African populations, who because of their distinct genetic makeup and environmental conditions, provide deeper insights into patterns of facial development. Patterns of facial shape development in African populations remain largely uncharacterised. Our study aimed to establish facial growth and development trajectories based on a cohort of 2874 Bantu Africans from Tanzania aged 6–18 years, with particular focus on identifying morphogenetic processes that lead to observed developmental shape changes. Procrustes ANCOVA suggested sexually dimorphic patterns of facial shape development (p = 0.0036). The forehead was relatively contracted during development in both sexes. The glabella region was more anteriorly displaced in females due to expansion in the region laterosuperior to the eyes. Nasal protrusion increased with development, which was found to arise from local expansion in the nasal alae and columella. Local expansion in the upper and lower labial regions resulted in forward displaced lips in both sexes, with the effect more pronounced in males. The mentum was displaced more anteriorly in females due to comparatively more expanded mental regions with development. The lateral facial region corresponding to the underlying body of the mandible were developmentally expanded but were posteriorly positioned due to protrusive growth of surrounding structures. Generalised additive modelling of Procrustes variance suggested that facial variation decreased non‐linearly with age (p < 0.05). Relative principal component analysis suggested that variations in facial outline shape were developmentally constrained, whereas nasolabial and mental regions, where developmental changes were significant, became morphologically diversified with development. In contrast to simple descriptive illustration of facial shape development, we gained transformative insights into patterns of facial shape development by analysing morphogenetic processes and variational properties. Our analytical framework is broadly applicable to morphometric studies on ontogenetic shape changes. [ABSTRACT FROM AUTHOR]