Sleep characteristics and changes in sleep patterns among infants in Bhaktapur, Nepal

OBJECTIVE

Sleep undergoes major changes during the first year of life, but the characteristics of sleep among infants in low and middle-income countries are not well documented. This study describes sleep characteristics and changes in sleep patterns in infants at 6 and 12months of age from Bhaktapur, Nepal.

METHODS

This was a community-based longitudinal study comprising 735 infants. Sleep characteristics were obtained by interview with the mother using the Brief Infant Sleep Questionnaires. The stability of sleep duration and night awakenings were estimated by logistic regression analysis.

RESULTS

Cosleeping in the parent's bed at 6 and 12months of age was almost universal (>97%). At 6months of age, 254 (35%) and at 12months of age, 341 (46%) infants had a total 24-hour sleep duration <12 hours. Night awakenings >3 times per night were common (65%) both at 6 and 12months of age. Infants with frequent nightly awakenings at 6months had increased odds of frequent nightly awakenings at 12months (OR=2.2; 95% CI: 1.6, 2.9). Very few (<3%) mothers reported sleep problems in their infants at 6 and 12months of age.

CONCLUSIONS

Cosleeping was almost universal among Nepalese infants, and very few of the mothers reported sleep problems in their infants. Infants at 6 and 12months had similar patterns for both sleep duration and nocturnal awakenings. For infants, there were increased odds of having similar sleep duration and nocturnal awakening at 6 and 12months.

Social withdrawal behaviour in Nepalese infants and the relationship with future neurodevelopment; a longitudinal cohort study

BACKGROUND

Social withdrawal in infants may be a signal of distress and a precursor for non-optimal development.

OBJECTIVE

To examine the relationship between infant social withdrawal and neurodevelopment up to 4 years in Nepalese children.

METHODS

A total of 597 Nepalese infants 6-11 months old were assessed with the modified Alarm Distress Baby Scale (m-ADBB), and of these, 527 with the Bayley Scales of Infant and Toddler Development 3rd edition (Bayley-III) during early childhood, and the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-IV) and NEPSY-II subtests at 4 years. We examined whether social withdrawal defined by the m-ADBB was associated with neurodevelopmental scores in regression models.

RESULTS

Children socially withdrawn in infancy had lower Bayley-III language scores (-2.6 (95% CI -4.5, -0.7)) in early childhood. This association seems to be driven by the expressive communication subscale (-0.7 (95% CI -1.0, -0.3)), but not the receptive communication subscale (-0.2 (95% CI -0.6, 0.1)). There were no differences in the other Bayley-III scores or the WPPSI-IV and NEPSY-II scores at 4 years in children who were socially withdrawn or not.

CONCLUSION

Social withdrawal in infancy was reflected in early language development but not cognitive functioning at 4 years.

The Effect of Vitamin B12 Supplementation on Leukocyte Telomere Length in Mildly Stunted Nepalese Children: A Secondary Outcome of a Randomized Controlled Trial

BACKGROUND

Vitamin B12 is essential for deoxyribonucleic acid synthesis and genome stability. A deficiency of vitamin B12 is associated with telomere shortening, genomic aging, and increased risk of chronic disease and mortality.

OBJECTIVES

The study aims to determine the effect of vitamin B12 supplementation on leukocyte telomere length (LTL) in infants at risk of vitamin B12 deficiency.

METHODS

The study was a predefined secondary analysis of a randomized controlled trial enrolling 600 Nepalese infants aged 6 -11 mo, who were supplemented with 2 μg (2-3 recommended daily allowances) vitamin B12 or placebo daily for 1 y. At the end of the study, LTL was measured in 497 participants. Mean LTL was compared between the treatment arms in the full sample and predefined subgroups based on markers of vitamin B12 status, hemoglobin, sex, and growth indices.

RESULTS

LTL at end-study did not differ between the vitamin B12 and placebo arm with a standardized mean difference (95% confidence interval) of 0.04 (-0.14, 0.21). There was no effect of vitamin B12 on LTL in any of the subgroups.

CONCLUSIONS

Providing daily vitamin B12 for 1 y during infancy in a population at risk of vitamin B12 deficiency does not affect LTL. This trial was registered at clinicaltrials.gov as NCT02272842.

The association between household biomass fuel use and leukocyte telomere length among toddlers in Bhaktapur, Nepal

BACKGROUND

Biomass fuels are still in use for cooking by many households in resource poor countries such as Nepal and is a major source of household air pollution (HAP). Chronic exposure to HAP has been shown to be associated with shorter telomere length in adults.

OBJECTIVES

To measure the association between exposure related to household biomass fuel in infancy and leukocyte telomere length (LTL) at 18-23 months of age among 497 children from Bhaktapur, Nepal.

METHODS

In a prospective cohort study design, we have collected information on household cooking fuel use and several clinical, anthropometric, demographic, and socioeconomic variables. We estimated the association between biomass fuel use and the relative LTL in multiple linear regression models.

RESULTS

Most of the families (78%) reported liquified petroleum gas (LPG) as the primary cooking fuel, and 18.7% used biomass. The mean relative (SD) LTL was 1.03 (0.19). Children living in households using biomass fuel had on average 0.09 (95% CI: 0.05 to 0.13) units shorter LTL than children in households with no biomass fuel use. The observed association was unaltered after adjusting for relevant confounders. The association between LTL and biomass use was strongest among children from households with ≤2 rooms and without separate kitchen.

SIGNIFICANCE

Exposure to biomass fuel use in early life might have consequences for longevity, and risk of chronic illnesses reflected in shortening of the telomeres. Our findings support the ongoing effort to reduce exposure to biomass fuel in low-resource settings.

IMPACT STATEMENTS

Biomass for cooking is a leading source of household air pollution in low and middle-income countries, contributing to many chronic diseases and premature deaths. Chronic exposure to biomass fuel through oxidative stress and inflammation has been associated with a shortening of the telomeres, a "biological marker" of longevity. This prospective cohort study describes the association between household biomass fuel use and leukocyte telomere length among 497 toddlers. Leukocyte telomere length was significantly shorter among children living in households with biomass fuel than in children from homes where mainly LPG was used for cooking.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov: NCT02272842, registered October 21, 2014, Universal Trial Number: U1111-1161-5187 (September 8, 2014).

The effect of vitamin B12 supplementation during pregnancy on infant growth and development in Nepal: a community-based, double-blind, randomised, placebo-controlled trial

BACKGROUND

Vitamin B12 is required for healthy infant growth and development, but low and marginal vitamin B12 status is endemic in low-income and middle-income countries. We aimed to measure the effect of vitamin B12 supplementation from early pregnancy until 6 months post partum on infant growth and neurodevelopment.

METHODS

In this community-based, double-blind, placebo-controlled trial, we randomly assigned (1:1) 800 pregnant women (aged 20-40 years) who were up to 15 weeks pregnant-recruited from home visits and outpatient departments at three hospitals in Nepal-to daily supplementation with 50 μg oral vitamin B12 or placebo until 6 months postpartum. Independent scientists generated the list that linked allocation to participants' study identification number. Participants were masked to group assignment and all investigators were masked until data cleaning was completed. The primary outcomes were length-for-age Z score (LAZ) at age 12 months and the cognitive composite score of the Bayley Scales of Infant and Toddler Development (3rd edition) at age 6 months and 12 months. The primary and secondary outcomes, including adverse events, were assessed in the intention-to-treat population, for all participants with available outcome data. This trial is registered with ClinicalTrials.gov, NCT03071666.

FINDINGS

800 eligible pregnant women were enrolled in the trial between March 28, 2017, and Oct 15, 2020, with 400 women randomly assigned to each group. Follow-up was completed on May 18, 2022. At baseline, 569 (71%) of 800 women had plasma vitamin B12 indicating low or marginal status (<221 pmol/L). We found no effect of vitamin B12 on the primary outcomes. The mean LAZ at age 12 months were -0·57 (SD 1·03) in the B12 group and -0·55 (1.03) in the placebo group (366 infants in the vitamin B12 group vs 363 infants in the placebo group) with a mean difference of -0·02 (95% CI -0·16 to 0·13). The mean cognitive composite scores were 97·7 (SD 10·5) in the B12 group and 97·1 (10·2) in the placebo group, with a mean difference of 0·5 (95% CI -0·6 to 1·7) measured in 364 and 361 infants. Stillbirths or infant deaths occurred in three (1%) of 374 women in the vitamin B12 group and nine (2%) of 379 women in the placebo group.

INTERPRETATION

Although vitamin B12 deficiency was prevalent in our study population and vitamin B12 supplementation from early pregnancy substantially improved vitamin B12 status, supplementation did not improve infant growth or neurodevelopment. Our findings support the current WHO recommendations of no routine vitamin B12 supplementation during pregnancy.

FUNDING

Research Council of Norway.

The reliability and predictive ability of the Test of Infant Motor Performance (TIMP) in a community-based study in Bhaktapur, Nepal

AIM

In a Nepalese setting, to measure the reliability of the Test of Infant Motor Performance (TIMP) and its ability to predict development scores at 6 months.

METHODS

Nepalese infants (n = 705) were assessed by the TIMP when they were 8-12 weeks old and the Bayley Scales of Infant and Toddler Development, 3rd edition (Bayley-III) at 6 months. Inter-rater agreement was expressed by intraclass correlation coefficients (ICCs), the internal consistency by Cronbach's alphas and Pearson correlation coefficients. Predictive ability was estimated in linear regression models.

RESULTS

Inter-rater agreement was excellent (ICCs > 0.93). Alphas for the TIMP total scores were 0.76 for infants born to term and 0.72 in those born preterm. Correlation coefficients between TIMP total and Bayley-III subscale-scores ranged from 0.05 to 0.28 for term infants and from 0.15 to 0.43 for preterm infants. Using American norms, 56.3 % had TIMP scores within average and 43.7 % below average range. Bayley-III subscale scores were lower in children with TIMP scores below the average range, with the strongest estimates for Gross motor and Socio-emotional development.

INTERPRETATION

The reliability of the TIMP was acceptable, and the TIMP could be a feasible tool to monitor infant motor development in low-resource settings. Properties of the TIMP differed according to gestational age.

The effect of infant vitamin B12 supplementation on neurodevelopment: a follow-up of a randomised placebo-controlled trial in Nepal

The most critical period for brain development is before a child's second birthday. Standardised tests measuring neurodevelopment are more reliable when administered after this period. Severe vitamin B12 deficiency affects brain development and function. In a randomised, double-blind, placebo-controlled trial in 600 Nepalese infants (6-11 months at enrolment), we found no effect of 2 µg vitamin B12 daily for a year on neurodevelopment. The primary objective of the current study was to measure the effect of the intervention on the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-IV) full scale intelligence quotient (FSIQ). We measured the effect on the Bayley Scales of Infant and Toddler Development 3rd edition at age 30-35 months (n 555). At age 42-47 months (n 533), we used the WPPSI-IV and subtests from the Neuropsychological Assessment, 2nd edition (NEPSY-II). We also used the FSIQ to estimate subgroup specific effects. The mean (sd) WPPSI-IV FSIQ in the vitamin B12 group was 84·4 (8·4) and 85·0 (8·6) in the placebo group (mean difference -0·5 (95 % CI -1·97, 0·94), P = 0·48). There were no effect of the vitamin B12 on any of the other neurodevelopmental outcomes and no beneficial effect in any of the subgroups. In conclusion, providing 2 µg of vitamin B12 for a year in infants at risk of vitamin B12 deficiency does not improve preschool cognitive function.

Associations between biomass fuel use and child health: a community-based study in Bhaktapur, Nepal

Background

Biomass fuel use for cooking is widespread in low- and middle-income countries. Previous studies have mainly focused on adverse health outcomes in adults or specific diseases. In a cohort among young children living in Bhaktapur, Nepal, we aimed to describe the association between the use of biomass cooking fuels in families with child health using measures of linear growth, cognition and chronic illness.

Methods

Caregivers of 600 marginally stunted children aged 6-11 months were interviewed about their primary source of cooking fuel at enrolment into a randomized controlled trial. Children's body length (n = 572) was measured at age 18-23 months. At the same time, blood samples (n = 497) were taken, and we measured leukocyte telomere length (LTL) as a marker of chronic disease risk. We chose LTL expressed as z-scores as a measure of chronic disease. Cognitive abilities were measured by the Wechsler Preschool and Primary Scale of Intelligence, 4th edition (WPPSI-IV) and NEPSY-II subtests when the children were 4 years old (n = 531). Associations were estimated in multiple regression models.

Results

About 18% of all families used biomass as primary cooking fuel. Children from families using biomass fuel were on average slightly shorter (mean difference 0.14 Z-scores, 95% CI: 0.28, 0.00), had lower IQ scores (mean difference 2.2 (95% CI: 0.5, 3.9), and shorter LTL (mean difference: 0.09 (95% CI: 0.05 to 0.13) compared to those not using biomass fuel. The observed associations were unaltered after adjusting for relevant confounders.

Conclusions

In children from households in poor, urban neighborhoods in Nepal, biomass fuel use for cooking was associated with health indicators for child growth and cognition as well as longevity and chronic illnesses reflected in shortening of telomeres. As this was an observational study, residual confounding cannot be excluded. Our findings support the ongoing effort to reduce exposure to biomass fuel in low-resource settings.

Key messages

Biomass fuel use for cooking in Nepalese families and child cognitive abilities, results from a community-based study

BACKGROUND

Biomass fuel use for cooking is widespread in low to middle income countries. Studies on the association between biomass fuel use and cognitive abilities in children are limited.

OBJECTIVE

To examine the association between biomass fuel use for cooking and cognitive abilities in Nepalese children at 4 years of age.

METHODS

In a cohort design we have information on biomass fuel use in the households of 533 children in infancy and cognitive abilities when they were 4 years old from a community-based sample. Cognitive abilities were measured by the Wechsler Preschool and Primary Scale of Intelligence, 4th edition (WPPSI-IV) and the NEPSY-II. We examined the associations between biomass fuel use and scores on the WPPSI-IV Full-Scale IQ (FSIQ) (primary outcome), and WPPSI index and NEPSY-II subtest scores in multiple linear regression models. The associations were also examined in predefined subgroups.

RESULTS

Ninety-nine (18.6%) of the families used biomass fuel for cooking. Children in these families had lower mean FSIQ than children in families with no biomass use (83.3 (95%CI 81.7, 85.0) vs. 85.3 (95%CI 84.5, 86.0)), with a mean difference of -2.2 (95%CI -3.9, -0.5) adjusting for demographics and socio-economic status. The association between biomass fuel use and cognitive abilities was strongest in subgroups of children from households with more than three rooms, with separate kitchen and bedroom, and with higher wealth-score. These interactions were significant for number of rooms in the home (p = 0.04), if the household had separate bedroom and kitchen (p = 0.05), and for the wealth-score (p = 0.03).

CONCLUSION

Biomass fuel use for cooking in Nepalese families was associated with lower overall cognitive abilities at 4 years. Uncertainties include exposure misclassification and unmeasured confounding. The associations between biomass fuel use and neurodevelopment in children needs further investigation with more precise measurements of the exposure.

The stability of the Bayley scales in early childhood and its relationship with future intellectual abilities in a low to middle income country

BACKGROUND

The Bayley Scales of Infant and Toddler Development is widely used worldwide. The objective of the current study was to measure the stability of the Bayley Scales during early childhood and its relationship with intellectual abilities at four years in young Nepalese children.

METHODS

In a prospective cohort we used the Bayley 3rd edition to measure early child development in 529 Nepalese children at 6-11, 18-23 and 30-35 months. At four years, we used the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) to measure intellectual abilities. We expressed the stability of the Bayley scores by intraclass correlation coefficients (ICCs) and concordance correlation coefficients (CCCs). The relationship between the Bayley scores and the WPPSI full-scale IQ (FSIQ) at four years was examined in regression models.

RESULTS

The ICCs between the Bayley scores across timepoints were 0.01 (95 % CI -0.06, 0.04), 0.19 (95 % CI 0.15, 0.26) and 0.22 (95 % CI 0.17, 0.28) for the Cognitive, Language and Motor composite scores. The CCC for the composite scores ranged from 0.05 to 0.20 between 6 and 11 and 30-35 months and from 0.20 to 0.36 between 18 and 23 and 30-35 months. The Bayley scores at 6-11, 18-23 and 30-35 months explained 3 %, 20 % and 36 % of the variation of the FSIQ.

CONCLUSION

The stability of the Bayley scales is poor in early childhood, and its relationship with future intellectual abilities is poor in infancy but improves slightly with age in early childhood. Findings from this large community-based cohort of healthy at-risk children are relevant when measuring early child development worldwide.

The association between biomass fuel use for cooking and linear growth in young children in Bhaktapur, Nepal

BACKGROUND

There are still many people in the world who prepare their meals on open fires or stoves using solid fuels from biomass, especially in low-and middle-income countries. Although biomass cooking fuels have been associated with adverse health impacts and diseases, the association with child linear growth remains unclear.

OBJECTIVES

In a cohort design, we aimed to describe the association between the use of biomass cooking fuels and linear growth in children aged 18-23 months living in the urban and peri-urban community of Bhaktapur, situated in the Kathmandu valley in Nepal.

METHODS

Caretakers of 600 marginally stunted children aged 6-11 months were interviewed about their source of cooking fuel and other socio-demographic characteristics at enrolment into a randomized controlled trial. Children's body length was measured when children were 18-23 months old. In linear regression models, we estimated the association between the use of biomass fuel and length-for-age Z-scores (LAZ), adjusted for relevant confounders. We repeated these analyses in pre-defined sub-groups and different percentiles of LAZ using quantile regression models.

RESULTS

Among study participants, 101 (18%) used biomass as cooking fuel. The association between biomass fuel and LAZ was not statistically significant in the full sample (adjusted regression coefficient: -0.14, 95% CI: -0.28, 0.00). The association was stronger in some of the sub-groups and in the lower tail of the LAZ distribution (those who are stunted), but neither reached statistical significance.

DISCUSSION

Children from households in poor, urban neighborhoods in Nepal which used biomass fuel for cooking were on average slightly shorter than other children, although the association only approached statistical significance. As this was an observational study, residual confounding cannot be excluded. Further studies are needed to confirm these associations, in particular those seen in certain sub-groups.

Impact of the COVID-19 pandemic on daily life and worry among mothers in Bhaktapur, Nepal

The COVID-19 pandemic has affected many aspects of daily life worldwide, but the impact may be higher for impoverished populations. The main aim of this study is to describe the impact of the COVID-19 pandemic on different aspects of daily life in mothers in Nepal. We included 493 mothers of children aged 54-71 months participating in a randomized controlled trial on vitamin B12 supplementation. Mothers answered questions regarding the exposure and impact of the pandemic on their daily lives, and pandemic-related worries and sleep problems. We examined the extent to which worry, and sleep problems differed between mothers according to their exposure to COVID-19, socioeconomic status, and previous symptoms of depression. The mean age (SD) of the mothers was 32.3 (4.6) years and 54% had education below the secondary level. Of the mothers, 5.4% had either been exposed to someone who had tested positive or who had a family member with COVID-19. One-third of the participants responded that the pandemic had affected their economic situation, employment, and family life to a great deal. Both mothers and fathers with educational levels above 10 years or households with higher socioeconomic status had significantly higher average worry scores (maternal p = 0.020 and paternal p = 0.005). Mothers with a history of symptoms of depression had significantly more worry-related sleep problems during the pandemic (p = 0.020) than those without a history of depressive symptoms. Our study underlines the negative impact of the COVID-19 pandemic on diverse aspects of everyday life of mothers in Nepal.

The effect of vitamin B12-supplementation on actigraphy measured sleep pattern; a randomized control trial

BACKGROUND

Vitamin B12 deficiency is common worldwide and has been associated with poor sleep. The effect of vitamin B12 supplementation on sleep in infants is not known.

AIMS

To measure the effect of daily supplementation of vitamin B12 for one year on sleep in infants at risk of deficiency.

METHODS

This was an individually randomized double-blind placebo-controlled trial in 600 infants in low-to middle-income neighborhoods in Bhaktapur, Nepal of daily supplementation of vitamin B12 for one year. Infants were included if they were 6-11 month year-old and with a length-for-age less than one z-score. Sleep was a predefined, secondary outcome, and was measured by actigraphy including sleep duration at night and total sleep duration (day and night), sleep onset latency (SOL), and wake after sleep onset (WASO). The effect of vitamin B12 on sleep was additionally assessed in predefined subgroups defined by stunting, underweight, vitamin B12 status, low birthweight, anemia and exclusive breastfeeding for 3 months.

RESULTS

There was no effect of vitamin B12 supplementation on sleep duration at night, total sleep duration, or WASO. There was a small significant negative effect for SOL. None of the included subgroup analyses revealed effect modification on any of the sleep outcomes.

CONCLUSION

Overall, vitamin B12 supplementation did not have an effect on sleep in infants or for high-risk subgroups, with the exception of a small negative effect for SOL. The present study does not support vitamin B12 supplementation to improve sleep in infants.

TRIAL REGISTRATION

clinicaltrials.gov: NCT02272842.

UNIVERSAL TRIAL NUMBER

U1111-1161-5187.

Opening up on airways: the purported effect of nasorespiratory obstruction on dentofacial growth

Nasorespiratory obstruction has been purported to influence dentofacial growth adversely. This has sparked considerable debate for decades with a resurgence in interest in 'airway friendly orthodontics' among both general and specialist dental practitioners. This critical review aims to evaluate the current literature relating to two questions: does nasorespiratory obstruction alter dentofacial growth, and does early intervention targeted at alleviating nasorespiratory obstruction improve dentofacial growth? The strength of association between nasorespiratory obstruction, mouth breathing and a long face is weak. The common methodological flaws in research include unblinded and cross-sectional study designs, a lack of adequate controls, inadequate follow-up, subjective assessments and inadequate statistical power. Vertical dentofacial growth has a strong genetic influence, which implies a relatively minor contribution of environmental factors including airway obstruction. The current evidence does not support recommending procedures, such as adenotonsillectomy and maxillary expansion, with the singular aim of negating a hyperdivergent (vertical) dentofacial growth pattern. In light of low-quality evidence, both the World Health Organization guidelines and ethical principles dictate that greater emphasis is placed on avoiding harm and wastage of resources over alternative options. These findings call for quality improvement in undergraduate and postgraduate curricula and continuing professional development for health professionals.

Factors determining cognitive, motor and language scores in low birth weight infants from North India

BACKGROUND

Children born with low birth weight (LBW) tend to have lower neurodevelopmental scores compared to term normal birth weight children. It is important to determine factors that influence neurodevelopment in these low birth weight children especially in the first 2-3 years of life that represents a period of substantial brain development.

METHODS

This secondary data analysis was conducted using data from LBW infants enrolled soon after birth in an individually randomized controlled trial (RCT) and followed up till end of 1st year. Neurodevelopmental assessment was done at 12 months of corrected age by trained psychologists using Bayley Scales of Infant and Toddler Development 3rd edition (Bayley-III). Factors influencing cognitive, motor and language scores were determined using multivariable linear regression model.

RESULTS

Linear growth (i.e., length for age z score, LAZ) [cognitive: Standardized ẞ-coefficient = 2.19, 95% CI; 1.29, 3.10; motor: 2.41, 95% CI; 1.59, 3.23; language: 1.37, 95% CI; 0.70, 2.04], stimulation at home [cognitive: 0.21, 95% CI; 0.15, 0.27; motor: 0.12, 95% CI; 0.07, 0.17; language: 0.21, 95% CI; 0.16, 0.25] and number of diarrhoeal episodes [cognitive: -2.87, 95% CI; -4.34, -1.39; motor: -2.62, 95% CI; -3.93, -1.29; language: -2.25, 95% CI; -3.32, -1.17] influenced the composite scores in all three domains i.e., cognitive, language and motor. While increase in LAZ score and stimulation led to increase in composite scores; an increase in number of diarrhoeal episodes was associated with decrease in scores. Weight for height z scores (WHZ) were associated with motor and language but not with cognitive scores. Additionally, a negative association of birth order with cognitive and language scores was noted.

CONCLUSIONS

The findings indicate the possible importance of promoting nutrition and preventing diarrhoea as well as ensuring optimal stimulation and nurturance at home for enhancing child development in LBW infants.

Agreement Between Mothers and Fieldworkers While Assessing Child Development Using Ages and Stages Questionnaires, Third Edition in Nepal

Background: The Ages and Stages Questionnaires, Third Edition (ASQ-3) is becoming a widely used developmental assessment tool. The ASQ-3 can be completed by the caregivers (referred to as “mail out”), or by trained personnel under direct observation of the children (referred to as “home procedure”).

Aim: The study was carried out to compare results obtained by the ASQ mail out with those of the ASQ home procedure in a community setting of Bhaktapur, Nepal.

Methods: Trained fieldworkers (FWs) performed developmental assessment of 134 children aged 9 months in their homes using the ASQ home procedure. A few days before these assessments, mothers were asked to fill in the same ASQ-3 questionnaire. The concordance correlation coefficient (CCC) was calculated to measure their agreement.

Result: The agreement between the ASQ mail out and home procedure was fair for the total score (CCC = 0.54). For the sub-scales, the agreement was good for the gross motor (CCC = 0.65), for the remaining subscales agreement was poor (CCC < 0.4).

Conclusion: In resource limited setting like Nepal, the ASQ mail out represents an easy method to assess child development by caretakers at home; however, with the poor agreement between different methods of assessments, we cannot conclude that a single method is superior or most optimal and this question should be investigated further. When either of the method home procedure or mail out is opted, the results should be interpreted with cautions.

Prevalence of Underweight, Overweight, and Obesity in Adults in Bhaktapur, Nepal in 2015-2017

Introduction: There is an increase in the double burden of malnutrition globally, with a particular rise documented in Asia. In Nepal, undernutrition has been prevalent for decades. Today, however, the incidence of overweight and obesity (OWOB) in the country has increased substantially. There is a need to conduct local studies reporting on the concurrent burden of both underweight and OWOB across adult populations. This study addresses this need by describing the distribution of body mass index (BMI) in a defined population of adults living in the peri-urban community of Bhaktapur, Nepal.

Material and methods: For this cross-sectional analysis, we used data that were available from 600 women and 445 men whose children were enrolled in an individually randomized, double-blind, placebo-controlled trial assessing the effect of daily vitamin B12 supplementation. Upon enrolment of their 6–11-month old children, mothers and fathers were interviewed about their socio-demographic details. In addition, their weight and height were measured by trained field workers. Each parent's BMI was calculated as the ratio of body weight (in kg) and height squared (in m), expressed as kg/m², and categorized according to the WHO recommendation. We used linear and multinomial logistic regression models to assess associations between the BMI of the mothers and fathers, and their baseline characteristics.

Results: The mean BMI was 23.7 kg/m² for both the mothers and fathers with a standard deviation (SD) of 3.6 and 3.7, respectively. The proportion categorized as underweight, overweight, and obese was also similar in the two groups with around 5% being underweight, 30% being overweight and 5% being obese. Age was positively associated with BMI in both groups. Those categorized as daily wage earner had a lower mean BMI than those in other occupational groups.

Conclusion: Our results contribute to documenting the burden of both under- and overnutrition in a selected group of young adults living in a peri-urban community in Nepal. As Nepal is undergoing an improvement in its economic situation, as well as a nutrition transition, it is important to provide sufficient information to enable timely action, and evidence-based decision-making to prevent a further increase in Nepal's growing double burden of malnutrition.

The Feasibility of the Full and Modified Versions of the Alarm Distress Baby Scale (ADBB) and the Prevalence of Social Withdrawal in Infants in Nepal

Background

Sustained social withdrawal in infancy may have organic and nonorganic causes and could hinder normal development. The Alarm Distress Baby (ADBB) scale is a widely validated screening tool of social withdrawal in children 2–24 months. The aim of the current study was to evaluate the full and modified ADBB in Nepalese infants in a community-based study.

Methods

We enrolled 600 infants who were video recorded during a pediatric examination. The 36 infants first enrolled were scored by an expert rater, and the subsequent 64 infants were scored by two trained staff with the full ADBB scale. Of the 600 enrolled infants, 597 videos (including the 100 infants scored with the full ADBB) were scored with the modified ADBB (m-ADBB) scale by the trained staff, with 7% double scoring. We measured the interrater agreement and psychometric properties of both scales.

Results

In the 64 infants scored with the full ADBB by two raters, the concordance correlation coefficients (CCCs) indicated poor interrater agreement. For the m-ADBB, the CCCs were better indicating acceptable agreement between raters. The greatest lower bound (GLB) for reliability coefficient for the full ADBB scored by an expert rater indicated good internal consistency, whereas the GLB coefficient for the m-ADBB indicated poorer internal consistency. The Spearman correlation coefficient between the total scores of the two versions was 0.82 (P < 0.001). Among the infants scored with the full ADBB, 25% had a score above cutoff (≥5). Scored with the m-ADBB in the full sample, 11.4% of the infants had a score above the suggested cutoff (≥2). In both versions, children achieved high scores on vocalization.

Conclusion

Our findings suggest that the m-ADBB is an acceptable approach to achieve adequate interrater agreement in a large community-based study in Nepal. Results indicate high prevalence of social withdrawal in this population. There are, however, uncertainties on the internal consistency of the scales in this setting, and the validity of the scales needs to be investigated further. More effective training strategies for administration and additional cultural-specific instructions could be important measures to explore before implementing the scale further in this setting.

Determinants of Cognitive Development in the Early Life of Children in Bhaktapur, Nepal

Background

Children in low and middle income countries may have many risk factors for poor cognitive development, and are accordingly at a high risk of not reaching their developmental potential. Determinants for cognitive development in early life can be found among biological and socioeconomic factors, as well as in stimulation and learning opportunities.

Objective

The present study aimed to identify determinants of cognitive, language and motor development in 6–11 months old Nepalese infants.

Methods

Six hundred infants with a length-for-age z-score <-1 were assessed with the Bayley Scales of Infant and Toddler development, 3rd edition (Bayley-III). Information on socioeconomic factors, child and maternal demographics, clinical and biological factors, and the home environment were collected. In a manual stepwise variable selection procedure, we examined the association between selected biological, socioeconomic and stimulation and learning opportunity variables and the Bayley-III cognitive, language and motor development subscale scores in multiple linear regression models.

Results

The length-for-age z-scores was positively associated with the cognitive composite score [standardized beta (ß): 0.22, p < 0.001] and the motor composite score [(ß): 0.14, p = 0.001]. Children born with low birth weight (<2500 g) scored significantly lower on all subscale scores. Diarrheal history was associated with poor language composite scores, and females had higher language composite scores than boys [(ß): 0.11, p = 0.015]. Children who had been hospitalized during the first month of life had also lower cognitive and motor composite scores than those who had not been hospitalized. Parental reports of physical punishment and lack of spontaneous vocalization were associated with poor cognitive and language composite scores, respectively. The statistical models with the various subscale scores as dependent variables explained between 8 to 16 percent of the variability in the cognitive developmental outcomes.

Conclusion

Our findings reveal important determinants for developmental scores in infancy, and underline the role of biological risk factors faced by marginalized children in low and middle income countries such as in Nepal.

Parental height modifies the association between linear growth and neurodevelopment in infancy

AIM

To estimate the extent to which maternal and paternal height modify the association between length-for-age Z-score (LAZ) and neurodevelopmental outcomes assessed by the Bayley Scales of Infant and Toddler Development, 3rd Edition (Bayley-III).

METHODS

Baseline data from a clinical trial in 600 Nepalese infants aged six to 11 months with LAZ less than -1 were utilised. The primary exposure was the LAZ score, interaction variables were maternal and paternal height, and the outcomes were Bayley-III cognitive, language and motor scaled scores. Linear regression and generalised additive model (GAM) were used to identify potential interactions.

RESULTS

Linear regression analysis stratified by parental height categories showed that association between unit increase in LAZ and cognitive scaled score differed across maternal (normal height: ß 1.16, 95% CI; 0.75, 1.57 and short height: ß 0.67, 95% CI; 0.28, 1.05) and paternal (normal height: ß 1.32, 95% CI; 0.91, 1.72 and short height: ß 0.61, 95% CI; 0.03, 1.18) height categories. Maternal height also modified the association between LAZ and fine motor scaled score.

CONCLUSION

The association between LAZ and neurodevelopmental outcomes was attenuated when maternal and paternal height was taken into account. Parental stature should be considered when using LAZ as a proxy for neurodevelopment among infants.

The feasibility of the Ages and Stages Questionnaire for the assessment of child development in a community setting in Nepal

BACKGROUND

The Ages and Stages Questionnaire Third Edition (ASQ-3) may be a feasible and cost-effective tool to screen children's development in resource poor settings. We have assessed the feasibility of the ASQ-3 "home procedure" when conducted by fieldworkers in a community-based nutritional interventional trial on early child development in Nepal.

METHOD

Six hundred children aged 6-11 months at risk of stunting were assessed by trained fieldworkers in their homes by the ASQ-3. Three fieldworkers performed standardization exercises and were double scored with a gold standard during the study period. Intraclass correlations (ICCs) were calculated to measure the interrater agreement. The internal consistency was expressed by standardized Cronbach's alphas. The association between total ASQ score and gestation, low birth weight, and stunted children is presented to give an estimate of the construct validity of the tool.

RESULT

Mean scores of the 600 Nepalese children were consistently lower than in the American norm sample. The ICCs from the standardization exercises were initially good to excellent but declined throughout the study period. The standardized alphas for the total score in the different age groups indicate good internal consistency but varied in the subscales. Children who were preterm, children with low birth weight, and children who were stunted scored substantially lower on the total ASQ score than those who were not.

CONCLUSION

Although the ASQ-3 "home procedure" is low at cost and easily accessible in a Nepalese context, the tool requires rigorous and stringent training to achieve acceptable interrater agreement. Further adjustment is required to achieve satisfactory internal consistency.

The Association Between Heart Rate Variability and Neurocognitive and Socio-Emotional Development in Nepalese Infants

BACKGROUND

Many young children in developing countries do not reach their developmental potential. Traditional methods for assessing developmental outcome are time consuming, thus, physiological measures that can contribute to the prediction of developmental outcomes in high risk groups have been suggested. Vagally mediated heart rate variability (vmHRV) is considered a neurophysiological or peripheral proxy for prefrontal and executive functioning and might serve as a supplement for traditional measurements of developmental status and as a potential useful risk indicator.

AIM

In the present study, we wanted to describe the vmHRV in Nepalese infants and relate it to the Bayley Scales of infant and toddler development, 3. edition (Bayley-III) subscales.

METHODS

600 Nepalese infants were included in the study. At 6-11 and 17-24 months, we measured neurodevelopmental and socio-emotional outcomes by the Bayley-III. Inter-beat intervals were recorded at two measurement points when the children were 17-24 months.

RESULTS

There was a high intraclass correlation between HRV indices generated from the two measurement points. No significant associations between vmHRV and Bayley-III sub scales were found at any time.

CONCLUSION

This study is the first to describe vmHRV in healthy infants and the relationship between Bayley-III scores. Our results suggest that vmHRV is not associated with measures of general development in infancy.

Earthquake Exposure and Post-traumatic Stress Among Nepalese Mothers After the 2015 Earthquakes

Introduction: Nepal suffered from major earthquakes in April 2015 resulting in great damage to the society. The objective of the current study is to describe the earthquake exposure, the impact on family’s daily life and the symptoms of post-traumatic stress disorder (PTSD) and their association in Nepalese mothers 20 months following the earthquakes.

Methods: In a clinical trial in Bhaktapur, Nepal, 558 mothers responded to an inventory on earthquake exposure and the Impact of Event Scale – Revised (IES-R) 20 months after the earthquakes. In multiple linear regression models, we estimated the associations between the earthquake exposure and the impact on the families’ life and the IES-R score.

Results: Over 60% reported that the earthquakes had a great deal of negative impact on their family’s life. In 4.7%, close family members died, and in 10.5%, family members were injured. 24% had IES-R scores indicating PTSD symptoms within clinical concern or a possible diagnosis. Lower levels of education were associated with higher scores on the total IES-R. Mothers who report that the earthquakes had a great deal of negative impact had higher total IES-R scores [9.8, 95% CI (5.9, 13.6)] compared to mothers that reported no such negative impact. Mothers with family members who were killed had higher IES-R scores [3.6, 95% CI (1.6, 5.5)] than those with no family members who died. Mothers assisting in rescue efforts had lower IES-R scores [2.8, 95% CI (0.8, 4.8)] than those not assisting.

Conclusion: Our study demonstrates high levels of exposure to traumatic events, large negative impact on the everyday life of the families, and a high level of PTSD symptoms. There was a consistent and graded association between the exposure variables and PTSD symptoms. The large impact of the earthquakes on these Nepalese mothers underscore the importance of awareness of mental disorders following major natural catastrophes for marginalized families.

Orofacial neuralgia associated with a middle cerebral artery aneurysm

Chronic orofacial pain of neuropathic origin can present diagnostic and management dilemmas to dental practitioners and also affects the patient's quality of life. Intracranial aneurysms are a potential cause of stroke (e.g. sub-arachnoid haemorrhage) that is usually associated with, high rates of mortality and morbidity. A patient who had been previously managed for symptoms of temporomandibular joint disorder (TMD) presented with sharp, shooting pain of moderate intensity. It was precipitated by swallowing, and radiated to the right throat, posterior border of the mandible, ear and temporomandibular joint. Clinical and radiological investigations ruled out odontogenic pain, TMD and other more common types of facial pain. Magnetic resonance imaging revealed a 7 × 6 mm aneurysm in the right middle cerebral artery (MCA) which was subsequently surgically clipped. Interestingly, the facial pain resolved after this procedure. Compression of the insular region of the brain innervated by the trigeminal, glossopharyngeal and vagus nerves provides a plausible explanation for the pain reported. To our knowledge, this is the first case of facial neuralgia associated with an aneurysm in the MCA which emphasizes the importance of a multidisciplinary approach in the diagnosis and management of unusual cases of chronic orofacial pain.

Acceptability and Reliability of the Bayley Scales of Infant and Toddler Development-III Among Children in Bhaktapur, Nepal

Background: The Bayley Scales of Infant and Toddler Development, 3rd edition (Bayley-III) is the most widely used developmental assessment tool for infants and toddlers worldwide, but less is known about its psychometric properties and feasibility in low and middle-income countries. Aim: To assess the psychometric properties and feasibility of the Bayley-III when used in a large scale randomized controlled intervention trial in Nepal. Methods: The participating infants were part of a randomized, doubled blind, placebo-controlled trial to measure the efficacy of vitamin B12 supplementation on growth and neurodevelopment. A total of 600 children aged 6-11 months were enrolled and included for developmental assessment. The Bayley-III measures child development across five domains: cognition, receptive and expressive language, fine and gross motor skills. Some items were culturally adapted. To measure and ensure appropriate inter-observer agreement, standardization exercises were performed during the initial training, and double scoring of 7% of test sessions were conducted throughout the study by two examiners. Results: The inter-rater agreement was excellent for both the standardization exercises before the start of the study, and for the quality control throughout the study with intraclass correlation coefficient ranging from 0.95 to 0.99. The internal consistency measured by the Cronbach's alpha coefficient ranged between 0.57 and 0.87. The subtests raw scores as well as scaled scores were significantly correlated (p < 0.001). The means and SDs of the scaled scores compared with American norms were similar to the distribution in the American sample, with the exception of the receptive (Mean = 7.7, SD = 2.2) and expressive (Mean = 7.3, SD = 1.9) language subtests that were lower than the American norms. Conclusion: The inter-rater reliability between the scorers on the Bayley-III was excellent both during standardization and for the quality control. The distributions for the cognitive and motor subscales are comparable to the American norms, while caution is needed in the interpretation of the language scales. The results suggest that Bayley-III is a feasible tool for the assessment of neurodevelopmental status in nutritional studies in low resource settings such as Nepal. Cultural adaptations, training and standardization are prerequisites for a valid and reliable assessment using the Bayley-III.

Effects of non-carious cervical lesion size, occlusal loading and restoration on biomechanical behaviour of premolar teeth

BACKGROUND

Information on fracture biomechanics has implications in materials research and clinical practice. The aim of this study was to analyse the influence of non-carious cervical lesion (NCCL) size, restorative status and direction of occlusal loading on the biomechanical behaviour of mandibular premolars, using finite element analysis (FEA), strain gauge tests and fracture resistance tests.

METHODS

Ten buccal cusps were loaded on the outer and inner slopes to calculate the strain generated cervically. Data were collected for healthy teeth at baseline and progressively at three lesion depths (0.5 mm, 1.0 mm and 1.5 mm), followed by restoration with resin composite. The magnitude and distribution of von Mises stress and maximum principal stress were simulated at all stages using FEA, and fracture strength was also determined (n = 7 per group).

RESULTS

There were significant effects of the lesion size and loading directions on stress, strain and fracture resistance (p < 0.05). Fracture resistance values decreased with increase in lesion size, but returned to baseline with restorations.

CONCLUSIONS

Combined assessment of computer-based and experimental techniques provide an holistic approach to characterize the biomechanical behaviour of teeth with both unrestored and restored NCCLs.

The effects of vitamin B12 supplementation in pregnancy and postpartum on growth and neurodevelopment in early childhood: Study Protocol for a Randomized Placebo Controlled Trial

INTRODUCTION

Vitamin B₁₂ is crucial for normal cell division and differentiation, and necessary for the development and myelination of the central nervous system. Pregnant mothers in resource poor settings are at risk for poor vitamin B₁₂ status. Poor vitamin B₁₂ status in infancy is linked to poor growth and neurodevelopment. Brain development starts from conception, and pregnancy is a period of rapid growth and development for the brain.

METHODS AND ANALYSIS

The study is an individually randomised double-blind placebo controlled trial in 800 pregnant Nepalese women randomised in a 1:1 ratio. A daily dose of 50 µg of vitamin B₁₂ or placebo is given to women from early pregnancy, not later than week 15, until 6 months after birth. Weekly visits are conducted in order to record compliance, growth and morbidity. The primary outcomes are scores on the cognitive, language and motor subscales of the Bayley Scales of Infant and Toddler Development, Third Edition, measured at 6 and 12 months of age, and growth (length and weight) measured at 6 and 12 months of age.

ETHICS AND DISSEMINATION

National Health and Research Council, Nepal (NHRC 253/2016) and Regional Committee for Medical and Health Research Ethics of Western Norway (2016/1620/REK vest) have approved the study. Investigators who have contributed to the conceptualising, conducting, as well as being involved in the data analyses and manuscript writing will be eligible for authorship and be responsible to share outcomes with different stakeholders through publications and workshops. The results from this study may support new dietary guidelines for Nepalese and possibly South Asian pregnant women that can lead to improved pregnancy outcomes, neurodevelopment and cognitive functioning in children.

TRIAL REGISTRATION NUMBER

Universal Trial Number: U1111-1183-4093.

TRIAL REGISTRATION

clinicaltrials.gov: NCT03071666. Protocol date: version 1.2, 1 June 2017.

The effect of vitamin B12 supplementation in Nepalese infants on growth and development: study protocol for a randomized controlled trial

BACKGROUND

Vitamin B₁₂ deficiency is one of the most common micronutrient deficiencies and is associated with poor cognitive development and growth. Vitamin B₁₂ is crucial for normal cell division and differentiation, and it is necessary for the development and myelination of the central nervous system. The aim of the present study is to measure the effect of daily supplementation of vitamin B₁₂ on the neurodevelopment and growth of young children in Nepal.

METHODS/DESIGN

We are conducting an individually randomized, double-blind, placebo-controlled trial with 600 marginally stunted children 6-11 months old (length for age less than -1 z-score). Children are randomized to receive a lipid-based paste containing vitamin B₁₂ or placebo daily for 12 months. The main outcomes are changes in growth (z-scores) and in neurodevelopment measured by the Bayley Scales of Infant and Toddler Development, Third Edition, from baseline until the end of the study.

DISCUSSION

If vitamin B₁₂ supplementation benefits early child development and growth, this will have consequences for dietary recommendations for malnourished children worldwide.

TRIAL REGISTRATIONS

ClinicalTrials.gov Identifier: NCT02272842 . Registered on 21 October 2014. Universal Trial Number: U1111-1161-5187. Registered on 8 September 2014.

Alterations in mandibular morphology associated with glypican 1 and glypican 3 gene mutations

OBJECTIVES

Glypican 1 (GPC1) and glypican 3 (GPC3) are bone co-regulators that act downstream in many of the signalling pathways associated with craniosynostosis. Morphometric data from GPC-knockout mice were analysed to determine whether elimination of GPC1 and GPC3 genes would alter mandibular morphology.

SETTING AND SAMPLE POPULATION

The murine model included five male and five female mandibles in each of GPC1-knockout, GPC1/GPC3-knockout and wild-type (control) groups. Female GPC3-knockout mice had a very high rate of perinatal lethality, and therefore, only five males were included in this group.

METHODS

The mandibular morphology of GPC1-knockout (n=10), GPC3-knockout (n=5), GPC1/GPC3-knockout (n=10) and wild-type (n=10) mice was compared by analysing five landmark-based linear dimensions: anterior and posterior lengths, as well as ascending, descending and posterior heights. Measurements were recorded on three-dimensional micro-CT reconstructions.

RESULTS

GPC3-knockout mandibles were larger than wild-type mandibles for all dimensions (P<.05). Mandibular heights were more affected than lengths. A decreasing trend of mandibular dimensions across the mouse groups (GPC3-knockout>GPC1/GPC3-knockout>GPC1-knockout=wild-type) (P<.05) indicated that an increase in mandibular size was associated with increased GPC3 expression, but not GPC1.

CONCLUSIONS

Alterations in GPC3 expression are likely to mediate changes to mandibular size in craniosynostosis. These findings have potential future applications in the prevention and treatment of craniosynostosis and associated craniofacial dysmorphology.

The influence of feeding crimped kernel maize silage on broiler production, nutrient digestibility and meat quality

Two experiments were carried out in parallel with male Ross 308 broilers over 37 d. An experiment with a total of 736 broilers was performed to study the effect of dietary inclusion of crimped kernel maize silage (CKMS) on broiler production and meat quality. Another study with 32 broilers was carried out from 21 to 25 d to investigate the inclusion of CKMS on nutrient digestibility. In both trials, 4 dietary treatments were used: wheat-based feed (WBF), maize-based feed (MBF), maize-based feed supplemented with 15% CKMS (CKMS-15) and maize-based feed supplemented with 30% CKMS (CKMS-30). Compared with MBF, the dry matter (DM) intakes of broilers receiving CKMS-15 and CKMS-30, respectively, were numerically 7.5 and 6.2% higher and feed conversion ratio 6 and 12% poorer (significant for 30% CKMS), although there were no significant differences in AME content between the three diets. At 37 d, the body weight of birds receiving 15% CKMS was similar to birds fed with MBF. However, the inclusion of 30% CKMS decreased broiler growth. Dietary supplementation with CKMS significantly reduced the apparent digestibility of phosphorus. The fat digestibility was significantly lower for CKMS-30 than for the other three diets. Broiler mortality decreased significantly when CKMS was added to the diet. The consumption of drinking water was significantly lower in all maize-based diets as compared to WBF and was lowest in broilers fed with CKMS-30. An improved litter quality in terms of DM content and a lower frequency of foot pad lesions was observed with broilers supplemented with both dietary levels of CKMS. The addition of CKMS to maize-based diets increased juiciness, tenderness and crumbliness of the meat. In conclusion, the dietary supplementation of 15% CKMS had no negative effect on broiler growth and positively influenced bird welfare in terms of mortality and foot pad health. Therefore, the addition of 15% CKMS to maize-based diets is considered an advantageous feeding strategy in broiler production.

Surface-Sensitive Microwear Texture Analysis of Attrition and Erosion

Scale-sensitive fractal analysis of high-resolution 3-dimensional surface reconstructions of wear patterns has advanced our knowledge in evolutionary biology, and has opened up opportunities for translatory applications in clinical practice. To elucidate the microwear characteristics of attrition and erosion in worn natural teeth, we scanned 50 extracted human teeth using a confocal profiler at a high optical resolution (X-Y, 0.17 µm; Z < 3 nm). Our hypothesis was that microwear complexity would be greater in erosion and that anisotropy would be greater in attrition. The teeth were divided into 4 groups, including 2 wear types (attrition and erosion) and 2 locations (anterior and posterior teeth; n = 12 for each anterior group, n = 13 for each posterior group) for 2 tissue types (enamel and dentine). The raw 3-dimensional data cloud was subjected to a newly developed rigorous standardization technique to reduce interscanner variability as well as to filter anomalous scanning data. Linear mixed effects (regression) analyses conducted separately for the dependent variables, complexity and anisotropy, showed the following effects of the independent variables: significant interactions between wear type and tissue type ( P = 0.0157 and P = 0.0003, respectively) and significant effects of location ( P < 0.0001 and P = 0.0035, respectively). There were significant associations between complexity and anisotropy when the dependent variable was either complexity ( P = 0.0003) or anisotropy ( P = 0.0014). Our findings of greater complexity in erosion and greater anisotropy in attrition confirm our hypothesis. The greatest geometric means were noted in dentine erosion for complexity and dentine attrition for anisotropy. Dentine also exhibited microwear characteristics that were more consistent with wear types than enamel. Overall, our findings could complement macrowear assessment in dental clinical practice and research and could assist in the early detection and management of pathologic tooth wear.

Indications for Three Independent Domestication Events for the Tea Plant (Camellia sinensis (L.) O. Kuntze) and New Insights into the Origin of Tea Germplasm in China and India Revealed by Nuclear Microsatellites

Background

Tea is the world’s most popular non-alcoholic beverage. China and India are known to be the largest tea producing countries and recognized as the centers for the domestication of the tea plant (Camellia sinensis (L.) O. Kuntze). However, molecular studies on the origin, domestication and relationships of the main teas, China type, Assam type and Cambod type are lacking.

Methodology/Principal Findings

Twenty-three nuclear microsatellite markers were used to investigate the genetic diversity, relatedness, and domestication history of cultivated tea in both China and India. Based on a total of 392 samples, high levels of genetic diversity were observed for all tea types in both countries. The cultivars clustered into three distinct genetic groups (i.e. China tea, Chinese Assam tea and Indian Assam tea) based on STRUCTURE, PCoA and UPGMA analyses with significant pairwise genetic differentiation, corresponding well with their geographical distribution. A high proportion (30%) of the studied tea samples were shown to possess genetic admixtures of different tea types suggesting a hybrid origin for these samples, including the Cambod type.

Conclusions

We demonstrate that Chinese Assam tea is a distinct genetic lineage from Indian Assam tea, and that China tea sampled from India was likely introduced from China directly. Our results further indicate that China type tea, Chinese Assam type tea and Indian Assam type tea are likely the result of three independent domestication events from three separate regions across China and India. Our findings have important implications for the conservation of genetic stocks, as well as future breeding programs.

Nanoscratch testing for the assessment of enamel demineralization under conditions simulating wine erosion

BACKGROUND

Erosive tooth wear and dentinal hypersensitivity are common problems affecting professional wine tasters. By using nanoscratch testing, the aim of this in vitro study was to assess enamel softening under conditions simulating 10 one-minute episodes of wine erosion.

METHODS

Ten enamel specimens were bathed in artificial saliva for 2 hours before being eroded for 10 episodes, with each episode comprising one minute of wine erosion followed by one minute of remineralization in artificial saliva. Nanoscratches were placed with a spherical tip (20 μm radius) in a nanoindenter under a load of 100 mN at baseline (stage 1), after a one-erosion episode (stage 2) and after 10-erosion episodes (stage 3).

RESULTS

There were significant effects of erosion stages on both scratch depth (p<0.001) and surface roughness (p<0.001). Post hoc tests showed significant differences in both scratch depths and surface roughness between stages 1 and 3 (p<0.001), and between stages 2 and 3 (p<0.01).

CONCLUSIONS

Enamel softening occurs at an early stage of wine tasting, emphasizing the need to implement early preventive strategies in professional wine tasters. Further research elucidating the fundamental mechanisms involved in early stages of erosion has the potential to lead to development of more effective preventive strategies.

Odontogenic facial swelling of unknown origin

BACKGROUND

Current radiography techniques have limitations in detecting subtle odontogenic anomalies or defects that can lead to dentoalveolar and facial infections. This report examines the application of micro-CT imaging on two extracted teeth to enable detailed visualization of subtle odontogenic defects that had given rise to facial swelling.

METHODS

Two extracted non-carious mandibular left primary canine teeth (73) associated with odontogenic infections were selected from two patients, and an intact contralateral tooth (83) from one of the patients was used as a control. All three teeth were subjected to three-dimensional micro-CT imaging at a resolution of 20 μm.

RESULTS

Tooth 73 from the first case displayed dentine pores (channels) that established communication between the pulp chamber and the exposed dentine surface. In comparison, tooth 73 from the second case had a major vertical crack extending from the external enamel surface into the pulp chamber. The control tooth did not display any anomalies or major cracks.

CONCLUSIONS

The scope of micro-CT imaging can be extended from current in vitro applications to establish post-extraction diagnosis of subtle odontogenic defects, in a manner similar to deriving histopathological diagnoses in extracted teeth. Ongoing technological advancements hold the promise for more widespread translatory applications.

Magnification error of digital x rays on the computer screen

Templating x-rays of total hip and knee replacements pre-operatively are important to plan surgery. This is usually done using acetate templates of the prosthesis on hard copies of the x-ray. With the change in practice, to use digital x-rays on computer screens instead of hard copies, it is important to assess if acetate templates can be used for digital x-rays on the computer screen. This is a retrospective x-ray study of 19 hip replacements and 30 knee replacements to assess their magnification using the Patient Archiving Computerised System (PACS) software. This study was done to assess the accuracy of magnification, using acetate templates over a computer screen. In total hip replacement, the outer cup diameter was also measured using the digital measurement scale. The mean magnification was 0.59 for the acetabular cup and the femoral stem in total hip replacement and 0.48 for the femoral and tibial implant in total knee replacement. The mean difference in cup diameter comparing to the real size was an excess of 10.21 mm. The study showed over-magnified hip and knee x-rays thus suggesting that acetate templates and measurement scales on PACS was not reliable.

Functional dental occlusion: an anthropological perspective and implications for practice

Physiologic changes occur in dental occlusion throughout life, resulting from the interplay between functional demands and reciprocating adaptive responses. These changes have been reported in the anthropological literature and they reflect evolutionary changes in the human stomatognathic system during the Paleolithic, hunter-gatherer period. Specific occlusal changes occur in response to different environments, leading to extensive variation within and between extinct and extant human populations. For example, functional demands can cause occlusal and interproximal tooth wear, resulting in shortening of the dental arch, continual tooth eruption and changes in masticatory patterns. Since the advent of farming through to our current industrialized culture, functional demands on the human masticatory system, and its adaptive responses to these demands, have been reduced considerably. Indeed, it is only occasionally that functional demands are severe enough to lead to obvious pathology in the modern human dentition. In contrast to normal masticatory activity, 'modern-day conditions' such as dental caries, periodontal disease and erosion, can lead to significant changes in dental occlusion that are pathological and need to be treated. The masticatory system is a dynamic, functional unit that displays considerable change over a lifetime. In this concept paper, it is proposed that modern human populations living in industrialized environments display dental occlusions that can be considered to be 'neotenous'; that is, our dentitions tend to reflect an unworn stage of our ancestors that was only seen in infants, juveniles and young adults. Clinicians can draw on both phylogenetic and ontogenetic perspectives of 'functional dental occlusion' to differentiate continual physiological changes occurring over time that require ongoing review, from pathological responses that require intervention.

Determining the direction of tooth grinding: an in vitro study

The analysis of microwear patterns, including scratch types and widths, has enabled reconstruction of the dietary habits and lifestyles of prehistoric and modern humans. The aim of this in vitro study was to determine whether an assessment of microwear features of experimental scratches placed on enamel, perpendicularly to the direction of grinding, could predict the grinding direction. Experimental scratches were placed using a scalpel blade on standardised wear facets that had been prepared by wearing opposing enamel surfaces in an electromechanical tooth wear machine. These control 'baseline' facets (with unworn experimental scratches) were subjected to 50 wear cycles, so that differential microwear could be observed on the leading and trailing edges of the 'final' facets. In Group 1 (n=28), the 'footprint' microwear patterns corresponding to the known grinding direction of specimens in the tooth wear machine were identified. Then, they were used to predict the direction of tooth grinding blindly in the same sample after a 2-week intermission period. To avoid overfitting the predictive model, its sensitivity was also cross-validated in a new sample (Group 2, n=14). A crescent-shaped characteristic observed in most experimental scratches matched the grinding direction on all occasions. The best predictor of the direction of grinding was a combined assessment of the leading edge microwear pattern and the crescent characteristic (82.1% in Group 1 and 92.9% in Group 2). In conclusion, a simple scratch test can determine the direction of tooth grinding with high reliability, although further improvement in sensitivity is desirable.

A qualitative assessment of non-carious cervical lesions in extracted human teeth

BACKGROUND

Opinions vary about the causes of non-carious cervical lesions (NCCLs). They have been attributed to toothbrush abrasion, acid corrosion (commonly termed dental erosion), and abfraction. The purpose of this study was to examine the microwear details of NCCLs in a collection of extracted human teeth using scanning election microscopy (SEM).

METHODS

Negative replicas of large NCCLs in 24 extracted human teeth were obtained in polyvinylsiloxane impression material (Light Body Imprint II, 3M ESPE) and viewed under SEM.

RESULTS

All NCCLs extended from the cemento-enamel junction to the root surface and they displayed a variety of wedge-shaped appearances. There was evidence of both abrasion and corrosion in 18 of the 24 teeth (75.0 per cent), abrasion only in one tooth (4.2 per cent) and corrosion only in five teeth (20.8 per cent). Horizontal furrows with smooth edges and minor scratch marks, characteristic of abrasion and corrosion, were noted in 13 teeth (54.2 per cent).

CONCLUSIONS

Based on microscopic assessment of a sample of extracted teeth, it appears that abrasion and corrosion are common associated aetiological factors in the formation of NCCLs.

A radiographic assessment of the prevalence of pulp stones in Australians

BACKGROUND

Pulp stones are discrete calcified bodies found in the dental pulp. The aims of this study were to calculate the prevalence of pulp stones in young Australian adults using radiographs, and to report any associations between occurrence of pulp stones and sex, tooth type, dental arch, side and dental status.

METHODS

From 217 undergraduate dental students, comprising 123 males and 94 females aged between 17-35 years, 3296 teeth were examined under 2x magnification on bitewing radiographs. Pulp stones were scored as present or absent, and associations with sex, tooth type, dental arch, side and dental status noted.

RESULTS

Pulp stones were found in 100 (46.1 per cent) of the subjects and 333 (10.1 per cent) of the teeth examined. Occurrences were rare in premolars (0.4 per cent) but significantly higher in molars (19.7 per cent). Pulp stones were significantly more common in first molars than in second molars, and in maxillary first molars than in mandibular first molars. Carious and/or restored maxillary right first molars and maxillary left second molars displayed higher prevalences of pulp stones than unrestored and intact molars.

CONCLUSION

Pulp stones may provide useful forensic information when examining dental records to identify deceased persons.