Southern Africans Research Articles

Public awareness and perception towards COVID-19 in Sub-Saharan African countries during the lockdown.

Background: The coronavirus disease (COVID-19) outbreak has caused a universal health crisis resulting in significant morbidities and mortalities particularly among high-risk groups. This study sought to determine regional factors associated with knowledge and attitude towards COVID-19 mitigation practices and risk perception of contracting the disease in Sub-Saharan African (SSA) countries. Methods: A cross-sectional anonymous online study was conducted among 1970 participants between April and May 2020, during the lockdown in many SSA countries. Recruitment of participants was via WhatsApp, Facebook and emails using authors’ networks. The outcome variables were KAP (knowledge, attitudes and practice) of COVID-19 and analysis of variance (ANOVA) with post hoc test was run to assess the level of KAP by four regions in SSA. Simple and multiple linear regression (MLR) analyses were performed to examine factors associated with the outcome measures in the four SSA regions. Results: Mean knowledge (P=0.707) and risk perception (P=0.904) scores by four regions in SSA did not differ significantly. However, the mean attitude score was higher among West Africans compared with Southern (P=0.019) and Central Africans (P=0.003). MLR analysis revealed that among those living in West (adjusted coefficient β=-0.83 95% CI: -1.19, -0.48) and Southern Africa (β=-0.91 95% CI: -1.42, -0.40), having a primary or secondary education was associated with a decrease in knowledge scores while not being worried about COVID-19 decreased risk perception scores across the four SSA regions(West [β=-6.57, 95% CI: -7.53, -5.62], East [β=-6.24: 95% CI: -8.34,-4.15], Central [β=-6.51, 95% CI: -8.70, -4.31], and Southern Africa [β=-6.06: 95% CI: -7.51, -4.60]). Except among Southern Africans, participants who practiced self-isolation had positive attitude towards COVID-19. Conclusion: Future research on health education regarding COVID-19 or a future related pandemic in SSA should target people with lower education, those who do not self-isolate, those living in Southern and Western Africa and not worried about contracting COVID-19.

Intraindividual variation in the cross‐sectional geometry of the first metatarsal, femur, and tibia

Objectives The examination of cross-sectional properties (CSP) of long bones can inform about differential activity patterns and levels of mobility. Typically, these analyses have focused on the femur and tibia, but metatarsals might also be informative. This study examines femora, tibiae, and first metatarsals to evaluate the relationships between long bone CSP within the lower limb and how this might improve our interpretations of metatarsal variability. Materials and Methods The study includes protohistoric Andaman Islanders (n = 26) and Later Stone Age (LSA) Southern Africans (n = 25) from approximately 10,000–500 BP. Skeletal data were acquired from past studies of these groups. Correlations were used to evaluate the relationships between CSP of lower limb bones within individuals. Principal component analyses were used to evaluate how each lower limb bone contributed to variation in CSP among individuals. Results The correlations between the CSP in the femur and tibia were always strong, but the correlations with the first metatarsal are variable. Variation in femoral loading largely drove PCAs, with less influence by the first metatarsal, or loading in the opposite direction. Discussion The femur and tibia experience similar patterns of mechanical loading, specifically in compression and tension, but the first metatarsal does not reflect the same biomechanical patterns as the femur and tibia. Similarly, the first metatarsal often drove variation in the opposite direction as the femur, indicating differences in the mechanical loading pattern between the two bones.

A review of the relevance of bottle gourd in Eastern and Southern African traditional music, and social life

Background: The history of several communities and tribes in Africa is incomplete without emphasising on the crucial role of the Cucurbitaceae family, especially the calabash or dried gourds, in Africa. The plant is extensively used in several traditional ceremonies and spiritual exercises, and in the production of various traditional African musical instruments which proffer economic incentives to stakeholders.Aim: To discuss the relevance of the bottle gourd in Eastern and Southern African nations in relation to the production of traditional musical instruments; the uses and impacts of the traditional musical instruments; and their morphology.Methods: A literature search was conducted on electronic databases such as Google Scholar, Google books, Scopus, and Web of Science. The search was performed using several terms and free text words, combining them in an appropriate manner. The authors further set inclusion and exclusion criteria to screen for relevant articles. Each of the identified articles was independently reviewed to determine eligibility and to extract study information.Results: The African continent has a deeply rich and fascinating traditional and cultural heritage such as ancestral worship, cleansing ceremonies, spiritual ceremonies, intervillage ceremonies and competitions, and royal ceremonies like enthronement of kings, royal weddings, royal funerals, and appeasement of the gods. Traditional musical instruments made with gourds (as the resonator) are prominently played during these ceremonies and spiritual exercises. The ceremonies are often accompanied by chanting and singing whilst traditional musical instruments such as rattles made of gourds or chordophones, in which gourds are used as resonators, are played.Conclusion: Bottle gourd is an important raw material in the assemblage of several Southern and Eastern Africa traditional musical instruments and is highly revered in the socio-cultural ceremonies and spiritual exercises of several tribes and communities across these regions. Hence, bottle gourd plays a vital role as a bedrock of the culture, social and spiritual life of these people and therefore reflects in the history and daily life of the Southern and Eastern Africans.

Revealing the Mutational Spectrum in Southern Africans With Amyotrophic Lateral Sclerosis.

Background and ObjectivesTo perform the first screen of 44 amyotrophic lateral sclerosis (ALS) genes in a cohort of African genetic ancestry individuals with ALS using whole-genome sequencing (WGS) data.MethodsOne hundred three consecutive cases with probable/definite ALS (using the revised El Escorial criteria), and self-categorized as African genetic ancestry, underwent WGS using various Illumina platforms. As population controls, 238 samples from various African WGS data sets were included. Our analysis was restricted to 44 ALS genes, which were curated for rare sequence variants and classified according to the American College of Medical Genetics guidelines as likely benign, uncertain significance, likely pathogenic, or pathogenic variants.ResultsThirteen percent of 103 ALS cases harbored pathogenic variants; 5 different SOD1 variants (N87S, G94D, I114T, L145S, and L145F) in 5 individuals (5%, 1 familial case), pathogenic C9orf72 repeat expansions in 7 individuals (7%, 1 familial case) and a likely pathogenic ANXA11 (G38R) variant in 1 individual. Thirty individuals (29%) harbored ≥1 variant of uncertain significance; 10 of these variants had limited pathogenic evidence, although this was insufficient to permit confident classification as pathogenic.DiscussionOur findings show that known ALS genes can be expected to identify a genetic cause of disease in >11% of sporadic ALS cases of African genetic ancestry. Similar to European cohorts, the 2 most frequent genes harboring pathogenic variants in this population group are C9orf72 and SOD1.

Economic, Health and Physical Impacts of COVID-19 Pandemic in Sub-Saharan African Regions: A Cross Sectional Survey.

PurposeThe key preventive measures adopted to minimise the spread of the coronavirus disease (COVID-19) had significant health, economic and physical impacts mostly in developing countries. This study evaluated the health, economic and physical impacts of COVID-19 lockdown measures among sub-Saharan African (SSA) population and associated demographic variations.MethodsA total of 1970 respondents took part in this web-based cross-sectional survey during the mandatory lockdown period in most SSA. The dependent variables were health (COVID-19 infection, hospitalisation), socioeconomic (lost job, closed down business) and physical impacts (separated from family) of COVID-19. Univariate and bivariate logistic regression analyses were used to explore the factors associated with each of the dependent variables by the four sub-regions (Southern, Western, Central and East Africa).ResultsThe respondents were aged 34.1 ± 11.5 years (range: 18–75 years) and mostly men (1099, 55%). 25.9% (n = 511) reported an impact of COVID-19 pandemic with significant regional variations (p < 0.0005, higher proportion were East 36.2% and Southern Africans 30.3%) but no gender (p = 0.334) and age group variations (p > 0.05). Among Central African respondents, more men than women lost their businesses (45.7% versus 14.3%, p = 0.002) and contracted COVID-19 infections (40.0% versus 18.2%, p = 0.024) during the study period. Multivariable analysis revealed that respondents from East (adjusted odds ratio [AOR] 1.95, 95% confidence interval [CI]: 1.42–2.69), Southern (AOR 1.46, 95% CI: 1.09–1.96) and Central Africa (AOR 1.47, 95% CI: 1.06–2.03) reported significantly higher impact of COVID-19. Those who reported family separation during the lockdown were more likely to be older participants (39–48 years, AOR 2.48, 95% CI: 1.11–5.57).ConclusionOne in four SSA respondents, mostly East and Southern Africans, were adversely affected by the COVID-19 pandemic during the lockdown. Interventions in high-risk populations are needed to reduce the health, socioeconomic and gender disparities in the impacts of COVID-19.

Opinion and uptake of chloroquine for treatment of COVID-19 during the mandatory lockdown in the sub-Saharan African region.

BackgroundAs the search for effective treatment of coronavirus disease 2019 (COVID-19) infection continues, the public opinion around the potential use of chloroquine (CQ) in treating COVID-19 remains mixed.AimTo examine opinion and uptake of CQ for treating COVID-19 in the sub-Saharan African (SSA) region.SettingThis study was conducted through an online survey software titled SurveyMonkey.MethodsAnonymous online survey of 1829 SSA countries was conducted during the lockdown period using Facebook, WhatsApp and authors’ networks. Opinion and uptake of CQ for COVID-19 treatment were assessed using multivariate analyses.ResultsAbout 14% of respondents believed that CQ could treat COVID-19 and of which, 3.2% took CQ for COVID-19 treatment. Multivariate analyses revealed that respondents from Central (adjusted odds ratios [aOR]: 2.54, 95% confidence interval [CI] 1.43, 4.43) and West Africa (aOR: 1.79, 95% CI 1.15, 2.88) had higher odds of believing that CQ could treat COVID-19. Respondents from East Africa reported higher odds for uptake of CQ for COVID-19 than Central, Western and Southern Africans. Knowledge of the disease and compliance with the public health advice were associated with both belief and uptake of CQ for COVID-19 treatment.ConclusionCentral and West African respondents were more likely to believe in CQ as a treatment for COVID-19 whilst the uptake of the medication during the pandemic was higher amongst East Africans. Future intervention discouraging the unsupervised use of CQ should target respondents from Central, West and East African regions.

Repeats expansions in ATXN2, NOP56, NIPA1 and ATXN1 are not associated with ALS in Africans.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized primarily by progressive loss of motor neurons. Although ALS occurs worldwide and the frequency and spectrum of identifiable genetic causes of disease varies across populations, very few studies have included African subjects. In addition to a hexanucleotide repeat expansion (RE) in C9orf72, the most common genetic cause of ALS in Europeans, REs in ATXN2, NIPA1 and ATXN1 have shown variable associations with ALS in Europeans. Intermediate range expansions in some of these genes (e.g. ATXN2) have been reported as potential risk factors, or phenotypic modifiers, of ALS. Pathogenic expansions in NOP56 cause spinocerebellar ataxia-36, which can present with prominent motor neuron degeneration. Here we compare REs in these genes in a cohort of Africans with ALS and population controls using whole genome sequencing data. Targeting genotyping of short tandem repeats at known loci within ATXN2, NIPA1, ATXN1 and NOP56 was performed using ExpansionHunter software in 105 Southern African (SA) patients with ALS. African population controls were from an in-house SA population control database (n = 25), the SA Human Genome Program (n = 24), the Simons Genome Diversity Project (n = 39) and the Illumina Polaris Diversity Cohort (IPDC) dataset (n = 50). We found intermediate RE alleles in ATXN2 (27–33 repeats) and ATXN1 (33–35 repeats), and NIPA1 long alleles (≥8 repeats) were rare in Africans, and not associated with ALS (p > 0.17). NOP56 showed no expanded alleles in either ALS or controls. We also compared the differences in allele distributions between the African and n = 50 European controls (from the IPDC). There was a statistical significant difference in the distribution of the REs in the ATXN1 between African and European controls (Chi-test p < 0.001), and NIPA1 showed proportionately more longer alleles (RE > 8) in Europeans vs. Africans (Fisher’s p = 0.016). The distribution of RE alleles in ATXN2 and NOP56 were similar amongst African and European controls. In conclusion, repeat expansions in ATXN2, NIPA1 and ATXN1, which showed associations with ALS in Europeans, were not replicated in Southern Africans with ALS.

Small body size phenotypes among Middle and Later Stone Age Southern Africans

Modern humans originated between 300 and 200 ka in structured populations throughout Africa, characterized by regional interaction and diversity. Acknowledgment of this complex Pleistocene population structure raises new questions about the emergence of phenotypic diversity. Holocene Southern African Later Stone Age (LSA) skeletons and descendant Khoe-San peoples have small adult body sizes that may reflect long-term adaptation to the Cape environment. Pleistocene Southern African adult body sizes are not well characterized, but some postcranial elements are available. The most numerous Pleistocene postcranial skeletal remains come from Klasies River Mouth on the Southern Cape coast of South Africa. We compare the morphology of these skeletal elements with globally sampled Holocene groups encompassing diverse adult body sizes and shapes (n = 287) to investigate whether there is evidence for phenotypic patterning. The adult Klasies River Mouth bones include most of a lumbar vertebra, and portions of a left clavicle, left proximal radius, right proximal ulna, and left first metatarsal. Linear dimensions, shape characteristics, and cross-sectional geometric properties of the Klasies River Mouth elements were compared using univariate and multivariate methods. Between-group principal component analyses group Klasies River Mouth elements, except the proximal ulna, with LSA Southern Africans. The similarity is driven by size. Klasies River Mouth metatarsal cross-sectional geometric properties indicate similar torsional and compressive strength to those from LSA Southern Africans. Phenotypic expressions of small-bodied adult morphology in Marine Isotope Stages 5 and 1 suggest this phenotype may represent local convergent adaptation to life in the Cape.

HIV stigma beliefs in context: Country and regional variation in the effects of instrumental stigma beliefs on protective sexual behaviors in Latin America, the Caribbean, and Southern Africa.

Does the relationship between the expression of HIV stigma beliefs and the practice of protective sexual behaviors vary by social context? To answer this question, we apply multilevel techniques to Demographic and Health Survey data from seven low HIV prevalence Latin American and Caribbean countries and seven high HIV prevalence Southern African countries to examine contextual variation in this relationship. We examine whether the relationship between stigma beliefs and sexual behaviors differs across these two sets of countries and across regions within each set of countries. We first find that in high prevalence Southern African countries, one unit increases in HIV stigma beliefs are associated with 8% declines in the odds of practicing protective sexual behaviors. Conversely, in low prevalence Latin American and Caribbean countries, unit increases in HIV stigma beliefs are associated with 8% increases in the odds of those same sexual behaviors. Second, the relationship between stigma beliefs and protective sexual behaviors varies across regions within each set of countries, with a wider variance in regional stigma effects located in Southern Africa than in Latin America and the Caribbean. Third, in Southern Africa, the negative effect of stigma beliefs is even more negative in regions where conservative stigma beliefs are pronounced. Overall, our findings demonstrate the importance of taking country and regional context into account when examining the degree to which HIV beliefs affect personal sexual behaviors, which in turn, can contribute to the spread of HIV. Importantly, the implications of our results offer potential guidance to experts who wish to design policies and programs aimed at reducing the expression of negative HIV beliefs towards those infected with HIV.

Human origins in a southern African palaeo-wetland and first migrations.

Anatomically modern humans originated in Africa around 200thousand years ago (ka)1-4. Although some of the oldest skeletal remains suggest an eastern African origin2, southern Africa is home to contemporary populations that represent the earliest branch of human genetic phylogeny5,6. Here we generate, to our knowledge, the largest resource for the poorly represented and deepest-rooting maternal L0 mitochondrial DNA branch (198 new mitogenomes for a total of 1,217 mitogenomes) from contemporary southern Africans and show the geographical isolation of L0d1'2, L0k and L0g KhoeSan descendants south of the Zambezi river in Africa. By establishing mitogenomic timelines, frequencies and dispersals, we show that the L0 lineage emerged within the residual Makgadikgadi-Okavango palaeo-wetland of southern Africa7, approximately 200ka (95% confidence interval, 240-165ka). Genetic divergence points to a sustained 70,000-year-long existence of the L0 lineage before an out-of-homeland northeast-southwest dispersal between 130 and 110ka. Palaeo-climate proxy and model data suggest that increased humidity opened green corridors, first to the northeast then to the southwest. Subsequent drying of the homeland corresponds to a sustained effective population size (L0k), whereas wet-dry cycles and probable adaptation to marine foraging allowed the southwestern migrants to achieve population growth (L0d1'2), as supported by extensive south-coastal archaeological evidence8-10. Taken together, we propose a southern African origin of anatomically modern humans with sustained homeland occupation before the first migrations of people thatappear to havebeen driven by regional climatechanges.

Human leukocyte antigen (HLA) diversity and clinical applications in South Africa.

The major histocompatibility complex, known as the human leukocyte antigen (HLA) complex in humans, forms an integral component of adaptive T cell immunity by presenting self and non-self peptides to the T cell receptor, thereby allowing clonal expansion of responding peptide-specific CD4+ and CD8+ T cells. HLA likewise forms an integral part of the innate immune response through the binding of killer-cell immunoglobulin-like receptor (KIR) molecules, which regulate the response of natural killer (NK) cells. The HLA complex is found on the short arm of chromosome 6 and is the most polymorphic region in the human genome. Africans are genetically more diverse than other populations; however, information on HLA diversity among southern Africans, including South African populations, is limited. Paucity of African HLA data limits our understanding of disease associations, the ability to identify donor-recipient matches for transplantation and the development of disease-specific vaccines. This review discusses the importance of HLA in the clinical setting in South Africans and highlights how tools such as HLA imputation might augment standard HLA typing methods to increase our understanding of HLA diversity in our populations, which will better inform disease association studies, donor recruitment strategies into bone marrow registries and our understanding of human genetic diversity in South Africa.

Southern Africans address human remains management.

Southern Africans address human remains management.

The Gift of Volunteering

Foreign aid to southern Africa has triggered the growth of a nonprofit sector that increasingly provides welfare and social support for needy populations. However, largely absent from research on this sector are substantive analyses of the contribution of voluntarism and interpersonal exchange to broader welfare development and social cohesion. This paper employs theories of gift exchange to analyze volunteer practices and localized interpretations of volunteering within the welfare structure of post-colonial Pretoria, South Africa, and Lusaka, Zambia. The analysis of ethnographic data pertaining to within- and between-group volunteering reveals particular patterns of “gifting,” which enable many southern Africans to overcome social divides, to strengthen existing bonds, and to fill gaps in the provision of basic public services. We conclude that volunteering succeeds as a form of welfare distribution precisely because of how actors frame their efforts as a gift—ensuring enduring social-relational dynamics and continued social service delivery.

The timing of permanent tooth development in a Black Southern African population using the Demirjian method.

Many aspects of growth have been documented for Black Southern African children, yet their dental development has not been comprehensively investigated. The present study was designed to provide information on age of attainment of dental development stages in Southern African children and to compare the findings with other populations. This was a community-based cross-sectional study of 642 children (270 males and 372 females). Panoramic radiographs of children aged 5 to 20years were assessed using Demirjian's eight stages of permanent tooth formation and age was estimated using Demirjian's method. Resulting dental ages were compared to the chronological ages. Probit regression analysis was employed to calculate the mean age of attainment of the developmental stages for the seven left mandibular teeth. Maturity scores and age of attainment were compared by sex and with published data on other populations. Females show significantly advanced dental maturity and dental ages, as well as earlier attainment of all stages of mineralization, compared to males (p < 0.05). The Demirjian method overestimated dental age in both males (0.8 ± 1.02years) and females (1.0 ± 0.98years). Cross-population comparisons illustrate that Black Southern African children are generally advanced in dental maturity compared to children of European and Asian ancestry. The Demirjian method significantly overestimated the chronological ages of Black Southern African males and females. Southern Africans attain dental maturity earlier than South Korean, Canadian, and Belgian children. These differences in dental maturity clearly illustrate the need for population-specific, rather than global, dental maturity standards.

Permanent tooth emergence: Timing and sequence in a sample of Black Southern African children.

This study investigates mean age, sequence, and temporal trends of permanent tooth emergence in Black Southern African children and compares the findings with other population samples. This community-based cross-sectional study involved 639 Black Southern African children between 5 and 20 years of age. Probit analysis was used to derive the mean age at emergence of the permanent teeth. Sex and cross-population comparisons were undertaken to determine similarities and differences in emergence timing and sequence. Females emerged all teeth earlier except for M3s (p < .05). Black Southern Africans have earlier mean ages of emergence compared to population samples from the USA, Europe, Australia, and Asia. Sexual dimorphism was detected in the mandibular I1/M1 emergence sequence (females, M1 I1 ; males, I1 M1 ). The sequence in males is similar in both jaws to males from other sub-Saharan African, USA, and European samples. Females show a similar sequence pattern in the maxilla with other sub-Saharan African, and also Australian and US females of European ancestry. There is a high frequency of polymorphism in the P1P2C1 emergence sequence, with significantly more P2P1C1 maxillary sequences seen among males. Polymorphic variation was common for the I1 M1 sequence in both males and females. Mean age of tooth emergence among Black Southern African children is similar to children from most other sub-Saharan African populations. No temporal change was seen in the mean age of emergence. Earlier permanent tooth emergence in Black Southern Africans is part of a general sub-Saharan pattern that is distinct from European and Asian populations.

Pharmacogenetic variation influences sensory neuropathy occurrence in Southern Africans treated with stavudine-containing antiretroviral therapy.

BackgroundThe use of the HIV antiretroviral drug stavudine (d4T), a thymidine analogue, is associated with the development of mitochondrial toxicities such as sensory neuropathy (SN). Genetic variation in genes relating to d4T transport and metabolism, as well as genetic variation in the thymidine synthesis pathway, could influence occurrence of d4T-related toxicity.MethodsWe examined this hypothesis in a cohort of HIV-positive South African adults exposed to d4T, including 143 cases with SN and 120 controls without SN. Ten SNPs in four genes associated with stavudine transport, and 16 SNPs in seven genes of the thymidine synthesis / phosphorylation pathway were genotyped using Agena mass spectrometry methods. Associations between sensory neuropathy and genetic variants were evaluated using PLINK by univariate and multivariable analyses.ResultsAge and height were significantly associated with SN occurrence. Using logistic regression with age and height as covariates, and uncorrected empirical p-values, genetic variation in SLC28A1, SAMHD1, MTHFR and RRM2B was associated with SN in South Africans using d4T.ConclusionVariation in genes relating to d4T transport and metabolism, as well as genetic variation in the thymidine synthesis pathway may influence occurrence of d4T-related SN. These data contribute to the characterisation of African pharmacogenetic variation and its role in adverse response to antiretroviral therapy.

Chronic Kidney Disease Risk in African and Caribbean Populations With HIV.

We conducted an observational cohort study of end-stage kidney disease (ESKD) in >7000 African and Caribbean people with HIV in the UK. Using Poisson regression and East Africans as the reference group, the adjusted incidence rate ratio (95% confidence interval) of ESKD was 3.14 (1.26-7.84) in Southern Africans, 6.35 (2.53-15.96) in West Africans, and 5.26 (1.91-14.43) in Caribbeans. Higher CD4 cell count and suppressed HIV replication were associated with reduced risk of ESKD. The risk of ESKD varied among HIV-positive people of African heritage, with the highest rates observed in those of West African descent.

Patterns of lateral enamel growth in Homo naledi as assessed through perikymata distribution and number

Perikymata, incremental growth lines visible on tooth enamel surfaces, differ in their distribution and number among hominin species, although with overlapping patterns. This study asks: (1) How does the distribution of perikymata along the lateral enamel surface of Homo naledi anterior teeth compare to that of other hominins? (2) When both perikymata distribution and number are analyzed together, how distinct is H. naledi from other hominins? A total of 19 permanent anterior teeth (incisors and canines) of H. naledi were compared, by tooth type, to permanent anterior teeth of other hominins: Australopithecus afarensis, Australopithecus africanus, Paranthropus robustus, Paranthropus boisei, Homo ergaster/Homo erectus, other early Homo, Neandertals, and modern humans, with varying sample sizes. Repeated measures analyses of the percentage of perikymata per decile of reconstructed crown height yielded several statistically significant differences between H. naledi and other hominins. Canonical variates analysis of percentage of perikymata in the cervical half of the crown together with perikymata number revealed that, in 8 of 19 cases, H. naledi teeth were significantly unlikely to be classified as other hominins, while exhibiting least difference from modern humans (especially southern Africans). In a cross-validated analysis, 68% of the H. naledi teeth were classified as such, while 32% were classified as modern human (most often southern African). Of 313 comparative teeth use for this analysis, only 1.9% were classified as H. naledi. What tends to differentiate H. naledi anterior tooth crowns from those of most other hominins, including some modern humans, is strongly skewed perikymata distributions combined with perikymata numbers that fall in the middle to lower ranges of hominin values. H. naledi therefore tends toward a particular combination of these features that is less often seen in other hominins. Implications of these data for the growth and development of H. naledi anterior teeth are considered.

The WITS Atlas: A Black Southern African dental atlas for permanent tooth formation and emergence.

To develop a population-specific atlas of permanent tooth emergence and formation for age estimation of Black Southern Africans. Using data from a cross-sectional study of 642 school children aged 5-20 years, panoramic radiographs taken during routine dental examination in a mobile treatment van were analyzed using the Demirjian method of eight (A-H) tooth formation stages. Tables of the stages of tooth development for each tooth, including the third molars, were generated separately for age cohorts and by sex. The most frequently occurring (modal) stage of tooth formation was considered the signature developmental stage for the age. The relationship of the third molar occlusal surfaces with occlusal tables on the radiographs were checked and compared with the findings recorded during intra oral examination. Comparison with the London atlas shows that at age 9.5 years, the canine and premolar emergence are at least one year ahead and the third molar formation completes four years earlier in the WITS Atlas. Similarities in advancement in tooth formation and emergence across sub-Saharan Africa suggest that the WITS Atlas can be used for those populations as well.

Accuracy of the Demirjian and Willems methods of age estimation in a Black Southern African population

The accuracies of the original Demirjian, modified Demirjian and Willems dental age estimation methods were compared for a Black Southern African population to determine their usefulness for forensic and anthropological purposes. Data were collected using a community-based prospective study design. Panoramic radiographs of seven left mandibular teeth from 540 children aged 5-15.99 years were scored using the three methods. Obtained estimates were compared to the chronological ages and mean absolute errors were calculated. The original Demirjian method significantly overestimated ages (males 0.85 years, female 1.0 years; mean absolute errors of 1.1 years for both sexes), as did the modified Demirjian method (males 0.90 years, females 1.21 years; mean absolute errors of males 1.1 years, females 1.4 years). The Willems method was the most accurate for Black Southern Africans, with the lowest significant mean difference (males 0.2 years, females 0.3 years) between dental and chronological age, with the least mean absolute errors (males 0.70 years, females 0.68 years).