Parity, dental caries and implications for maternal depletion syndrome in northern Nigerian Hausa women.

BACKGROUND: Female reproductive history, especially high parity, affects general health and may impact negatively on oral health. While parity has been positively linked to tooth loss, the specific association between parity and caries has not been adequately investigated. AIM: To determine the association between parity and caries in a population of higher parity women. Influences of likely confounders (age, socio-economic status, reproductive parameters, oral health practices and sugar consumption between meals) were considered. METHODS: This was a cross-sectional study involving 635 Hausa women of varying parity aged 13-80 years. Socio-demographic status, oral health practices and sugar consumption were obtained using a structured interviewer-administered questionnaire. All decayed, missing and filled teeth due to caries (excluding third molars) were noted, and tooth loss etiology was queried. Associations with caries were evaluated through correlation, ANOVA, post hoc analyses and Student's t tests. Effect sizes were considered for magnitude of differences. Multiple regression (binomial model) was used to investigate predictors of caries. RESULTS: Hausa women had a high prevalence of caries (41.4%) despite low sugar consumption; nonetheless the overall mean DMFT score was very low (1.23 ± 2.42). Older, higher parity women experienced more caries, as did those with longer reproductive spans. Additionally, poor oral hygiene, use of fluoride toothpaste and frequency of sugar consumption were significantly associated with caries. CONCLUSION: Higher parity (>6 children) was associated with higher DMFT scores. These results suggest that a form of maternal depletion, expressed as heightened caries susceptibility and subsequent tooth loss, occurs with higher parity.

Three-dimensional geometric morphometric studies of modern human occipital variation.

OBJECTIVES: To investigate three-dimensional morphological variation of the occipital bone between sexes and among populations, to determine how ancestry, sex and size account for occipital shape variation and to describe the exact forms by which the differences are expressed. METHODS: CT data for 214 modern crania of Asian, African and European ancestry were compared using 3D geometric morphometrics and multivariate statistics, including principal component analysis, Hotelling's T2 test, multivariate regression, ANOVA, and MANCOVA. RESULTS: Sex differences in average occipital morphology are only observed in Europeans, with males exhibiting a pronounced inion. Significant ancestral differences are observed among all samples and are shared by males and females. Asian and African crania have smaller biasterionic breadths and flatter clivus angles compared to Europeans. Asian and European crania are similar in their nuchal and occipital plane proportions, nuchal and occipital angles, and lower inion positions compared to Africans. Centroid size significantly differs between sexes and among populations. The overall allometry, while significant, explains little of the shape variation. Larger occipital bones were associated with a more curved occipital plane, a pronounced inion, a narrower biasterionic breadth, a more flexed clivus, and a lower and relatively smaller foramen magnum. CONCLUSIONS: Although significant shape differences were observed among populations, it is not recommended to use occipital morphology in sex or population estimation as both factors explained little of the observed variance. Other factors, relating to function and the environment, are suggested to be greater contributors to occipital variation. For the same reason, it is also not recommended to use the occiput in phylogenetic studies.

Association between parity and tooth loss among northern Nigerian Hausa women.

BACKGROUND: Female reproduction is associated with physiological, metabolic, and nutritional demands that can negatively affect health and are possibly cumulative when parity is high. While it is probable that maternal oral health is similarly affected, available evidence is based on fairly low parity populations and likely confounders affecting oral health status were not considered. AIM: To determine the relationship between parity and tooth loss in a population with many high parity women. Contributions of age, reproductive and socioeconomic parameters, and oral health practices were considered. MATERIALS AND METHODS: This was a cross-sectional study involving 612 Hausa women of all parity levels aged 13-65 years. Women with ≥5 children were considered high parity. Sociodemographic status and oral health practices were collected using a structured interviewer-administered questionnaire. All teeth present, (excluding third molars) and missing teeth were noted, with inquiries regarding tooth loss etiology. Associations with tooth loss were evaluated through correlations, ANOVA, post hoc analyses and Student's t tests. Effect sizes were used to interpret the magnitude of differences. Multiple regression (negative binomial model) was used to investigate predictors of tooth loss. RESULTS: Hausa women had a low prevalence of tooth loss, despite poor oral hygiene, and limited dental care. Older, middle SES, and higher parity women experienced significantly more tooth loss. Additionally, increased duration of reproductively active years was significantly related to fewer remaining teeth. CONCLUSION: Higher parity was related to greater tooth loss in Hausa women. Women with ≥5 children experienced more loss than lower parity age mates.

Anastrozole promotes implantation by altering the expression of paxillin and fak in rat luminal uterine epithelium / El anastrozol promueve la implantación alterando la expresión de paxilina y fak en el epitelio uterino luminal de rata

An alternative hyper-ovulator inducer to replace clomiphene citrate (CC) is needed as it is unsuitable for women with polycystic ovarian syndrome and is associated with low pregnancy rates. Anastrozole is an effective hyper-ovulator inducer, but has not been well researched. In order to determine the effectiveness of anastrozole as a hyper-ovulator inducer and to an extent compare it with CC in similar situations, this study ascertained the effects of these drugs on the expression of the focal adhesion proteins, paxillin and FAK, which are uterine receptivity markers in the surface luminal uterine epithelial cells of day 1 and day 6 pregnant Wistar rats. The results show that paxillin is localized in focal adhesions at the base of the uterine epithelial cells at day 1 of pregnancy whereas at day 6, paxillin disassembles from the basal focal adhesions and localizes and increases its expression apically. FAK is faintly expressed at the basal aspect of the uterine epithelial cells while moderately expressed at the cell-to-cell contact at day 1 in all groups from where it disassembles and relocates apically and becomes more intensely expressed at day 6 of pregnancy in untreated and anastrozole treated rats. Although paxillin is localized apically at day 6, its expression is significantly down-regulated with CC treatment suggesting its interference with the implantation process. These findings seem to suggest that anastrozole could favor implantation.

Para reemplazar el citrato de clomifeno (CC) es necesario un inductor de hiperovulación alternativo, ya que no es adecuado para mujeres con síndrome de ovario poliquístico y está asociado con tasas bajas de embarazo. El anastrozol es un inductor eficaz del hiper-ovulador, pero no se ha investigado adecuadamente. Con el fin de determinar la efectividad del anastrozol como inductor del hiper-ovulador y, en cierta medida, compararlo con CC en situaciones similares, este estudio determinó los efectos de estos fármacos en la expresión de las proteínas de adhesión focal, paxillin y FAK, uterinas marcadores de receptividad en la superficie luminal de células uterinas epiteliales, del día 1 y día 6 en ratas Wistar preñadas. Los resultados muestran que la paxilina se localiza en adherencias focales en la base de las células epiteliales uterinas en el día 1 del embarazo, mientras que en el día 6, la paxilina se desmonta de las adherencias focales basales y localiza y aumenta su expresión apicalmente. FAK se expresa débilmente en el aspecto basal de las células epiteliales uterinas, mientras que se expresa moderadamente en el contacto de célula a célula en el día 1 en todos los grupos, donde se separa y se reubica apicalmente y se expresa con mayor intensidad el día 6 de la preñez, en pacientes no tratados y tratados. ratas tratadas con anastrozol. Aunque la paxillina se localiza apicalmente en el día 6, su expresión está significativamente disminuida con el tratamiento con CC, lo que sugiere su interferencia con el proceso de implantación. Estos hallazgos sugieren que el anastrozol podría favorecer el proceso de implantación.

Does nutrition have an effect on the timing of tooth formation?

BACKGROUND: The effect of nutritional status on the timing of permanent tooth formation is not well understood, despite clear evidence that systemic stresses result in enamel defects during tooth formation. AIM: This study investigated the effect of nutritional status (measured as BMI, height, weight, mid-upper arm circumference, and head circumference) on permanent tooth formation. METHOD: This was a prospective cross-sectional study involving 642 (270 males, 372 females) healthy Black South African participants aged 5-20 years. The height and BMI were converted to z-scores using WHO z-score for age tables. The participants were grouped into underweight/short for age (<-2), normal (≥ - 2 to 2.0) and overweight/obese/tall for age (>2). Panoramic radiographs of the children were assessed using Demirjian's eight stages of permanent tooth formation and age was estimated using Demirjian's method. Probit regression analysis was used to calculate the mean age of attainment of the developmental stages for the left mandibular teeth (I2-M2). RESULTS: There was significant advancement in the age of attainment of the final (H) stage for the majority of permanent teeth in the overweight (mean male BMI 22.9; female 27.94) group compared to the underweight (p < .05). Negative binomial regression indicated that age, height, and BMI were significant predictors of the dental maturity score for males (p < .05), while age, height, weight, BMI and HC were significant predictors for females (p < .05). CONCLUSION: Nutritional status had a significant effect on the timing of tooth formation in males and females in the study population. The effect was mainly noticeable for children in the extremes of the spectrum of BMI z-scores.

Is parity a cause of tooth loss? Perceptions of northern Nigerian Hausa women.

BACKGROUND: Reproduction affects the general health of women, especially when parity is high. The relationship between parity and oral health is not as clear, although it is a widespread customary belief that pregnancy results in tooth loss. Parity has been associated with tooth loss in some populations, but not in others. It is important to understand the perceptions of women regarding the association between parity and tooth loss as these beliefs may influence health behaviors during the reproductive years. AIM: To explore the views of Hausa women regarding the link between parity and tooth loss. METHODS: Qualitative data were collected through a grounded theory approach with focus group discussions (FGDs) of high and low parity Hausa women (n = 33) in northern Nigeria. Responses were elicited on the causes of tooth loss, effects of tooth loss on women's quality of life, issues of parity and tooth loss, and cultural beliefs about parity and tooth loss. The data were analyzed thematically using ATLAS-ti. RESULTS: Respondents associated tooth loss with vomiting during labor, a condition termed 'payar baka'. Poor oral hygiene, excessive consumption of refined carbohydrates, tooth worm, cancer and ageing were also believed to cause tooth loss. The greatest impacts of tooth loss on the lives of the respondents were esthetic and masticatory changes. CONCLUSION: Respondents perceived that parity is indirectly linked to tooth loss, as reflected in their views on the association between vomiting during labor and tooth loss.

First systematic assessment of dental growth and development in an archaic hominin (genus, Homo) from East Asia.

Several human dental traits typical of modern humans appear to be associated with the prolonged period of development that is a key human attribute. Understanding when, and in which early hominins, these dental traits first appeared is thus of strong interest. Using x-ray multiresolution synchrotron phase-contrast microtomography, we quantify dental growth and development in an archaic Homo juvenile from the Xujiayao site in northern China dating to 161,000-224,000 years or 104,000-125,000 years before present. Despite the archaic morphology of Xujiayao hominins, most aspects of dental development of this juvenile fall within modern human ranges (e.g., prolonged crown formation time and delayed first molar eruption). For its estimated age-at-death (6.5 years), its state of dental development is comparable to that of equivalently aged modern children. These findings suggest that several facets of modern human dental growth and development evolved in East Asia before the appearance of fully modern human morphology.

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

BACKGROUND: Many aspects of growth have been documented for Black Southern African children, yet their dental development has not been comprehensively investigated. AIM: 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. METHOD: This was a community-based cross-sectional study of 642 children (270 males and 372 females). Panoramic radiographs of children aged 5 to 20 years 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. RESULTS: 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 ± 1.02 years) and females (1.0 ± 0.98 years). Cross-population comparisons illustrate that Black Southern African children are generally advanced in dental maturity compared to children of European and Asian ancestry. CONCLUSION: 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.

OBJECTIVES: 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. MATERIALS AND METHODS: 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. RESULTS: 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. DISCUSSION: 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.

Characterization of the tissue crossing the supratrochlear aperture of the humerus using histochemical techniques.

INTRODUCTION: The supratrochlear aperture (STA) is the opening observed in the septum that separates the olecranon from the coronoid fossae. Numerous studies have shown that there is considerable variation in the occurrence of this feature within and among populations. MATERIALS AND METHODS: Cadavers (n = 43) were assessed for the presence of the STA by means of X-ray. Ten samples of STA-bearing bones and an equal number of controls without STA were obtained from cadavers using a hole saw. These samples were decalcified, fixed in formalin and processed for histological assessment in differing (ascending) grades of alcohol before being embedded in paraffin wax. Sections (10 µm thick) were stained with haematoxylin and eosin (H&E) for general architecture as well as the rapid one-step Mallory-Heidenhain stain for bone and connective tissue. RESULTS: The STA samples exhibited an abundance of connective tissue arranged in regular bundles of fibers across the STA. In contrast, the controls showed only bone tissue in the septum. DISCUSSION AND CONCLUSION: The arrangement of connective tissue fibers organized in regular bundles is a characteristic of strength, which may indicate that the STA is under sustained stress or pressure from the olecranon and coronoid processes of the ulna. It remains debatable whether the STA should continue to be considered as a foramen in life as we demonstrate that it is obliterated by connective tissue. It contains no neurovascular structures, making it unlike other structures defined as foramina.

Three-dimensionally derived interlandmark distances for sex estimation in intact and fragmentary crania.

The skull is the element most frequently presented to forensic anthropologists for analysis yet weathering, corpse maiming, and scavenger activity often result in damage and fragmentation. This fragmentation results in a reduction in the number of traditional calliper derived measurements that can be obtained and subjected to discriminant based analyses for sex estimation. In this investigation, we employed three-dimensional geometric morphometric methods to derive novel interlandmark distance measures across six regions of the cranium including the basicranium, basipalate, zygoma, orbits and the cranium globally to create functions to discriminate sex with high efficacy, even in the event of fragmentation. Forty-five homologous landmarks were digitised across each of 227 (114 males and 113 females) South African crania of European descent (white) sampled from the Raymond A Dart Collection of Human Skeletons, housed in the School of Anatomical Sciences, University of the Witwatersrand, South Africa. A total of 990 interlandmark distances (ILDs) were mathematically derived using Pythagorean geometry. These ILDs were then filtered by region and subjected to both direct and stepwise discriminant function analyses. Discriminant equations where derived for each region and achieved the following average cross-validated sex estimation accuracies: basicranium-74%; basipalate-80.2%; zygomatic-82.4; orbits-71.8%; nasomaxilla-83.7%; global cranium-88.2%. A large number of the ILDs used to derive the discriminant functions are novel, demonstrating the efficacy of geometric morphometric methods and illustrating the need to reassess old methods of data collection using modern methods to determine whether they best capture biological differences. The results of this study provide an invaluable contribution to forensic anthropology in South Africa as it provides an accurate, practical means of assessing sex using fragmentary material that may otherwise have been disregarded. These will undeniable aid in accurate sex estimation and ultimately, victim identification.

Focal adhesion proteins, vinculin and integrin ß5, during early pregnancy in rat uterine epithelial cells: anastrozole favors their normal distribution / Proteínas de adhesión focales, vinculina e integrina ß5, durante el embarazo temprano en células epiteliales uterinas de rata: anastrozol favorece su distribución normal

SUMMARY: An alternative superovulator to replace clomiphene citrate is needed as clomiphene citrate is associated with low pregnancy rates. Anastrozole is an effective superovulator, but it has not been well researched. In order to determine the effectiveness of anastrozole as a superovulator and to compare it with clomiphene citrate in similar situations, this study ascertained the effects of these drugs on the expression of the focal adhesion proteins, vinculin and integrin β5, which are uterine receptivity markers, in the uterine epithelial cells of day 1 and day 6 pregnant Wistar rats. The results show that vinculin and integrin β5 are co-localized at the base of the uterine epithelium at day 1 of pregnancy whereas at day 6, they disassemble from the basal focal adhesions and co-localize and significantly increase their expression apically (p≤0.0001). Moreover, there is a significant difference in the protein expression levels of vinculin and integrin b5 in uterine luminal epithelial cells between untreated (control) and chlomiphene citrate treated rats (p≤0.0001), anastrozole and chlomiphene citrate treated rats at day 6 (p≤0.0001) suggesting the interpretation that anastrozole seems to enhance their expression in order to perhaps assist in the implantation process of the blastocyst. The immunofluorescence experiments agree with the vinculin and integrin β5 gene expression findings in which at day 6 of pregnancy, vinculin and integrin β5 gene expression are significantly upregulated in uterine luminal epithelial cells in the anastrozole treated group relative to the calibrator sample (p≤0.0001). These findings suggest that anastrozole is implantation friendly.

RESUMEN: Es necesario un superovulador alternativo para reemplazar el citrato de clomifeno, debido a que está asociado con bajas tasas de preñez. El anastrozol es un superovulador eficaz, sin embargo es poca su investigación. Con el fin de determinar la efectividad del anastrozol como superovulador y compararlo con citrato de clomifeno en situaciones similares, se determinaron los efectos de estos fármacos sobre la expresión de las proteínas de adhesión focal, vinculina e integrina β5, en marcadores de receptividad uterina en días 1 y 6, en las células epiteliales uterinas de ratas Wistar preñadas. Los resultados muestran que la vinculina y la integrina β5 se co-localizan en la base del epitelio uterino al día 1 de la gravidez mientras que al día 6 se desmontan de las adherencias focales basales, co-localizan y aumentan significativamente su expresión apicalmente (p≤0.0001). Además, existe una diferencia significativa en los niveles de expresión de proteína de vinculina e integrina β5 en células epiteliales luminales uterinas entre ratas no tratadas (control) y tratadas con citrato declomifeno (p≤0.0001), ratas tratadas con anastrozol y citrato declomifeno al día 6 (p≤0,0001) sugiriendo la interpretación de que el anastrozol parece mejorar su expresión con el fin de ayudar en el proceso de implantación del blastocisto. Los experimentos de inmunofluorescencia coinciden con los resultados de la expresión de los genes vinculina e integrina β5 en los cuales al día 6 de la preñez, la vinculina y la integrina β5 están significativamente reguladas en células epiteliales luminales uterinas en el grupo tratado con anastrozol con respecto a la muestra del calibrador (p<0,0001). Estos hallazgos sugieren que el anastrozol es favorable para la implantación.

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).

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

Current dental maturity charts, such as the widely applied London atlas, do not take into consideration advanced tooth emergence and formation patterns observed in children of African ancestry. The result is inaccurate age estimation in Southern Africa, a region where there is great forensic and anthropological need for reliable age estimation. OBJECTIVES: To develop a population-specific atlas of permanent tooth emergence and formation for age estimation of Black Southern Africans. MATERIALS AND METHODS: 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. RESULTS: 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. DISCUSSION: 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.

The Demirjian versus the Willems method for dental age estimation in different populations: A meta-analysis of published studies.

BACKGROUND: The accuracy of radiographic methods for dental age estimation is important for biological growth research and forensic applications. Accuracy of the two most commonly used systems (Demirjian and Willems) has been evaluated with conflicting results. This study investigates the accuracies of these methods for dental age estimation in different populations. METHODS: A search of PubMed, Scopus, Ovid, Database of Open Access Journals and Google Scholar was undertaken. Eligible studies published before December 28, 2016 were reviewed and analyzed. Meta-analysis was performed on 28 published articles using the Demirjian and/or Willems methods to estimate chronological age in 14,109 children (6,581 males, 7,528 females) age 3-18 years in studies using Demirjian's method and 10,832 children (5,176 males, 5,656 females) age 4-18 years in studies using Willems' method. The weighted mean difference at 95% confidence interval was used to assess accuracies of the two methods in predicting the chronological age. RESULTS: The Demirjian method significantly overestimated chronological age (p<0.05) in males age 3-15 and females age 4-16 when studies were pooled by age cohorts and sex. The majority of studies using Willems' method did not report significant overestimation of ages in either sex. Overall, Demirjian's method significantly overestimated chronological age compared to the Willems method (p<0.05). The weighted mean difference for the Demirjian method was 0.62 for males and 0.72 for females, while that of the Willems method was 0.26 for males and 0.29 for females. CONCLUSION: The Willems method provides more accurate estimation of chronological age in different populations, while Demirjian's method has a broad application in terms of determining maturity scores. However, accuracy of Demirjian age estimations is confounded by population variation when converting maturity scores to dental ages. For highest accuracy of age estimation, population-specific standards, rather than a universal standard or methods developed on other populations, need to be employed.

Third molar impaction and agenesis: influence on anterior crowding.

Background Third molar influence on anterior crowding is controversial, but they are assumed to play a major role in compromising dental arch space. Aim To evaluate the relationship among impaction, agenesis and crowding in black South African males. Subjects and method Mandibles and maxillae of 535 black South African males in the Raymond A. Dart Collection of Human Skeletons, University of the Witwatersrand were examined for anterior crowding and third molar agenesis and impaction. Dental crowding was determined using Little's irregularity index. Results Individuals with impaction showed more moderate-to-extreme crowding than those with agenesis. Bilateral third molar presence was more frequently associated with ideal-to-minimal crowding. Weak positive but significant correlations between crowding and impaction were found (mandible, ρ = 0.154, p = 0.000; maxilla ρ = 0.130, p = 0.000). The direction was the opposite for bilateral presence of molars (mandible, ρ = -0.135, p = 0.02; maxilla, ρ = -0.111, p = 0.010). Odds of mandibular crowding were greatest in individuals with impaction (OR = 3.22, CI = 1.716-6.05, p < 0.001). Maxillary results were similar. Conclusion Third molar impaction plays a role in anterior crowding. Third molar presence was not associated with anterior crowding, while agenesis did not explain absence of crowding.

A radiographic investigation of the relationships between humeral cortical bone thickness, medullary canal width and the supratrochlear aperture (STA).

The supratrochlear aperture (STA) is a perforation of the septum between the olecranon and coronoid fossae of the humerus. Bones with STA are prone to supracondylar fractures and are thought to have narrower medullary canals. Our aim was to explore the relationship of the STA with medullary canal width and humeral size. The study employed a case-control research design with approximately equal numbers of individuals with and without STA from South African Whites, Blacks, and the Mixed ethnic group. Radiographs were taken anteroposteriorly using a Lodox Statscan and Image J® software was used to acquire measurements from the radiographs. In the proximal diaphysis, the mean medullary canal width was significantly smaller for STA humeri (13.59 vs. 14.72 mm). The same was true for the midshaft (10.21 vs. 10.84 mm) and the distal portion (10.05 vs. 10.63 mm). While STA humeri appeared to have narrower medullary canal dimensions, this was not the case after standardizing for bone size. The smaller medullary canal width reported in the literature for STA-bearing humeri is, therefore, due to bone size differences and not STA presence. This is supported by the strong positive correlation between bone size and medullary canal width irrespective of STA status. Thus, the medullary canal width increases with bone size independent of STA status. We, therefore, propose that bone size, and not STA presence, is the major factor to consider when choosing rods for intramedullary fixation.

An anatomical and osteometric study of the femoral sulcus angle in adult Malawians.

BACKGROUND: Femoral sulcus angle is particularly important in clinical evaluation of patellofemoral joint. Individuals show considerable differences in asymmetrical dimensions of the femur. OBJECTIVES: To determine the size of femoral sulcus angles in adult black Malawians using the skeletal collection in the department of Anatomy, College of Medicine and assess their gender differences; to compare femoral sulcus angles of Malawians with other ethnic groups. METHODS: A cross sectional study was done in which femoral sulcus angles of dry bones were measured using a goniometer. RESULTS: There is no significant difference in the mean sulcus angles between right and left femora in males (p=0.8100) and females (p=0.0742); between all males combined and females combined (p=0.8845). There is a significant difference in the mean between all left femora combined and all right femora combined (p=0.0260). CONCLUSION: This study has provided the mean size of the femoral sulcus angle of adult Malawians. These findings suggest that the size of the sulcus angle cannot determine gender among adult black Malawians suggesting the interpretation that femora asymmetric dimensions are population specific, which should be considered in the patellofemoral joint evaluation.

Morphometric Characteristics of the Humerus and Ulna in Limbs Bearing the Supratrochlear Aperture (STA).

The supratrochlear aperture (STA) is a perforation of the septum found between the olecranon and coronoid fossae of the humerus. Its prevalence is population specific and varies by sex. There is no consensus on the etiology of this feature despite decades of investigation. Two aspects of the mechanical theory, which states that the STA is formed when the ulnar olecranon and coronoid processes impinge upon the septum separating the olecranon and coronoid fossae, were investigated. First, osteometric measures of bone size were used to test the proposition that larger humeri are less prone to STA formation. We compared the dimensions of STA bearing humeri with those lacking STAs and investigated which skeletal features discriminate among South African populations. To specifically evaluate the mechanical theory that articulation with the olecranon and coronoid fossae may result in STA formation, dimensions of the olecranon and coronoid processes were compared. Our results verified that smaller individuals are prone to STA formation and that a significantly longer olecranon process is associated with the aperture. The olecranon process length and olecranon-coronoid distance were the main contributors to STA presence. Variables that contributed the most towards discrimination among the South African populations were the olecranon fossa depth and right humeral head circumference. An inverse relationship between the olecranon process length and olecranon fossa depth was also associated with presence of the STA.