Neurovascular territories of the canine fossa: Analysis of a South African population.

BACKGROUND: The canine fossa, a depression on the surface of the maxillary bone, is important clinically due to the nexus of the neurovascular elements which occur in this region and supply the superficial and deep structures of the face. While it is known that there is much variation in the neurovascular structures of this region, little is known about sex differences. The aim of this study was to investigate and map the neurovascular branching within the region of the canine fossa of a South African population, with particular reference to any sex differences. METHODS: Sixty hemifaces (n=30 female; n=30 male) of individuals between the ages of 40 and 100years were dissected. The origin, number of branches, connections between branches, origin of connecting branches and the distribution of the neurovascular structures associated with the mid-facial and canine fossa regions were documented. The data obtained was qualitative and was statistically analysed with SPSS v26 statistical analysis software. Frequency and contingency tables, along with Chi-squared analysis and Fischer's Exact test, were used for quantitative data analysis. RESULTS: While high levels of variation in the neurovascular elements were documented, there was no statistically significant variation between the sexes. A sex variation was only observed for the terminal branches of CN VII with females displaying a lower number of buccal nerve terminal branches than males. CONCLUSION: While only one sex difference of significance was found in the highly variable neurovascular structures resident in the region of the canine fossa, the variability of the neurovascular elements is of importance to surgeons.

Contributions of the pars lateralis, pars basilaris and femur to age estimations of the immature skeleton within a South African forensic setting.

Dental development and eruption sequences have prevailed as the gold standard in age estimations of previously unidentified immature individuals within a legal context. However, in the absence of the dentition, skeletal assessments have served as a frequently applied alternative. While various cranial and postcranial skeletal elements have been used in estimating age of the immature skeleton, little is known about the anthropometric value of the pars basilaris, pars lateralis and femur as skeletal age estimation tools. Thus, this study aimed to assess if these bones of the immature human skeleton were useful elements in estimating the age of prenatal and postnatal individuals. These bones were excised from the remains of 74 unclaimed human immature individuals and evaluated using traditional anthropometric methods. The study sample was sourced from the Johannesburg Forensic Pathology Services (JFPS) and the Johannesburg Forensic Paediatric Collection (JFPC), University of the Witwatersrand and subdivided into an early prenatal (younger than 30 gestational weeks); late prenatal (30 to 40 gestational weeks) and postnatal (birth to 7.5 months) age ranges. Statistically significant differences (p ≤ 0.05) were found when assessing the maximum length, sagittal length, maximum width and distal width of the bones across each of the age ranges (30 gestational weeks to 7 postnatal months). The cranial and postcranial skeletal elements investigated in this study provide a valuable contribution to skeletal ageing in African individuals.

Bone mineral density of human ear ossicles: An assessment of structure in relation to function.

Human ear ossicles are essential for normal sound conduction from the external environment to the inner ear. These bones are subjected to high biomechanical loads due to the sustained vibrations which occur with reception of sound. It is expected that the bones would undergo a significant amount of remodeling and change in bone mineral density during the lifespan of an individual. Therefore, the aim of the study was to evaluate the possible changes in bone mineral density of regions of the ossicular chain during postnatal life. Forty four left and 36 right sets of human ear ossicles, ranging from a sub-adult age group to a mature adult age group, were sourced from the School of Anatomical Sciences, University of Witwatersrand. The ear ossicles were scanned using a micro-focus CT X-ray. A three-dimensional reconstruction of each ossicle was created from the CT scan. Bone mineral density was then determined at specific sites on the ossicles. There was no statistically significant variation found in the bone mineral density in relation to the age of the specimens. However, the handle of the malleus, the incudo-stapedial joint and the insertion site for the tendon of stapedius had lower bone mineral densities when compared to adjacent articulation and nonattachment sites on the ossicular chain. This is possibly due to biomechanical stress in response to sound conduction rather than ageing. Lower bone mineral density may be indicative of regions that experience the highest biomechanical force, thus, resulting in increased remodeling. Clin. Anat. 31:1158-1166, 2018. © 2018 Wiley Periodicals, Inc.

Micro-CT assessment of changes in the morphology and position of the immature mandibular canal during early growth.

PURPOSE: The mandibular canal contributes to the development and growth of the mandible, as it acts as a conduit for the growing inferior alveolar neurovascular structures. A clear understanding of the canal's pathway is, therefore, important in interpreting the growth pattern of the inferior alveolar neurovascular bundle. This study investigated the position of the mandibular canal within the body of the mandible and its general dimensions within a pediatric collection of mandibles. METHODS: The sample included 45 mandibles and was subdivided into three: group 1 (30 gestational weeks to birth), group 2 (birth to 12 months), and group 3 (1 to 4 years). Mandibles were scanned using a Nikon XTH 225L micro-CT unit. Scanning conditions ranged between 85 kV/83 µA and 100 kV/100 µA. Measurements included: the maximum width and height of the mandibular canal and distances between the mandibular canal and the relevant surfaces of the mandible. Data analysis included an ANOVA, MANOVA, and principal component analysis. RESULTS: The mandibular canal increased significantly in size from 30 gestational weeks to 12 months relative to the deciduous molar crypts. Postnatally, the mandibular canal increased significantly in height at the level of the second deciduous molar crypt. The canal lies closer to the buccal surface in the region of the first and second deciduous molar teeth. CONCLUSION: The consistency in the positioning of the mandibular canal within the body of the mandible may assist in predicting the occurrence of aberrant growth patterns, particularly during the initial stages of growth.

An assessment of early mandibular growth.

Quantification of skeletal data has been shown to be an effective and reliable method of demonstrating variation in human growth as well as for monitoring and interpreting growth. In South Africa as well as internationally, few researchers have assessed mandibular growth in late fetal period and early childhood and therefore standards for growth and age determination in these groups are limited. The purpose of this study was to evaluate growth in the mandible from the period of 31 gestational weeks to 36 months postnatal. A total of 74 mandibles were used. Dried mandibles were sourced from the Raymond A. Dart Collection (University of Witwatersrand), and cadaveric remains were obtained from the Universities of Pretoria and the Witwatersrand. The sample was divided into four groups; 31-40 gestational weeks (group 1), 0-11 months (group 2), 12-24 months (group 3), and 25-36 months (group 4). Twenty-one osteological landmarks were digitized using a MicroScribe G2. Ten standard measurements were created and included: the maximum length of mandible, mandibular body length and width, mandibular notch width and depth, mental foramen to inferior border of mandible, mandibular basilar widths bigonial and biantegonial, bigonial width of mental foramen and mental angle. Data were analyzed using PAST statistical software and Morphologika2 v2.5. Statistically significant differences were noted in the linear measurements for all group comparisons except between groups 3 and 4. The mandible morphologically changed from a round, smooth contour anteriorly to adopt a more sharp and narrow adult shape. A progressive increase in the depth and definition of the mandibular arch was also noted. In conclusion, the mandible initially grows to accommodate the developing tongue (up to 11 months), progressive dental eruption and mastication from 12 to 36 months. Mastication is associated with muscle mass development; this would necessitate an increase in the dimensions of the mandibular notch and associated muscle attachment sites. These findings might be valuable in the estimation of age in unidentified individuals and to monitor prenatal growth of the mandible for the early diagnosis of conditions associated with stunted mandibular growth.

The application of thin layer activation for on-line erosion monitoring.

The washout of volcanic ash into the feedwater of a hydroelectric power station resulted in enhanced erosion of generator components. The damage prompted two novel applications of the thin layer activation (TLA) technique. TLA was used to select more resistant materials, and also as the basis of an automated, on-line alarm system to warn station operators on the likelihood of further damage. The latter application demonstrated that plant protection against irregular events is practical using TLA.