Objective: To assess the effect of using a 3-D atlas on academic performance and compare it with the use of power point presentations during online lectures for gross anatomy of the head. Study Design: Comparative prospective study. Place and Duration of Study: Department of Anatomy, Dental College, Heavy Industries Taxila Education City Institute of Medical Sciences, Taxila Pakistan, from Jun to Jul 2020. Methodology: Forty-nine students from first year BDS were selected through nonprobability convenience sampling. They were assigned to two groups, A and B comprising of 25 and 24 students respectively. Group A was taught gross anatomy of head region via Zoom lectures employing a digital three-dimensional anatomy atlas application (Visual body, 2019). Group B was exposed to only two-dimensional pictures through presentations during their lectures. Ten teaching sessions were conducted with post session MCQ based assessments. One comprehensive assessment was conducted at the completion of the region. Results were compared for both groups. Results: The mean scores for three of the post session assessment tests were higher for group A (15.72 ± 2.03, 15.28 ± 2.79, 16.92 ± 2.13) as compared to that of group B (14.64 ± 3.42, 13.66 ± 3.00, 15.04 ± 3.01) (p<0.05). Similarly, the mean score for comprehensive assessment for group A (35.36 ± 6.02) was also more than that of group B (31.41 ± 6.88) (p<0.05). Conclusion: Three-dimensional viewing of structures led to better academic performance as compared to that of presentations with two dimensional pictures.

Background: The sclera is the outer strong opaque covering of the eye that functions as protective layer and provides site for attachment of extra ocular muscles. Aim: To study the microscopic anatomy of sclera in chick at various stages of embryological development keeping in mind the practical application of this information in understanding human development and disease processes. Methodology: It was an experimental study. The study was carried out at department of Anatomy, CPSP Regional Centre, Islamabad. Eyeballs were collected from group A, B and C (n=30 each) on day 10, 12 and 15 of incubation respectively. Dissected out tissues were processed and stained with Hematoxylin & Eosin and Alizarin red. The prepared specimens for group A and C were analysed under light microscope while the specimens from group B were observed via stereomicroscope. Data was evaluated by using SPSS version 23. Independent t-test was applied with p-value of less than 0.05 was considered significant. Results: As the chondrocytes in cartilaginous layer of sclera became mature, they change their shape from flattened to more rounded cells. The proteoglycan content in the cartilaginous matrix increased. The mean number of chondrocytes increased from 17.4 ±1.4/unit area on day 10 to 10.0 ±0.8/unit area on day 15. The mean thickness of cartilaginous layer increased from 44 ±2.4µm on day 10 to 77 ±8.3 µm on day 15 of development. Calcification of scleral ossicles became obvious at about 12 days of incubation when seen under stereomicroscope. Practical Implication: This study highlighted that understanding for the development of scleral elements (understudied tissue of the eye) can be critical in research involving autoimmune diseases and neural crest defects. Considering similar developmental stages among humans as in chick embryo. Conclusion: It was concluded that growth of sclera in eye of chick has been indicated by increase in thickness of its layers and increase in the number of chondrocytes/unit area and progressing calcification of ossicles in its bony part. Keywords: Chick Embryo, Chondrocytes, Hyaline Cartilage and Ossicular Ring.

Background: Women suffering from seizure-related illnesses are prescribed phenytoin during pregnancy if the benefits outweigh the risks. But the teratogenic effect of this drug on limb development needs exploration. This study was designed to investigate the time-mediated teratogenic effect of sodium phenytoin on limb development of chick embryos on days 04 and 09 of development using the stereomicroscope and at the time of hatching. Material and Methods: This randomized control trial comprised of two main groups of fertilized chicken eggs (Egyptian Fayoumi breed), control group A and experimental group B, each having 90 eggs. Each experimental egg was injected with sodium phenytoin (3.5 mg, teratogenic dose) just before incubation. Both the groups were divided into three subgroups each A1, A2, & A3/B1, B2 & B3. Stereomicroscope was used to observe the limb buds and cartilaginous elements in subgroups 1 and 2 on days 04 and 09 of development respectively. The embryos of subgroups 3 were assessed for gross limb deformities on hatching. Survival was noted in all the subgroups.Results: The difference in limb bud size between experimental and controls was statistically insignificant. There was no variation or deformity in the bones. The experimental group 3 had gross limb defects on hatching and the difference in survival was also statistically significant in subgroups 3.Conclusion: Prenatal administration of sodium phenytoin induces limb defects in chick embryos as evident after hatching but limb anomalies are not observed on days 04 and 09 of development as investigated by stereomicroscope. We conclude that the teratogenic effect of phenytoin is time-mediated.

Background: Arsenic is highly toxic agent and a risk factor for disease and disability. Arsenic is present in drinking water of many developing and developed countries including Pakistan and due to rapid industrialization its quantity in soil and water is increasing day by day.Methods: In an 18 month study in which we took two principal groups, labelled as control group A and experimental group B. The animals of experimental group B were administered 4 µg of sodium arsenite dissolved in 10 ml of distilled water by oral gavage daily for 14 days. The uterus was removed and processed for paraffin embedding and stained with hematoxylin and eosin (H and E). The histological parameters; uterine luminal diameter, height of uterine luminal epithelium, area occupied by epithelial component of uterine glands and the thickness of myometrium were measured and evaluated by civil AutoCAD 2013 software. The data was analyzed statistically with the statistical package for social sciences (SPSS).Results: Histological results showed the degenerative effects. The luminal diameter of uterine horns was reduced in experimental animals. The height of uterine epithelium was reduced. Area occupied by epithelial component of uterine glands was reduced along the reduction in the thickness of myometrium.Conclusions: The histological abnormalities observed in uterus showed that the degenerative effects may be due to oxidative stress produced by the exposure to sodium arsenite. As sodium arsenite produces the oxidative stress by the formation of free radicals and by the denaturation of proteins.