Browsing by Author "Handler, Emma"
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Item An Analysis of Student Satisfaction with Active Learning Techniques in an Online Graduate Anatomy Course: Consideration of Demographics and Previous Course Enrollment(2023) Bradley, Libby; Meyer, Kim; Robertson, Taylor; Kerr, Marcel; Maddux, Scott D.; Heck, Amber; Reeves, Rustin; Handler, EmmaPurpose: Online learning has become an essential part of mainstream higher education, allowing greater access for students. With the increase in online course enrollment, specifically that of anatomy, understanding online teaching best practices is critical. Active learning has previously shown many benefits in face-to-face anatomy courses, including increases in student satisfaction. Currently, no research has measured the satisfaction of several active learning techniques implemented in an asynchronous, online graduate anatomy course. Methods: This study compared the student satisfaction achieved by four active learning techniques with consideration of demographics and previous course enrollment. Survey questions consisted of multiple-choice and Likert-style that asked students to indicate their level of satisfaction with the active learning techniques. One hundred seventy (170) students completed the online anatomy course and surveys. Results: Students were more satisfied with question constructing and jigsaw than with concept mapping and team-learning module. Additionally, historically excluded student groups (underrepresented racial minorities) were more satisfied with active learning than White students. Age, gender, previous anatomy experience and/or online course experience did not influence the satisfaction of the active learning techniques. However, students with higher GPAs and those who had no graduate degree were more satisfied with the active learning techniques than students who had lower GPAs and those with a graduate degree. Conclusion: These findings provide evidence that students enrolled in an online graduate anatomy course were satisfied with the active learning techniques, dependent on the specific technique, demographics, and previous course enrollment. Results provide anatomy educators with a better understanding of which techniques work best in an online anatomy course. Currently, there is a lack of research comparing active learning techniques in an online learning environment. These findings provide online anatomy educators with evidence that active learning techniques improve satisfaction, with consideration of student demographics and previous course enrollment.Item Assessing Ecogeographical Variation in the Nasal Passages Utilizing 3D Semilandmarks(2021-05) Ward, Lyndee A.; Maddux, Scott D.; Menegaz, Rachel A.; Handler, EmmaPrior research has shown strong statistical relationships between geographically-patterned variation in nasal skeletal morphology and global climatic conditions. Specifically, the nasal skeletons of individuals indigenous to cold-dry environments tend to be longer, taller, and especially narrower, than those from hot-humid environments. As the nasal passages heat and humidify inspired air for entry into the lungs, this morphological patterning is believed to reflect the specific air-conditioning demands of different climates. However, while it is widely assumed the morphology of the nasal skeleton accurately reflects that of the functional (soft-tissue) nasal passages, the existence of ecogeographic variation in the three-dimensional (3D) nasal soft tissues has yet to be empirically demonstrated. This study investigates 3D shape variation in decongested soft-tissue nasal passages of individuals ancestrally derived from cold-dry (CD) and hot-humid (HH) environments (n=20). Using 3D Slicer and Avizo, a total of 260 semilandmarks were collected from the decongested nasal passages of Each individual. General Procrustes Analysis (GPA) was then used to align the semilandmark configurations of all 20 individuals and a Principal Component Analysis (PCA) was subsequently performed using the Geomorph package in R. Our results indicate PC1 (19.13%) largely contrasts CD individuals with positive PC1 scores (relatively narrower nasal passages) from HH individuals with negative PC1 scores (relatively wider nasal passages). These results generally conform to morphological expectations, suggesting a general concordance between skeletal and decongested soft-tissue nasal anatomy. This study thus provides the impetus for future research investigating the relationship between ecogeographic variation in nasal soft-tissue anatomy and air-conditioning physiology.Item Contrast-enhanced micro-CT approaches for visualizing musculoskeletal development in neonatal mice(2023) Stalls, Javan; Miller, Courtney; Gonzales, Lauren; Lesciotto, Kate; Handler, Emma; Organ, Jason; Menegaz, Rachel A.Contrast-enhanced micro-CT approaches for visualizing musculoskeletal development in neonatal mice Javan A. Stalls, Courtney A. Miller, Jason M. Organ, Emma K. Handler, Lauren A. Gonzales, Kate M. Lesciotto, Rachel A. Menegaz Purpose: While there are many forms of radiological imaging that can be used to gather anatomical data from biological specimens, computed tomography (CT) imaging has been the gold standard for visualizing dense tissue, such as bone, with detailed resolution. However, this imaging modality is not well suited for soft tissues (muscle, brain, abdominal organs, cartilage, etc.) due to their decreased tissue density. The inability to distinguish between soft tissues in CT scans limits our ability to investigate the bone-muscle interactions known to stimulate and direct bone modeling during early postnatal development. The development of contrast-enhancing staining agents, capable of binding materials to increase their radiodensity, has allowed for more accurate and enhanced visualizations of less dense soft tissues, such as muscle and brain structures. Contrast agents such as iodine have differential affinities for the different soft tissues in the body allowing for easier visualization and segmentation of soft tissues in relation to the skeleton. Previous studies have used contrast-enhanced CT (CE-CT) scanning to analyze early development of mice from prenatal stages to postnatal day 7. However, additional CE-CT imaging during the first three postnatal weeks is needed to understand muscle-bone interactions during critical periods of behavioral development, such as suckling and weaning. The goal of this project is to develop a CE-CT protocol and corresponding anatomical atlas showing the development of skeletal and soft tissue structures in the crania of neonatal mice from birth to weaning. Methods: Neonatal and preweaning mice (B6C3Fe a/a-Col1a2OIM/J) were euthanized on day of birth (P0), postnatal day 7 (P7), and postnatal day 14 (P14). Ethanol-fixed tissues were submerged in 1.25% iodine in 70% ethanol (I2E) for 2-14 days, with the skin intact in order to preserve cutaneous musculature. Both pre-stained and post-stained tissues were scanned using a MRS CT-80 micro-CT machine (20 µm3 voxel resolution). Results: Preliminary CE-CT scans following 10 days in an iodine stain present improved visualization of soft tissue (brain structures, cranial muscles, salivary glands) when compared to the baseline bone CT scans. Conclusion: These scans will be used to develop 3D models of musculoskeletal ontogeny from birth-weaning, providing insights into this critical developmental period. The use of CT contrast agents such as iodine offers new opportunities to investigate the anatomical interactions of bone and muscle during early development, and can be applied to investigate models of both normal growth and pathological disorders affecting musculoskeletal growth.Item Cranial Bone Ossification Trajectories in a Mouse Model of Osteogenesis Imperfecta(2023) Miller, Courtney; Lugo, Laura; Husain, Tooba S.; Organ, Jason; Handler, Emma; Gonzales, Lauren; Menegaz, Rachel A.Purpose: Osteogenesis imperfecta (OI) is a genetic disorder that affects the production of type I collagen. Altered collagen production results in delayed or impaired skeletal formation and biomineralization. It also results in the defining characteristics of OI: brittle bones and high rates of fractures. Investigations of skeletal growth in OI have primarily focused on the postcranial skeleton, where interrupted, atypical, and disorganized ossification is seen at long bone growth plates. However, few studies have investigated changes in craniofacial growth in OI and there are currently few early interventions to improve growth trajectories in this region. The current medication prescribed for children with OI to improve skeletal growth, such as bisphosphonates, have major side effects and are not suitable for long-term use. A better understanding of craniofacial development in OI can help with targeting specific developmental stages when new treatments can be administered to provide the best results. The aim of this study is to examine cranial ossification from birth to weaning to determine where and when differences in growth occur in OI. We hypothesize that starting at birth mice with OI will have delayed craniofacial growth due to the poor collagen formation. Methods: To test our hypothesis, we collected cranial bone volumes from micro-CT scans of the homozygous recessive OI murine model (OIM or B6C3Fe a/a-Col1a2oim/oim) and compared them to their wild type (WT) littermates. The OIM model has a COL1A2 mutation that has been found to express a similar skeletal phenotype to the severe form (type III) of OI in humans. Bone volumes were collected from birth (P0) and weaning (P21) from the nasal, frontal, parietal, interparietal, and occipital bones (n=2/genotype/timepoint). Results: At birth, OIM and WT bone volumes were similar. By weaning, bone volume was lower in OIM mice compared to WT mice. Our results demonstrate that OIM mice have reduced rates of bone ossification between birth and weaning, and these differences are most profound in the facial and occipital regions. Additionally, OIM skulls are characterized by low bone volume and potential delays in the closure of cranial sutures and fontanelles. Conclusions: This study suggests that the divergence in cranial ossification rates related to COL1A2 mutations occurs postnatally. Interventions to recover craniofacial bone growth in this experimental model should focus on the critical growth period between birth and weaning. Results from this research have the potential to assist in developing treatments and highlight the importance of early life development of the craniofacial bones in human patients with OI.Item Dental Tissue Changes in Juvenile and Young Adult Mice with Osteogenesis Imperfecta(2022-05) Moore, Jacob C.; Handler, Emma; Menegaz, Rachel A.; Gonzales, Lauren A.Osteogenesis imperfecta (OI) encompasses a heterogeneous family of heritable connective tissue disorders characterized by insufficient or malformed type I collagen protein causing bone fragility, skeletal deformity, and significant dental issues. The most prominent oral characteristic of OI patients, dentinogenesis imperfecta (DI), is characterized by dentition with significant discoloration and structural defects. During normal dental development, specialized cells secrete layers of collagen-rich matrix, which are then mineralized to form the two hard tissues of the tooth – the enamel, the protective tissue that forms the crown of the tooth, and the dentin, which sits internal to the enamel and forms the bulk of the tooth. Importantly, the matrix on which dentin forms is primarily composed of type I collagen. In DI, the secretion of malformed type I collagen in the developing dentin matrix disrupts the normal regulation and organization of this process, causing issues such as hypomineralization, disorganized dentin tubule structure, and dentin hypertrophy. These abnormal structural properties result in the disease phenotype of DI, including discoloration, enamel attrition, and spontaneous dental fractures. This practicum aims to investigate the dental effects of OI by comparing mineralized dental tissue volumes of mice with a type I collagen mutation with wild-type mice with littermates at the juvenile and adult life stages. The animal model under study, the oim mouse (B6C3FE a/a-Col1a2OIM/J), produces abnormal type I collagen due to a mutation in the COL1A2 gene. Mice that are homozygous for this mutation demonstrate a severe OI phenotype, while heterozygotes demonstrate a mild OI phenotype. Prior studies demonstrate that adult oim mice have dental issues similar to those of humans with OI, including reduced dentin tubule density and dentin cross-sectional area. However, the effects of these mutations on dental tissues across the juvenile and young adult periods have not yet been characterized.Item Effects of Osteogenesis Imperfecta on Dental Tissue Volumes in Mice(2022) Moore, Jacob; Handler, Emma; Menegaz, Rachel A.; Gonzales, Lauren; Organ, JasonOsteogenesis imperfecta (OI), commonly known as brittle bone disease, is associated with lifelong dental problems, including increased dental fractures, discolored teeth, and malocclusion. OI is a disorder of the type I collagen protein. Insufficient amounts or misshapen forms of this protein lead to disruptions in the microstructure of bone and teeth tissues. Dentin, the hard tissue which comprises the bulk of the tooth and absorbs shock forces during chewing, develops on a type I collagen matrix. Thus, collagen abnormalities in OI lead to disorganized and less stable dentin. Further, teeth in people with OI frequently exhibit dentin hypertrophy, where increased amounts of dentin are deposited at the interior of the tooth, shortly after dental eruption. Enamel, unlike dentin, develops on a matrix of non-collagenous proteins, and is thought to develop normally in OI. However, abnormalities in the underlying dentin in OI can lead to enamel fractures. Finally, the teeth in people with OI have often been noted to be smaller than those of people without OI. Because dental development occurs early in life, there is a lack of data surrounding the developmental processes and associated issues in dental development of children with OI. Mice are commonly used models for dental development, yet, this process has not yet been studied in mice. The objective of this study is to compare dental tissue volumes of teeth from mice with OI (oim) and wild type mice (wt) at different developmental stages to determine the degree of volume and gross dental size differences during late growth stages. Three-dimensional models of upper and lower first molars and incisors were created from microCT scans from oim and wt mice. Scans were taken at weaning age (four weeks after birth; "W4") and young adulthood (sixteen weeks after birth; "W16"). Dental tissue volumes were measured using 3D Slicer and normalized to mandibular centroid size. Mann-Whitney U tests were used to compare tissue volumes between genotypes and age groups. At W4 and W16, oim mice had significantly lower dentin volumes and total tooth volumes for upper incisors than wt mice (p < 0.05), with no significant difference between groups for other tooth types at either timepoint. At W16, total tooth volume was significantly lower in oim mice for molars before adjusting for mandible size (p < 0.05). For both oim and wt groups, W16 mice had significantly greater dentin, enamel, and total tissue volumes for lower and upper incisors compared to W4 mice (p < 0.05), as well as greater dentin volumes for lower molars (p < 0.05). These results demonstrate that the trend of smaller teeth in humans with OI also holds for the oim mouse. These differences are present at both the juvenile and young adult life stages. This affirms the oim mouse as a possible model for dental development in humans with OI. Further studies are needed to determine the developmental program of these volume differences at earlier growth stages.Item Effects of Osteogenesis Imperfecta on the Cochlea and Sensorineural Hearing(2022) Huston, Lila Athena; Menegaz, Rachel A.; Handler, Emma; Organ, Jason; Gonzales, LaurenBackground: Osteogenesis imperfecta (OI), a developmental disorder of type I collagen, is known to cause hearing loss in ~ 60% of the diseased population. Identified forms include conductive hearing loss (17.4% of OI patients), involving loss of function within the ossicular chain, and sensorineural hearing loss (25.8%), resulting from damage to the cochlea, with the most predominant form being mixed hearing loss (56.8%), involving damage to both the cochlea and ossicles. While OI-related pathologies have largely focused on the middle ear, the pathological appearance of the cochlea (the organ most often compromised in OI-related hearing loss) has gained little focus. In this study, we examine OI-related pathologies on the cochlea in a mouse model for the severe type III OI, to document 1) any visible variation between WT and OI variants, and 2) assess the encroachment of the otic capsule onto the cochlea by analyzing differences in duct volumes. We hypothesize that cochlea in mice with OI will have less consistent morphology overall than their WT counterparts due to abnormal growth of the bony capsule. Methods: 16 week old OIM mice (B6C3Fe a/a-Col1a2oim/J) (n=6) were compared to unaffected wildtype (WT) littermates (n=6) with no known hearing defects. High-resolution micro-CT scans were created for all specimens and 3D models and volumes of the cochlea were generated using 3D Slicer software. Two-tailed Mann-Whitney U-tests were used to investigate differences between 1) right and left ears of the same mouse to examine intraindividual symmetry and 2) differences in volumes between WT and OI cochlea. Results: No major morphologic differences between OI and WT were observed, except for minor areas of higher ossification at the base of the cochlea, mostly within the OI sample. Within WT specimens, we observed little intraindividual difference in the cochlear volume (0-3%). Within OI specimens, significant differences were observed in cochlear volume between right and left ears in the same animal (4-15%; p< 0.05), indicating potential unilateral effects. When average WT and OI volumes were compared, there was much overlap between the two samples although the OI volumes had a significantly larger range than the WT range (Mann-Whitney U, p< 0.05). Discussion: Overall, our results indicate that mice with OI are much more likely to have evidence of unilateral cochlear volume losses, despite very little difference in overall shape appearance, possibly due to bony capsule encroachment. This find indicates an extremely high potential for sensorineural and mixed hearing loss in OI-bred mice and elucidates at least one mechanism behind how this type of hearing loss might be occurring. Little is known about the pathological appearance of the cochlea in OI, leading to difficulty in managing hearing loss. Further investigation of the etiology and progression of cochlear pathologies will allow for better outcomes in hearing for those patients afflicted with OI-related hearing loss.Item Impact of gross anatomy review on ultrasound learning in first-year medical students: A pilot study(2024-03-21) Robertson, Taylor; Reeves, Rustin; Meyer, Kimberly; Satsky Kerr, Marcel; Handler, EmmaIntroduction: Ultrasound (US) integration in undergraduate medical education (UME) has been a popular topic for the past decade. Current literature indicates ultrasound inclusion in UME is commonly integrated in gross anatomy instruction or clinical skills courses. US inclusion in gross anatomy focuses on overall anatomy understanding, whereas US in clinical skills courses focuses on the diagnostic application of medical imaging. Although there is plenty of literature demonstrating the benefits of US inclusion in gross anatomy, there is little research looking at the use of gross anatomy reviews prior to learning clinical ultrasound. Further, there is little research investigating how transferable gross anatomy identification is to ultrasound anatomy identification. Therefore, this study's purpose is to assess the effects of gross anatomy review prior to learning clinical ultrasound. Methods: 22 first year medical students interested in joining the ultrasound interest group (USIG), an extracurricular student group, participated in the study in the spring semester of 2023. There were four ultrasound imaging modules taught during the semester: cardiopulmonary, liver/biliary, E-fast, and musculoskeletal. Students were divided into two groups where they were required to participate in a pre-module quiz, attend the ultrasound instruction, then complete a post-module quiz and survey after the ultrasound instruction. The EXP group had to participate in an additional anatomy review prior to the ultrasound instruction session. Pre- and post-module quizzes contained gross anatomy structures of the relevant anatomy for the module, along with paired ultrasound images of that anatomical structure. The quizzes for each module were identical to each other allowing repeated measures. This allows for tracking students ability to transfer knowledge from gross anatomy identification to ultrasound anatomy identification. Groups switched treatments for each module, allowing equal exposure to both treatments. Quiz scores were compared within and between groups, setting significance level at p<0.05. Results: Both CON and EXP groups significantly improved in their performance from pre-quiz to post-quiz in all four sub-scores for Module 1 (p<.001 for overall; d=1.3, US; d=1.16 and transfer; d=1.34, p<.05 for anatomy; d=.51) and Module 4 (p<.001 for overall; d=1.1,and transfer; d=.74, p<.01 for anatomy; d=.67, and US; d=1.47). Significant increases were seen in three sub-scores for module 2 (p<.01 for overall; d=.77, and US; d=.65, p<.05 for transfer; d=.46). There were no significant increases in performance from pre-quiz to post-quiz in module 3. Looking at self-improvement between groups, the EXP group did show higher mean gains than the CON group and mild to moderate effect sizes, although these comparisons were not significant. The EXP group showed higher mean scores on post-quiz assessments for most sub-scores, including mild to moderate effect sizes, although none of these were significant. Conclusion: Ultrasound is a valuable tool in all areas of medicine, especially in anatomy learning. This study shows that a gross anatomy review does have a positive impact on student performance when learning US. Medical students learning US may receive benefit from a gross anatomy review to reintroduce previously learned material and further reinforce US instruction.Item Incorporating ultrasound imaging in graduate gross anatomy labs improves learning(2023) Robertson, Taylor; Meyer, Kim; Kerr, Marcel; Reeves, Rustin; Handler, EmmaPurpose: Teaching ultrasound imaging is on the rise in both undergraduate and medical anatomy education. Despite the vast literature surrounding these areas, there is little research exploring the use of ultrasound in preparatory graduate programs, which emphasize credential enhancement for professional school applications. The purpose of this study is to identify the effects of ultrasound imaging inclusion in a graduate gross anatomy course. Methods:Students in the Master of Medical Sciences program enrolled in the gross anatomy course, a prosection-based cadaver lab that included pinned cadaver stations and an ultrasound station. Using ultrasound, teaching assistants imaged live human volunteers to demonstrate anatomical structures that students previously learned at the cadaver stations. To assess learning, students were given one ultrasound image question on each lab practical exam. Students also completed a pre- and post-course survey regarding perceptions of ultrasound inclusion in the course. Student lab practical scores and final course grades from the 2019 cohort were used as a historical control. Students in the 2022 cohort’s lab practical grades, final course grades, and survey data were used in statistical analysis. Classes disrupted by Covid-19 were excluded (2020 & 2021 cohorts). Results: 205 students from the 2019 cohort and 167 students from the 2022 cohort participated in this study, with 29 students from the 2022 cohort responding to the surveys. Students in the 2022 cohort had significantly higher lab practical scores in practicals 2 (p<.001, d=.361), 3 (p<0.001, d=1.038), 4 (p<.001< d=.487) and 5 (p<.001, d= .412). Survey data revealed that there was a significant increase (p<.001, d=1.203) in learning outcome achievement from pre-survey to post-survey. Students who correctly answered the ultrasound question performed significantly better on practicals 3 (p=.005) and 4 (p=.005) than those who missed the ultrasound question. Conclusion: These findings suggest that ultrasound imaging in a gross cadaver lab is beneficial to masters' students’ learning and understanding of gross anatomy and structural relationships. The utilization of ultrasound during cadaveric anatomy courses improves learning and outcome achievement in these graduate students. This hands-on instructional procedure would likely have the same effect on other cadaveric anatomy courses such as those in health sciences and medical curricula.Item Massage application to decrease anesthetic spread in brachial plexus blocks: A cadaveric study(2022) Coffman, Taylor; Fisher, Cara L.; Handler, Emma; Nash, DanielIntroduction: Peripheral nerve blocks of the brachial plexus have become increasingly popular for upper limb surgery due to the benefits of using regional anesthesia. However, anesthetic from supraclavicular nerve blocks can spread medially and anesthetize the phrenic nerve, leading to partial paralysis of the diaphragm, also known as hemidiaphragmatic paresis. The addition of ultrasound guidance has reduced the incidence of phrenic nerve involvement due to the ability to see the spread of anesthetic in real time. There has been little research focused on whether or not ultrasound massage could manipulate anesthetic distally down the arm and away from the phrenic nerve. The aim of this study is to determine if ultrasound massage can be used to minimize the spread of anesthesia medially. Methods: Four fresh frozen cadavers were injected with 15 mls of a 25:75 mixture of methylene blue and 2% lidocaine. The specimens were divided into control (n=4) and massage (n=4) groups. A nurse anesthetist used ultrasound guidance to perform a supraclavicular block. Immediately following injection, the massage group received 5 distally directed massage strokes with the ultrasound transducer. After 15 minutes, both groups were dissected and measurements of anesthetic spread were taken. The medial spread was measured in all four cadavers and distal spread was measured in three out of the four. Results: Spread of anesthetic medially was not reduced in the massage group when compared to the control group. Distal spread of the anesthetic was increased in the massage group when compared to the control group (p< 0.05). Conclusions: The similarity of medial spread between the two groups implies ultrasound massage application will not prevent phrenic nerve palsy any more than a traditional supraclavicular block. The increased distal spread of the anesthetic suggests this technique can improve anesthesia to the brachial plexus by increasing the area the anesthetic travels. Significance: The incidence of phrenic nerve palsy during a supraclavicular block has decreased since the introduction of ultrasound, but some reservations persist when using the technique in non-healthy patients. Phrenic nerve palsy can cause respiratory distress in patients with pre-existing respiratory condition. Given the small sample size, continued study of this method is needed to further evaluate if this method could be used to reduce incidence of phrenic nerve palsy.Item Massage Application to Decrease Anesthetic Spread in Supraclavicular Blocks: A cadaveric study(2022-08) Coffman, Taylor G.; Handler, EmmaItem Massage application to increase spread of local anesthesia in sciatic nerve blocks: a cadaveric study(2021) Robertson, Taylor; Fisher, Cara; Handler, Emma; Nash, DanielIntroduction: Sciatic nerve blockades are essential for treatment of a variety of lower limb pathologies. Due to the complexity and variation of anatomical landmarks, ultrasound (US) is used to guide injection of local anesthesia. In patients with thicker thigh girth (i.e., obese patients) excess tissue can distort US penetration, diminishing efficacy of the nerve block and/or post-operative pain. Dye tracing techniques have been used to test the effectiveness of nerve blocks, but there is little research on using massage to increase anesthetic spread. Therefore, this study will assess whether local massage can spread anesthetic proximal to the injection site. Methods: Fresh cadaveric legs were injected with 15cc's of 25:75 mixture of methylene blue dye and 0.5% bupivacaine. The specimens were divided into control (non-massage) and experimental (massage) groups. Nerve blockades with dye were performed by an anesthetist using US guidance at the popliteal fossa traveling proximally until the formation of the sciatic nerve, where the location was tagged. Immediately following, experimental specimens received repeated, proximally directed massages with the US transducer head. Specimens from both groups were dissected to expose the sciatic nerve. Measurements of the distance traveled from marked site of injection to proximal end of dyed area were measured and compared using statistical analysis. Results: Researchers expect significant difference in distance of injected materials proximal to injection site in the massage group compared to the experimental group. Conclusion: Post-injection massage can be used in clinical settings to increase efficacy of higher risk local anesthetic injections.Item Massage application to increase the spread of local anesthesia in sciatic nerve blocks: A cadaver study(2022) Robertson, Taylor; Fisher, Cara L.; Handler, Emma; Nash, DanielIntroduction: Sciatic nerve blocks are essential for surgical treatment of various lower limb pathologies. Due to the complexity and variation of anatomical landmarks, ultrasound (US) guided injection of local anesthesia has become common practice. In patients with thicker thigh girth (i.e., obese patients) excess tissue may distort US penetration thereby diminishing efficacy of the nerve block and/or cause severe post-operative pain. Dye tracing techniques have been used to test the effectiveness of nerve blocks, but there is little research on using massage to manipulate anesthetic spread. Therefore, the aim of this study is to assess the effects of massage to manipulate local anesthesia spread in sciatic nerve blocks. We hypothesize massaging after injection will increase the spread of local anesthesia compared to non-massage post injection. Methods: Forty un-fixed cadaveric legs were injected with a mixture of methylene blue dye and 2% Lidocaine Hydrochloride. Specimens were divided into non-massage (control) (n=20) and massage (n=20) groups. Sciatic nerve blocks were performed by a nurse anesthetist using US guidance at the popliteal fossa traveling proximally until the sciatic nerve was identified and the location was tagged. Immediately following, massage group specimens received five repeated proximally directed massages with the US transducer head. Specimens from both groups were then dissected to expose the sciatic nerve. Measurements of the distance traveled from marked site of injection to proximal end of dyed area were measured and compared. Results: Spread of local anesthesia in the inferior-superior direction was significantly higher in the massage group than the control group (p≤0.05). Conclusions: Massaging post-injection caused a greater spread of local anesthesia during sciatic nerve block. Significance: Sciatic nerve block techniques often utilize nerve stimulation to identify the sciatic nerve location. This may be due to lack of US penetration through the gluteus maximus muscle. In patients with thicker thigh girth due to subcutaneous fat, imaging visibility may be more difficult as well. Our findings suggest that clinicians may block the sciatic nerve at a more distal location with US guidance and manipulate the anesthesia to the region of interestItem Masticatory muscle morphology in early postnatal mice with osteogenesis imperfecta(2024-03-21) Ansari, Zahra; Miller, Courtney; Emmanuel, Tanusha; Handler, Emma; Gonzales, Lauren; Organ, Jason; Menegaz, Rachel A.Purpose: Osteogenesis imperfecta (OI) is a connective tissue disorder resulting from mutations in COL1A1 or COL1A2, responsible for encoding type I collagen alpha chains. While OI is primarily distinguished by manifestations of bone fragility, including recurrent fractures and bone deformities, muscle abnormalities have also been documented in those affected by OI. While prior research has shown postcranial muscle weakness in mouse models of OI, it remains unclear whether this also applies to feeding musculature and if these differences are present at birth or develop postnatally. This study investigates the development of the masticatory muscles during the early postnatal period in a mouse model. Our hypothesis posits that mice affected by OI will exhibit decreased muscle mass, and therefore potentially weaker muscles, in comparison to unaffected mice. Methods: Cranial tissues from OIM mice (B6C3Fe a/a-Col1a2oim/J) and unaffected wild type (WT) littermates were collected at day of birth (P0) and postnatal day 14 (P14). Tissues were fixed and stained with 1.25% buffered Lugol’s solution, then micro-CT scanned with a reconstruction of 0.02 mm3 voxels. 3D Slicer software was used to isolate and measure the volumes of the superficial masseter, deep masseter, and temporalis muscles. Muscle volumes were compared between genotypes using a Mann-Whitney U test. Results: At birth, no significant differences were observed in body mass or muscle volumes between OIM and WT mice. A trend was observed for OIM mice to have lower superficial masseter volumes compared to WT mice at P0, but this difference was not significant. At P14, OIM mice have significantly lower body weights (p=0.002). Data collection is ongoing for volumetric muscle data from the P14 stage. After birth, body masses diverge rapidly between OIM and WT mice. These growth curves suggest poor feeding performance during the suckling stage in OIM mice. Although masticatory muscle volumes (similar to body mass) start out similar between genotypes at birth, a trend for decreased superficial masseter volume in OIM mice suggests feeding musculature will also lag behind unaffected mice during early postnatal growth. Conclusion: The production of strain above an osteogenic threshold by feeding musculature is critical to typical craniofacial growth during early life. Weaker masticatory muscles may produce lower (yet still osteogenic) levels of strain, contributing to the midfacial hypoplasia seen in OIM mice. A better understanding of muscle development during this critical growth period will provide insight on feeding disorders seen in OI, and the development of the craniofacial phenotype in pediatric patients with OI.Item Neurocranial Growth in the OIM Mouse Model of Osteogenesis Imperfecta(2022-05) Husain, Tooba S.; Menegaz, Rachel A.; Handler, Emma; Gonzales, Lauren A.Item Neurocranial Growth in the OIM Mouse Model of Osteogenesis Imperfecta(2022) Husain, Tooba S.; Miller, Courtney; Steele, Ashley T.; Gonzales, Lauren; Handler, Emma; Organ, Jason; Menegaz, Rachel A.Osteogenesis imperfecta (OI) is a disorder of type I collagen characterized by abnormal bone formation and weakened bone architecture. Human patients with OI have larger cranial vaults (macrocephaly), altered cranial base morphology including basilar invagination and platybasia (skull base flattening), and midfacial underdevelopment. The neurocranial changes may affect both underlying nervous tissue and growth patterns of the facial skeleton. However, we still do not fully understand how and when these divergent morphologies occur. The aims of this study are: (1) to investigate the integrated development of the skull and the brain in amouse model of OI; and (2) to identify the developmental trajectories of these structures to facilitate future therapeutic interventions. We hypothesize that compared to unaffected mice, mice with OI will have decreased brain volumes due to an overall reduction in cranial size and decreased cranial base angles (CBA) due to platybasia. To test these hypotheses, we used the osteogenesis imperfecta murine (OIM or B6C3FE a/a-Col1a2/J), a model for the severe type III OI in humans, and unaffected wild-type (WT) littermates. Mice were imaged using in vivo micro-computed tomography (micro-CT) at the juvenile (week 4; 10 OIM/14 WT) and adult (week 16; 9OIM/11 WT) stages. All measurements were taken in 3D Slicer software. 82 cranial landmarks were used to calculate centroid size, an estimate of overall head size. The segmentations tool was used to create virtual endocasts as a proxy for brain volume. The angle tool was used to measure CBA in the midsagittal plane using threelandmarks: foramen cecum, midsphenoidal synchondrosis, and basion. Mann-Whitney U tests were used to compare centroid sizes, brain volumes, and CBA between the genotypes. Both juvenile (p=0.008) and adult (p=0.003) OIM mice were found to have absolutely smaller brains than WT mice. However, OIM mice also have significantly smaller cranial centroid sizes compared to WT mice (p=0.003, p< 0.001). When scaled to cranial size, juvenile mice had relatively larger brain volumes (p=0.016) butadult OIM relative brain volumes were not significantly different from WT. No significant difference was seen in CBA at the juvenile (p=0.065) or adult (p=0.171) stages, however a trend was observed for decreased CBA at the adult stage. These results suggest that neurocranial dysmorphologies in OI may be more severe at earlier stages of postnatal development. Previous analyses of these mice have documented relative skeletal macrocephaly in both juvenile and adults, however here we document an increase in relative endocranial volume only at the juvenile stage. A reduction in CBA during growth, possibly due to platybasia, may underlie this decoupling between external and internal cranial morphology. Future work will investigate the effect of CBA on facial growth and midfacial underdevelopment in these mice. A better understanding of the integration and growth trajectory of the neurocranium is foundational for formulating treatments to manage basicranial instabilities in patients with OI. Support or Funding Information Funding was provided by an Indiana University Collaborative Research Grant, Ralph W. and Grace Showalter Trust, and a UNTHSC Physiology & Anatomy SEED Grant.Item Osteogenesis Imperfecta: An analysis of the inner ear development in Mus musculus (house mouse) with comments on hearing quality(2022-05) Huston, Lila A.; Gonzales, Lauren A.; Handler, Emma; Menegaz, Rachel A.; Millar, J. CameronOsteogenesis imperfecta (OI), a developmental disorder of type I collagen, is known to cause hearing loss in ~ 60% of the diseased population. Identified forms include conductive hearing loss (17.4% of OI patients), involving loss of function within the ossicular chain, and sensorineural hearing loss (25.8%), resulting from damage to the cochlea, with the most predominant form being mixed hearing loss (56.8%), involving damage to both the cochlea and ossicles. While OI-related pathologies have largely focused on the middle ear, the pathological appearance of the cochlea (the organ most often compromised in OI-related hearing loss) has gained little focus. In this study, we examine OI-related pathologies on the cochlea in a mouse model for the severe type III OI, to document 1) the morphological differences in the inner ear for adult wildtype mice compared to OI mice in order to determine the anatomy of the diseased state, and 2) intraindividual variation between cochlea of WT and OI mice to determine potential asymmetry in the etiology of the inner ear. We hypothesize that cochlea in mice with OI will have less consistent morphology overall than their WT counterparts due to abnormal growth of the bony capsule. 4 week and 16 week old OIM mice (B6C3Fe a/a-Col1a2oim/J) (n=25) were compared to unaffected wildtype (WT) littermates (n=29) with no known hearing defects. High-resolution micro-CT scans were created for all specimens and 3D models and volumes of the cochlea were generated using 3D Slicer software. Two-tailed Mann-Whitney U-tests were used to investigate differences between 1) right and left ears of the same mouse to examine intraindividual symmetry and 2) differences in volumes between WT and OI cochlea. No major morphologic differences between OI and WT were observed, except for minor areas of higher ossification at the base of the cochlea, mostly within the OI sample. Within WT specimens, we observed little intraindividual difference in the cochlear volume (0-3%). Within OI specimens, significant differences were observed in cochlear volume between right and left ears in the same animal, indicating potential unilateral effects (Mann-Whitney U, p<0.05). When average WT and OI volumes were compared, there was much overlap between the two samples although the OI volumes had a significantly larger range than the WT range (Mann-Whitney U, p=0.704 (w16), p=0.703 (w4)). Overall, our results indicate that mice with OI are much more likely to have evidence of unilateral cochlear volume losses, despite very little difference in overall shape appearance, possibly due to bony capsule encroachment. This find indicates an extremely high potential for sensorineural and mixed hearing loss in OI-bred mice and elucidates at least one mechanism behind how this type of hearing loss might be occurring. Little is known about the pathological appearance of the cochlea in OI, leading to difficulty in managing hearing loss. Further investigation of the etiology and progression of cochlear pathologies will allow for better outcomes in hearing for those patients afflicted with OI-related hearing loss.Item Osteogenesis Imperfecta: Implications of Using Micro-CT for Visualizing Developmental Variation in the Middle and Inner Ear of OIM Mice(2023) Judd, Dallin; Stucki, Brenton; Miller, Courtney; Handler, Emma; Menegaz, Rachel A.; Gonzales, LaurenOsteogenesis Imperfecta: Implications of Using Micro-CT for Visualizing Developmental Variation in the Middle and Inner Ear of OIM Mice Dallin R. Judd1, Brenton R. Stucki1, Courtney A. Miller2, Emma Handler3, Rachel A. Menegaz2, Lauren A. Gonzales2 1 Texas College of Osteopathic Medicine, University of North Texas Health Science Center, TX 2 Department of Physiology and Anatomy, University of North Texas Health Science Center, TX 3 Department of Anatomy and Cell Biology, University of Iowa, IA Osteogenesis imperfecta (OI), also known as brittle bone disease, is a genetic bone disorder caused by mutations in the genes COL1A1 and COL1A2, which are responsible for encoding type I collagen. Much is known regarding the effects of the disease on cranial and postcranial elements. However, little is known regarding the pathogenesis and physical manifestations of OI in the ear despite the high rates of hearing loss in patients with OI (~60% of the population is affected). Because ossification or demineralization of structures in the ear may affect the efficacy of certain treatments like cochlear implants, this information deficit limits the treatment options available for OI patients. Thus, the purpose of our research is to visualize and document anatomic variation in the ears of mice bred to have the Type III OI genetic variant in order to better understand the cause of OI-related hearing loss. 3D models of the middle and inner ears were created from micro-CT scans that also employed two new contrast-enhanced methods to visualize the cochlea and middle ear (malleus, incus, and stapes). All CT scanning were done on the UNTHSC campus using the new Small Animal Imaging Facility (SAIF) as part of a previous study. The scan resolution was approximately 20μm. The studied WT and OIM mouse samples include three time points intended to capture a developmental sequence: 0-day-old (WT=20, OIM=29), 7-day-old (WT=23, OIM=23), and 14-day-old mice (WT=22, OIM=18). The visualization software Avizo was then used to digitally segment the bone of the inner ear and middle ear. Gross anatomic differences are currently being documented for each region. Previous work has shown higher levels of ossification and marked bony encroachment of the otic capsule onto the cochlea in the adult OIM mouse model, potentially damaging the soft tissue of the membranous labyrinth. This research uses micro-CT imaging designed to capture a developmental sequence, giving us the potential to elucidate how and when the bony intrusions are impacting surrounding structures. Insight into this anatomical damage may help further clarify OI-related pathology, including the distinction between hearing loss associated with the middle ear (conductive hearing loss) vs. hearing loss associated with the inner ear (sensorineural hearing loss). Furthermore, a preliminary analysis of the developmental sequence should provide insight into when these anatomical changes are first occurring. Upon completion, this research will demonstrate the efficacy of using these new imaging approaches for studying minute structures of the ear and may markedly advance our understanding of the pathogenesis of OI-related hearing loss.Item Pre-weaning craniofacial development in mice with Osteogenesis Imperfecta(2024-03-21) Miller, Courtney; Emmanuel, Tanusha; Gonzales, Lauren; Handler, Emma; Organ, Jason; Menegaz, Rachel A.The craniofacial region plays a pivotal role in various physiological functions, including mastication, speech, and respiration. Early life behaviors have a profound role in shaping adult structure and function. In the early stages of life, all mammals undergo the transition from suckling to mastication, a period coinciding with rapid cranial biomineralization. Osteogenesis imperfecta (OI), a genetic disorder that impacts the production of type I collagen, disrupts biomineralization, leading to craniofacial growth differences affecting overall quality of life. This study investigates the preweaning craniofacial growth trajectory in mice OI (the OIM mouse) compared to unaffected wild type (WT mice). We hypothesize that mice with OI will exhibit smaller overall size and greater craniofacial variation than WT mice due to the abnormal collagen synthesis during skull development. Micro-CT based geometric morphometric analyses of the OIM mouse model (B6C3Fe a/a-Col1a2oim/J) were used to compare craniofacial size and shape differences at birth (P0; n=27 OIM / 20 WT) and postnatal days 7 (P7; n=21/21) and 14 (P14; n=16/20). The SlicerMorph package for 3D Slicer software was used to generate landmark point clouds for the cranium and mandible. Dimension ratios were calculated as width/length for the crania. Principal component analysis with Procrustes ANOVA were used to examine differences between genotypes at each time point, and a canonical variate analysis (CVA) used to identify shape features that maximize the distinction between genotypes across all time points. Results reveal the development of significant differences in both shape and size between the genotypes following birth. At birth, size and shape are similar between genotypes. However, by P7 and P14, OIM mice are significantly (p<0.05) smaller and display pronounced shape changes (p<0.001) characterized by larger neurocranium and shorter viscerocranium. Additionally, OIM mice have significant mandibular alterations by P7 (p<0.001) - shorter ramus, more posterior position of the coronoid, and shorter and wider dental arcade. All of these changes align with the suckling developmental stage, suggesting changes in the ratio of growth between the neurocranium and the viscerocranium during early life. Widening the neurocranium while shortening the viscerocranium during this critical developmental stage alters the masticatory muscle line of action, consequently, influences the health of individuals with OI. These findings underscore the suckling stage’s significance in shaping the foundational structures for later life, providing insights into OI craniofacial development, and suggest potential benefits to directing interventions toward an earlier time point for more effective treatment of OI.Item Putting the Pieces Together of an Online Classroom with the Help of Jigsaw(2022) Bradley, Libby; Handler, EmmaPurpose: Anatomy has been deemed a cornerstone course within the health sciences. Recently, there has been an increase in online courses taught at university-level, including anatomy courses. Although there has been an increase in online teaching and learning in anatomy, there is still uncertainty regarding whether academic performance, satisfaction, and perceptions are equivalent between online and in-person anatomy courses. Additionally, throughout graduate courses, traditional learning (i.e., solely lecture-focused) has begun to transition with the implementation of active learning (i.e., an approach in which students are asked to engage in the learning process (not solely lecture-focused)). Previous research studies have established the effects of different active learning techniques implemented within in-person graduate anatomy courses, but little research has investigated the effects of active learning techniques implemented within online graduate anatomy courses. Therefore, a pilot study was conducted within an online Medical Science master's anatomy course measuring the perceived effects that jigsaw had on students' perception and satisfaction. Methods: Jigsaw was incorporated into 5 units of an online anatomy course. Students were randomly assigned into three expert groups, which were assigned objectives to review from lecture material. Then, two students from each expert group were assigned to teaching groups. In their teaching groups, each student created a short video to teach their designated objectives to their peers. At the end of the semester, students were asked to participate in the research study by completing a post-course survey that asked questions pertaining to course perceptions and satisfaction and their experiences regarding the active learning technique. Data was collected through Qualtrics and analyzed in NCSS using Spearman's correlation coefficient and Chi-squared tests. Results: Results from the post-course survey indicated that 77.3% of students (n=21) were satisfied with jigsaw. Moreover, students that used the teaching materials that their peers created during the teaching groups portion of jigsaw were 10% more satisfied than the students that did not (p< 0.05). Additionally, a significant, positive correlation was found when asked how effective jigsaw was when learning the course material compared to the helpfulness of jigsaw (p< 0.05). Conclusion: These findings suggest that the students that actively participated in jigsaw perceived more effectiveness and satisfaction than the students that did not. Researchers are expanding on this study with the implementation of several other active learning techniques to examine the effects when comparing academic performance, perceptions, and satisfaction. While the benefits of active learning are widely known within in-person courses, there is little research on the effects of active learning within online courses. Furthermore, there is no research investigating the effects of jigsaw implementation within an online graduate anatomy course. With the help of this study and future research, a greater understanding can be found concerning how students can best learn in an online learning environment, with the implementation of active learning.