Exploring predoctoral dental student use of YouTube as a learning tool for clinical endodontic procedures.

PURPOSE/OBJECTIVES: The goal of the present study was to examine perceived barriers to achieving clinical competence in endodontics and explain how YouTube is used to supplement formal education in this discipline. METHODS: Postgraduate endodontic students conducted focus groups with fourth-year dental students at NYU College of Dentistry. The discussion was facilitated by a semistructured interview guide. Open-ended questions about participants' perceived barriers to clinical competency in endodontics, experiences using YouTube to learn about clinical endodontics, and preferences for video format learning were asked. Demographic information was gathered. Thematic analysis of data was conducted and data collection was terminated once saturation was achieved. RESULTS: Thirty fourth-year dental students were enrolled in the study. The majority, 96.7%, reported using YouTube as a learning tool for dental procedures and 83.3% to learn about endodontics, specifically. The following domains were explored during data analysis: barriers to clinical competency, YouTube uses/experiences, and content preferences. The following themes within barriers to clinical competency were identified: psychological, educational, and clinical. Within the YouTube domain, the following themes were examined: goals of use, timing and frequency of use, search strategies, benefit/ shortcomings of YouTube, and validity of content. Students primarily used YouTube to enhance confidence and understand procedural flow. CONCLUSION: YouTube videos were primarily used to help students overcome perceived educational and psychological barriers that resulted in gaps in confidence and knowledge of performing endodontic procedures. Dental students placed high value on easily accessible video content of limited duration, where clinical procedures were performed on live patients.

Metastatic breast cancer cells in lymph nodes increase nodal collagen density.

The most life-threatening aspect of breast cancer is the occurrence of metastatic disease. The tumor draining lymph nodes typically are the first sites of metastasis in breast cancer. Collagen I fibers and the extracellular matrix have been implicated in breast cancer to form avenues for metastasis. In this study, we have investigated extracellular matrix molecules such as collagen I fibers in the lymph nodes of mice bearing orthotopic human breast cancer xenografts. The lymph nodes in mice with metastatic MDA-MB-231 and SUM159 tumor xenografts and tumor xenografts grown from circulating tumor cell lines displayed an increased collagen I density compared to mice with no tumor and mice with non-metastatic T-47D and MCF-7 tumor xenografts. These results suggest that cancer cells that have metastasized to the lymph nodes can modify the extracellular matrix components of these lymph nodes. Clinically, collagen density in the lymph nodes may be a good marker for identifying lymph nodes that have been invaded by breast cancer cells.