A quick method to expose the structures and relations of the middle ear and inner ear by cadaveric dissection.

INTRODUCTION: The temporal bone contains structures related to hearing and balance, and is a valuable learning resource for medical students and trainee surgeons. The middle ear and inner ear are difficult to demonstrate by cadaveric dissection as the structures are closely contained in a small space in the dense temporal bone. Consequently, the teaching and learning of the ear are largely relegated to virtual and theoretical images, and models, which has resulted in a knowledge gap in medical students and prospective surgeons. The present study aimed to elucidate a technique that exposes the structures and relations of the middle and inner ear by cadaveric dissection. MATERIALS AND METHODS: Forty-seven adult formalin-fixed cadaveric specimens were dissected by the proposed technique. The method was evaluated based on the extent of the structures exposed and time taken for dissection. RESULTS: The method exposed all the contents and relations of the middle and inner ear, including the course of the facial nerve in the petrous temporal bone, in a few minutes, without use of specialized instruments like saw, drill, endoscope, operating microscope or electric trephine. CONCLUSION: This dissection method combines maximal exposure of the structures and relations of the middle and inner ear with a short dissection time, sans use of specialized tools. It can be incorporated in the gross anatomy curriculum for medical studentsdue to the short dissection time and completeness of structures exposed. The prosected specimen can also be plastinated for use as a teaching-learning resource for medical students and surgeons.

Bee Honey as a Safer Alternative for Routine Formalin Fixation.

Background Formaldehyde (10% buffered formalin) is still in use as the gold standard fixative in the field of biology however, as reported by Occupational Safety and Health Administration (OSHA) the use of formalin causes health hazards due to its toxicity. Hence, we considered to substitute formalin with natural Bee-Honey to achieve a formalin free laboratory for preservation of the biological specimens. Objective To assess the efficacy of honey as a fixative agent for the preservation of the tissue specimens and to study their cellular and structural characteristics by using routine stains, special stains and Immunohistochemistry (IHC) and compare its effectiveness with the currently, universally accepted formalin fixation. Method Our study contained sample size of 10 tissue specimens. All samples were fixed in two different solutions one in honey and other in conventionally used formalin solution for 24 hrs in room temperature and then were routinely processed, sectioned and stained using routine, special stains and with immuno-histochemical markers. The slides were viewed by two independent examiners and the entire procedure was blind folded. Result We obtained good comparable results with bee honey for Hematoxylin and Eosin, special stains including immunohistochemistry when compared to formalin fixed tissues. Conclusion Based on the observations of this study, it can be suggested that natural bee honey could be a safer alternative to formalin as a fixative, considering the health hazards of formalin.