Introduction: The right and the left atria of the human heart communicate with the right and left ventricle through the respective orifices. These orifices are guarded by atrioventricular valves. The right atrioventricular valve is called as tricuspid valve because it has three cusps. While the left atrioventricular valve referred to as mitral valve, or bicuspid valve because it has two cusps. Presence of one or multiple accessory leaflets in the valves and absence of one or multiple leaflets in the valves is known. Data regarding shape of cusps or leaflets on cadaveric study in literature is limited. Hence, an attempt is made to study variation in the shape of leaflets of valves and the shape of accessory leaflets when seen. Shape of leaflets play a key role in designing the prototype of valves for valve replacement. Materials and Methods: A total of 120 cadaveric human hearts were dissected in the Department of Anatomy at Padmashree Dr. D. Y. Patil Medical College, Pimpri, Pune. Data were also collected from Anatomy Departments of other Medical Colleges. Variations in the shape of leaflets of the mitral and tricuspid valves were noted. Presence of accessory leaflets and their shape was also recorded. Results: Leaflets of both the valves were predominantly triangular in shape. The shape of accessory leaflets was also triangular. However, the leaflets did show variations in shape such as rectangular, D shape, semicircular. The incidence and significance of the variations in the shapes are discussed in the study. Conclusion: Atrioventricular valve leaflets show numerous variations in the shapes. Such diversity in the shapes of valves is of immense value in designing prototype of mitral and tricuspid valve prosthesis. However, this is a study done by dissection on static hearts. In life, there may be subtle changes in the shape of valves. The study should be extended further by doing observations on two-dimensional echo and transesophageal echocardiography.
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