四尖圆内旋轮线, 四尖内摆线

hypocycloid of three cusps four of a kind imperial collection of four to the power of four within the four corners of four four-flush four poles four corners two-four four-wheeler hypocycloid cusps of mitral valve tipping of cusps Abnormal number of cusps cusps of pulmonary cusps of pulmonary valve restoration of cusps cusps of aortic valve Cusps cusps Supernumerary cusps of mitral valve prolate hypocycloid