Ballet dancer diagnosed with os trigonum; however, i have no pain en pointe. i only have pain after intense jumps and prolonged demi-pointe or pli. ?

An os trigonom: Is simply an extra bone. So, it would be important to figure out what is specifically causing the pain. Is your flexor tendon to the big toe inflamed at the back of the talus etc? This would be visualized on an MRI which if you haven't had would be a good idea. The issue then becomes how to treat....In a ballerina i would likely advise against any steroid usage. Perhaps, a period of rest/therapy.

Conservative: It is great that you are not having symptoms most of the time. Ballet is extremely rough on the feet. The problem comes from the tendons and ligaments sliding around the bone and becomes irritated with extreme plantar flexion. Physical therapy such as electrical stimulation and therapeutic ultrasound are great adjuncts to such strains and overuse. Try all conservative means first.