Preheat the oven to 400 degrees F. Place sweet potatoes on a baking sheet and roast until easily pierced with a fork, about 1 hour. Peel the sweet potatoes while still hot. Combine the potatoes, butter, salt, orange juice, maple syrup, and chicken broth in a large bowl. Mash with a potato masher until the potatoes are smooth. Serve immediately. (This can be prepared a day ahead and reheated).