A medical device and methods for filling tissue are disclosed. The device has a first configuration for delivery into tissue to be filled and a second configuration in which the device either expands, or is forced to expand within the tissue to be filled. The exterior profile of the expanded device may be customized along its length, to achieve a desired result. The device is adapted to be placed in the skin, and may be used to reduce facial wrinkles or augment facial features such as the lips.