Box braids are known for the box like parts interwoven with extensions to generally get an astounding look. While extensions are used for this style, they're not required. In most cases, extra hair is used for an overall uniform look in length and thickness. When synthetic hair is added, the ends are often briefly burned in order to make the tips smooth. It necessarily doesn't have to be burned, they can be dipped into hot water just for same reason as been burned.