Final answer:
Fixed appliances, commonly known as braces, are used in orthodontics to realign teeth by applying continuous pressure through wires.
Step-by-step explanation:
The statement that fixed appliances are also known as braces is true. Braces are a type of orthodontic fixed appliance used to correct dental issues by applying continuous pressure over a period of time to slowly move teeth into a desirable alignment. This is achieved through the tension applied by a wire that runs through the braces, as demonstrated in the referenced figures, where the force applied by the wire, Fapp, aims straight towards the back of the mouth to correct the position of a protruding tooth.