Sentence:  Not only does the attachment on the tooth surface (called a <WSD>bracket</WSD>) allow the tooth to be moved vertically or tilted, but also a force couple can be generated by the interaction between the <WSD>bracket</WSD> and an archwire running through the <WSD>bracket</WSD>. 
Meaning of the word marked with <WSD> tags:  Any intermediate object that connects a smaller part to a larger part, the smaller part typically projecting sideways from the larger part.