Orthodontic treatment involving extraction of teeth, oftenly requires closure of extraction spaces. Thus space closure,is an important step in fixed Orthodontic mechanotherapy, solely dictated by clinician treatment objective, irrespective of method employed. It is individually tailored based on the diagnosis and treatment planning. Based on desired Orthodontic tooth movement, Friction mechanics or Frictionless mechanics can be used during space closure. Friction or sliding mechanics involves either moving the bracket along an arch wire or sliding the archwire though brackets and tubes. Whereas Frictionless mechanics involves closing loops fabricated either in a full or sectional arch wire. The objective of this book is to provide an overview of mechanics used in Space closure.