BIOMECHANICS: Patient Preparation -- Initial arches to align and level the occlusal plane -- Rotated teeth -- Extraction spaces -- Anchorage control -- Rational use of elastics -- Ideal final arches. CLINICAL APPLICATIONS: Correction of the lower anterior crowding -- Correction of Class II in adult patients -- Normalization of the deep-bite -- The best protocol to extraction cases -- Lingual orthodontics in children. FINISHING IN LINGUAL ORTHODONTICS: Finishing procedures: how to enhance esthetics -- Long term  results -- Summary and outlook.