Optimum force system for intrusion and extrusion of maxillary central incisor in labial and lingual orthodontics

To achieve intrusion or extrusion, M:F ratios required in LaO were same i.e. 8:1 for aforementioned heights of bracket slot from incisal edge but different in LiO i.e. 0:1, 1:1, 2:1 and 3:1 for the heights of 3 mm, 4 mm, 5 mm and 6 mm respectively.