Background and Aim: The purpose of this study was to compare labial and lingual forces for the rate of canine retraction and three dimensional control of molar and canine using sliding mechanics.
Methods: Ten patients with Angle’s Class I malocclusion with bimaxillary protrusion indicated for first premolar extraction were selected and a split mouth study was designed: 40 canines were divided into four groups based on the arch and type of force: UB (upper canine - labial force), LB (lower canine – labial force), UL (upper canine – lingual force), LL (lower canine- lingual force). The rate of retraction of canine, molar and canine rotation, molar and canine angulation and molar anchorage loss in sagittal and vertical plane was assessed using study models and orthopantomograph (OPG). Paired and unpaired t test were used for intra and inter group comparison. The level of significance was set as .05.
Results: The rate of canine retraction was significantly (P<.001) faster for labial forces than lingual forces using sliding mechanics. However, significantly (P<.001) greater amount of molar rotation was observed using lingual forces. There was no significant difference (P<.05) regarding canine rotation using labial forces. The molar anchorage loss in sagittal plane was significantly (P<.001) lesser using lingual forces.
Conclusion: Canine retraction was faster when labial forces were applied using sliding mechanics whereas 3D-molar control was better when lingual forces were applied which is advantageous for critical anchorage cases.