Variations in the Perception of Ideal Bracket Location and its Implications for the Pre-adjusted Edgewise Appliance

An investigation was undertaken of the variability in the perception of ideal bracket location for the pre-adjusted edgewise appliance by the same clinician (intra-clinician variability) and between different clinicians (inter-clinician variability). The effect of recent training and experience upon this variability, as well as the likely changes in crown inclincation and root apex positioning, was also assessed. Results show that both intra- and inter-clinician variability for the long axis of the clinical crown (LACC) angulation was large while very small variations occurred in the location of the long axis (LA) point. Experience and training significantly reduced the variability in LACC angulation, but had little effect on the LA point location. The likely clinical implications are limited to only minor changes in crown inclination and root apex position for the majority of clinicians. However, the extreme intra-clinician variations found in LACC angulation could well result in poor root apex positioning.