Reliability Of Lateral Cephalogram Versus Study Cast In Assessment Of Anchorage Loss With Corticotomy

: Objectives: The aim of the study was to compare the effectiveness of lateral cephalogram and study cast measurements in assessment of anteroposterior molar movement with corticotomy assisted en masse retraction. Materials and Methods: This retrospective study was done on pre and post treatment study casts and lateral cephalograms of previously treated twenty female patients, age range (18-25 years) with Class II division 1 malocclusion where orthodontic treatment entailed extraction of upper first premolars. Patients were orthodontically treated with preadjusted edgewise appliances. Anchorage was reinforced by transpalatal arch with engagement of second molar. En masse retraction of the maxillary anterior teeth using sliding mechanics. Flapless piezoelectric corticotomy was done. The anchorage loss was assessed through pterygoid vertical method on digitally traced lateral cephalograms. Maxillary casts were digitally scanned. The distance between medial end of third palatal rugae and central fossa of anchor molar was measured to evaluate the anteroposterior molar movement. Statistical Analysis was performed to compare the mean values of anchorage loss measured on lateral cephalograms and study models. Results: Anchorage loss measurements were statistically significant on both lateral cephalogram and study cast with corticotomy assisted en masse retraction. There was no significant difference between the mean horizontal movement of maxillary first molar measured on the lateral cephalogram and that was seen on the study cast. Conclusion: Study cast was as reliable as lateral cephalogram in assessment of anchorage loss. Either of the methods could be used to measure anteroposterior tooth movement.