Efficiency Evaluation Of Maxillary Molar Distalization Using Invisalign Based On Palatal Rugae Registration

Introduction:This study attempted to evaluate Invisalign efficiency by comparing the actual achieved clinical outcome to the anticipated maxillary molar distalization movement presented by Clincheck program employing the palatal rugae area for digital models registration,alignment,and evaluation.Increasing the physician’s awarance of Invisalign appliance ability may contribute to expect changes and taking targeted steps to reduce the likelihood of mid-course correction or retreatment attempt in the future.Methods:This research sample consisted of thirty-eight adult participants with an average of 25.4 years of age who have been suitable to be treated with Invisalign aligner therapy and required distalization of their upper molars to correct different malocclusion.Two digital models were generated prior to and immediately after maxillary 1^stand 2^ndmolar distalization was achieved using an i Tero intra-oral scanner.By selecting the area palatal rugae for the registration process,the two digitized treatment models were superimposed using the GOM inspect software.The predicted tooth movement derived from the tooth movement table of Clincheck compared to the achieved clinical values.One hundred forty-two maxillary molars（71-first molar and 71-second molar）were measured for distal movement and the role of composite attachment in the distalization process,and 228 upper anterior teeth were evaluated for anterior anchorage loss.Results:The overall efficiency of upper molar distal movement produced by Invisalign was73.8 percent,with the maxillary first molar demonstrating a slightly higher efficiency（75.5percent）than the maxillary second molar（72.2 percent）when a mean distalization movement of 2.6mm was prescribed.Maxillary 1^stand 2^ndmolar anticipated distal movement（P<0.0001）have shown significant differences from the achieved clinical outcome.The result of presence or absence of tooth-colored attachments for the upper 1^stmolar（P=0.552）and upper 2^ndmolar（P=0.941）demonstrated no significant differences statistically.Additionally,results of anterior anchorage loss in reactive response to molar distal displacement revealed significant correlation for upper central incisor（r=0.3900,P<0.008）,and lateral incisor（r=0.3595,P<0.013）,while no significant correlation for canine（r=0.1307,P=0.217）.Conclusions:Identification and management of the counter-effects are vital if maxillary molars are planned to move distally,particularly if the patient is originally described with a large overjet so that the need to apply overcorrection or the employment of auxiliaries can be anticipated earlier.When a mean distalization movement of 2.6mm was prescribed,Invisalign can be utilized effectively in adult patients seeking orthodontic treatment.