Evaluating The Efficacy Of Smarttrack On Rotating Anterior Tooth And Measuring Factors By Using Categorical Regression Analysis

Objective:In this study,we evaluated the clinical efficacy of SmartTrack aligner material on anterior tooth undergoing rotational movement about 15 ~ 30 degrees by calculating accuracy and the differences between predicted and achieved amounts,and examined the impacts of age,sex,the location of the teeth,the amount of predicted rotational movement,attachments,interproximal reduction,and the total number of active aligners on anterior tooth undergoing rotational movement.Materials and Methods:A total of 212 anterior teeth undergoing rotational movement about 15~30 degrees were selected from the four location of the teeth including maxillary central incisor,maxillary lateral incisor,mandibular central incisor and mandibular canine.Those anterior teeth belong to 123 patients aging from 10 to 45.All patients have received orthodontic treatment with SmartTrack(LE30)aligner material.They completed their first series of aligners and had a refinement.Attachment usage,IPR prescription,the total number of active aligners,initial and predicted models were obtained from the initial ClinCheck.Achieved models were obtained from the refinement ClinCheck.The amount of predicted tooth movement and the amount of achieved tooth movement for rotational movement were determined by the way of a surface/surface matching algorithm using the 3-dimensional image analysis software NX imageware.The accuracy and the differences between predicted and achieved amounts were calculated from the amount of predicted tooth movement and the amount of achieved tooth movement for rotational movement.Data were analyzed using descriptive statistics,factor and categorical regression analyses(CATREG).Categorical regression analyses were used to investigate predictor variables.And a subgroup analysis was performed.Results:When the amount of rotational movement was 15~30 degrees,the mean accuracy of anterior rotational movement was 77.33%,and the mean differences between predicted and achieved amounts was 4.46°.Age,the location of the teeth,interproximal reduction were the significant predictors of the accuracy of anterior rotational movement,while age,interproximal reduction,the location of the teeth,the amount of predicted rotational movement were the significant predictors of the differences between predicted and achieved amounts.The younger the age is,the smaller the amount of predicted rotational movement is,the better the expression of rotational movement of the anterior tooth is;the expression of rotational movement is more predictable when IPR is not prescribed;the expression of rotational movement varies with different locations of the tooth,among which the maxillary lateral incisors are the worst.However,sex and the total number of active aligners had no significant effect on the expression of rotational movement.Subgroup analysis showed that in the mandibular canine with no IPR group,the expression of rotational movement was significantly increased by optimized rotation attachment,optimized root control attachment or rectangular attachment.Conclusions:The SmartTrack aligner material can predictably derotate anterior teeth about 15~30 degrees.The efficacy was found to decrease with age.Because the expression of rotational movement of the maxillary lateral incisors is the worst,very close monitoring of the maxillary lateral incisors is recommended.It is effective in controlling rotational movement of rounded teeth,while using an optimized rotation attachment,optimized root control attachment or rectangular attachment.Prescribe interproximal reduction may decreased the predictability of rotational movement.The smaller the amount of predicted rotational movement is,the smaller the differences between predicted and achieved amounts is,suggesting that when developing the ClinCheck treatment plan,care should be taken to adjust all those unnecessary movements and simplify the treatment plan to increase predictability and reduce the occurrence of tracking issue.