An analysis of influencing factors of attachment loss in clear aligner treatment

Objective The purpose of this study was to analyze the influencing factors of attachment loss in clear aligner treatment. Methods A clinical observation was performed on 1-year follow-up clinical data of 51 patients who had clear aligner treatment with 1091 attachments. The status of attachment loss was recorded. Different factors affecting attachment loss were analyzed. Associations between these variables and attachment loss were analyzed using univariate analyses and multivariable logistic regression. Results Univariate analyses revealed that the factors affecting the attachment loss were molar attachment(losing rate=22.4%, P=0.006), traditional attachment(losing rate=20.4%, P=0.000), having food without appliance(losing rate=18.3%, P=0.001) and aligner removal frequency more than or equal to five times a day(losing rate=20.2%, P=0.014). However, upper or lower teeth, first bonding or second bonding, choice of food and removal method of clear aligner had no impacts on attachment loss according to univariate analysis. The geometry of attachment (P=0.001, OR=1.782), aligner removal frequency (P=0.031, OR=1.440) and presence or absence of appliance when having food (P=0.001, OR=0.451)were proved to be significant independent predictors of attachment loss with multivariable logistic regression analysis. Having food with appliance may be a disincentive of attachment loss. Conclusions The traditional attachment and aligner removal frequency ( more than or equal to five times a day) may lead to attachment loss. Having food with appliance may prevent attachment loss. Key words: Clear aligner; attachments loss; influencing factors