RESUMEN
Objective To explore the related factors that might had effect on orthodontic patients' esthetic evaluation of axial dental midline angulation from three aspects which are ideal value,detectable value and tolerable value.Methods Photographs of a smiling woman was digitally manipulated to produce models with left or right maxillary axial dental midline angulations in 2° increments.These digital photographs models were used to develop an electronic questionnaire in combination with corresponding guidance for each question.The electronic questionnaire was applied to investigate the esthetic evaluation of axial dental midline angulation from 222 orthodontic patients who complied with the inclusion criteria.Esthetic evaluation included three aspects,the ideal value,the detectable value and the tolerable value,which represented the degrees of maxillary axial dental midline angulations the patients considered to be ideal,detectable and tolerable,respectively.The patients' personal information and clinical orthodontic examination results were collected as well.Results The mean detectable value and tolerable value were 4.9° and 9.7°,the median of detectable value and tolerable value were 5°and 9.5°.Logistic regression analysis was applied to explore the influence of seven factors on each evaluator's ideal value,detectable value and tolerable value.The seven factors were gender,marriage condition,education level,orthodontic treatment condition,malocclusion index,dental esthetic rating from others and from themselves.The statistical analysis indicated education level and orthodontic treatment condition were the influential factors of detectable values,while the tolerable values were influenced by the education level and gender.The ideal value converged to 0° and none of the factors had effect on it.Conclusions The education level,orthodontic treatment condition and gender are considered to be the influential factors of the esthetic evaluation of axial dental midline angulation.