Abstract
OBJECTIVES: Andrews six elements was used to explore the possible influences of gender, extraction/non-extraction, and different bracket types on the evaluation of orthodontic treatment outcome. METHODS: Digital data from 320 selected orthodontic cases in Kunming Medical University Affiliated Stomatological Hospital during the period of 2016-2020 were divided into groups in accordance with gender, tooth extraction, and type of orthodontic brackets (DamonQ self-ligating brackets and MBT brackets). Measurement was performed using Andrews six elements as standard. The mean and standard deviation of each individual score and total score for different groups were calculated and statistically tested. RESULTS: The differences in total scores between female and male cases exhibited no statistical significance (P>0.05). By contrast, the scores in skeletal width change of the maxilla between extraction cases and non-extraction cases presented statistical significance (P<0.05). Moreover, the scores in the anteroposterior change in the position of the maxillary incisors, the bucco-lingual border change of the mandibular arch, and the skeletal width change of the maxilla between the DamonQ self-ligating bracket and MBT bracket cases presented statistical significance (P<0.05). The cases with DamonQ self-ligating brackets had significantly lower scores than the cases with MBT brackets in the bucco-lingual border change of the mandibular arch, the skeletal width change of the maxilla, and the anteroposterior change in position of the maxillary incisors. CONCLUSIONS: Digital 3D models can be used in the clinical retrospective studies of patients after orthodontic treatment. These models can be measured repeatedly and have clinical application value. For cases with incomplete orthodontic treatment, the control of the anteroposterior position of the incisor and the width of the arch of the upper tooth is crucial. Total treatment efficiency between female and male cases exhibited no difference, but the skeletal width change of the maxilla between extraction and non-extraction cases may exert an effect on cases with complete orthodontic treatment. The group that used DamonQ self-ligating brackets may achieve good adjustment of the bucco-lingual border change of the arch.