{'fraction_non_alphanumeric': 0.03157063930544594, 'fraction_numerical': 0.010260457774269928, 'mean_word_length': 4.686098654708521, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
[Investigation on the effects of different brackets on the three-dimensional direction of the arch in the non reduction treatment].

PURPOSE
To compare the three-dimensional effect between traditional brackets and Damon self- ligating brackets on the arch during non-extraction treatment.


METHODS
Forty-five patients with non-extraction treatment were included in this study. The patients were randomly divided into 3 groups. Patients in group A were treated with traditional brackets and Nickel titanium wire. Patients in group B were treated with Damon 3mx brackets and Cu-NiTi wire. Patients in group C were treated with traditional brackets and Cu-NiTi wire.Dentitions were aligned in each group according to the same order of arch wire and time. The widths of arch and cephalometric data, such as U1-SN, U1-PP, L1-MP, U6-PP (mm), L6-MP (mm) and other related datas, in T1 and T2 were measured and analyzed with SPSS 22.0 software package.


RESULTS
Expansion and protrusion of the arch were observed, but there was no significant difference before and after treatment among 3 groups.


CONCLUSIONS
There is no difference in the three-dimensional effect between Damon brackets and traditional brackets in non-extraction treatment of patients with mild crowding.