INFLUENCE OF DAMON AND CONVENTIONALBRACKETS ON SOFT TISSUES AND SMILE ESTHETICS ENSUING NON-EXTRACTION TREATMENT

Objectives: Facial and smile esthetics are the principal reasons nowadays for which patients pursue orthodontic treatment and so, the knowledge of the effects of orthodontic treatment on facial esthetics is of paramount importance to orthodontists. Orthodontic literature contains more studies comparing the effects of Damon and Conventional MBT brackets on skeletal and dental structures than on soft tissues and smile esthetics. This study aims to evaluate and compare soft tissues and smile esthetic changes in non-extraction cases treated using Damon and Conventional MBT brackets.

Methods: Thirty participants were divided into 2 groups, Group I comprised of 15 subjects treated using Damon brackets and Group II comprised of 15 subjects treated using Conventional MBT brackets. Smile esthetic parameters were evaluated on frontal smiling photographs in form of ratios while linear and angular measurements were made on lateral cephalograms.

Results: For soft tissue parameters, in Damon group, labrale inferior to E-line and Na-Pog line increased significantly, sulcus inferior to E-Line decreased significantly and nasolabial angle increased significantly. In conventional group, labrale superior to Na-Pog line increased significantly and upper lip length increased significantly. When mean treatment changes in both groups were compared, no significant difference in any linear or angular soft tissue parameters was found except for significant increase in E-Line to labrale inferior in Damon group. For smile esthetic scores, visible dentition width to smile width ratio increased significantly in damon group while smile height to smile width ratio decreased significantly in conventional group. When mean treatment changes in both groups were compared, no significant difference was found.

Conclusions: Both soft tissue and smile esthetics finished in a similar manner after treatment and so, the overall choice of non-extraction treatment modality should not be dependent on the type of bracket system.

研究目的：如今，面部与微笑美学是患者寻求正畸治疗的主要动因，掌握正畸治疗对面部美学的影响对正畸医师而言极为重要。目前正畸领域文献中，对比戴蒙托槽（Damon bracket）与传统MBT托槽（MBT bracket）对骨骼及牙齿结构影响的研究，远多于针对软组织与微笑美学的相关研究。本研究旨在评估并对比采用戴蒙托槽与传统MBT托槽治疗的非拔牙病例中，软组织与微笑美学的变化情况。

研究方法：本研究纳入30名受试者，分为两组：Ⅰ组为15例采用戴蒙托槽治疗的受试者，Ⅱ组为15例采用传统MBT托槽治疗的受试者。微笑美学参数通过正面微笑照片以比值形式进行评估，同时在头颅侧位片（lateral cephalogram）上开展线性与角度测量。

研究结果：针对软组织参数，戴蒙组中，下唇点至E线（E-line）的距离、鼻根点-颏前点（Na-Pog）线距离均显著增加，下唇沟至E线的距离显著降低，鼻唇角显著增大；传统MBT组中，上唇点至Na-Pog线的距离显著增加，上唇长度显著增加。对比两组治疗后的平均变化量，除戴蒙组中E线至下唇点的距离显著增加外，其余线性与角度软组织参数均无显著差异。在微笑美学评分方面，戴蒙组可见牙列宽度与微笑宽度的比值显著升高，而传统MBT组微笑高度与微笑宽度的比值显著降低。对比两组的平均治疗变化量，未发现显著差异。

研究结论：两种托槽系统治疗后，软组织与微笑美学的改善效果均趋于一致，因此非拔牙正畸治疗方案的整体选择，不应依赖于托槽系统的类型。