目的:评估上颌切牙的2D和3D自然对称性。
方法:对59名年轻的成年志愿者进行上颌藻酸盐印模。性别,正畸治疗史,并收集了优势手。对于2D分析,使用数字卡尺测量上颌铸模。对于3D分析,使用实验室扫描仪扫描铸件,并评价对侧切牙唇面对称性。进行了曼-惠特尼测验和学生t检验,α=0.05。
结果:结果表明对侧中切牙或侧切牙之间缺乏相同的长度,具有最小的相同宽度测量值。68%的中切牙和73%的侧切牙显示长度差异超过0.2毫米。中切牙在宽度上比侧切牙表现出更多的相似性,61%的中切牙和47%的侧切牙在0.2毫米以下有差异。高度不对称的对侧牙齿之间的差异位于过渡线上。性二态的影响,正畸因素,而主手在门牙对称性上无统计学意义。
结论:天然上颌切牙的2D和3D对称性很少见。3D对称性在正畸治疗状态中保持一致,性别,和支配的手,表明它独立于这些参数。
结论:为了实现自然和美观的微笑康复,必须很好地理解上颌切牙的对称性。在我们的研究中,上颌切牙的2D和3D对称很少发生,但是中切牙在宽度上比侧切牙更相似,在0.2毫米的差异。另一方面,高度不对称的对侧牙齿之间的差异位于过渡线。这些结论应包含在进一步的计算机辅助三维微笑设计中。
OBJECTIVE: To assess the 2D and 3D natural symmetry of the maxillary incisors.
METHODS: Maxillary alginate impressions were taken of 59 young adult volunteers. Gender, orthodontic treatment history, and dominant hand were collected. For 2D analysis, a digital caliper was used for measurements on maxillary casts. For 3D analysis, the casts were scanned using a lab scanner, and the labial surface symmetry of contralateral incisors was evaluated. Mann-Whitney tests and Student\'s t-test were performed, α = 0.05.
RESULTS: Results indicated a lack of identical lengths among contralateral central or lateral incisors, with minimal occurrences of identical width measurements. 68% of central incisors and 73% of lateral incisors showed differences in length exceeding 0.2 mm. Central incisors showed more similarities than lateral incisors in width, with 61% central incisors and 47% lateral incisors having differences under 0.2 mm. The differences between highly asymmetrical contralateral teeth are situated at the transitional lines. The influence of sexual dimorphism, orthodontic factors, and the dominant hand on incisors\' symmetry was not statistically significant.
CONCLUSIONS: 2D and 3D symmetry of the natural maxillary incisors are rare. 3D symmetry remains consistent across orthodontic treatment status, gender, and dominant hand, suggesting its independence from such parameters.
CONCLUSIONS: To achieve a natural and aesthetic smile rehabilitation, the symmetry of the maxillary incisors must be well understood. In our study, 2D and 3D symmetry of the maxillary incisors occurred rarely, but central incisors showed more similarities than lateral incisors in width, with differences under 0.2 mm. On the other hand, differences between highly asymmetrical contralateral teeth are situated at the transitional lines. These conclusions should be included in further computer-assisted three-dimensional smile designs.