Borba Alexandre Meireles, José da Silva Everton, Fernandes da Silva André Luis, Han Michael D, da Graça Naclério-Homem Maria, Miloro Michael
Researcher, Program on Integrated Dental Sciences, Faculty of Dentistry, University of Cuiabá, Cuiabá, MT, Brazil; Post-Doctorate Researcher, Department of Oral and Maxillofacial Surgery, Traumatology and Prosthesis, Faculty of Dentistry, University of São Paulo, São Paulo, SP, Brazil; Visiting Researcher, Department of Oral and Maxillofacial Surgery, University of Illinois-Chicago, Chicago, IL.
Former Master of Science Student, Master of Science Program on Integrated Dental Sciences, Faculty of Dentistry, University of Cuiabá, Cuiabá, MT, Brazil.
J Oral Maxillofac Surg. 2018 Aug;76(8):1746-1752. doi: 10.1016/j.joms.2018.01.002. Epub 2018 Jan 12.
To verify predicted versus obtained surgical movements in 2-dimensional (2D) and 3-dimensional (3D) measurements and compare the equivalence between these methods.
A retrospective observational study of bimaxillary orthognathic surgeries was performed. Postoperative cone-beam computed tomographic (CBCT) scans were superimposed on preoperative scans and a lateral cephalometric radiograph was generated from each CBCT scan. After identification of the sella, nasion, and upper central incisor tip landmarks on 2D and 3D images, actual and planned movements were compared by cephalometric measurements. One-sample t test was used to statistically evaluate results, with expected mean discrepancy values ranging from 0 to 2 mm. Equivalence of 2D and 3D values was compared using paired t test.
The final sample of 46 cases showed by 2D cephalometry that differences between actual and planned movements in the horizontal axis were statistically relevant for expected means of 0, 0.5, and 2 mm without relevance for expected means of 1 and 1.5 mm; vertical movements were statistically relevant for expected means of 0 and 0.5 mm without relevance for expected means of 1, 1.5, and 2 mm. For 3D cephalometry in the horizontal axis, there were statistically relevant differences for expected means of 0, 1.5, and 2 mm without relevance for expected means of 0.5 and 1 mm; vertical movements showed statistically relevant differences for expected means of 0, 0.5, 1.5 and 2 mm without relevance for the expected mean of 1 mm. Comparison of 2D and 3D values displayed statistical differences for the horizontal and vertical axes.
Comparison of 2D and 3D surgical outcome assessments should be performed with caution because there seems to be a difference in acceptable levels of accuracy between these 2 methods of evaluation. Moreover, 3D accuracy studies should no longer rely on a 2-mm level of discrepancy but on a 1-mm level.
在二维（2D）和三维（3D）测量中验证预测的手术移动与实际获得的手术移动，并比较这两种方法之间的等效性。
对双颌正颌手术进行回顾性观察研究。将术后锥形束计算机断层扫描（CBCT）图像与术前扫描图像进行叠加，并从每张CBCT扫描图像生成一张侧位头影测量X线片。在二维和三维图像上识别蝶鞍、鼻根和上颌中切牙切端标志点后，通过头影测量比较实际移动和计划移动。采用单样本t检验对结果进行统计学评估，预期平均差异值范围为0至2毫米。使用配对t检验比较二维和三维值的等效性。
46例的最终样本通过二维头影测量显示，水平轴上实际移动与计划移动之间的差异对于预期平均值0、0.5和2毫米具有统计学意义，而对于预期平均值1和1.5毫米无统计学意义；垂直移动对于预期平均值0和0.5毫米具有统计学意义，而对于预期平均值1、1.5和2毫米无统计学意义。对于三维头影测量的水平轴，预期平均值0、1.5和2毫米存在统计学意义上的差异，而预期平均值0.5和1毫米无统计学意义；垂直移动对于预期平均值0、0.5、1.5和2毫米显示出统计学意义上的差异，而对于预期平均值1毫米无统计学意义。二维和三维值的比较在水平轴和垂直轴上均显示出统计学差异。
二维和三维手术结果评估的比较应谨慎进行，因为这两种评估方法在可接受的准确性水平上似乎存在差异。此外，三维准确性研究不应再依赖2毫米的差异水平，而应依赖1毫米的差异水平。
