基于下颌运动轨迹数据指导的数字化全冠咬合面精度评价

Assessment of the reproducibility of occlusal morphology for digital full crown designed by mandibular trajectory data

目的 :定量比较基于下颌运动轨迹数据及平均值虚拟[牙合]架指导设计的全冠修复体咬合面的精度。方法 :选择全口恒牙列完整、符合入组标准的15名志愿者作为研究对象,其中,男9例,女6例,平均年龄22~30岁。分别利用下颌运动轨迹数据及平均值虚拟[牙合]架在修复设计软件中指导数字化全冠的咬合面设计,并分别与原始天然牙咬合面进行形态偏差比较。采用SPSS 25.0软件包对数据进行统计学分析。结果:基于下颌运动轨迹数据及平均值虚拟[牙合]架指导设计的修复体咬合面总体偏差为平均正向偏差(269.9±63.1)和(318.7±51.3)μm,平均负向偏差(-175.8±78.2)和(-253.7±65.6)μm,均方根值(root mean square,RMS)(267.1±84.9)和(304.1±82.2)μm。修复体上解剖特征点在垂直方向上与原始天然牙咬合面相应解剖特征点的距离为近中颊尖(197.6±86.2)和(288.0±79.6)μm,远中颊尖(176.3±85.3)和(297.7±63.2)μm,近中舌尖(171.6±62.4)和(246.4±62.8)μm,远中舌尖(166.2±64.6)和(232.5±70.7)μm,中央窝(104.9±42.2)和(219.1±69.1)μm。2种方法指导设计的全瓷冠与原始天然牙咬合面的平均负向距离、RMS值以及在中央窝最低点和远中颊尖最高点的垂直距离具有统计学差异(P<0.05)。结论:下颌运动轨迹数据和平均值虚拟[牙合]架指导设计的数字化全冠与原始天然牙咬合面形态存在一定差异,下颌运动轨迹数据组的偏差更小。

PURPOSE: To metrically assess the reproducibility of mandibular trajectory data and mean frame parameter in guiding the design of occlusal morphology of prosthesis. METHODS: Fifteen subjects with complete dentition were selected, including 6 females and 9 males, with an average age of 22-30 years old. The mandibular trajectory data and mean frame parameter were used to guide the design of occlusal morphology of the prosthesis in the CAD system, then the oc-clusal morphology was compared to the original natural teeth. The data were statistically analyzed by SPSS 25.0 software package. RESULTS: The general deviation of occlusal morphology between the prosthesis guided by mandibular trajectory data and mean frame parameter with the natural teeth was as follows: mean positive distance was(269.9 ±63.1) μm,(318.7±51.3) μm;mean negative distance was(-175.8±78.2) μm,(-253.7±65.6) μm;root mean square(RMS) was(267.1±84.9) μm and(304.1±82.2) μm. The vertical distance on mesial buccal cusp was(197.6±86.2) μm and(288.0±79.6) μm,distal buccal cusp was(176.3±85.3) μm and(297.7±63.2) μm, mesial lingual cusp was(171.6±62.4) μm and(246.4±62.8) μm,distal lingual cusp was(166.2±64.6) μm and(232.5±70.7) μm, central fossa was(104.9±42.2) μm and(219.1±69.1) μm.RMS, mean(-) and vertical differences of central fossa and distal buccal cusp were significantly different(P<0.05). CONCLUSIONS: The occlusal morphology of the prosthesis designed under the guidance of mandibular trajectory data and mean frame parameter both have significant differences with natural occlusion, but the deviation guided by mandibular trajectory data is lower.