计算机辅助测量颧眶骨折术前后眼眶容积的临床意义

目的:通过测量颧眶骨折术前术后眼眶容积的变化,得出术后可能仍然出现眼球内陷的术前眼眶容积大小。方法:20例颧眶骨折患者在术前及行坚固内固定术后,分别做多排三维螺旋CT(MSCT)扫描,利用Simplant软件测量眼眶容积进行比较,并做统计学分析。结果:术前20例患者均存在眼眶容积的增大,与健侧眼眶容积相比增大范围为0.07～7.50cm3。术前两侧眼眶容积差值的平均值为(3.06±1.96)cm3,术后差值减少到(0.93±1.00)cm3,术前术后眼眶容积存在显著差异(P<0.01)。10例患者术后仍然存在不同程度的眼球内陷,其术前眼眶容积差值为(4.60±1.27)cm3。结论:眼眶容积测定有助于术者制定手术方案,恢复应有的眼眶容积。     

眼球突度和眼眶容积比的实验研究

目的：通过Hertel眼球突度测量计测量新鲜尸体上眼球突度与眼眶容积的变化,得到两者之间的直线关系。方法：选择新鲜尸体5具共10侧眼眶,将气管插管的气囊部分置入眶底与眶骨膜之间,用注射器注入7ml生理盐水,每抽出1ml生理盐水后,用Hertel眼球突度测量计测量眼球突度,共得到80个数据,采用SAS6.12软件包进行统计学分析。结果：眼球突度与眼眶容积之间呈线性相关关系,Y=8.57-0.96X（r=-0.86,P=0.0001≤0.05）。结论：气管插管球囊是一种测量眼眶容积变化的有效实验工具。新鲜尸体上眼球突度与眼眶容积增量之间存在直线相关关系。     

基于螺旋CT影像的计算机辅助重建及测量上颌窦的实验研究

目的：建立一种基于螺旋CT影像的计算机辅助重建及测量上颌窦的方法,为上颌窦辅助诊断、手术治疗提供参考。方法：利用64排螺旋CT对60例正常成人（男30例,女30例）颌骨进行薄层容积扫描,将DICOM数据输入计算机辅助软件Simplant,重建上颌窦,测量相关数据并进行统计学分析。结果：上颌窦前后径均值为（35.12±3.47）mm,上下径均值为（39.58±2.96）mm,左右径均值为（32.14±2.50）mm,上颌窦容积均值为（15187.16±596.12）mm3。左右侧上颌窦径线值和容积无显著差异。男女性上颌窦径线值和容积无显著性差异。结论：利用该方法获得的上颌窦重建影像和测量数据可以为上颌窦影像诊断和手术治疗提供参考。     

眼眶骨折标准诊断CT层面的确定与应用研究

目的:确定跟眶骨折的CT标准诊断层面,描述CT标准层面上的眼眶形态.方法:42侧正常眼眶和21例单侧骨折眼眶,摄取CT数据,输入图像软件.在设定的CT标准诊断层面上描述眶底、眶内壁、两者交界区的形态特征.与手术所见对照,评价眼眶骨折在标准层而的检出率.结果:设定9个标准层面.在4个矢状层面上,眶底形态靠外侧呈Ⅰ型,靠内侧呈Ⅱ型.圆孔层面眶底最深[男性(36.26±4.72)mm,女性(34.81±4.76)mm].在3个冠状层面上,眶内下壁交角由前向后逐渐增大,男性分别为(128.33±19.11)°、(132.57±22.17)°和(137.44±20.87)°,女性分别为(129.55±22.32)°、(134.95±25.50)°和(139.46±22.80)°.在轴位层面上,眶内/外缘到视神经管内口内/外壁距离男性分别为(38.47±4.41)mm和(47.13±4.10)mm,女性分别为(38.21±5.63)mm和(45.79±5.41)mm.冠状层面的眶底和眶内壁骨折检出率93.75%～100%,9个层面的总检出率为100%.结论:提出的9个CT标准层面可作为眼眶骨折的常规诊断层面.     

应用螺旋CT及Simplant软件测量种植区颌骨骨密度

目的:应用螺旋CT结合Simplant专业软件对颌骨种植区骨密度进行定量测量,结合Lekholm和Zarb分类法对种植区骨进行分类.方法:对53例拟种植患者进行上下颌骨螺旋CT扫描.扫描图像应用Simplant专业软件进行重建,对136个种植位点的骨密度进行测量,骨密度以Hounsfield units(HU)表示.采用SPSS11.0软件包对数据进行统计学分析,以Mann-Whitney U检验比较不同区域骨密度的差异,并结合Lekholm和Zarb分类法进行分类.结果:所有种植位点的平均骨密度为(714.66±273.72)HU,下颌前牙区的平均骨密度值最大,为(962.96±92.21)HU.其次为上颌前牙区(786.15±188.74)HU、下颌后牙区(785.79±290.91)HU,上颌后牙区骨密度值最小,为(569.67±244.34)HU.所有种植位点中,Ⅳ类骨占26.5%,下前牙区Ⅳ类骨最少,上颌后牙区Ⅳ类骨最多(P＜0.01).结论:下颌前牙区平均骨密度值最大,上颌后牙区平均骨密度值最小.大多数种植位点骨密度分类为Ⅰ类骨和Ⅱ/Ⅲ类骨.Ⅳ类骨所占比例较小.螺旋CT可以提供种植区骨密度的信息,对种植的术前设计和术后评估有重要意义.     

计算机导航在单侧眼眶骨折眶壁重建中的应用评价

目的 评价导航系统在单侧眼眶骨折眶壁重建中的应用效果.方法 在导航指导下完成眶壁重建的15例单侧眼眶骨折患者纳入研究,其中,男性7例,女性8例,平均年龄(34.3±9.5)岁.术前CT扫描、数据导入BrainLab导航系统工作站、以健侧眼眶CT数据的镜像作为参考,完成术前设计.对粉碎性严重眶壁骨折则以镜像数据为基础,制作模板并在模板上完成钛网预成形;如眶壁骨折较局限,则采用羟基磷灰石补片在术中直接完成眶壁缺损修复.在导航系统的指导下分别以钛网(10例)、羟基磷灰石补片(5例)完成眶壁重建.术后再次CT扫描,评价导航系统应用效果4个变量:①整体眶腔容积差;②眶壁疝出组织体积;③眼球内陷程度;④重建误差.由于羟基磷灰石在CT中显像效果差,因此,只测量钛网移植病例的重建误差.结果 所有病例均未出现视神经损伤、感染或植入体排斥等并发症.经测量术前平均眼球内陷(3.5±1.6) mm、整体眼眶容积差(4.5±1.8) ml、疝出组织体积(2.1±0.7)ml;术后以上3项指标分别降低到(1.3 ±0.6) mm、(1.8±0.9) ml和(0.7 ±0.3)ml.统计学测量显示,眶内壁和下壁的重建误差分别为(2.5±0.6) mm和(2.1 ±0.4)mm.结论 单侧眼眶骨折治疗应用导航系统可以得到精确的眶壁重建和满意的治疗效果.     

睁眼数字化面模在眶缺损仿真修复中的应用

目的:建立睁眼面部三维数字化模型,实现单侧眼眶部缺损的计算机仿真设计。方法:采用位相测量轮廓技术直接对患者面部三维轮廓信息进行采集,重建缺损面部睁眼的三维数字化模型。在Geom agic实体构造软件中,利用健侧眼眶部组织数据经镜像反转获得缺损区睁眼状态的三维实体数据。结果:完成了单侧眼眶部缺损面部组织的三维重建,获得了修复缺损区眼眶组织的三维实体数据并达到对称、逼真的设计效果。结论:应用位相测量轮廓术和逆向工程软件进行单侧眼眶部缺损修复的计算机辅助设计是一种切实可行的方法。     

单侧眶部缺损患者面部三维数字化重建及眼部测量

目的:建立单侧眶部缺损患者睁眼面部三维数字化模型,对健侧眼眶部主要标志点、线进行三维测量,为眶部赝复体的制作提供必要的测量数据.方法:采用3DSS结构光三维扫描仪,结合geomagic软件对一单侧眶部缺损患者进行三维重建,并对健侧眼部进行三维测量.结果:建立了患者睁眼面部三维数字化模型,获得了眼眶部各个标志点、线的测量数据.结论:睁眼三维面部数字化模型及其测量数据能够为单侧眶缺损修复提供必要的参考依据.     

螺旋CT三维重建在外鼻形态测量上的初步研究

目的:当今对唇腭裂畸形鼻的检测和对术后效果的评价尚缺乏一种简单有效的手段,有必要建立一种精确测量外鼻的方法。方法:采用螺旋CT三维重建后,应用Amira软件对10例正常外鼻进行定点及线距的测量,并与应用人体学测量后得到的数据配对比较。应用SPSS11.5统计软件及配对t检验进行统计学分析。结果:所得数据经配对t检验后发现,所有测量数据在人体学测量与CT测量这两种方法之间差异无显著性意义(P>0.05)。结论:本研究建立了一套完整的应用三维CT及测量软件精确测量外鼻的方法。     

非单纯性眼眶骨折眶腔容积改变与眼球内陷相关性研究方法初探基于CT图像数据的计算机辅助测量

目的应用计算机辅助三维CT影像分析系统，测量分析非单纯性眼眶骨折术前术后眶腔容积变化，为定量诊断和矫治骨折继发眼球内陷探索可行性研究方法。方法2004年10月～12月北京大学口腔医院颌面创伤中心经治的7例颅颌面创伤合并单侧非单纯性眼眶骨折。投照薄断层（0．625mm）CT，将图像数据以DICOM格式输入图像分析软件，对眼眶及眶内容物进行三维重建。描述眶腔破坏特征。测量眼球突度、原骨折和虚拟恢复眶外缘后的眶腔容积，并做术前术后比较分析。结果应用该系统可形象直观地显示眼眶畸形部位、范围。定量明确眼眶体积扩大量。在该类眼眶骨折中，骨折可波及整个眶壁。与眶缘骨折相比较，眶壁骨折与眼球内陷关系密切。术前术后比较，眼球内陷得到不同程度的改善，健患侧眼眶体积之差进一步缩小。结论基于CT图像数据的计算机图像分析系统可以清晰直观的显示出骨折眶壁畸形，以及健患侧眶腔体积的差异。球前和球后眶腔容积差可以为进一步探求眼眶破坏与眼球内陷的相关关系及量化诊断提供重要参数。     

Measurement of orbital volume by a 3-dimensional software program: an experimental study.

PURPOSE: This study reports a simple method with high accuracy for determining orbital volume from computed tomography (CT) scans. MATERIALS AND METHODS: The volume of 20 orbits was evaluated in 20 dry skulls by use of a 3-dimensional software program in General Electric High-Speed Advantage CT/I (Milwaukee, WI), and compared with the volume obtained by direct measurement using the water displacement method. Accuracy of volume measurement by this software program was assessed statistically by paired samples t-test. RESULTS: The mean volume was found to be 28.37 mL +/- 2.15 by direct impression and 28.41 mL +/- 2.09 by the software program. Volume difference between the 2 methods averaged 0.93 +/- 1.08 mL for each orbit (P < .01). The correlation between the techniques was found to be high (r = 0.887, P < .01). There was no significant volume discrepancy between the 2 methods. CONCLUSION: Measurement by the technique described is an easy and accurate method of assessing the volume of the orbit.     

A computer-based method for calculation of orbital floor fractures from coronal computed tomography scans

PURPOSE: A computer program recently developed for the calculation of the orbital floor and fracture areas from coronal computed tomography (CT) scans was used in a study to evaluate the accuracy and ability of this new method. MATERIAL AND METHODS: The size of orbital floors and fabricated fractures in 14 dried, anatomic specimens were measured in coronal CT scans by 3 independent observers. Based on this data set, the orbital floor and fracture regions were calculated with the newly developed computer program. These calculated regions were then compared with a direct measurement of the specimens that had been obtained by digital photography. The accuracy of the computer-based calculations was assessed using Lin's concordance correlation coefficient. RESULTS: The size of the orbital floor (mean +/- SD) was found to be 5.21 +/- 0.39 cm(2) by direct measurement of the specimens and 5.30 +/- 0.52 cm(2) by calculation with the computer program. The region of the fracture (mean +/- SD) was 1.05 +/- 0.64 cm(2) by direct measurement and 1.01 +/- 0.62 cm(2) by computer calculation. The between-method mean difference (direct measurement minus computer based calculation) was -0.09 cm(2) (or 1.7% of mean orbital floor region) for orbital floor region and 0.04 cm(2) (or 3.8% of mean fracture region) for fracture region. CONCLUSIONS: This accurate and time-saving method is practicable for determining the size and location of orbital floor fractures. This calculation program can be advantageously applied in the clinical management of blowout fractures of the orbit.     

Linear accuracy and reliability of cone beam CT derived 3-dimensional images constructed using an orthodontic volumetric rendering program

OBJECTIVE: To compare accuracy of linear measurements made on cone beam computed tomographic (CBCT) derived 3-dimensional (3D) surface rendered volumetric images to direct measurements made on human skulls. MATERIALS AND METHODS: Twenty orthodontic linear measurements between anatomical landmarks on 23 human skulls were measured by observers using a digital caliper. The skulls were imaged with CBCT and Dolphin 3D (version 2.3) software used to generate 3D volumetric reconstructions (3DCBCT). The linear measurements between landmarks were computed by a single observer three times and compared to anatomic dimensions using Student's t-test (P < or = .05). The intraclass correlation coefficient (ICC) and absolute linear and percentage error were calculated. RESULTS: The ICC for 3DCBCT (0.975 +/- 0.016) was significantly less than for skull (0.996 +/- 0.007) measurements. Mean percentage measurement error for 3DCBCT (2.31% +/- 2.11%) was significantly higher than replicate skull measurements (0.63% +/- 0.51%). Statistical differences between 3DCBCT means and true dimensions were found for all of the midsagittal measurements except Na-A and six of the 12 bilateral measurements. The mean percentage difference between the mean skull and 3D-based linear measurements was -1.13% (SD +/- 1.47%). Ninety percent of mean differences were less than 2 mm, and 95% confidence intervals were all less than 2 mm except for Ba-ANS (3.32 mm) and Pog-Go(left) (2.42 mm). CONCLUSIONS: While many linear measurements between cephalometric landmarks on 3D volumetric surface renderings obtained using Dolphin 3D software generated from CBCT datasets may be statistically significantly different from anatomic dimensions, most can be considered to be sufficiently clinically accurate for craniofacial analyses.     

眶底和眶内侧壁骨折后眶内软硬组织移位的相关性

目的:对眶底和眶内侧壁骨折范围面积的大小和眶内移位软组织体积之间关系进行相关性研究。方法:15例颧眶骨折伴有眶底、眶内侧壁骨折、眶内软组织移位的患者分别做MSCT扫描,利用Simplant软件测量眶底和眶内侧壁骨折范围面积的大小和眶内移位软组织体积,做统计学分析,并将骨折形态以STL格式文件存储。结果:平均眶底骨折范围面积的大小为(4.64±0.77)cm2,平均眶底移位软组织体积是(2.58±1.33)cm3,两者相关关系是y=1.18602x-2.929,R=0.683。平均眶内侧壁骨折范围面积的大小为(5.53±1.14)cm2,平均移位软组织体积是(2.59±1.05)cm3,两者相关关系是y=0.6894x-1.1342,R=0.7829。结论:眶底和眶内侧壁骨折范围面积大小与其相应移位软组织容积存在线性相关关系。     

眶底骨折与眶底软组织移位相关性研究

目的：对眶底骨折范围面积的大小和眶底移位软组织体积之间关系进行相关性研究。方法：15例颧眶骨折伴有眶底骨折及眶底软组织移位的患者分别做MSCT扫描,利用Simplant软件测量眶底和眶底侧壁骨折范围面积的大小和眶底移位软组织体积,做统计学分析,并将骨折形态以STL格式文件存储。结果：平均眶底骨折范围面积大小为（4.64±0.77）cm2,平均眶底移位软组织体积为（2.58±1.33）cm3,两者相关关系是y=1.18602x-2.929,R=0.683。结论：眶底骨折范围面积大小与其相应移位软组织容积存在线性相关关系。     

Volumetric analysis of extraction sockets using cone beam computed tomography: a pilot study on ex vivo jaw bone

Aim: The aim of this study was to determine the accuracy of volumetric analysis of extraction sockets using cone beam computed tomography (CBCT). Material and Methods: The volume of 40 dental alveoli in nine dry skull specimens (four mandibles and five maxillae) was determined by measuring the volume of the tooth socket impression using the water displacement technique. This was considered as the gold standard. Then, the tooth socket was scanned with CBCT and data were uploaded in the semi‐automated Livewire^® segmentation software. The software segments the tooth socket in consecutive 1 mm‐thick two‐dimensional slices. After segmentation, the total volume of the delineated socket was computed. The statistical difference between direct volumetric measurements and those obtained with CBCT imaging was assessed using the Student paired t‐test. Result: The mean socket volume of the skull specimens was 227±91 mm³ when obtained by direct measurement and 225±90 mm³ when obtained by CBCT imaging. Student paired t‐test showed no significant differences between both volume measurements (p>0.1). Conclusions: CBCT permits imaging of anatomical structures in three planes and allows for reliable volume estimates. The results should be verified in clinical circumstances and might have potential applicability for evaluation of extraction socket healing under different conditions.     

锥形束CT结合simplant软件在颌面部三维测量中的初步研究

目的：探讨锥形束CT（Cone Beam CT,CBCT）结合simplant软件对颌面部硬组织进行三维测量的临床应用价值。方法：对1例正常牙合成年人（男性,年龄：22岁）的颌面部进行CBCT扫描,数据经DICOM格式直接转入Simplant软件中,通过软件对扫描数据进行多平面重建,以获得扫描区的冠状面、矢状面、轴面图像,采用Simplant软件中McNamara分析法对颌面部硬组织进行测量。采用SPSS11.5软件包对1周内5次测量的数据进行配对t检验,验证该方法的可靠性。结果：simplant软件测得前后5个阶段的数据无统计学意义。结论：CBCT技术结合simplant软件提供了方便、快捷、准确的计算机辅助测量分析平台,可为有关牙颅面发育畸形提供相关诊治依据。     

2D- and 3D-based measurements of orbital floor fractures from CT scans.

OBJECTIVE: Two methods for area and volume calculation of the orbit were evaluated following blow-out fractures of the orbital floor using computed tomography (CT) scans. MATERIAL AND METHODS: Isolated blow-out fractures of the orbital floor in human cadavers were simulated by fracturing the orbital floor and placing a defined volume of silicone within each defect. The area of fracture and the volume of silicone simulating herniated periorbital tissue were evaluated in 16 orbits by the use of a three-dimensional (3D) CT-based software package (Analyze((R)); Mayo Clinic, Rochester, MN, USA) and software based on two-dimensional (2D) coronal CT scans. Both methods were compared with direct anatomical measurements and evaluated with Lin's concordance coefficient (rho(c)). RESULTS: Between-method concordance of area and volume calculation were rho(c)=0.962, and 0.872 for the 3D-CT-based method, and 0.981 and 0.952 for the 2D-CT method, respectively. The time allocated for measurement was significantly longer for the 3D-CT than for the 2D-CT method (p<0.001). CONCLUSION: Calculations of blow-out fractures of the orbital floor by 3D-CT and 2D-CT method are accurate for assessing the area of fracture and the volume of herniated tissue. Lesser processing time and simple usage favour the 2D-CT-based calculation method.     

Secondary post-traumatic enophthalmos: high-resolution magnetic resonance imaging compared with multislice computed tomography in postoperative orbital volume measurement.

PURPOSE: Multislice computed tomography (MSCT) was the modality of choice for orbital volume measurement. This first prospective study compares MSCT with high-resolution magnetic resonance imaging (MRI) combined with micro (MRImc) and headcoil (MRIhc) in volumetric evaluation of the postsurgical enophthalmic orbit. PATIENTS AND METHODS: Morphologic and dimensional changes of the orbit, eyebulb, and fat content were investigated 3 to 4 months after reconstruction of complex orbital fractures in 36 patients. Image analysis and volumetric assessment from 2-dimensional and 3-dimensional-MRImc and MRIhc were compared with MSCT. The volume segmentation algorithm operated on multispectral, 3-dimensional MR data acquired at isotropic proton density weighted acquisitions. RESULTS: CT and MRI volume data correlated significantly (P < .01). Enlargement of the posterior segment often resulted in orbital geometry change from conical to convex. Even cases of correct orbital reconstruction presented significant volume enlargement compared to the contralateral side (P < .01). The retro bulbar fat showed itself fragmented and was dislocated in the medial posterior region mostly. We found reduced sagittal eye projection, increased width of the orbital rim, and dislocation of the posteromedial orbital floor (P < .01). High correlation was detected between orbital volume increment and degree of enophthalmos (0.93 mm per 1 cm3 orbital volume enlargement diameter) (P < .01). CONCLUSIONS: As MRI orbital volume measurement permitted prediction of postsurgical enophthalmos, which is related to possible failure in orbital volume correction and reduction of the posterior medial bulge and not to fat content changes, it is suited for planning secondary correction.