【作者】 任敏；

【导师】 庄洪兴； 蒋海越； 杨庆华；

【作者基本信息】 中国协和医科大学 ， 外科学， 2008， 博士

【摘要】 背景:对于颅面诸骨中唯一能活动的下颌骨,因其在口腔功能和人体容貌方面的重要作用,一直备受口腔颌面外科、颅面外科及整形外科等多个外科领域的高度关注。以往对于下颌骨解剖结构的标志点的定位和指标的测量多是基于实体或二维图像的定点和测量。MSCT扫描加三维重建技术的出现和发展,迅速在颅颌面形态学的研究及临床外科领域得以广泛应用,也为深入开展活体下颌骨的研究提供了可能。目的:建立一套基于MSCT扫描VRT三维重建测量的汉族成年人群活体下颌骨数据库及显示系统,建立各测量指标分侧和分性别的正常值和界限值,并寻求各指标之间的联系和规律,为临床实践提供指导,进一步为建立中国数字化人体数据库积累数据。本课题由两部分组成:第一部分:下颌骨MSCT三维重建测量的精确度评价及三维测量研究方法:通过对20具离体下颌骨多个指标(每具下颌骨双侧共126项距离测量指标和6项角度测量指标)MSCT扫描VRT三维重建测量与实体解剖测量结果进行统计对比分析,对下颌骨MSCT扫描VRT三维重建测量的精确度进行评价,并对三维测量进行深入研究。结果:(1)MSCT扫描VRT三维重建测量结果分左右侧统计分析,双侧间均无统计学差异(P＞0.05)。(2)实体解剖测量结果分左右侧统计分析,除一项外其他各项双侧间均无统计学差异(P＞0.05)。(3)对两种测量方法测量结果之间进行统计分析,除一项外其他各项均无统计学差异(P＞0.05)。第二部分:基于MSCT汉族成年人群活体下颌骨三维测量数据库的建立方法:通过对经过严格挑选的400例(男女各200例)汉族成年志愿者活体下颌骨进行MSCT扫描VRT三维重建,对各指标(每例活体下颌骨双侧共202项距离测量指标、8项角度测量指标和14项观察指标)测量结果进行统计分析,建立各测量指标分侧、分性别的正常值及界限值;并对部分测量指标间进行相关回归分析,建立回归方程。结果:(1)建立了一套基于MSCT扫描VRT三维重建的汉族成年男女活体下颌骨三维测量数据库,建立了各测量指标分侧和分性别的正常值和界限值;绝大多数测量指标左右侧间均无统计学差异(P＞0.05),而男女性别间则具有统计学差异(P＜0.05)。(2)通过对两组8个测量指标之间进行相关性分析,每组各测量指标之间均具有显著的正相关关系(r＞0.950,P＜0.001),并进行回归分析和建立回归方程。(3)从3个不同平面对下颌升支厚度进行了精确测量,描绘出了下颌升支不同平面皮髓质骨分布情况及其厚度。(4)对颏孔和下颌孔的相关指标进行了观察和精确测量,描绘出了其与下颌骨诸结构的绝对和相对位置关系。(5)发现和证实95.75%以上研究对象存在颏管,颏管起始于下颌管末端,以约62°角向后上外方走行开口于颏孔。(6)从6个断面对下颌神经管的管径及其与下颌骨各壁的距离进行了精确测量和研究,下颌管总体偏向内侧壁和下颌下缘走行,一般在接近颏孔区才迅速跨过中线向颊侧走行、在颏孔下方越过颏孔前行一定距离后向后上外方折返改称颏管。(7)对下颌管与第一、二、三磨牙根尖距离进行了精确测量和分析,描绘出了下颌管与磨牙根尖的位置关系。结论:(1)MSCT扫描VRT三维重建是目前公认最适合硬组织的扫描重建方式。重建影像上任意一点的三维座标恒定,不需确定定位平面,测量数值同屏显示,无论影像结构如何旋转、缩放、切割,数值始终恒定。(2)MSCT扫描VRT三维重建测量具有较高的精确度,完全可以替代实体解剖测量,应用于人类下颌骨尤其是活体下颌骨的三维立体观察和精确测量,解决了实体解剖测量无法在活体上直接应用的难题。(3)建立了一套基于MSCT扫描VRT三维重建的汉族成年男女活体下颌骨三维测量数据库,建立了各测量指标分侧和分性别的正常值和界限值。建立一套活体下颌骨三维立体图像显示系统,可以从不同角度、不同平面和断面进行观察和测量,对临床实践具有较大的指导意义,丰富了中国数字化人体数据库。(4)对两组多个指标之间相关关系的研究及回归方程的建立,可以通过对下颌骨某些指标的测量和分析来计算和推测其他指标的具体数值,为临床手术提供指导,尤其是指导下颌骨缺损的修复。(5)对下颌升支不同平面皮髓质骨厚度的深入研究,为髁突骨折轴向拉力螺钉固定隧道的制备提供了参考。对颏孔和下颌孔及其与下颌骨位置关系的深入研究,为该区域手术和阻滞麻醉提供了依据。下颌角肥大是一个综合征象,其诊断和治疗不能单单依据下颌角角度的大小,应综合多种因素。(6)颏管的发现和证实,否定了人们长期以来颏孔以前为安全区的错误观念。从多个断面对下颌神经管的三维走行进行了精确测量和研究,从总体上描绘出了下颌管在下颌骨中的三维行程。从多个断面对磨牙根尖与下颌管位置关系进行了深入研究,为下齿槽神经损伤的防治提供了参考。更多还原

【Abstract】 Background:In medical domain,since the structures of human organs are complicated and the shapes are multiplicate,if one is not an expert with enough practical experience,he couldn’t schemed the three-dimensional shape of an organ and the relationship of the tissues around it just based on two-dimensional images. Additionally,the way of each person’s thought is not always the same,which is bound to bring about some deviation,even mistake.So it is difficult for a doctor in diagnosing diseases,explaining symptoms,even evaluating the correctness and objectivity of a medical treatment just based on two-dimensional images with the increasingly development of medicine.Fortunately,the development of computed tomography and three- dimensional reconstruction and visualization technique have brought a revolution in medicine.Mandible is a relatively significant bone among craniofacial bone structure,which is a crucial factor to influence the low face shape and the mastication function,and it is always dealt with in the field of plastic surgery, craniofacial surgery,dentofacial surgery and even tooth implantation area.So it is especially necessary for us to study the mandible through three-dimensional reconstruction and measurement.Objective:To establish the adults’ in vivo mandible three-dimensional measurement database of the Han Nationality and three-dimensional display system of which based on MSCT scan with VRT technique three-dimensional reconstruction and measurement,to establish the normal value and interval value of each measurement index of each side and sex,and to explore the relations and rules among them.In order to guarantee clinical practice,and also to store up data for Visible Human Project of China.This paper included two parts as follows:PartⅠ:Accuracy evaluation and study of mandible three-dimensional reconstruction and measurement based on MSCTMethods:Twenty ex vivo mandibles were studied and measured by two methods as MSCT scan with VRT three-dimensional reconstruction and measurement and dissection measurement(126 distance indexes and 6 angle indexes were measured on each mandible).The accuracy of the former method was evaluated by contrasting of two,and further study was focused on three-dimensional measurement.Results:(1) The indexes’ results of MSCT scan with VRT three-dimensional reconstruction and measurement of each side showed no statistical difference(P＞0.05).(2) The indexes’ results of dissection measurement of each side showed no statistical difference(P＞0.05) except one.(3) The indexes’ results put together by two sides of two methods showed no statistical difference(P＞0.05) except one.PartⅡ:Establishment of adults’ in vivo mandible three-dimensional measurement database of the Han Nationality based on MSCTMethods:400 volunteers’(200 males and 200 females) in vivo mandibles of the Han Nationality adults undergone strictly selection were studied through MSCT scan with VRT three-dimensional reconstruction and measurement.202 distance indexes,8 angle indexes and 14 observation indexes were measured on both sides of each mandible.To establish the normal value and interval value of each index of each side and sex,then explore the relations and rules among them.Correlation and regression analysis was done among some indexes,and regression equation was established.Results:(1) The normal value and interval value of each measurement index of each side and sex based on MSCT scan with VRT three-dimensional reconstruction and measurement has been established,most of the indexes between two sides showed no statistical difference(P＞0.05),but there was statistical difference(P＜0.05) in most of the indexes between male and female.(2) Correlation analysis was done among 8 indexes in two teams,which showed that there was positive correlation (r＞0.950,P＜0.001) between every two indexes in each team,so regression analysis was done and equation established.(3) The thickness of mandibular ramus in three different section planes was measured and studied,so the distribution and thickness of the cortex and medulla of the ramus was described precisely.(4) The mental foramen, mandibular foramen and the structures around them were observed and undergone precision measurement,the absolute and relative position of them and the relation of them to their surroundings in the mandible was described.(5) Mental canal was found and confirmed in over 95.75%mandibles,mental canal originated from the end of mandibular canal,went backward,superior and outside in an angle of 62 degree and ended up at mental foreman.(6) The caliber of the mandibular canal and the distance from which to the superior and inferior margin and the medial and lateral wall around in six different sections was measured and studied,the mandibular canal went forward near medial cortex and inferior margin of the mandible body in all six sections,then steped over neutral line in the mental foreman area and went forward for some distance near the lateral cortex,then went backward,superior and outside which was called mental canal.(7) The distance from the mandibular canal to the apex of molar root was measured and the absolute and relative position of which to the apex of molar root in the mandible was described precisely.Conclusions:(1) MSCT scan with VRT three-dimensional reconstruction is now admitted as the most preferable method used for bone scan and reconstruction.The coordinate of every point is constant in the reconstructed image,no reference plane needed when measuring.The result is shown at the same screen when measuring.The figure is constant even if the reconstructed image is rotated,zoomed,cut and so on.(2) MSCT scan with VRT three-dimensional reconstruction and measurement can replace dissection measurement completely in three-dimensional viewing and measuring of human mandible,especially of the mandible in vivo for it’s higher accuracy.So the problem of the dissection measurement couldn’t directly used in vivo is resolved.(3) The adults’ in vivo mandible three-dimensional measurement database of the Han Nationality and three-dimensional display system of which based on MSCT scan with VRT technique is established.The normal value and interval value of every index on each side and sex is established.The three-dimensional image can be viewed and measured in any angle,plane and section.The results can not only guarantee the clinical practice,but also store up data for Visible Human Project of China.(4) Through correlation and regression analysis between some indexes and regression equation’s establishment.When one index or more is measured,some other indexes’ reference value could be calculated or presumed through regression equation,which can provide reference for clinical practice,especially for mandible defect repairing.(5) The thickness of mandibular ramus in three different section planes had been measured and studied,which can provide reference for condylar fracture repairing when the tunnel of tensile force screw through the ramus is done.The mental foramen, mandibular foramen and the structures surrounding had been observed and measured precisely,which can provide reference for operation and block anesthesia in these areas.Mandibular angle hypertrophy is a synthetic symptom,whose diagnosis and treatment shouldn’t base on mandibular angle merely,many other factors should be included.(6) Mental canal’s found and confirmed denies the mistake concept that the area between two lateral mental foramens is safe.The distance of mandibular canal to the superior and inferior margin and the medial and lateral wall around in six different sections had been observed and measured precisely,the three-dimensional course of the mandibular canal in mandible is described totally.The relationship between mandibular and apex of molar root had been observed and measured in several different sections,which provide references for inferior alveolar nerve injury prevention and cure.更多还原