数字化印模及图像处理技术在鼻赝复中的应用

应用自主研发的三维光学测量系统分别为1名鼻缺损患者和1名志愿者取制数字化面部印模。应用逆向工程图像处理软件，分别将两者数字化印模的原始数据进行删减和平滑后，利用软件拼合功能将志愿者的鼻提取，并在患者面部鼻缺损区进行拼接，从而完成鼻赝复体图像的三维重建。应用光学数字化印模技术能清晰的取得患者和志愿者面部三维图像模型，通过图像处理软件处理后，良好的重建了患者完整自然的面部三维模型，志愿者鼻形在患者面部贴合良好。提示光学数字化印模和图像处理技术能较好的进行患者面部形态三维重建，并将辅助颌面部赝复体的设计和制作。     

四种超硬石膏模型精度及抗弯强度的比较

背景: 在临床上,超硬石膏广泛应用于制作固定义齿、大支架可摘义齿等需精细复制口腔情况的工作模型,其抗弯强度足够抵抗脱模时的力量不会发生模型牙体的折断。但当印模为硬质材料如聚醚橡胶印模等,存在牙体折断现象。 目的：比较4种超硬石膏YCG,丹特纳,贺利氏,穗诚模型的尺寸精度及抗弯强度。 方法:制作三单位固定桥和长方体(50 mm× 10 mm×5 mm)的金属模具,灌注4种超硬石膏模型,分别采用万能工具显微镜和万能试验机测量其尺寸精度及抗弯强度。 结果与结论：YCG、丹特纳、贺利氏、穗诚4种超硬石膏近远中方向尺寸精度均值分别为:15.043,15.034,15.037,15.040 mm,颊舌方向为：7.020,7.015,7.019,7.019 mm,牙体长轴方向为：8.022,8.018,8.019, 8.02 mm。4种超硬石膏模型抗弯强度均值分别为：15.687,13.000,22.521, 18.675 MPa。4种石膏模型尺寸精度差异无显著性意义 (P > 0.05),但抗弯强度差异有高度显著性意义(P < 0.01)。贺利氏石膏抗弯强度显著高于其他3种石膏 (P < 0.01),穗诚石膏抗弯强度显著高于丹特纳(P < 0.01)。说明贺利氏石膏的抗弯强度是4种超硬石膏中最高者,穗诚的抗弯强度高于丹特纳,提示临床上应根据实际情况尽量选择抗弯强度大的石膏材料。     

结构光三维测量轮廓技术及快速成型技术在颌面赝复中的应用*☆

目的：应用印模技术取得面部软组织外形信息，容易受患者体位、印模材料等因素影响，为克服其缺陷，尝试采用结构光三维测量轮廓技术结合快速成型技术进行颌面部赝复设计。 方法：应用自主研发基于结构光三维测量轮廓技术原理的三维光学测量系统（TDOS），对2007-04上海第九人民医院口腔修复科收治的1名电击伤术后严重面部缺损的患者进行面部外形信息采集。使用Imageware和 Geomagic studio图像处理软件，对光学测量系统采集的面部原始外形信息进行去除噪声和平滑处理，并通过软件对面部图像进行拼合及三角化，形成患者面部完整的3D图像模型。该3D模型在逆向工程处理软件中修饰，生成3mm厚度的数字化模型，并以.stl格式保存，最终导入熔融挤压成型的快速成型机，制作全面部树脂模型，与患者面部实际外形、尺寸比较。 结果：利用三维光学测量系统采集的面部数字化三维模型形象、完整，得到的面部数据信息经图像处理软件处理后，能生成光顺、清晰的面部CAD模型。该模型经由逆向工程软件修饰并转化格式后能导入熔融挤压成型快速成型机，并成功制作出面部树脂模型，该树脂模型与患者面部实际高度相似。 结论：基于结构光三维测量轮廓技术结合快速成型技术，能辅助面部信息采集和模型制作。比较印模技术和其他三维测量方法，它能安全准确地获取面部外形信息并形成实体模型。该方法能辅助颌面部缺损的赝复计划制定和赝复体设计制作，增进医患交流。     

三维标测中轮廓数据的误差校正研究

摘要：目的：外加电场条件下对体内坐标进行测量,并对重复定位精度进行验证。方法：针对不同类别的均匀介质电阻抗属性在恒压电场条件下电势梯度的变化规律,提出被测点空间位置精确测量的具体求解方法,同时通过测量点实际值和被测结果之间进行坐标变换来对测量误差进行校正。结果：测量结果和实际尺寸的最大偏差=±1.056mm,尺寸相对误差＜5％。结论：证明了三维电场进行物体内部空间坐标精确探测的可行性。同时,作为物体内部被测点的一种新的标测手段,该方法可为心脏电生理手术的位置点探测奠定技术基础。     

三维测量技术在口腔正畸学中的应用

背景：三维测量技术有助于正畸医师更直观逼真、快捷、简便地对牙合颌面畸形进行正确诊断、治疗设计、疗效预测及评价。 目的：对各种三维测量技术在口腔正畸学中的应用进行综述。 方法：应用计算机检索CNKI和Medline数据库中1997/2010-01关于三维测量技术的文章,在标题和摘要中以“三维测量技术;口腔正畸学;错牙合畸形;颌面畸形”或“Three dimensional measurement technique;Orthodontic;Malocclusion;Facial defomity”为检索词进行检索。选择文章内容与三维测量技术在口腔医学中的应用相关,同一领域文献则选择近期发表或发表在权威杂志文章。初检得到145篇文献,根据纳入标准选择22篇文章进行综述。 结果与结论：口腔正畸临床上对各种三维测量技术的关注和应用越来越多,三维测量技术在飞速发展并已在口腔正畸领域内有一定的地位。     

硅橡胶材料在总义齿再修复中的应用

背景：总义齿再修复中，充分参考旧义齿的可利用信息是获得良好治疗效果的关键。 目的：观察硅橡胶材料在总义齿再修复中的应用效果。 方法：选择10例戴用旧义齿多年的无牙颌患者，利用技工用硅橡胶翻制旧义齿，同时结合硅橡胶印模材料在试排牙后进行口内印衬的方法重新制作总义齿。采用重复测量方差分析法研究两组新义齿使用前(旧义齿)及使用后2周、1个月、3个月、6个月咀嚼效率的变化。另选择10例患者按照常规方法重做义齿为对照。 结果与结论：时间、处理因素(不同制作方法)的作用以及两者之间的交互作用对义齿咀嚼效率的影响差异有显著性意义(P < 0.01)。与对照组同一时点比较，实验组新义齿使用2周、使用1个月的咀嚼效率较高(P < 0.05)。实验组新义齿使用2周的咀嚼效率较使用前有明显改善(P < 0. 01)，与使用后1个月比较差异无显著性意义(P > 0.05)。结果提示在总义齿再修复中，利用硅橡胶材料的特性，参考旧义齿的可利用信息，可使新义齿在戴牙早期即恢复较高的咀嚼效率，降低患者对新义齿的适应时间。 关键词：硅橡胶；总义齿；咀嚼效率；印模材料；口腔生物材料 doi:10.3969/j.issn.1673-8225.2010.25.021     

MRI影像下股骨髁间窝三维数字化解剖学数据与实体解剖测量值的差异

背景：X射线、CT、MRI二维图像测量股骨髁间窝受投照体位、选取测量层面等影响,测量准确性较差。 目的：比较MRI影像下股骨髁间窝三维数字化模型测量值和尸体实体解剖测量值的差异,探讨基于MRI影像下三维数字化模型的准确性。 方法：对尸体膝关节标本行MRI扫描,将MRI图像导入Mimics软件对股骨髁间窝进行三维数字化重建,测量三维数字化髁间窝的相关解剖学数据,同时对尸体标本进行解剖,测量实体解剖学数据。 结果与结论：三维数字化重建髁间窝顶长度、髁间窝宽度、内外髁宽度、髁间窝指数测量值与实体解剖测量值差异无显著性意义(P > 0.05)。说明基于MRI影像下股骨髁间窝的三维数字化模型能够准确反映实体标本信息,可用于正常人股骨髁间窝的解剖学研究。     

参考桩钉修正曲面断层片垂直向的测量值*

背景：牙周病的诊断和治疗过程中常需测量牙槽骨高度和牙根长度,用曲面断层片对其进行定量测量的可靠性一直存在争议。 目的：验证用参考桩钉修正曲面断层片垂直向测量值的可行性。 方法：采用20例正畸患者的寄存模,在模型中的磨牙区、双尖牙区、尖牙区和切牙区嵌入5.00 mm钢珠作为测量对象,并在与钢珠相应的位置放置10.0 mm桩钉作参照物。拍摄模型的曲面断层片,测量钢珠影像垂直径,用桩钉校准和修正测量结果,比较钢珠影像测量值和真实值的差异。 结果与结论：用单一部位的参照物和1组参照物的平均值来校准,不同区域和不同桩钉放置方法测量结果的失真率不同,部分区域的失真率≥5%。在测量区域相应的部位放置完全垂直于牙合 平面的参考桩钉来修正测量值,可提高各区域测量结果的准确性,其失真率皆<1%,修正后的结果不受参照物的影响。而用贴在模型牙槽骨表面的参考桩钉来修正测量值,所得结果不理想。     

建立荷人结肠癌裸鼠移植瘤模型及MRI成像检查

背景：肿瘤移植瘤动物模型是探索和模拟肿瘤在人体内生物学行为的一种较为理想的方法,但应用MRI对模型进行评价的研究较少。 目的：应用人结肠癌LoVo细胞接种裸鼠,鼠间移植传代,建立人结肠癌裸鼠移植瘤模型,并应用MRI进行初步评价。 方法：采用细胞移植和瘤块移植两种方法建立裸鼠移植瘤模型,观察移植瘤大体形态和组织病理学改变,测定宿主血液中的癌胚抗原值,应用免疫组化法观察肿瘤细胞中癌胚抗原的的分布,对6只裸鼠移植瘤模型进行MRI成像检查,并测量肿瘤、肝脏、肌肉组织的T1WI和T2WI的信噪比和三者的T1,T2值。 结果与结论：移植瘤的形态和功能特性与原发肿瘤基本相似,移植瘤的移植成功率为100%;6只裸鼠模型的MRI测量结果显示,其肿瘤、肝脏、肌肉的T1WI平均信噪比分别为26.19,22.71,26.62;T2WI平均信噪比分别为9.42,7.66,8.59;平均T1值分别为1039.22,907.63,1611.51ms;平均T2值分别为109.95,37.31,64.35 ms。结果证实荷人结肠癌裸鼠模型的MRI成像图像清楚,组织分辨率高,测定组织的T1值和T2值可作为定量指标进行分析。     

颌面缺损结构光三维测量与螺旋CT扫描图像的配准

背景：目前尚无一种数字化信息采集技术能完全满足颌面缺损赝复的需要。因此,如能将光学三维测量与CT扫描数据的配准应用于颌面缺损,将为该疾病的诊断、治疗计划和赝复提供足够的软硬组织形态信息。 目的：通过结构光三维测量与螺旋CT扫描重建模型的配准,构建一个高象素、复合内部骨结构的三维虚拟颌面缺损模型,并评估配准的精确度。 方法：对上海第九人民医院口腔颌面外科收治的1名大面积复杂颌面缺损患者,分别使用自主研发的结构光三维光学测量系统和螺旋CT进行颌面部扫描和信息采集。分别使用Geomagic studio与自主研发的CAD-FacePros软件重建三维模型。使用CAD-FacePros软件,先通过面部解剖标志进行初配定位,再经迭代近邻点算法进行精确配准,将结构光测量获得的面部三维模型与CT重建后的颌面软组织模型进行匹配。使用CAD-FacePros软件计算两个匹配后模型间的最近点间距,获得模型配准误差。 结果与结论：通过配准构建了一个高象素、复合内部骨结构的三维虚拟颌面缺损模型。平均配准误差为0.5 mm,颌面部大部分区域的配准误差在1.0 mm以内,颊部配准误差稍大。提示通过结构光三维测量与螺旋CT扫描重建模型的配准,构建高象素、复合内部骨结构的三维虚拟颌面缺损模型是可行的。     

Basilar impression of the skull in patients with adult coeliac disease and after gastric surgery

Chamberlain's, McGregor's and Bull's angle measurements for basilar impression of the skull were made on 22 adult patients with idiopathic steatorrhoea (probable gluten enteropathy), 24 patients who had had previous gastric surgery, and 48 control subjects. For each of the three measurements a value greater than the mean plus two standard deviations was taken as the upper limit of normal. In seven patients with adult steatorrhoea all three measurements were abnormal suggesting basilar impression, while basilar impression was probable in only one patient who had gastric surgery. The trend towards abnormal measurements was significant in the steatorrhoea patients but not in those who had gastric surgery. Basilar impression also was present in patients who did not have rickets or present evidence of osteomalacia. It was argued that this study could support a hypothesis that some cases of primary basilar impression of the skull are secondary to bone softening associated with malabsorption in early life, the evidence of which may have disappeared in adult life.     

羟乙基淀粉一步与两步法分离骨髓单个核细胞及血小板的比较

背景：羟乙基淀粉和淋巴细胞分离液两步法分离骨髓有核细胞,可以提高单个核细胞的浓缩效率,但对血小板残留量的研究未见报道。 目的：明确羟乙基淀粉两种分离方法浓缩骨髓单个核细胞的效率和残留血小板的量。 方法：骨髓来自在新疆医科大学第一附属医院行成体自体骨髓有核细胞移植治疗相关疾病分离骨髓的检测标本。采用羟乙基淀粉自然沉降和羟乙基淀粉沉降后再用淋巴细胞分离液分离骨髓细胞。观察两种方法分离骨髓细胞后有核细胞、单个核细胞、血小板数。 结果与结论：羟乙基淀粉两步法分离骨髓后有核细胞悬液中单个核细胞均值为89%,一步法为45%。两步法浓缩单个核细胞的百分率高于一步法(P < 0.05);残留血小板数(中位数：73.00)低于一步法(中位数：367.50)(P < 0.05)。结果表明,羟乙基淀粉和淋巴细胞分离液两步法分离骨髓细胞中单个核细胞和血小板的效果优于一步法。     

MR nerve imaging in a prospective cohort of patients with suspected carpal tunnel syndrome

OBJECTIVES: To evaluate the reliability and diagnostic accuracy of high-resolution MRI of the median nerve in a prospectively assembled cohort of subjects with clinically suspected carpal tunnel syndrome (CTS). METHODS: The authors prospectively identified 120 subjects with clinically suspected CTS from five Seattle-area clinics. All subjects completed a hand-pain diagram and underwent a standardized nerve conduction study (NCS). The reference standard for determining CTS status was a classic or probable hand pain diagram and NCS with a difference >0.3 ms between the 8-cm median and ulnar peak latencies. Readers graded multiple imaging parameters of the MRI on four-point scales. The authors also performed quantitative measurements of both the median nerve and carpal tunnel cross-sectional areas. NCS and MRI were interpreted without knowledge of the other study or the hand pain diagram. RESULTS: Intrareader reliability was substantial to near perfect (kappa = 0.76 to 0.88). Interreader agreement was lower but still substantial (kappa = 0.60 to 0.67). Sensitivity of MRI was greatest for the overall impression of the images (96%) followed by increased median nerve signal (91%); however, specificities were low (33 to 38%). The length of abnormal signal on T2-weighted images was significantly correlated with nerve conduction latency, and median nerve area was larger at the distal radioulnar joint (15.8 vs 11.8 mm(2)) in patients with CTS. A logistic regression model combining these two MR variables had a receiver operating characteristic area under the curve of 0.85. CONCLUSIONS: The reliability of MRI is high but the diagnostic accuracy is only moderate compared with a research-definition reference standard.     

Interpreting palmar sweat prints

The plastic impression method to assess the number of active palmar sweat glands (PSI) was used to study changes of sweat gland activity during several phases of dental treatment. Subjects were 64 female and 38 male patients at a dental surgery. At the beginning they scaled five typical dental situations in terms of perceived threat: waiting-room before treatment: sitting down in the dental chair; dentist enters and starts treatment; after treatment in the dental chair; and back in waiting-room after treatment. Four prints were taken in the waiting-room before treatment and one in each other situation described above. The average of prints 3 and 4 was used for phase comparisons. Palmar sweat index values were generally in accordance with the threat of the situations. In particular there was a rise from waiting-room to sitting down in the dental chair and a further increase at the dentist's entry, whereafter values dropped considerably. A significant decrease from the first two waiting-room values to the following two suggests that the PSI reacts sensitively to the novelty of the assessment procedure itself and that the very first recordings should hence not be taken into evaluation.     

Treatment of bruxism in individuals with developmental disabilities: A systematic review

We reviewed studies involving the treatment of bruxism (i.e., teeth clenching or teeth grinding) in individuals with developmental disabilities. Systematic searches of electronic databases, journals, and reference lists identified 11 studies meeting the inclusion criteria. These studies were evaluated in terms of: (a) participants, (b) procedures used to assess bruxism, (c) intervention procedures, (d) results of the intervention, and (e) certainty of evidence. Across the 11 studies, intervention was provided to a total of 19 participants aged 4–43 years. Assessment procedures included dental screening under sedation and interviews with caregivers. Intervention approaches included prosthodontics, dental surgery, injection of botulinum toxin-a, behavior modification, music therapy, and contingent massage. Positive outcomes were reported in 82% of the reviewed studies. Overall, the evidence base is extremely limited and no definitive statements regarding treatment efficacy can be made. However, behavior modification and dental or medical treatment options (e.g., prosthodontics) seem to be promising treatment approaches. At present, a two-step assessment process, consisting of dental screening followed by behavioral assessment, can be recommended.     

Interictal spike localization using a standard realistic head model: simulations and analysis of clinical data.

OBJECTIVES: In this paper realistic and standard realistic head models were applied to neural source localization. METHODS: Three different triangulated head structures; the brain, the skull and the scalp were constructed from MRI information of each patient. For each subject the exact positions of the electrodes were digitized. RESULTS: The influence of the number of triangles and of the skull conductivity on the accuracy of the method was tested. The use of a standard realistic head model instead of spherical models is proposed in cases where detailed MRI information is not available, and the accuracy of this procedure is tested with dipole simulations. These techniques were applied also to EEG signals from 3 patients with focal epilepsy. In all cases the neural activity was assumed to be confined to a small portion of cortical tissue, so that the neural generator was approximated to a current dipole. The realistic head model localization is discussed on the basis of neuroimaging information. CONCLUSIONS: We show that the standard realistic head model is two or 3 times better than the spherical model for dipole localization and we propose it as a good alternative to the spherical model for EEG data processing, in cases where full MRI information is not available.     

Motivation and value influences in the relative balance of goal-directed and habitual behaviours in obsessive-compulsive disorder

Our decisions are based on parallel and competing systems of goal-directed and habitual learning, systems which can be impaired in pathological behaviours. Here we focus on the influence of motivation and compare reward and loss outcomes in subjects with obsessive-compulsive disorder (OCD) on model-based goal-directed and model-free habitual behaviours using the two-step task. We further investigate the relationship with acquisition learning using a one-step probabilistic learning task. Forty-eight OCD subjects and 96 healthy volunteers were tested on a reward and 30 OCD subjects and 53 healthy volunteers on the loss version of the two-step task. Thirty-six OCD subjects and 72 healthy volunteers were also tested on a one-step reversal task. OCD subjects compared with healthy volunteers were less goal oriented (model-based) and more habitual (model-free) to reward outcomes with a shift towards greater model-based and lower habitual choices to loss outcomes. OCD subjects also had enhanced acquisition learning to loss outcomes on the one-step task, which correlated with goal-directed learning in the two-step task. OCD subjects had greater stay behaviours or perseveration in the one-step task irrespective of outcome. Compulsion severity was correlated with habitual learning in the reward condition. Obsession severity was correlated with greater switching after loss outcomes. In healthy volunteers, we further show that greater reward magnitudes are associated with a shift towards greater goal-directed learning further emphasizing the role of outcome salience. Our results highlight an important influence of motivation on learning processes in OCD and suggest that distinct clinical strategies based on valence may be warranted.     

Intracranial cavity volume can be accurately estimated from the weights of intracranial contents: confirmation by the dental plaster casting method.

Intracranial cavity volume is used to evaluate brain size relative to the intracranial space. This volume can theoretically be obtained from the weights and densities of the brain and surrounding cerebrospinal fluid (weight method). However, the accuracy of this method has not been examined. In this study, we examined the reliability of the weight method, by comparing the intracranial cavity volumes of 41 post-mortem cases obtained by the weight method (ICVw) with those obtained by a dental plaster casting method (ICVcast) which was shown to be unbiased. The ICVw was not significantly different from the ICV cast (P=0.49, paired t-test), and the standard error of difference was 18 ml (1.3% of ICVcast). These results show that the weight method is reliable, and applicable to routine autopsies.