Human jaw joint hypermobility: Diagnosis and biomechanical modelling

Patients with hypermobility disorders of the jaw joint experience joint sounds and jerky movements of the jaw. In severe cases, a subluxation or luxation can occur. Clinically, hypermobility disorders should be differentiated from disc displacements. With biomechanical modelling, we previously identified the anterior slope angle of the eminence and the orientation of the jaw closers to potentially contribute to hypermobility disorders. Using cone‐beam computed tomography (CBCT), we constructed patient‐specific models of the masticatory system to incorporate these aspects. It is not known whether the clinical diagnosis of hypermobility disorders is associated with the prediction of hypermobility by a patient‐specific biomechanical model. Fifteen patients and eleven controls, matched for gender and age, were enrolled in the study. Clinical diagnosis was performed according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and additional testing to differentiate hypermobility from disc displacements. Forward simulations with patient‐specific biomechanical models were performed for maximum opening and subsequent closing of the jaw. This predicted a hypermobility disorder (luxation) or a control (normal closing). We found no association between the clinical diagnosis and predictions of hypermobility disorders. The biomechanical models overestimated the number of patients, yielding a low specificity. The role of the collagenous structures remains unclear; therefore, the articular disc and the ligaments should be modelled in greater detail. This also holds for the fanned shape of the temporalis muscle. However, for the osseous structures, we determined post hoc that the anterior slope angle of the articular eminence is steeper in patients than in controls.     

2种材料嵌体用于后牙Ⅱ类洞修复的临床效果比较

目的: 比较CAD/CAM全瓷嵌体与Ceramage 聚合瓷嵌体修复活髓后牙Ⅱ类洞的临床效果。方法: 选取牙体缺损活髓后牙需制备Ⅱ类洞的患者97例,共100颗患牙。随机分为2组,分别制作CAD/CAM全瓷嵌体与Ceramage 聚合瓷嵌体修复。比较2组修复后12个月、24个月的效果,参照改良美国公共卫生服务评价体系（USPHS）,评价术后牙敏感、修复体折裂、修复体脱落、边缘着色情况。采用SPSS13.0软件包对2种材料嵌体修复12个月、24个月的计数资料进行X²检验,等级资料进行Wilcoxon秩和检验。结果: 12个月时,2组病例均修改成功,结果无显著差异（P>0.05）。24个月时,术后牙敏感、修复体脱落例数,2组比较无显著差异（P>0.05）;修复体折裂发生例数,聚合瓷组低于全瓷组（P<0.05);边缘着色发生例数,聚合瓷组高于全瓷组（P<0.05）。结论: 聚合瓷嵌体修复活髓后牙Ⅱ类洞术后抗折裂力高于CAD/ CAM 全瓷嵌体,缺点是边缘着色发生率较高,应根据患者的需求选择合适的修复方案。     

Need for diagnostic-centric care in dentistry: A case study from the Marshfield Clinic Health System

Background

The study objective was to evaluate the workflow of dental providers who use the existing electronic dental record (EDR) system at a large regional health care system to establish a diagnostic-centric culture as part of their dental practice. A further goal focused on identifying when improvements to the workflow and design of the EDR may be indicated.

低剂量螺旋CT在有症状患者胸部检查的应用分析

目的：探究低剂量螺旋CT在有症状患者胸部检查中的应用价值。方法：筛选有胸部症状患者90例,所有患者均经2种方法来检测,其一为常规剂量螺旋CT对其进行检查,其二为低剂量螺旋CT进行检查,对比两种检查方法的效果。结果：于患者病灶、病灶定性及病灶结构方面进行检查,低剂量螺旋CT及常规剂量螺旋CT检出率均无显著差异,但通过靶向扫描或高分辨扫描,可显著提高诊断率。结论：低剂量螺旋CT与常规剂量对有症状患者胸部检查有一致的应用价值,低剂量螺旋CT扫描加病变部位靶向扫描是胸部CT检查的最有效方案。     

Biomechanical investigation into the torsional failure of immature long bone

Approximately 50% of infant and toddler long bone fractures are attributed to non-accidental trauma; however, differentiating from benign mechanisms is subjective, due to an absence of evidence-based diagnostic tools. Previous studies investigated small ranges of rotational velocities in animal long bone models, although did not report the variation in the spiral fracture angle. This study considered the fracture angle as a potential clinical measure, correlating this data with a wider range of rotational velocities. The spiral fracture angle was measured relative to the long axis, whilst noting the narrowest diaphysial diameter, location of the fracture, and the extent of comminution and periosteal disruption. Twenty-six bones failed in spiral fracture, with the potting material failing in the remaining tests. All spiral fractures centred on the narrowest diaphysial diameter. Slower rotational velocities caused fracture angles approaching 45°, whereas fractures at greater velocities caused fracture angles nearer 30°. A relatively strong trend (R² = 0.78) is reported when the normalised fracture angle (against the narrowest diaphysial dimension) was plotted against the rotational rate. A relationship has been identified between the angle of spiral fracture and the rotational velocity using the immature bovine metatarsal model. This trend forms a scientific foundation from which to explore developing a diagnostic, evidence-based tool that may ultimately serve to assist differentiating between accidental and non-accidental injury.     

急性脊柱外伤影像诊断价值比较分析

目的：探讨急性脊柱挫伤的影像诊断价值.材料与方法：搜集60例脊柱外伤患者行X线、CT和MRI检查,对其三者进行对比分析.结果：椎体骨折45例：X线显示椎体骨折41例,累及115节椎体（90.6％）,伴附件骨折32处（61.5％）.CT显示椎体骨折45例,累及127节椎体（100.0％）,伴附件骨折52处（96.2％）,脊髓损伤3例,硬膜外下血肿2例.MR显示椎体骨折44例,累及123节椎体（96.9％）,伴附件骨折48处（92.3％）,韧带损伤16处,脊髓损伤10例,硬膜外下血肿6例.椎体挫伤15例：MRI显示23节椎体挫伤,伴附件挫伤7处;X线和CT均未发现异常.结论：显示骨折CT敏感度优于MRI和X线平片,显示骨挫伤和韧带、脊髓损伤MRI明显优于CT和X线平片.     

螺旋CT在无典型临床表现阑尾炎诊断中的应用与价值

目的探讨螺旋CT在无典型临床表现阑尾炎诊断中的应用价值。方法收集临床首次诊断未考虑阑尾炎经手术和病理证实的患者28例,回顾分析阑尾炎的CT表现特点。结果特征性征象：异常阑尾和（或）阑尾粪石,伴周围炎性反应。继发征象：盲周炎症及蜂窝组织炎脓肿。高度怀疑征象：远处脓肿。结论症状和体征不典型的阑尾炎临床诊断困难,根据CT表现,大多数病例可以得到正确诊断,为临床提供有利的诊断及手术依据。