Temporomandibular joint internal derangement: detection with 12.5 MHz ultrasonography

The purpose of this study was to determine whether 12.5 MHz ultrasonography (US) could be used to assess the presence or absence of temporomandibular joint (TMJ) internal derangement (ID). In 48 consecutive patients with TMJ disorders 192 TMJ positions were investigated by US to analyse the functional disc-condyle relationship (DCR). In order to compare the respective findings with those of a diagnostic method offering a high accuracy, coronal and sagittal magnetic resonance imaging was carried out immediately afterwards. With US showing a sensitivity of 0.58 and 0.75, and a specificity of 0.92 and 0.84 for disc displacement with and without reduction, the data revealed US to be marginal in detecting the presence, but sensitive in detecting the absence of the respective types of a TMJ ID. In addition, with a positive predictive value of 0.83 and 0.71, and a negative predictive value of 0.81 and 0.87 for disc displacement with and without reduction, the results indicate that US may be insufficient in establishing a correct diagnosis for the presence or absence of the respective types of TMJ ID. Regarding the diagnosis of absence or presence of TMJ ID, the results demonstrate high-resolution (HR)-US to be sensitive in detecting the absence, and reliable in predicting the presence of TMJ ID. In view of the fact that the 12.5 MHz US technique proved to be a reliable diagnostic aid for the detection of normal, and the prediction of abnormal DCR, the results of this study should be of further interest and encourage research in its potential uses and diagnostic capabilities.     

颞下颌关节骨关节炎与关节内紊乱关系的研究

目的 :探讨颞颌关节骨关节炎 (TMJOA)与颞颌关节内紊乱 (TMJID)的关系。方法 :利用MRI金标准 ,对 44例颞颌关节紊乱病患者 88侧关节完成开闭口T1加权成像 ,观察盘突关系和骨改变。结果 :88个关节中40 .9% ( 3 6/88)表现为TMJID ,13 .6% ( 12 /88)表现为TMJOA ,骨改变的分布情况 :正常盘突关系 (NDCR)关节中 2个 ,破坏和骨赘各 1个 ;可复性关节盘前移位 (ADDR)关节中 3个全部表现为骨破坏 ;不可复性关节盘前移位 (AD DWR)关节中 7个 ,表现为髁状突变平 3个 ;表现为破坏、骨赘、硬化和短小各 1个 ,统计学分析发现TMJOA与TMJID具有显著相关性。结论 :TMJOA的发生与关节结构紊乱显著相关。由于TMJOA可独立于TMJID之外而单独存在 ,目前将TMJOA看作是与TMJID密切相关的另一类疾病较为合适。     

颧骨骨折复位径路与固定部位的临床研究

目的　探讨颧骨骨折复位的径路与钛板固定部位。方法　总结 6 5例 (6 5 / 70 )颧骨或颧骨复合体骨折手术复位固定患者的软组织切口、钛板固定部位、钛板数目 ,术后随访 3～ 2 4个月 ,按三级标准评价手术效果 ,其中包括面形和功能的恢复 ,手术切口愈合情况 ;观察术后X线片 ,统计钛板的固定部位、数目及手术并发症。结果　手术软组织切口均一期愈合 ;面形恢复满意、两侧对称、开闭口功能正常 18例 (2 5 7% ) ;面形恢复两侧基本对称 ,开闭口功能正常 4 6例 (6 5 8% ) ;面形恢复两侧不对称 ,开闭口功能基本恢复为 6例 (8 5 % ) ;头皮下血肿 5例 ,钛板外露 1例 ,头皮有不规则瘢痕且宽度 >0 5cm 6例 ,额部和头皮感觉异常 8例。结论　应用冠状切口 (包括口内联合切口 )对 5 1例(5 1/ 6 5 )进行颧骨和颧骨复合体骨折复位固定 ,具有术野显露广泛、在明视下解剖复位、精确固定的优点。 6 5例共用钛板 179块 ,坚固内固定具有精确固位、外形稳定的优点。单纯颧骨骨折下端内陷或外翘移位可做一点固定 ,其他骨折尤其是复杂或陈旧性骨折均应做二点或多点固定     

44例面中部骨折病例的回顾性研究

目的：探讨面中部骨折的临床特点与治疗效果。方法：广州军区武汉总医院口腔科1999．1～2003．5面中部骨折住院病例44例，对年龄、性别、骨折类型、手术方式等进行分析。结果：43例经治疗取得了满意效果，1例陈旧性骨折面形及咬胎关系恢复欠佳。结论：开放复位固定是面中部骨折的主要治疗手段，上颌前庭沟黏膜切口是面中部骨折理想的手术径路。     

犬下颌骨骨折小钛板坚强内固定的组织学观察

目的:评价小钛板用于犬下颌骨线性骨折的效果。方法:选用12只杂种犬,随机分为实验组和对照组2组,于犬左侧下颌骨中段造成线性骨折,实验组应用钛接骨板(MNS104),长4孔钛板和ψ2.0mm×7mm钛钉加以固定;对照组不用任何材料固定。2组均分别于实验的第20天和第40天各取半数动物处死,应用四环素荧光标记方法及组织学观察,评价骨折愈合情况。测算四环素荧光染色切片上荧光带的宽窄,应用SPSS10.0统计软件包进行t检验,比较骨折愈合的速度。结果:小钛板的固定效果显著优于空白对照,四环素荧光染色可见,实验组的成骨速度显著优于空白组,其荧光宽度均值(0.1967mm)显著大于空白组均值(0.0891mm),P<0.05。结论:小钛板可以保证下颌骨骨折一期愈合。     

Differential localization of laminin gamma and integrin beta in primary cultures of the rat gingival epithelium

OBJECTIVES: The aim of this study was to investigate the differential immunolocalization of laminin gamma(2) and integrin beta(4) in primary cultures of the rat gingival epithelium. METHODS: The gingival epithelium was obtained from Sprague-Dawley rats and was cultured in serum-free keratinocyte growth medium (DK-SFM). Western blotting analysis, immunofluorescence, confocal laser scanning microscopy (CLSM), and immuno-gold labeling for laminin gamma(2) and integrin beta(4) were employed. CLSM images for laminin and integrin were analyzed in horizontal (x-y axis) and in vertical (x-z axis) sections. RESULTS: Both laminin gamma(2) and integrin beta(4) were detected by Western blot analysis in the gingival epithelium. Immunolocalization of laminin gamma(2) was distinct in the cytoplasm to form one or two irregular rings in gingival epithelial cells. By contrast, integrin beta(4) was localized diffusely in the cytoplasm. F-actin (indicating actin filaments) was clearly discernible at the periphery of the cytoplasm to form a cellular fringe. In x-z axis images obtained by CLSM, laminin gamma(2) was recognized as large foci in the most inner portion just above the basal plasma membrane. Integrin beta(4) existed in the area where F-actin was labeled surrounding the membrane. Immuno-electron microscopy showed that 10nm colloidal gold particles indicating laminin gamma(2) were mainly localized at the extracellular portion and in the peripheral cytoplasm, whereas integrin beta(4) was distributed in the cytoplasm close to the basal plasma membrane but not in extracellular regions. CONCLUSIONS: In primary cultures of the rat gingival epithelium, both laminin gamma(2) and integrin beta(4) may be produced by the epithelium, and irregular rings of laminin gamma(2) are formed in areas where gingival cells adhere to the extracellular matrix.     

TMJ symptoms reduce chewing amplitude and velocity,and increase variability

Objective: The null hypothesis was that mandibular amplitude, velocity, and variability during gum chewing are not altered in subjects with temporomandibular joint (TMJ) internal derangements (ID).

Methods: Thirty symptomatic subjects with confirmed ID consented to chew gum on their left and right sides while being tracked by an incisor-point jaw tracker. A gender and age matched control group (p > 0.67) volunteered to be likewise recorded. Student’s t-test compared the ID group’s mean values to the control group.

Results: The control group opened wider (p < 0.05) and chewed faster (p < 0.05) than the ID group. The mean cycle time of the ID group (0.929 s) was longer than the control group (0.751 s; p < 0.05) and more variable (p < 0.05).

Discussion: The ID group exhibited reduced amplitude and velocity but increased variability during chewing. The null hypothesis was rejected. Further study of adaptation to ID by patients should be pursued.     

Open mandibular condylotomy (osteotomy) with precision scaphoid staple osteosynthesis and meniscopexy. A description of the operation

The technical minutiae of the operation of open mandibular condylotomy and precision scaphoid staple osteosynthesis with meniscoplasty or meniscopexy is described and illustrated. The operation is regarded as an evolution of closed condylotomy described by Ward in 1961 and is indicated for those cases of severe and persistent temporomandibular joint pain and crepitus unresponsive to skilled conservative treatment over a reasonable time. The success of the procedure is probably the sequel of a partial denervation of the joint capsule associated with arthrotomy, the interruption of venous hypertension, the relocation of the mandibular condyle and enlargement of the joint space. The operation is also applicable to cases of active (and inactive) mandibular condylar hyperplasia wherein a condylar neck ostectomy and staple is used to ablate an active growth centre or correct a lesser degree of mandibular asymmetry.     

下颌骨延长术后牵张器拆除时机的实验研究

目的 :研究家兔下颌骨延长术后新生骨回缩情况 ,确定牵张器的拆除时机。方法 :成年家兔 16只 ,体重 2 .4～ 2 .6kg ,随机等分为 4组 ,每组 4只 ;行双侧下颌骨骨切开术 ,采用内置式牵张器对双侧下颌骨同时进行牵引。延迟期 :7d ;牵张期 :10d ;牵引速率 0 .5mm/次 ,2次 /d ;保持期分别为 2周、4周、8周、12周。保持期后行第二次手术取出牵张器 ,并同时植入钛钉为参照 ,判断下颌骨改建后新成骨有无缩短 ,观察期为 8周。结果 :保持期为 2周、4周组的实验动物新生骨在 8周后明显回缩 ,分别为 2 .1± 1.2mm、1.4± 1.3mm ;而保持期 8周、12周组 ,8周后新生骨未见明显回缩。结论 :兔下颌骨牵张延长术后 ,牵张器应在保持期 8周拆除 ;拆除过早 ,新生骨区产生明显回缩。     

Evaluation of internal adaptation in ceramic and composite resin inlays by silicon replica technique

This study was aimed at investigating the internal adaptation of a ceramic (Ceramco II) and two composite resin inlay materials (SureFil and 3M Filtek Z 250) using silicon replica technique as an indicator. Forty-five standard mesial-occlusal-distal (MOD) cavities were prepared into brass moulds by using computer numerically controlled system. Inlays were prepared according to manufacturers' instructions with indirect methods. Replicas of the prepared cavities and inlays were produced with a polyvinyl siloxane material (Elite H-D). The spaces between inlays and cavities were filled by different coloured light-body polyvinyl siloxane material. Two parallel slices (mesio-distally) were obtained from the replicas with a sharp blade. Different coloured polyvinyl siloxane material thickness between cavity and inlay was measured at seven points (mesial, occlusal and distal). The data were evaluated with anova and Tukey's honestly significantly different (HSD) statistical tests. In the SureFil and Ceramco II groups, the sizes of the contraction gaps at mesial and distal gingival floors were greater than that of the occlusal marginal walls. In comparison of gap formation at occlusal regions, while the 3M composite group showed highest gap values (204.33 +/- 75.45 microm), the Ceramco II group revealed the lowest (141.17 +/- 23.66 microm) (P < 0.05). At the gingival floors, gap formation of Ceramco II group was the highest (227.08 +/- 51.95 microm). Neither the 3M Filtek Z250 nor SureFil group showed any statistical difference between gap values of their self-occlusal and gingival floors (P > 0.05). In conclusion, our results showed that ceramic inlays did not confer any big advantage for internal adaptation over the composite inlays.