PTEN、p27在口腔粘膜白斑和口腔癌组织中的表达及意义

目的　探讨抑癌基因PTEN、p2 7在口腔粘膜白斑 (oralleukoplakia ,OLK)和口腔癌 (oralsquamouscellcancer,OSCC)组织中的蛋白表达及意义。方法　应用免疫组化S -P法检测 10例正常口腔粘膜、2 5例口腔粘膜白斑 (其中白斑伴上皮异常增生 15例 ,白斑不伴上皮异常增生 10例 )及 32例口腔癌组织中抑癌基因PTEN和p2 7的蛋白表达情况。结果　正常口腔粘膜和白斑不伴上皮异常增生组织中PTEN和 p2 7蛋白全部阳性表达 ;白斑伴上皮异常增生组织中PTEN和 p2 7蛋白阳性表达率分别为93.3%、73.3%。OSCC组织中PTEN蛋白阳性表达率为71.9% ,其中高、中、低分化OSCC组织中PTEN蛋白阳性表达率分别为 85 .7%、75 %和 33.3% ,统计学分析表明PTEN在OSCC组织中的蛋白表达与组织分化程度明显相关 (P <0 .0 5 )。OSCC组织中 p2 7蛋白的阳性表达率为4 0 .6 % ,其中高、中、低分化OSCC组织中p2 7蛋白的阳性表达率分别为 4 2 .9%、4 1.7%和 33.3% ,统计学分析表明p2 7在OSCC组织中的蛋白表达与组织分化程度无明显相关 (P >0 .0 5 )。结论　OSCC组织中PTEN和 p2 7蛋白的阴性表达率较高 ,说明PTEN和 p2 7基因突变或缺失在OSCC的发生发展过程中起重要作用。     

Metastases to lingual lymph nodes from squamous cell carcinoma of the tongue

The diagnosis of squamous cell carcinoma (SCC) of the tongue metastasising to the lingual lymph nodes is rare. Until now lingual lymph nodes have not been mentioned in any system of lymph node classification. We report a case of SCC of the tongue with metastases to the lymph nodes in the superficial floor of the mouth, and to levels I and II lymph nodes. We provide evidence of the existence of lingual lymph nodes, and validate the practice of removing the lymph node-bearing-tissue of the floor of the mouth during neck dissection in cancers of the oral cavity.     

Measuring clinical attachment: reproducibility of relative measurements with an electronic probe.

During the past few years, improvements in detecting longitudinal changes in clinical attachment or alveolar bone density have been introduced. For example, constant-force electronic probes and computer-assisted subtraction analysis of longitudinal radiographs have been reported to be more sensitive and reproducible in detecting changes in clinical attachment or alveolar bone density, respectively. Use of these new technologies requires that sources of measurement error be identified and their contribution quantified. This study investigated the reproducibility of a constant-force electronic probe in a careful clinical setting. Measurements were performed from individually fabricated acrylic stents. Three groups of subjects were selected for the study: 10 adults without oral disease, 10 adults with gingivitis, and 10 adults with moderate periodontitis. Four probing designs were employed to investigate the reproducibility of the probe. In design A, the probe tip was left in the sulcus between successive probings. In design B, the probe tip was removed from the gingival margin between probings but the next probing followed immediately. In design C, successive whole-mouth probings were interrupted by a 5-minute interval and a mouth rinse. In design D there was a 4-week interval between each successive probing. Three measurements were taken at each site for each design. The main purpose of this study was to identify variance components in the attachment level variation. The maximum probing error standard deviation ranged from 0.2 to 0.3 mm depending on the periodontal health of the subject. This level of variation is considerably smaller than that found in most previous studies.(ABSTRACT TRUNCATED AT 250 WORDS)     

功能矫治器矫治安氏Ⅱ类Ⅰ分类错He的软组织侧貌变化

目的 用5项软组织美学指标，评价功能矫治器矫治安氏类Ⅰ分类错殆的软组织变化。方法 对21例安氏类Ⅰ分类错He患者用功能矫治器(FR-2)矫治前后的X线头影测量片进行分析，对比治疗前后软组织5项美学指标的变化。结果 通过早期的功能矫形治疗，患者大多数美学指标接近正常值范围，但也有部分指标改善不明显。结论 功能矫治能使大多数患者软组织侧貌得到明显改善，但存在个体差异，部分病例仍需要二期治疗。     

应用植入控释系统进行一次法根管治疗术的动物实验研究

目的：利用自制含氯霉素、甲硝唑等药物的控释系统，对实验家兔的血药浓度、药物抗菌活性和家兔根管、尖周组织的病理观察，为今后临床应用提供理论和实验依据。方法：应用组织病理观察和液相色谱分析技术。结果：用ＨＰＬＣ法得出实验用家兔血药浓度和抗菌活性均为阴性，根管及尖周组织病理切片无特殊表现。结论：自制控释系统是一种无毒、无副作用、有效的根管治疗药物剂型，可进行临床应用。     

正畸用粘接剂底涂剂的研制

目的 开发能与牙釉质产生较强粘接力，提高托槽在牙面上的粘接强度。提供正畸治疗理想的底涂剂。方法 引入不同活性稀释单体组成不同的底涂剂配方，进行粘接抗剪切强度测试。结果 筛选出以极性适中的HAMA组成的底涂剂，其性能较同类产品更为杰出，粘接抗剪切强度达23.6MPa。结论 在传统底涂剂配方中引入极性适中，液体表面张力适当的HAMA所形成的PR-2配方是本研究的理想的底涂剂配方。     

Shaping ability of progressive versus constant taper instruments in curved root canals of extracted teeth

AIM: To compare the shaping ability of progressive versus constant taper shaft instruments in curved root canals of extracted human teeth. METHODOLOGY: A total of 40 root canals of mandibular molars with curvatures ranging between 20 degrees and 40 degrees were divided into two groups of 20 canals each and embedded in a muffle system. The root canals sectioned horizontally at three levels before preparation and then remounted into the mould. All root canals were prepared with ProTaper (progressive taper) or Hero Shaper (constant taper) instruments. Pre- and post-instrumentation radiographs and cross-sectional images were obtained. The parameters evaluated were: working safety (instrument failure, apical blockage and loss of working length) and shaping ability (straightening, cross-sectional area, transportation and centring ability). The data were analysed statistically using Student's t-test. RESULTS: No instrument fractured during preparation. One Hero Shaper instrument permanently deformed. Both instrument systems maintained working length well. The canals prepared with Hero Shaper instruments were straightened to a lesser degree (P < 0.05). ProTaper instruments removed more dentine in the coronal and the middle sections of the canals. Canals prepared with Hero Shaper instruments had less transportation (P < 0.01) and better centring ability (P < 0.05) in the apical section. CONCLUSIONS: Both instrument systems were safe to use and maintained working length well. The canals prepared with Hero Shaper had less transportation and were better centred in the apical region, possibly because their smaller taper reduced instrument stiffness.     

Heterotrophic ossification on a skin graft in a postburn scar of the chin

Some patients who have heterotrophic ossification (HO) in a postburn scar are occasionally seen in the clinic. The occurrence of HO following hip and abdominal surgery is common in males, whereas females are frequently affected following burns. The HO of skin grafts in burn scars of the superior body parts is uncommon, especially on the face. We report a recent case of a male patient in whom HO arose on skin grafts on his chin. The patient presented with a history of a painless chin mass for 48 years. Computed tomography scan suggested that the mass was located within subcutaneous tissue away from the lower jaw. The density of the mass was almost the same as the cortical bone of the lower jaw. The mass was completely resected under general anesthesia. It was a rectangular mass of 3× 0.5× 0.3 cm. Histological examination gave the diagnosis of HO, which was also confirmed by immunohistochemical stainings for vimentin. Recurrence was not found in this case by clinical and radiologic follow-up at 1 year after surgery.