牙种植数字化全景X线片失真率的临床评价

目的:了解数字化全景片失真率的大小以及在临床效果评价中的指导意义。方法:对术前使用统一直径钢珠的放射模板56个修复病例162个种植体拍摄数字化全景X线片,应用Cliniview5.1分析软件对各部位钢珠进行测量3次,取均值。了解拍摄后影像中钢珠的变化情况。结果:采用数字化全景X线片技术可观察到上下颌骨不同区域钢珠失真率与标准钢珠直径差异很小,失真率范围为0.2%￣2%,不同区域钢珠测量值之间有明显差异(P〈0.05〉):下颌前牙区与下颌双尖牙区、下颌前牙区与下颌磨牙区、下颌双尖牙区与上颌磨牙区、上颌磨牙区与下颌磨牙区钢珠测量值之间存在显著性差异。结论:数字化全景X线片对拟种植部位骨量进行评估可得出准确的数据。尽管不同区域钢珠测量值之间存在差异,但并不影响其测量值应用于临床的准确性。     

OSAHS与无睡眠呼吸障碍老年腭咽及其周围组织结构的MRI比较研究

目的研究睡眠呼吸暂停低通气综合症(OSAHS)与无睡眠呼吸障碍的老年男性腭咽及周围组织结构的三维形态差异.材料与方法70岁以上老年男性18名,根据夜间多导睡眠监测结果,8人AHI＞10,定为OSAHS组(T1组);10人AHI≤10,为无睡眠呼吸障碍组(T2组).所有受试者均行磁共振(MRI)检查,对两组腭咽及周围组织的MRI测量结果进行比较.结果①OSAHS组腭咽体积、截面积明显小于无睡眠呼吸障碍组;②与无睡眠呼吸障碍组相比OSAHS组腭咽左右径明显小、前后径/左右径之比明显大.③OSAHS组腭咽侧壁厚明显大于无呼吸障碍组、脂间距也明显小于后者.④两组的腭咽前壁厚度、后壁厚度、脂肪垫体积、舌体积、软腭体积没有显著差异.结论老年男性OSAHS患者由于腭咽侧壁增厚及咽旁脂肪垫的挤压,使腭咽左右径减小、截面积减小且形状趋圆,腭咽体积也减小.     

骨髓间充质干细胞移植促进大鼠下颌骨牵张成骨的实验研究

目的:探讨大鼠下颌骨牵张间隙内移植自体骨髓间充质干细胞,促进骨痂形成的可行性。方法:选用54只雄性SD大鼠,密度梯度离心法分离骨髓间充质干细胞(MSCs)。所有大鼠行右侧下颌骨牵张;并于术后随机分为试验和对照2组。牵张结束时,实验组牵张间隙内注射自体MSCs;而对照组只注射等量生理盐水。分别于固定期第2、4、8周分3批处死大鼠,进行放射学、组织学观察,并对骨组织形态计量学参数进行统计学分析(t检验)。结果:放射学和组织学观察表明,2组牵张间隙内均形成了骨痂组织,但实验组新生骨组织显著多于对照组。计量学分析也显示,各时间点实验组新生骨量(NBV1和NBV2)和新生骨小梁宽度(TNT)均显著高于对照组(P<0.01)。结论:牵张间隙内行自体骨髓MSCs移植,可有效促进新骨形成,缩短固定期;该方法对众多的颅颌面外科畸形的矫治极具价值。     

The Brisbane Statistical Division Survey of Adult Dental Health 1984. 3. Dental health status and treatment needs

Dental status and treatment requirements were investigated in 1504 subjects. Mean numbers of decayed, missing and filled (DMF) teeth for the various age groups were: 15–19 years, 6.2; 20–24 years, 10.6; 25–29 years, 15.8; 30–34 years, 18.1; 35–44 years, 20.4; 45–54 years, 23.0; 55–64 years, 26.2; and 65 years and older, 28.7. Total tooth loss did not occur in the 15–19 years or 20–24 years groups. In the 25–29 years group 2.6 per cent of subjects had lost all their teeth, 4.2 per cent in the 30–34 year group and 5.0 per cent in the 35–44 year group. The figures for the older age groups rose dramatically with almost 60 per cent of the 65 year and older age group having lost all their natural teeth. Treatment requirements for all age groups were low. In the 15–19 year age group 62.4 per cent of subjects had no treatment requirements. In other age groups the proportion was lower, ranging from 43.2 to 55.9 per cent. The periodontal condition of subjects was relatively good with only 3.3 per cent requiring complex treatment for severe forms of periodontal disease. A high proportion (over 50 per cent in all but the 15–19 year age group) required scaling and improved personal oral hygiene.     

Hepatitis B: a perspective

A bstract — Hepatitis B is becoming increasingly common in the community. Carriers are generally difficult to identify in dental practice, and therefore preventing transmission of the disease depends primarily on sound general clinical hygiene.     

The use of arthrography in management of temporomandibular joint problems

A bstract — Arthrography is useful in selecting those patients with severe dysfunction of the temporomandibular joint who would benefit from surgery. Plain films are usually unrewarding in the diagnosis of soft tissue abnormalities of the joint. Three cases are presented, illustrating the most common problems encountered and diagnosed by arthrography.     

Direction of the mental canal in human mandibles

The direction of the mental canal was calculated in the horizontal and vertical planes with a view to aiding anaesthetic techniques. Based on our data, it is advisable to give the following approximate inclinations to the needle when penetrating the mental canal in anaesthetic procedures: 55 degrees postero-anteriorly in relation to a horizontal plane and 40 degrees latero-medially in relation to a horizontal line tangent to the body of the mandible at the level of the mental foramen.     

ICRF154,加热对腺样囊性癌ACC-2细胞放射增敏的实验研究

目的研究ICRF154和加热对腺样囊性癌ACC－2细胞放射增敏的作用。方法以腺样囊性癌ACC－2细胞作为实验模型，用新抗癌药ICRF154在乏氧条件下研究该药的放射增敏性以及加热对放射的增敏效应。结果在0．2mmol／L浓度和2个小时作用时间下，ICRF154对ACC－2细胞有放射增敏作用，增敏比为1．22、放射后加热43℃，30分钟对ACC－2细胞有显著的放射增敏作用，增敏比为1．51。用上述浓度和作用时间ICRF154，作用于ACC－2细胞后进行照射，照华后即行加热43℃，30分钟，增敏比为1．67，表明ICRF154和加热的放射增敏作用有加成效应。结论ICRF154的放射增敏机制可能与其抑制拓扑异构酶Ⅱ，从而抑制DNA损伤的修复有关。     

非调和型正畸粘接剂的粘接强度考察

采用一种自制的非调和型正畸粘接剂,考察了牙釉质与正畸托槽在五种实验条件下的粘接抗张强度。结果表明该粘接剂不需调和,操作时间充裕,具有足够的初始粘接强度和长期粘接强度,其平均粘接抗张强度大于7MPa,特别适用于对多个正畸附件的粘接。     

基质金属蛋白酶-7和c-myc在口腔鳞状细胞癌中的表达和意义

目的研究基质金属蛋白酶-7(MMP-7)与c-myc在口腔鳞状细胞癌组织中的表达及其意义。方法应用免疫组化EliVisionTM法分别检测MMP-7和c-myc在49例口腔鳞状细胞癌和5例正常口腔黏膜上皮中的表达情况。结果1)MMP-7和c-myc在口腔鳞状细胞癌组织中的阳性表达率分别为83.7%和77.6%。2)在不同病理分级、不同临床分期和有无淋巴转移的口腔鳞状细胞癌组织中MMP-7阳性表达率的差异有统计学意义(P<0.05)。3)在不同病理分级和有无淋巴转移的口腔鳞状细胞癌组织中c-myc阳性表达率的差异亦有统计学意义(P<0.05)。4)口腔鳞状细胞癌组织中MMP-7和c-myc的表达呈正相关(P<0.05)。结论MMP-7和c-myc在口腔鳞状细胞癌组织中均有高表达,在口腔鳞状细胞癌的发病过程中,其高表达具有协同效应,共同促进口腔鳞状细胞癌的发生和发展。