根管预备程度对无髓牙根管壁应力影响的分析

目的 分析不同根管腔的直径对根管壁应力的影响。方法 在已建立的下颌第一磨牙模拟常规法根管预备修改的实验模型基础上，再修改根管腔直径，使根管直径扩大到牙根直径的1／3和1／2，并在修改模型上加载，计算在不同加载条件下牙齿各部及管壁的最大应力。结果 根管腔直径增大会引起根管壁应力的升高，该变化主要出现在根管口和根上1／3段，侧向加载时产生的应力差异大于垂直加载时产生的应力差异。结论 根管预备应以去除根管壁的感染物质，获得良好的根管成形为原则，过度的预备不仅没有必要，甚至有害。     

骨髓移植诱导免疫耐受家兔全耳同种移植

目的　为了减轻免疫诱导过程中对受体的侵袭 ,进一步探讨以家兔为动物模型 ,通过异体骨髓移植诱导同种皮肤移植免疫耐受。方法　通过骨髓腔内直接注射异体骨髓细胞 ,进行骨髓移植。结果　皮片的平均存活时间是 (88.0± 6 .0 )天 (P <0 .0 0 1 )。为了探讨其普遍性 ,我们用此诱导方法 ,还进行了同种全耳移植。平均存活时间是 (1 4 6 .0± 1 5 .1 )天 ,并有 1只移植耳存活时间已超过 1年 ,未见任何排斥反应。结论　本研究证明了以家兔为动物模型 ,在不使用免疫抑制剂的情况下 ,通过骨髓腔内直接注射异体骨髓细胞 ,进行骨髓移植的方法 ,不仅在皮肤移植上可以诱导长期稳定的特异性免疫耐受 ,而且在实质性器官耳的同种移植上取得了良好的效果     

慢性鼻窦炎对中耳听阈的影响

目的 探讨慢性鼻窦炎对中耳听阈的影响。方法 对53例慢性鼻窦炎病人、10例健康成人行纯音测听。采用多状态Logistic回归模型，对慢性鼻窦炎可能影响听阈的因素进行评价。结果 ①53例中，正常听阈35例（66．04％），轻度聋16例（30．19％），中度聋2例（3．77％）。②各频率鼻窦炎组与对照组、鼻窦炎各分型之间听阈比较，有统计学意义（P〈0．05）。③慢性鼻窦炎对中耳听阈的影响因素中，经过多状态Logistic回归模型的逐步筛选，显示2项因素可能影响听阈，即筛窦CT分型呈硬化型，鼻窦炎分型分期较重时。结论 ①慢性鼻窦炎可影响听阈，随慢性鼻窦炎分型分期加重，听力损伤加重。②筛窦呈硬化型、鼻窦炎分型分期重时，可能影响最大。     

Canal wall reconstruction and mastoid obliteration with composite multi-fractured osteoperiosteal flap

We used inferior pedicled composite multi-fractured osteoperiosteal flap (CMOF), our original and new surgical approach, to obliterate the mastoid cavity and reconstruct the external auditory canal (EAC) to prevent the open cavity problems. CMOF was used to obliterate the mastoid cavity and reconstruct the EAC in 24 patients (13 women, 11 men; age span 12–51 years) who underwent radical mastoidectomy to treat the chronic otitis media between 1998 and 2004. Small meatoplasty was done in all 24 patients to relive their aesthetical concerns. Temporal bone CT scanning was done to observe the neo-osteogenesis in the mastoidectomy cavity and the CMOF, and the EAC volume was measured postoperatively. All our patients were followed-up for 2 years. The epithelization of the new EAC in our patients was complete at the end of the second month. Cholesteatoma, granulation, and recurrence of osteitis did not occur in any of the patients. We saw the new bone formation filling the mastoid cavity in the postoperative temporal bone CT scanning images. The mean volume of the new EAC on the 24th month was 1.83 ± 0.56 cm³. We had an almost natural EAC, which owed its existence to the neo-osteogenesis that grows behind the CMOF, which we use to obliterate the mastoid cavity and to reconstruct the EAC.This technique, composite multi-fractured osteoperiosteal flap, was presented in the symposium of Gulhane Military Medical Academy on otology and audiology, 15–18 September, 2005, Antalya, Turkey.     

Comparative observation of protective effects of earplug and barrel on auditory organs of guinea pigs exposed to experimental blast underpressure

Objective: To explore the protective effects of earplug and barrel on auditory organs of guinea pigs exposed to experimental blast underpressure (BUP). Methods : The hearing thresholds of the guinea pigs were assessed with auditory brainstem responses ( ABR). The traumatic levels of tympanic membrane and ossicular chain were observed under stereo-microscope. The rate of outer hair cells (OHCs) loss was analyzed using a light microscope. The changes of guinea pigs protected with barrel and earplug were compared with those of the control group without any protection. Results: An important ABR threshold shift of the guinea pigs without any protection was detected from 8h to 14d after being exposed to BUP with a peak ranging from -64.5 kPa to -69.3 kPa (P<0.01). The rate of perforation of tympanic membrane reached 87.5 % and that of total OHCs loss was 19.46%±5.38% at 14d after exposure. The guinea pigs protected with barrel and earplug had lower ABR threshold and total OHCs loss rate compared with the animals without any protection (P<0.01). All of the tympanic membrane and ossicular chain of the protected animals maintained their integrities. Meanwhile, the guinea pigs protected with the barrel had lower ABR threshold and total OHCs loss rate than those with earplug (P<0.01). Conclusions: The earplug and barrel have protective effects against BUP-induced trauma on auditory organs of the guinea pigs and the protective effects of barrel are better than those of earplug.     

小耳畸形残耳软骨的生物化学研究

目的　探讨正常耳软骨与先天性小耳畸形的残耳软骨生化成分的异同 ,进而推论小耳畸形的病因。方法　选取年龄在 10岁左右 ,Tanzer分类ⅡA型的 7例先天性小耳畸形患者的残耳软骨 (A组 )。同时取 7名同龄尸体的正常耳廓耳甲部分的软骨 (B组 )。各取 7份标本做生化检查 ,测定胶原、糖胺多糖 (glycoaminoglycan ,GAG)含量 ;硫酸软骨素 (chondroitinsulfate,Chs)、硫酸角质素 (keratansulfate ,KS)和透明质酸 (hyaluronan ,HA)各占GAG的百分含量。结果　A组与B组之间胶原含量差异无显著性意义 ;GAG含量差异有显著性意义A组 (49.0 0± 2 5 .6 0 ) μg/mg比B组 (2 8.2 5± 4 .80 ) μg/mg多。在GAG中的组成部分中 ,A组HA(38.96± 4 .97) %、Chs(2 9.0 2± 4 .12 ) %、KS(32 .16± 7.4l) %与B组HA(32 .94± 3.2 4 ) %、Chs(33.10± 2 .6 1) %、KS(33.96± 1.6 6 ) %之间HA和Chs含量差异有显著性意义 ,而KS含量差异无显著性意义。结论　残耳软骨与正常耳软骨中胶原含量无差异 ,但含GAG前者比后者多。在GAG中的各成分的百分含量中 ,残耳软骨含HA较高 ,Chs较低 ,KS与正常耳软骨无差异。     

First branchial cleft fistula presenting with external opening on earlobe

First branchial cleft fistula is a rare congenital malformation of the head and neck with an incidence of less than 10% of all branchial cleft defects. We herein report a 15-year-old girl who had a cystic mass in the postauricular region with an external opening on the posterior face of the earlobe. Surgical exploration revealed that a second sinus tract was passing through the conchal cartilage without going beyond the skin of the external acoustic meatus. The mass and the tract were excised along with the opening on the earlobe as well as the skin island surrounding the opening. The case was treated surgically with success .The significance of our case was the location of external opening on the earlobe.     

耳蜗的扫描电镜观察

为研究柯替氏器的超微结构,用豚鼠、猫及4个月胎儿的耳蜗,在扫描电镜下观察。柯替氏器呈螺旋梯状,围绕在蜗轴周围。蜗尖部的柯替氏器较宽,蜗底部的较窄,其上方的前庭膜由单层扁平上皮组成,上皮表面有微绒毛。紧贴表面的盖膜由原纤维组成。大多数原纤维平行排列,表面与边缘的原纤维多交织成网。柯替氏器中有3排外毛细胞与1排内毛细胞,二者之间有柱细胞头板,外毛细胞上的听毛排列成W形,内毛细胞上的听毛排列成弧形。此外,所有细胞表面均有微绒毛。在轻度噪音刺激后,听毛减少并紊乱,微绒毛也减少或消失。 4月胎儿的柯替氏器有3～4排外毛细胞,其表面为绒球状听毛,后来发育为W形排列。内毛细胞为1排,表面为束状的原始听毛,后变为弧形排列。本文还观察到断裂的柯替氏器中,暴露出外毛细胞的柱状胞体及底部的杯状支持结构。外毛细胞由外指细胞所肩托。外指细胞的指突与外毛细胞均倾斜排列,交错成一定角度。当暴露出外柱细胞时,其胞体上细下粗,表面有传入神经纤维。当外毛细胞、外柱细胞等掀向上方后,可见隧道中纵行的神经纤维束及其分支,即螺旋隧道束与放线隧道纤维,它们系橄榄耳蜗束的传出纤维。