Comparative bactericidal exposures for selected oral bacteria using carbon dioxide laser radiation

Although relatively high CO2 laser energies have been shown to sterilize root canals, the response of several bacterial strains to decreasing exposures of CO2 laser energy remains unknown. Freshly grown bacterial cells were irradiated on glass microscope coverslips. A comparison of equivalent energy exposures with differing parameters was made on the bacterial viability. No statistically significant difference was found in the energy required to kill closely related bacterial species. However, the energy density required to kill greater than 99.5% of the bacteria is less than 200 J/cm2, much less than that shown to sterilize in a previous study.     

颈静脉窝的应用解剖学研究

本文通过200例成人颅颈静脉窝的观察与测量,对颈静脉窝的形态、位置及其与颅后窝、面神经管垂直部、鼓环的局部解剖关系进行研究,为临床应用及体质调查提供资料。     

后天性外耳道狭窄的手术治疗

目的探讨后天性外耳道狭窄的手术治疗方法及效果。方法对26例（27耳）外耳道狭窄行外耳道成形术或厢乳突根治鼓室成型术，取大腿内侧自体游离中厚皮片植皮，碘仿纱条压迫并扩张耳道。结果26例病人27耳随访6个月至8年，24耳外耳道宽敞，无再狭窄；3耳出现轻度狭窄，发生率11．1％（3／27），效果满意。结论对后天性外耳道狭窄的治疗可根据狭窄的原因、部位及程度等不同情况采用外耳道成形、游离中厚皮片移植或同时进行乳突根治鼓室成型术等手术治疗，术后局部换药，即能取得较好效果。     

显微内窥镜下治疗腰椎间盘突出症和腰椎管狭窄症

目的探讨显微内窥镜(MED)治疗腰椎间盘突出症和腰椎管狭窄症的临床效果。方法MED下切除增生内聚的关节突、肥厚的黄韧带及突出的椎间盘，彻底解除对硬膜、神经根的压迫。结果随访324例，按中华骨科学脊柱学组腰背痛手术评定标准，优297例，良14例，差13例，疗效优良率达96．0％，结论MED损伤小、恢复快、疗效好。     

牙根发育不良疾病的研究进展

牙根发育不良疾病是牙齿根部生理性发育出现障碍的疾病。其发病率为1%~10%,乳、恒牙列均可发生,其结果可导致牙根缺如或短根,严重者可造成牙齿过早脱落。国外学者将该疾病统称为短根异常疾病。其发病因素有遗传性疾病、全身性疾病、外源性因素和医源性因素等。     

Histometric study of root resorption on human premolars following experimental replantation

Abstract – A histometric method was applied for evaluation of root resorption in 57 experimentally replanted teeth and 22 controls. Representative axiobuccolingual sections were selected for measurement of resorptions at a magnification of × 40. The frequency of root resorption in the control teeth was low. In replanted teeth marked resorptive activity elicited by the trauma appeared after 2 wk. The extent of active resorptions increased until the third postoperative week. On an average 14% of the root periphery was affected at this stage. After the sixth postoperative week progressive cement deposition took place in the resorption lacunae. Incidental ankylosis of the periodontal membrane also occurred from this observation time but there was no increase among the long-term groups.     

颈椎管哑铃形肿瘤的显微外科治疗

目的探讨不同入路显微手术切除颈椎管哑铃形肿瘤的手术方法,总结其主要优点和术后并发症情况。方法2004年5月至2006年7月共收治16例颈椎管哑铃形肿瘤,其中5例肿瘤最大径超过5cm。5例巨大肿瘤中4例位于上颈段,采用侧方改良的极外侧入路（后外侧肌间入路）, 1例外院手术复发的巨大肿瘤位于中颈段,采用分次后正中和前路联合切除并行后方和前方内固定加前方植骨融合;1例肿瘤椎管外部分向前方生长,采用颈前入路切除后行前方植骨融合加内固定,其余10例采用后正中入路,其中1例超过中线的肿瘤采用全椎板切除加椎管成形,7例半椎板切除, 1例复发肿瘤原路切除,1例未切除椎板切除肿瘤。结果手术全切肿瘤14例,次全切2例。所有病例术后症状均有明显改善,其中2例巨大肿瘤患者术后出现低氧血症,重新气管插管后逐渐恢复, 1例巨大肿瘤患者术后脑脊液漏皮下积液,经穿刺置管引流数日后恢复正常。其中12例随访9-18个月,无一例复发或出现脊柱不稳定的情况。结论对于颈椎管哑铃形肿瘤,应尽可能采用创伤小的手术方式,在切除肿瘤的同时,减少棘突、韧带、椎板以及小关节的破坏,减小创伤和对脊柱稳定性的破坏,预防脊柱后凸和侧凸畸形的发生。极外侧入路适用于微创切除体积较大的高颈段椎管哑铃形肿瘤,较小的肿瘤可以采用后正中入路半椎板开窗手术,对骨质破坏严重者需在切除肿瘤后行内固定手术。     

Real-time refinement of subthalamic nucleus targeting using Bayesian decision-making on the root mean square measure.

The subthalamic nucleus (STN) is a major target for treatment of advanced Parkinson's disease patients undergoing deep brain stimulation surgery. Microelectrode recording (MER) is used in many cases to identify the target nucleus. A real-time procedure for identifying the entry and exit points of the STN would improve the outcome of this targeting procedure. We used the normalized root mean square (NRMS) of a short (5 seconds) MER sampled signal and the estimated anatomical distance to target (EDT) as the basis for this procedure. Electrode tip location was defined intraoperatively by an expert neurophysiologist to be before, within, or after the STN. Data from 46 trajectories of 27 patients were used to calculate the Bayesian posterior probability of being in each of these locations, given RMS-EDT pair values. We tested our predictions on each trajectory using a bootstrapping technique, with the rest of the trajectories serving as a training set and found the error in predicting the STN entry to be (mean +/- SD) 0.18 +/- 0.84, and 0.50 +/- 0.59 mm for STN exit point, which yields a 0.30 +/- 0.28 mm deviation from the expert's target center. The simplicity and computational ease of RMS calculation, its spike sorting-independent nature and tolerance to electrode parameters of this Bayesian predictor, can lead directly to the development of a fully automated intraoperative physiological procedure for the refinement of imaging estimates of STN borders.     

暴露前牙龈下残根进行桩冠修复

本文综述了暴露前牙龈下残根进行桩冠修复的两种方法,即牵引法与牙冠延长术,并对两者进行了比较、总结,在临床上有指导意义。     

上颌第一磨牙近中颊根第二根管的治疗体会

目的 探讨在临床上上颌第一磨牙近中颊根第二根管（MB2）的发现及扩通。方法 在25例需要进行根管治疗的上颌第一磨牙上寻找MB2，若无法找到，使用超声根管异物清除工作尖10P清理髓底及慢速圆钻去除预计位置部分牙本质，再次寻找。找到后通畅根管，若无法扩通，使用慢速圆钻在MB2根管口处向根方去除少量牙本质。结合使用EDTA再次通畅根管。结果 25颗治疗齿中有13颗找到MB2（52％），其中2颗是在超声根管锉清理髓室底后发现的，4颗在进一步去除MB2根管口位置的牙本质后发现。8颗治疗齿的MB2通畅（32％），其中3颗自然扩通，5颗在去除MB2根管口处部分矛本质并使用EDTA后通畅。结论 临床上上颌第一磨牙MB2发现率为52％。扩通率为32％。掌握MB2的解剖位置，使用超声方法以及EDTA可提高MB2的发现率和扩通率。