共查询到19条相似文献，搜索用时 203 毫秒
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研究目的:探讨同一患者不同时期所拍的锥形束计算机断层摄影(CBCT)是否因每次拍摄时投照角度不可能完全一致而影响数据测量的准确性。创新要点:提出了一种人类后牙拔除后观察牙槽突外形变化的准确、无创、科学的定位方法。研究方法:选择首都医科大学附属北京口腔医院种植中心60名患者两份于上颌后牙种植前后拍摄的CBCT影像资料。以磨牙根分叉区三个牙根开始分开处(图像上显示为三根恰好融合的点)为基准点定位两次CBCT的起始水平断层。在第一次CBCT的起始水平断层上,连线牙列远端磨牙参照点即矢状断层起点与近端双尖牙的髓室中心进行矢状断层重建。若实验牙为第一磨牙,找到通过其腭根髓室中心的矢状断层;若实验牙为第二双尖牙,找到通过其髓室中心的矢状断层。记录由矢状断层起点到实验牙移动的层数N,在水平断层上测量实验牙牙槽骨宽度,在实验牙髓室中心的矢状断层上测量牙全长。在第二次CBCT中依据第一次记录的移动层数N定位矢状断层,在定位后的矢状断层上测量实验牙全长,在水平断层的相应定位处测量牙槽骨宽度。重要结论:利用本研究提出的定位方法可以精准定位同一患者不同CBCT影像资料中的同一断层,从而实现拔牙位点动态连续观察。 相似文献
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研究目的：探讨同一患者不同时期所拍的锥形束计算机断层摄影（CBCT）是否因每次拍摄时投照角度不可能完全一致而影响数据测量的准确性。创新要点：提出了一种人类后牙拔除后观察牙槽突外形变化的准确、无创、科学的定位方法。研究方法：选择首都医科大学附属北京口腔医院种植中心60名患者两份于上颌后牙种植前后拍摄的CBCT影像资料。以磨牙根分叉区三个牙根开始分开处（图像上显示为三根恰好融合的点）为基准点定位两次CBCT的起始水平断层。在第一次CBCT的起始水平断层上,连线牙列远端磨牙参照点即矢状断层起点与近端双尖牙的髓室中心进行矢状断层重建。若实验牙为第一磨牙,找到通过其腭根髓室中心的矢状断层;若实验牙为第二双尖牙,找到通过其髓室中心的矢状断层。记录由矢状断层起点到实验牙移动的层数N,在水平断层上测量实验牙牙槽骨宽度,在实验牙髓室中心的矢状断层上测量牙全长。在第二次CBCT中依据第一次记录的移动层数N定位矢状断层,在定位后的矢状断层上测量实验牙全长,在水平断层的相应定位处测量牙槽骨宽度。重要结论：利用本研究提出的定位方法可以精准定位同一患者不同CBCT影像资料中的同一断层,从而实现拔牙位点动态连续观察。 相似文献
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目的：研究不同的义齿设计与末端游离缺牙的牙槽骨吸收的关系．方法：选择末端游离缺牙的患者76例,其中采用RPI型卡环18例,RPA型20例,传统三臂卡环15,冠外附着体23例．义齿修复前以及修复后12个月拍摄基牙及远中牙槽骨定位X线片,计算剩余牙槽嵴的骨吸收量．结果：末端基牙远中牙槽骨的吸收：冠外附着体组吸收量最低,RPA组和RPI组低于传统三臂卡环组．结论：近中牙合支托设计的卡环,较远中牙合支托设计的卡环,更利于维护末端基牙远中牙槽骨的健康;冠外附着体更有利于保护基牙． 相似文献
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《赤峰学院学报(自然科学版)》2008,(Z1)
目的:分析上颌前部埋伏多生牙X线片定位的准确性。方法:对168例上颌前部埋伏多生牙采用偏心投射法拍摄定位牙片,对定位牙片把握性较小的病例,辅助拍摄轴向咬合片和头颅侧位定位片,以验证定位牙片的准确性,以此决定多生牙拔除的手术进路。结果:本组168颗埋伏多生牙采用偏心投射法拍摄定位牙片,其定位的准确性与术中情况完全一致。定位牙片定位可疑时,其可靠性也得到了轴向咬合片和头颅侧位定位片的验证。结论:定位牙片仍可视为一种可信的上颌前部埋伏多生牙的定位方法,可为多生牙的拔除提供相应的手术进路。 相似文献
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总结临床使用直丝弓技术矫治安氏Ⅱ'错(牙合)拔牙病例的疗效,操作要领和注意事项.方法对25例年轻恒牙(牙合)安氏Ⅱ'错采用拔除4)/(4 4)/(4进行直丝技术矫治.结果25例患者平均年龄13.4岁,平均矫治时间24.5个月,矫治完成后均达到理想的侧面外形,磨牙关系由Ⅱ类改为Ⅰ类关系.前牙覆(牙合)覆盖正常,尖窝关系良好,尖牙成Ⅰ类关系.矫治前后头影测量显示ANB角由平均5.5°±2.1°改正为3.1°±1.3°,代表面部软组织侧面外形的Z角由60.5°±5.6°改变为77°±5.8°,代表上下颌矢状关系的AO-BO距离由(6.5±2.3)mm改为(3.1±1.1)mm.结论直丝弓技术矫治Ⅱ'错(牙合),临床效果良好,椅旁操作时间短,值得推广使用. 相似文献
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随着人工种植牙的不断广泛应用于临床并取得比较好的效果 ,目前种植体的植入方法正由过去的延期种植转向即刻种植 .笔者在近二年的人工种植体即刻种植 2 6例临床运用中观察体会到即刻种植技术与一般的种植技术相比 ,具有疗程短 ,费用低 ,骨损伤小 ,避免患者承受长期缺牙痛苦等特点 ,同时它能有效地解决拔牙后牙槽骨吸收导致骨量不足而使种植体植入困难或无法植入等问题 .本文就即刻种植临床应用方面的一些问题作一探讨 相似文献
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《赤峰学院学报(自然科学版)》2021,(4)
目的:探讨蒙汉族人群上颌前牙不同位点的唇侧骨壁厚度的异同及意义。方法:选取我院2018年11月～2019年11月收治的120例需要拍摄CBCT的蒙汉族患者作为研究对象,按照民族分为蒙古族组(60例)、汉族组(60例),分别测量蒙汉族患者唇侧骨壁不同位点的厚度,比较两组不同位点间的统计学差异。结果:蒙古族患者于位点1处的骨壁厚度大于汉族患者,差异有统计学意义(P0.05);蒙古族患者于位点2处的骨壁厚度大于汉族患者,差异有统计学意义(P0.05);蒙古族患者于位点3处的骨壁厚度大于汉族患者,差异有统计学意义(P0.05)。结论:数据的统计学差异对于牙齿种植及前牙美学的修复有重要意义。 相似文献
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[目的]探讨一种更直观的多生牙定位方法———多生牙切线位定位。[方法]收集48例患有多生牙的患者,应用切线投照技术原理结合X线胃肠机的特点对多生牙生长位置进行定位,并与临床常规使用的根尖水平移位投照定位法进行比较。[结果]①切线位定位法照片直观清晰,判断结果一目了然。②一次性定位片成功率,多生牙切线位定位法照片高达93.75%,根尖片水平移位投照定位法只有79.17%。③两种定位法对多生牙唇、腭侧判断准确率相接近,切线位定位法89.58%,根尖片水平移位定位法91.67%。[结论]切线位定位法的可操作性优于根尖片水平移位定位法,为颌面外科多生牙拔除术的手术进路提供了另一种新的思路,建议配有荧光屏X线机的口腔医院推广使用。 相似文献
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《泰州职业技术学院学报》2003,3(5):65-67
总结临床使用直丝弓技术矫治安氏Ⅱ'错(牙合)拔牙病例的疗效,操作要领和注意事项.方法对25例年轻恒牙(牙合)安氏Ⅱ'错采用拔除4)/(4
4)/(4进行直丝技术矫治.结果25例患者平均年龄13.4岁,平均矫治时间24.5个月,矫治完成后均达到理想的侧面外形,磨牙关系由Ⅱ类改为Ⅰ类关系.前牙覆(牙合)覆盖正常,尖窝关系良好,尖牙成Ⅰ类关系.矫治前后头影测量显示ANB角由平均5.5°±2.1°改正为3.1°±1.3°,代表面部软组织侧面外形的Z角由60.5°±5.6°改变为77°±5.8°,代表上下颌矢状关系的AO-BO距离由(6.5±2.3)mm改为(3.1±1.1)mm.结论直丝弓技术矫治Ⅱ'错(牙合),临床效果良好,椅旁操作时间短,值得推广使用. 相似文献
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Juan LI Lingfang SHI Xiayao ZHANG Luxi WENG Hong CHEN Jun LIN 《Journal of Zhejiang University. Science. B》2021,22(2):146
Midpalatal corticotomy-assisted rapid maxillary expansion(MCRME)is a minimally invasive treatment of maxillary transverse deficiency(MTD)in young adults.However,the effect of MCRME on respiratory function still needs to be determined.In this study,we evaluated the changes in maxillary morphology and the upper airway following MCRME using computational fluid dynamics(CFD).Twenty patients with MTD(8 males,12 females;mean age 20.55 years)had cone-beam computed tomography(CBCT)images taken before and after MCRME.The CBCT data were used to construct a threedimensional(3 D)upper airway model.The upper airway flow characteristics were simulated using CFD,and measurements were made based on the CBCT images and CFD.The results showed that the widths of the palatal bone and nasal cavity,and the intermolar width were increased significantly after MCRME.The volume of the nasal cavity and nasopharynx increased significantly,while there were no obvious changes in the volumes of the oropharynx and hypopharynx.CFD simulation of the upper airway showed that the pressure drop and maximum velocity of the upper airway decreased significantly after treatment.Our results suggest that in these young adults with MTD,increasing the maxillary width,upper airway volume,and quantity of airflow by MCRME substantially improved upper airway ventilation. 相似文献
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涡轮机法与凿骨劈冠法在拔除阻生智齿中的临床比较 总被引：1，自引：0，他引：1
目的：比较涡轮机去骨拔除法（试验组）与凿骨劈冠拔除法（对照组）在拔除下颌中位和低位阻生智齿时的临床疗效。方法：280颗下颌中位和低位阻生智齿随机分成两组,试验组采用涡轮机去骨拔除法,对照组采用凿骨劈冠拔除法,记录手术时间,观察患者术后疼痛程度、张口受限、颞下颌关节功能紊乱及干槽症发生情况。结果：试验组手术时间、患者术后疼痛程度、颞下颌关节功能紊乱、张口受限及干槽症的发生率均小于对照组,两组间发生率有统计学差异。结论：涡轮机去骨拔除法拔除下颌中位和低位阻生智齿较传统凿骨劈冠法有较多优点,值得临床推广。 相似文献
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Rong-yang Wang Min Han Hong Liu Chun-ling Wang Hong-hong Xian Lei Zhang Shi-jie Zhang Dong-xu Liu 《Journal of Zhejiang University. Science. B》2012,13(11):942-947
To propose a method of establishing the reference mandibular plane (MP), which could be reestablished according to the coordinates of the reference points, and then facilitate the assessment of anterior alveolar morphology using cone beam computed tomography (CBCT), sixty patients with bimaxillary protrusion were randomly selected and CBCT scans were taken. The CBCT scans were transferred to Materialism’s interactive medical image control system 10.01 (MIMICS 10.01), and three dimensional models of the entire jaws were constructed. Reference points determining the reference MP were positioned in the coronal, axial, sagittal windows, and the points were exactly located by recording their coordinates in the interfaces of software. The reference MP provided high intra-observer reliability (Pearson’s r 0.992 to 0.999), and inter-observer reliability (intra-class correlation coefficients (ICCs) 0.996 to 0.999). 相似文献
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目的研究三明治法Onlay植骨结合GBR技术应用于上颌骨洞穿性骨缺损后牙槽嵴水平向及垂直向骨量的变化;评价该项技术在口腔种植中的应用效果。方法抽取泰州市中医院近年的5名病例作为研究对象,通过口腔专科检查和口腔颌面CT检查进行术前评估,通过Onlay植骨结合GBR技术修复骨缺损区,恢复缺牙区的骨量和缺失牙,手术后8个月通过CT检查,评估骨增量效果,并行种植修复。结果植骨术后8个月,患者缺牙区牙槽嵴水平骨量提升4.2mm,垂直骨量提升18mm,患者口腔软组织、牙龈颜色、牙龈乳头均基本恢复正常,供骨区无神经症状、继发性感染及其他不适。种植体骨结合良好,稳定性佳,患者对修复效果满意。种植牙留存率100%。结论三明治法Onlay自体骨移植结合GBR技术是解决上颌骨洞穿性骨缺损的有效临床途径,能够使牙槽骨水平向及垂直向骨量均得到良好改善,为后期的种植修复提供良好的骨基础。 相似文献
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观察模拟4000m高住低练后力竭运动对大鼠肾EPO表达及RBC、Hb和HCT的影响,为科学的低氧训练提供实验依据.研究结果表明:(1)与常氧组相比,无论是高住组、常氧运动组或者高住低练组EPO值均升高,其中高住8 h组与常氧组相比EPO有显著性差异(P<0.05);(2)与常氧组相比,高住8 h组和高住12 h组RBC、Hb、HCT值上升,但无显著性差异(P>0.05),而常氧运动组和高住8 h运动组RBC、Hb、HCT值显著下降(P<0.05);高住8 h运动组与高住8h组比较,RBC、Hb、HCT值显著下降(P<0.05).适宜的低氧刺激可以提高机体的有氧能力,其中以低氧8小时的4周4000米海拔高度低氧刺激效果显著,考虑与EPO、RBC、Hb、HCT的升高有关;低氧后运动,血液RBC、Hb、HCT值显著下降,说明低氧刺激、运动强度过大,而使机体有氧能力下降. 相似文献
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吴立东 《浙江大学学报(A卷英文版)》2004,5(10):1270-1278
Objective: To observe the accuracy of femoral preparation and the position of the cementless prosthesis in femoral cavity, and to compare the results between the computer-assisted surgical group (CASPAR) and the conventional group. Methods: Ten femoral components were implanted either manually or by CASPAR in cadaver femurs. The specimens were cut to 3 mm thick slices. Microradiograms of every slice were sent to a computer for analysis with special software (IDL). The gaps and the medullary cavities between component and bone, the direct bone contact area of the implant surface,the gap width and the percentage of gap and bone contact area were measured in every slice. Results: In the proximal implant coated with HA of the CASPAR group, the average percentage of bone contact reached 93.2% (ranging from 87.6% to 99.7%); the average gap percentage was 2.9% (ranging from 0.3% to 7.8%); the maximum gap width was 0.81 mm and the average gap width was only 0.20 mm. While in the conventional group, the average percentage of bone contact reached 60.1% (ranging from 49.2% to 70.4%); the average gap percentage was 32.8% (ranging from 25.1% to 39.9%); the maximum gap width was 2.97 mm and the average gap width was 0.77 mm. The average gap around the implant in the CASPAR group was only 9% of that in the manual group; the maximum and average gap widths were only about 26% of those in the manual group. On the other hand, the CASPAR group showed 33% higher bone contact than the manual group. Conclusion: With the use of robotics-assisted system, significant progress can be achieved for femoral preparation in total hip arthroplasty. 相似文献
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Objective: To observe the accuracy of femoral preparation and the position of the cementless prosthesis in femoral cavity, and to compare the results between the computer-assisted surgical group (CASPAR) and the conventional group. Methods: Ten femoral components were implanted either manually or by CASPAR in cadaver femurs. The specimens were cut to 3 mm thick slices. Microradiograms of every slice were sent to a computer for analysis with special software (IDL). The gaps and the medullary cavities between component and bone, the direct bone contact area of the implant surface, the gap width and the percentage of gap and bone contact area were measured in every slice. Results: In the proximal implant coated with HA of the CASPAR group, the average percentage of bone contact reached 93.2% (ranging from 87.6% to 99.7%); the average gap percentage was 2.9% (ranging from 0.3% to 7.8%); the maximum gap width was 0.81 mm and the average gap width was only 0.20 mm. While in the conventional group, the average 相似文献