Histological suture changes following retraction of the maxillary anterior bone segment after corticotomy

Abstract By cephalometric and dental cast analyses, the effects of corticotomy in combination with 45–50 days retraction of the maxillary anterior segment were evaluated in five female Japanese monkeys (Macaca fuscata). In addition, microscopic changes of the related sutures were examined. According to the analyses of the dental casts, the retraction of the maxillary anterior segment m the experimental group was increased when compared with that of the control group.‘There was no change in Occlusal molar relationship. The cephalometric analysis revealed that the “Point A” and “Metal Implant” on the mid-sagittal site between the upper central incisors in the experimental group showed more pronounced retraction than that in two untreated control animals. These results were histologically evaluated by changes of the suture structure: irregularity of functional arrangement of component cells and fibers, an increase in number of cells, resorption and formation of bone, and an enlargement of the suture width. Resorption of tooth roots and alveolar bone, and irregularity of the periodontal ligament were observed. In general, these histological changes appeared more extensive in the control specimens compared with the experimental Specimens. The osseous histological changes were mainly observed in the compact bone area, while in the spongy bone area of both control and experimental specimens only minimal changes occurred. These results demonstrated the efficacy of combining a corticotomy procedure with retraction of the maxillary anterior bone segment by an orthodontic force.     

微波照射对牙本质晶体结构影响的研究

目的:研究微波照射对人离体牙牙本质晶体结构的影响。方法:选取7对同名前磨牙,每对同名牙按照实验要求制备成4个试件,并将其随机分为4组,对照组不做任何处理,处理组分别用40W微波照射牙本质面3s、5s和7s后,应用X射线衍射方法检测全部牙本质试件的晶体结构。结果:牙本质的主要物相组成为羟基磷灰石。与对照组相比较,微波照射后的牙本质的晶体结构趋向于结晶度更高的羟基磷灰石。且随着照射时间的延长,作用效果更显著。结论:微波照射对牙本质的晶体结构有影响,使牙本质的晶体结构趋于更稳定。     

螺旋CT测量颅面三维结构矫治变化的方法学研究

目的设计应用螺旋CT的三维重建技术测量颅面牙齿的三维结构变化的方法。方法 以鼻额缝的前上部中点(N点),蝶鞍前壁上后缘中点(S’点),和枕骨大孔前缘下后中点(B点)为基准点建立以S’点为原点的测量三维坐标系。用Unisight软件在MPR相下获得各点原始三维坐标值,通过数学计算得到各测量点在测量三维坐标系下的坐标值。结果经统计学检验,此方法的测量结果重复性好,精确度符合要求。结论此种方法可以用于螺旋CT对于颅面牙齿三维变化的测量研究。     

熔附条件对牙科复合树脂中SP1 SiO_2表面结构及形态的影响

目的:研究熔附温度和熔附时间对多微孔纳米二氧化硅粒子(SP1 SiO2)表面结构及形态的影响。方法:将SP1SiO2以250℃/h的升温速度分别升至500、650、800、950、1100℃,并分别保持10、30min和3h制作试样,进行表面结构及形态测试。结果:随烧结温度的增高和时间的延长,SP1 SiO2颗粒表面的Si-OH键特征峰值逐渐减弱,条件为950℃、10min和30min,650℃、3h时完全消失;随着熔附温度的升高和熔附时间的延长颗粒增大、粒度分布变窄。结论:熔附温度和熔附时间影响SP1 SiO2颗粒表面的Si-OH含量和颗粒大小、粒度分布。     

恒牙初期侧切牙反（牙合）的头影测量分析

目的研究恒牙初期1个及两个侧切牙同时反（牙合）对颌骨发育的影响.方法通过X线头影测量对76例恒牙初期侧切牙反（牙合）患者颅面硬组织形态选用DOWS分析法和Steiner分析法进行研究.结果一个侧切牙反（牙合）对上颌骨发育无影响,对下颌骨发育有一定影响,而两个侧切牙同时反（牙合）时,上下颌骨发育有显著影响.结论侧切牙反（牙合）宜早期进行矫治.     

Clinical and pathologic factors associated with the relapse of fibrous gingival hyperplasia

BackgroundThe association between clinicopathologic characteristics and the relapse of fibrous gingival hyperplasia is unknown.MethodsThe records of 211 consecutive patients with a clinicopathologic diagnosis of fibrous gingival hyperplasia were retrieved. Patients who experienced relapse after surgical excision of the lesion were considered case patients (n = 30). All control patients were informed that there was no recurrence (n = 181). Logistic regression was used to evaluate the associations among different characteristics and the recurrence. Stratified analyses on sex was applied to identify the different associations.ResultsBinary logistic regression showed that patients with ulcer (odds ratio [OR], 3.23; 95% CI, 1.18 to 8.83) or mechanical stimulation (OR, 2.42; 95% CI, 1.03 to 5.68) had a higher risk of experiencing recurrence. Stratified analysis of sex identified significant association in females (ulcer: OR, 4.04; 95% CI, 1.14 to 14.34; mechanical stimulation: OR, 3.30; 95% CI, 1.15 to 9.42). No significant difference was observed in males (ulcer: OR, 2.44; 95% CI, 0.40 to 15.06; mechanical stimulation: OR, 1.62; 95% CI, 0.28 to 9.40). Male patients with larger epulides had fewer recurrence (OR, 0.13; 95% CI, 0.02 to 0.74). There was no significant difference in pathologic calcification between case and control patients (P > .05).ConclusionsPatients with ulcer and mechanical stimulation may have a high risk of experiencing recurrent epulis.Practical ImplicationsMore attention should be paid to patients with ulcer and mechanical stimulation. Apart from complete surgical removal, it is important to remove local stimulation to prevent recurrence of these lesions.     

A reconstructed computerized tomographic comparison of Ni-Ti rotary GT files versus traditional instruments in canals shaped by novice operators

AIM: The aim of this study was to compare the effects of preparation with conventional stainless steel Flexofiles and Gates Glidden burs versus nickel-titanium GT rotary files in the shaping of mesial root canals of extracted mandibular molars. METHODOLOGY: A total of 54 canals from 27 mesial roots of mandibular molar teeth were prepared using one of two methods by novice dental students. One canal in each root was prepared by a crown-down approach. utilizing stainless steel Flexofiles and Gates Glidden burs. The other canal was prepared using nickel-titanium GT rotary files in a crown-down fashion as recommended by the manufacturer. Preoperative CT scans of each root were recorded and 50 canal specimens were available for postoperative comparisons. Following canal shaping, postoperative scans were superimposed on the original images. Changes in canal area, canal transportation and thickness of remaining root structure at strategic levels of the root were analyzed. The time taken for each method was also noted. RESULTS: At the coronal and mid-root coronal one-third sections, the rotary GT files produced a significantly smaller postoperative canal area (P < 0.05). In the mid-root sections there was significantly less transportation of the root canal toward the furcation, and less thinning of the root structure with GT files compared to the stainless steel files (P < 0.05). Overall, there was greater conservation of structure coronally and more adequate shape in the mid-root level. The GT rotary technique was significantly faster than the stainless steel hand-held file technique (P < 0.0001). Two GT instruments fractured during the study. CONCLUSIONS: Under the conditions of this study, novice dental students were able to prepare curved root canals with Ni-Ti GT rotary files with less transportation and greater conservation of tooth structure, compared to canals prepared with hand instruments. The rotary technique was significantly faster.     

鹅不食草正丁醇部位化学成分研究

[目的]对鹅不食草干燥全草乙醇提取物正丁醇部位的化学成分进行研究,为鹅不食草的系统研究和开发利用提供物质基础。[方法]通过大孔吸附树脂、Sephadex LH-20色谱、ODS柱色谱、薄层色谱和高效液相色谱等现代色谱分离手段对鹅不食草干燥全草的正丁醇部位化学成分进行系统分离,通过对其理化性质及谱学数据的分析,对分离所得化合物进行结构鉴定。[结果]从鹅不食草干燥全草95%乙醇和60%乙醇合并提取物中分离得到了化合物14个,分别鉴定为木犀草素-7-O-β-D-葡萄糖苷(1),槲皮素-3-O-β-D-葡萄糖苷(2),芹菜素-7-O-β-D-葡萄糖醛酸苷(3),nudicaucins A(4),guaiacin D(5),绿原酸(6),4,5-二咖啡酰奎宁酸-甲酯(7),对羟基苯甲酸(8),水杨酸(9),芥子酸(10),芥子酸甲酯(11),阿魏酸(12),咖啡酸甲酯(13),丁香酸(14)。[结论]化合物1~14均为首次从石胡荽属植物中分离得到。     

激励结构视角下的管理模式在口腔科中的作用

目的 探讨激励结构视角下的管理模式在口腔科中的应用价值。方法 对浙江省立同德医院口腔科2018 年1 月至2019 年12 月的90 例口腔疾病患者进行研究,2018 年1—12 月45 例为对照组,行常规管理;2019 年1—12 月45 例为观察组,实施激励结构视角下的管理模式,两组均由同一批医生提供医疗服务（n=20）,比较两组医生工作能力、服务质量、患者依从性、满意度和风险事件发生率。结果 观察组工作能力得分为（84.62±5.94）分,工作质量得分为（85.44±5.44）分,依从性为95.66%,满意度为97.78%,高于对照组的（75.02±6.06）分、（76.10±6.08）分、77.78%和80.00%,差异有统计学意义（P＜0.05）。结论 在口腔科管理工作中应用激励结构视角下的管理模式,可促进科室医生工作能力的提升,改善口腔科工作质量,利于提高患者依从性和满意度,存在推广价值。     

帕金森病伴RBD患者睡眠结构与认知功能及自主神经功能症状的相关性

目的 探究帕金森病伴快速眼动期睡眠行为障碍（RBD）患者睡眠结构与认知功能及自主神经功能症状的相关性。方法 回顾性分析2017年6月—2019年6月在张家口市第一医院就诊的160例帕金森病患者,根据其是否伴有RBD分为研究组（帕金森病伴RBD）80例与对照组（单纯帕金森病）80例。检测并比较两组患者的睡眠结构与认知功能及自主神经功能症状,并采用Pearson相关系数分析研究组患者睡眠结构与自主神经功能症状评分的相关性。结果 研究组的NREM1+2期睡眠比例、睡眠潜伏期、REM睡眠潜伏期、消化系统、泌尿系统、心血管系统的症状评分大于对照组（P <0.05）;NREM3+4期睡眠比例、REM期睡眠比例、REM睡眠潜伏期、REM睡眠周期、TST、SE、MMSE、MoCA评分小于对照组（P <0.05）。相关性分析结果显示,NREM1+2期睡眠比例与体温调节系统评分呈负相关（r =-0.341,P <0.05）;NREM3+4期睡眠比例与泌尿系统评分呈负相关（r =-0.344,P <0.05）;睡眠潜伏期与MMSE、消化系统、泌尿系统、心血管系统评分呈正相关（r =0.569、0.606、0.671和0.403,均P <0.05）;REM睡眠潜伏期与消化系统、泌尿系统、心血管系统评分呈正相关（r =0.630、0.600和0.361,均P <0.05）;REM睡眠周期与消化系统、泌尿系统、心血管系统评分呈正相关（r =0.571、0.599和0.357,均P <0.05）;TST与消化系统、泌尿系统、心血管系统评分呈正相关（r =0.678、0.631和0.369,均P <0.05）;SE与消化系统、泌尿系统、心血管系统评分呈正相关（r =0.554、0.559和0.406,均P <0.05）。结论 睡眠结构与认知功能及自主神经功能（消化系统、泌尿系统、心血管系统）存在一定相关性,可推断帕金森病伴RBD患者睡眠结构紊乱可加重认知功能障碍和自主神经功能症状。