预成纤维桩应用于冠改向修复的初步研究

将80颗人离体牙模拟不同种倾斜角度（舌侧倾斜30°、15°，颊侧倾斜15°、30°，无倾斜）配伍分10组（n ＝8），实验组采用预成纤维桩修复，对照组采用钴铬合金铸造桩修复，各组均行铸造金属冠修复。电子万能试验机测试各组抗折载荷。结果显示修复倾斜牙时，纤维桩与铸造桩修复体之间抗折载荷无统计学差异。2种桩修复体受力过载时，主要为不可修复性折裂。根管桩种类与改向角度之间的交互作用没有统计学意义（P ＞0．05），即根管桩种类与改向角度均不会改变对方对抗折载荷的影响。     

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??Objective    To compare the short-term clinical effect of different degrees of wear in the posterior area of the implant denture. Methods    From January 2009 to December 2013??469 patients??the average age was 50.9??with partial loss of posterior teeth were followed up for 6 - 72 months. According to the degree of wear of natural teeth??they were divided into three groups??the non-wear group of 201 cases??457 implants????163 cases in mild-wear group??289 implants????105 cases in severe-wear group??235 implants??. The five-year cumulative survival rates of implants in the three groups were counted and the numerical values of bone resorption around the implants were measured. Results    Three groups of patients had no implant loss??the 5-year retention rate was 100%??there was no significant difference in bone resorption at the end of 3 months??6 months??1 year and 2 years after the repair??P > 0.05????there was no significant difference in the incidence of postoperative complications??P > 0.05??. Conclusion    In short time??the patients with mild wear and severe wear can have good clinical effect??whereas long-term effect need to be followed up.     

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??Objective??To evaluate the clinical effect of maxillary sinus lifting??bone graft??and simultaneously placement of implants in severely atrophic maxillae and the stability of cylindrical implants. Methods??Totally 20 patients with 30 Straumann tissue-level implants were included. After osteotome sinus floor elevation and grafting??implants were inserted. Patients were recalled at 1 and 3-years follow-up. Implant success??resonance frequency analysis??clinical and radiographic outcomes were recorded. Results??At 3-year examination??the implant success rate was 96.7%. The ISQ value was 71.1±4.15??69.6 ± 5.01??68.4 ± 4.34 and 72.8 ± 6.42 at implant insertion??2??4 and 12 weeks after surgery. Modified bleeding index was 0.53 ± 0.40 and 0.61 ± 0.31 at 1 and 3-year examination. Probing depth was??3.21 ± 0.67??mm and??3.45 ± 0.71??mm at 1 and 3-year examination. Modified plaque index was 0.48 ± 0.44 and 0.52 ± 0.51 at 1 and 3-year examination. No significant difference was found between two examinations. Marginal bone loss increased from ??1.16 ± 0.27??mm at 1-year follow-up to ??1.45 ± 0.39?? mm at 3-year follow-up??the difference reached statistically significant??P < 0.05??. Implant apex height decreased from ??2.05 ± 0.43??mm at baseline to ??1.85 ± 0.75??mm at 1-year and ??1.42 ± 0.69??mm at 3-year follow-up??the difference reached statistically significant??P < 0.05??. Conclusion??Maxillary sinus lifting??bone graft??and simultaneously placement of implants could be a predicable treatment option in severely atrophic maxilla. In addition??cylindrical implants could achieve enough stability during the healing phrase. High success rate could be achieved in the short term.     

末端根帽支撑的MK1附着体在下颌单侧后牙缺失修复中的临床应用

目的：评价末端根帽支撑的MK1附着体在下颌单侧后牙缺失修复中的临床效果。方法：以29例采用MK1附着体进行修复治疗的患者作为研究对象，实验组以10例患者修复体远中处有经根帽修复后的残根，其余19位患者作为对照组。1年后随访，从患者主观感受、临床检查及X线检查评价修复效果。结果：实验组、对照组患者对MK1附着体义齿的主观满意度分别为8．38±0．85、8．27±1．10，两组间无统计学差异（P〉0．05）。实验组、对照组缺牙区牙槽嵴吸收例数分别为0例、5例，差异无统计学意义（P〉0．05）；实验组、对照组近缺牙区基牙牙槽骨吸收例数分别为0例、5例，差异无统计学意义（P．〉0．05）；实验组、对照组义齿修整例数分别为1例、10例，差异有统计学意义（P〈0．05）。结论：MK1附着体义齿稳定及固位性能艮好，是一种较理想的下颌单侧后牙缺失的固定一活动联合修复体。末端残根根帽修复后更利于MK1的临床疗效。     

唇腭裂患者前牙区恒牙的发育异常

唇腭裂是口腔颌面部最常见的先天畸形,常伴发各种恒牙发育异常,尤其是靠近裂隙的前牙区.相较国外,目前国内对此的研究缺乏,本文对调查唇腭裂患者中切牙、侧切牙和尖牙区的形态、数目、萌出异常和牙根发育等各类发育异常的文献作回顾性概述,为临床医师早期酌情涉入治疗和适当降低序列治疗的难度和复杂性提供依据.     

Leonardo da Vinci's “A Skull Sectioned”: Skull and dental formula revisited

What can be learned from historical anatomical drawings and how to incorporate these drawings into anatomical teaching? The drawing “A skull sectioned” (RL 19058v) by Leonardo da Vinci (1452–1519), hides more detailed information than reported earlier. A well‐chosen section cut explores sectioned paranasal sinuses and ductus nasolacrimalis. A dissected lateral wall of the maxilla is also present. Furthermore, at the level of the foramen mentale, the drawing displays compact and spongious bony components, together with a cross‐section through the foramen mentale and its connection with the canalis mandibulae. Leonardo was the first to describe a correct dental formula (6424) and made efforts to place this formula above the related dental elements. However, taking into account, the morphological features of the individual elements of the maxilla, it can be suggested that Leonardo sketched a “peculiar dental element” on the position of the right maxillary premolar in the dental sketch. The fact that the author did not make any comment on that special element is remarkable. Leonardo could have had sufficient knowledge of the precise morphology of maxillary and mandibular premolars, since the author depicted these elements in the dissected skull. The fact that the author also had access to premolars in situ corroborates our suggestion that “something went wrong” in this part of the drawing. The present study shows that historical anatomical drawings are very useful for interactive learning of detailed anatomy for students in medicine and dentistry. Clin. Anat., 2013. © 2012 Wiley Periodicals, Inc.     

Hedgehog signaling regulates dental papilla formation and tooth size during zebrafish odontogenesis

Background : Intercellular communication by the hedgehog cell signaling pathway is necessary for tooth development throughout the vertebrates, but it remains unclear which specific developmental signals control cell behavior at different stages of odontogenesis. To address this issue, we have manipulated hedgehog activity during zebrafish tooth development and visualized the results using confocal microscopy. Results : We first established that reporter lines for dlx2b, fli1, NF‐κB, and prdm1a are markers for specific subsets of tooth germ tissues. We then blocked hedgehog signaling with cyclopamine and observed a reduction or elimination of the cranial neural crest derived dental papilla, which normally contains the cells that later give rise to dentin‐producing odontoblasts. Upon further investigation, we observed that the dental papilla begins to form and then regresses in the absence of hedgehog signaling, through a mechanism unrelated to cell proliferation or apoptosis. We also found evidence of an isometric reduction in tooth size that correlates with the time of earliest hedgehog inhibition. Conclusions : We hypothesize that these results reveal a previously uncharacterized function of hedgehog signaling during tooth morphogenesis, regulating the number of cells in the dental papilla and thereby controlling tooth size. Developmental Dynamics 244:577–590, 2015. © 2015 Wiley Periodicals, Inc.     

Failure of eruption of first permanent molar teeth: a diagnostic challenge

Ankylosis, mechanical and primary failure of eruption of molar teeth are rare and often difficult to distinguish between. All may have significant repercussions on the occlusion and successful management may involve invasive procedures. We present a case where an initial presentation characteristic of mechanical failure of eruption (ankylosis) of a first permanent molar tooth was excluded following a period of monitoring. Subsequent relief of crowding using a removable and then sectional fixed orthodontic appliance allowed spontaneous eruption of the tooth obviating the need for surgical intervention. This case highlights the utilisation of conservative treatment options until a diagnosis was confirmed to minimise the risk of iatrogenic damage and unnecessary treatment.