Tooth

牙齿
  • 文章类型: Journal Article
    博尔特农场是一系列非人类化石遗址的名称,这些遗址通常被认为是人类摇篮中最古老的上新世遗址之一,南非。本文报告了在Milo\的洞穴和Bolt\的农场的Aves洞穴中首次结合铀系列和电子自旋共振(US-ESR)测年的结果。提出了牙釉质碎片和牙釉质粉末的年龄进行比较。US-ESR,计算了EU和LU模型。总的来说,粉末年龄与以前的铀铅和古地磁年龄估计一致,这表明年龄在3.15至2.61Ma之间,并提供了米洛洞穴的第一个年龄在3.1至2.7Ma之间。最终年龄并不过度依赖于所使用的模型(US-ESR,LU或欧盟),它们都在错误中重叠。这些年龄都与基于第一阶段Metridiochoerusandrewsi的生物年龄估计(<3.4->2.6Ma)一致。Milo'sCave的初步古磁分析表明,该地点发生了反转,主要是中间方向。这表明矿床可能在ESR年龄误差范围内的~3.03至3.11Ma之间。这进一步表明,博尔特农场的古洞穴矿床年龄不超过3.2Ma。这项研究表明,US-ESR测年有可能将人类摇篮中的化石遗址测年至3Ma以上。然而,建议对3Ma以上的站点进行大量样品分析,以进行US-ESR测年。
    Bolt\'s Farm is the name given to a series of non-hominin bearing fossil sites that have often been suggested to be some of the oldest Pliocene sites in the Cradle of Humankind, South Africa. This article reports the results of the first combined Uranium-Series and Electron Spin Resonance (US-ESR) dating of bovid teeth at Milo\'s Cave and Aves Cave at Bolt\'s Farm. Both tooth enamel fragments and tooth enamel powder ages were presented for comparison. US-ESR, EU and LU models are calculated. Overall, the powder ages are consistent with previous uranium-lead and palaeomagnetic age estimates for the Aves Cave deposit, which suggest an age between ~3.15 and 2.61 Ma and provide the first ages for Milo\'s Cave dates to between ~3.1 and 2.7 Ma. The final ages were not overly dependent on the models used (US-ESR, LU or EU), which all overlap within error. These ages are all consistent with the biochronological age estimate (<3.4->2.6 Ma) based on the occurrence of Stage I Metridiochoerus andrewsi. Preliminary palaeomagnetic analysis from Milo\'s Cave indicates a reversal takes place at the site with predominantly intermediate directions, suggesting the deposit may date to the period between ~3.03 and 3.11 Ma within error of the ESR ages. This further suggests that there are no definitive examples of palaeocave deposits at Bolt\'s Farm older than 3.2 Ma. This research indicates that US-ESR dating has the potential to date fossil sites in the Cradle of Humankind to over 3 Ma. However, bulk sample analysis for US-ESR dating is recommended for sites over 3 Ma.
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  • 文章类型: Journal Article
    肩袖修复手术经常失败,在美国每年进行的600,000次维修中,有20%至94%导致了肩袖的撕开。失败的最常见原因是缝合线在抓握点处通过肌腱撕裂。为了解决这个问题,我们从Pythonoidea超家族的蛇的特殊牙齿中汲取灵感,抓住软组织而不撕裂。为了将这种无损的夹持方法应用于肌腱的手术修复,我们开发并优化了一种蟒蛇牙启发装置,作为目前肩袖缝合修复的辅助手段,发现其修复强度几乎提高了一倍.综合模拟,3D打印,离体实验揭示了牙齿形状和抓握力学之间的关系,通过将应力分布在附件覆盖区上,使得能够优化临床相关装置,从而显著增强肩袖修复。这种方法建议了传统缝合范例的替代方法,并且可以降低肩袖修复后肌腱再撕裂的风险。
    Rotator cuff repair surgeries fail frequently, with 20 to 94% of the 600,000 repairs performed annually in the United States resulting in retearing of the rotator cuff. The most common cause of failure is sutures tearing through tendons at grasping points. To address this issue, we drew inspiration from the specialized teeth of snakes of the Pythonoidea superfamily, which grasp soft tissues without tearing. To apply this nondamaging gripping approach to the surgical repair of tendon, we developed and optimized a python tooth-inspired device as an adjunct to current rotator cuff suture repair and found that it nearly doubled repair strength. Integrated simulations, 3D printing, and ex vivo experiments revealed a relationship between tooth shape and grasping mechanics, enabling optimization of the clinically relevant device that substantially enhances rotator cuff repair by distributing stresses over the attachment footprint. This approach suggests an alternative to traditional suturing paradigms and may reduce the risk of tendon retearing after rotator cuff repair.
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  • 文章类型: English Abstract
    The segmentation of dental models is a crucial step in computer-aided diagnosis and treatment systems for oral healthcare. To address the issues of poor universality and under-segmentation in tooth segmentation techniques, an intelligent tooth segmentation method combining multiple seed region growth and boundary extension is proposed. This method utilized the distribution characteristics of negative curvature meshes in teeth to obtain new seed points and effectively adapted to the structural differences between the top and sides of teeth through differential region growth. Additionally, the boundaries of the initial segmentation were extended based on geometric features, which was effectively compensated for under-segmentation issues in region growth. Ablation experiments and comparative experiments with current state-of-the-art algorithms demonstrated that the proposed method achieved better segmentation of crowded dental models and exhibited strong algorithm universality, thus possessing the capability to meet the practical segmentation needs in oral healthcare.
    三维牙颌模型的分割是计算机口腔辅助诊疗系统的关键步骤。针对牙齿分割技术普适性差、欠分割的问题,提出一种结合多种子区域生长和边界延伸的智能牙齿分割方法。该方法结合牙齿的负曲率网格的分布特点获得新种子点,通过差异性区域生长适应了牙齿顶面和侧面间的差异性结构,并结合几何特征对初次分割的边界进行延伸,有效弥补了区域生长的欠分割缺陷。在实验中,通过与当前经典的算法进行对比和消融实验,表明本文方法能够更好地分割拥挤的牙颌模型,具有较强算法普适性,已具备满足口腔诊疗中实际分割需求的能力。.
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  • 文章类型: Journal Article
    The stages of preoperative planning and surgical treatment of compromised teeth by the method of autotransplantation of a tooth are presented on the example of two clinical cases. The autotransplantation method can be considered an alternative to dental implantation when strictly adhering to the surgical protocol and careful selection of patients.
    Представлены этапы предоперационного планирования и хирургического лечения скомпрометированных зубов методикой аутотрансплантации зуба на примере двух клинических случаев. Способ аутотрансплантации можно считать альтернативой дентальной имплантации при соблюдении хирургического протокола и тщательном отборе пациентов.
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  • 文章类型: Journal Article
    有关健康牙齿组织的Hounsfield值范围的信息可能成为评估牙齿健康的附加工具,可以使用,在其他数据中,用于后续机器学习。
    我们研究的目的是确定以Hounsfield单位(HU)为单位的牙齿组织密度。
    总样本包括研究时年龄在10-11岁的36名健康儿童(n=21,58%的女孩和n=15,42%的男孩)。分析了320颗牙齿组织的密度。数据表示为均值和SDs。使用Student(1尾)t检验确定显著性。统计学意义设置为P<0.05。
    分析了320颗牙齿组织的密度:72颗(22.5%)第一恒磨牙,72个(22.5%)永久性中央切牙,27颗(8.4%)第二乳磨牙,40(12.5%)第二前磨牙的牙胚,37(11.6%)第二前磨牙,9(2.8%)第二恒磨牙,第二恒磨牙的牙胚为63个(19.7%)。对数据的分析表明,儿童健康牙齿的组织具有不同的密度范围:牙釉质,从平均2954.69(SD223.77)HU到平均2071.00(SD222.86)HU;牙本质,从平均1899.23(SD145.94)HU到平均1323.10(SD201.67)HU;和纸浆,从平均420.29(SD196.47)HU到平均183.63(SD97.59)HU。下颌骨和上颌骨中永久性中央切牙的组织(牙釉质和牙本质)的平均密度最高。没有可靠地确定有关牙齿组织密度的性别差异。
    对牙齿组织的Hounsfield值的评估可用作评估其密度的客观方法。如果确定釉质的密度,牙本质,和牙髓不符合健康牙齿组织的值范围,那么它可能表明病理。
    UNASSIGNED: Information about the range of Hounsfield values for healthy teeth tissues could become an additional tool in assessing dental health and could be used, among other data, for subsequent machine learning.
    UNASSIGNED: The purpose of our study was to determine dental tissue densities in Hounsfield units (HU).
    UNASSIGNED: The total sample included 36 healthy children (n=21, 58% girls and n=15, 42% boys) aged 10-11 years at the time of the study. The densities of 320 teeth tissues were analyzed. Data were expressed as means and SDs. The significance was determined using the Student (1-tailed) t test. The statistical significance was set at P<.05.
    UNASSIGNED: The densities of 320 teeth tissues were analyzed: 72 (22.5%) first permanent molars, 72 (22.5%) permanent central incisors, 27 (8.4%) second primary molars, 40 (12.5%) tooth germs of second premolars, 37 (11.6%) second premolars, 9 (2.8%) second permanent molars, and 63 (19.7%) tooth germs of second permanent molars. The analysis of the data showed that tissues of healthy teeth in children have different density ranges: enamel, from mean 2954.69 (SD 223.77) HU to mean 2071.00 (SD 222.86) HU; dentin, from mean 1899.23 (SD 145.94) HU to mean 1323.10 (SD 201.67) HU; and pulp, from mean 420.29 (SD 196.47) HU to mean 183.63 (SD 97.59) HU. The tissues (enamel and dentin) of permanent central incisors in the mandible and maxilla had the highest mean densities. No gender differences concerning the density of dental tissues were reliably identified.
    UNASSIGNED: The evaluation of Hounsfield values for dental tissues can be used as an objective method for assessing their densities. If the determined densities of the enamel, dentin, and pulp of the tooth do not correspond to the range of values for healthy tooth tissues, then it may indicate a pathology.
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  • 文章类型: Journal Article
    脊椎动物在其骨骼中使用磷酸盐矿物磷灰石,这使得它们能够发育成牙釉质等组织,其特点是硬度和弹性的突出组合。据推测,最早的脊椎动物骨骼组织的进化,在已灭绝的牙形牙的牙齿中发现,是由适应牙科功能驱动的。我们定量地检验了这一假设,并证明了在整个牙形牙的早期进化过程中,晶体学顺序与对食品加工的形态适应同时增加。磷灰石晶体的c轴垂直于功能性进料表面取向,对单轴压缩应力的最强抵抗力是沿细齿的长轴赋予的。我们的结果支持在第一批骨骼化的脊椎动物中增加对生物矿化的控制,并使我们能够测试牙体牙体多样性的功能形态和材料特性模型。
    Vertebrates use the phosphate mineral apatite in their skeletons, which allowed them to develop tissues such as enamel, characterized by an outstanding combination of hardness and elasticity. It has been hypothesized that the evolution of the earliest vertebrate skeletal tissues, found in the teeth of the extinct group of conodonts, was driven by adaptation to dental function. We test this hypothesis quantitatively and demonstrate that the crystallographic order increased throughout the early evolution of conodont teeth in parallel with morphological adaptation to food processing. With the c-axes of apatite crystals oriented perpendicular to the functional feeding surfaces, the strongest resistance to uniaxial compressional stress is conferred along the long axes of denticles. Our results support increasing control over biomineralization in the first skeletonized vertebrates and allow us to test models of functional morphology and material properties across conodont dental diversity.
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  • 文章类型: Case Reports
    颅内脓胸是一种罕见但严重且危及生命的感染。它是在硬膜下或硬膜外间隙中的脓性物质的积累,导致硬膜下积脓或颅内硬膜外脓肿的发展,分别。发病率和死亡率的发生率很高,因为诊断通常不被怀疑。牙齿来源的感染可能是造成这种状况的原因。
    一名22岁的女性患者和30岁的男性患者,都没有明显的病史,表现为硬膜下积脓和颅内硬膜外脓肿,分别,两者都使牙齿起源的泛鼻窦炎复杂化。成功的结果是通过手术引流病灶,抗生素治疗,并拔除受影响的牙齿。女性患者接受了神经后遗症的进一步治疗,而男性患者出院,无神经系统并发症。
    牙源性颅内化脓是一种罕见但极其严重的并发症。最常见的牙齿起源是有根尖周受累的龋齿和牙周炎。智齿拔除是这种感染最常见的牙科手术。多学科方法对于识别和治疗可疑的口腔来源至关重要。手术方式的抗生素治疗是金标准治疗。
    这种牙源性感染的后遗症非常罕见,但它可以通过良好的口腔卫生和去除脓肿的牙齿来预防。
    UNASSIGNED: Intracranial empyema is a rare but serious and life-threatening infection. It is an accumulation of purulent material in the subdural or extradural space leading to development of subdural empyema or intracranial epidural abscess, respectively. The incidence of morbidity and mortality is high because the diagnosis is often unsuspected. Infections of dental origin could be responsible for such condition.
    UNASSIGNED: A 22-year-old female and 30-year-old male patients, both with no significant medical history, presented with subdural empyema and intracranial epidural abscess, respectively, both complicating pan-sinusitis of dental origin. Successful outcomes were achieved with surgical drainage of the lesions, antibiotic therapy, and extraction of affected teeth. Female patient underwent further management for neurological sequelae, while male patient was discharged without neurological complications.
    UNASSIGNED: Intracranial suppuration of odontogenic origin is an uncommon but extremely serious complication. The most common dental origins are caries with periapical involvement and periodontitis. Wisdom tooth extraction is the most common preceding dental procedure for this infection. A multidisciplinary approach is essential for the identification and treatment of suspected oral sources. Antibiotic therapy with surgical approach is the gold standard treatment.
    UNASSIGNED: This sequel to odontogenic infection is quite rare, but it can be prevented by a good oral hygiene and removal of abscessed teeth.
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  • 文章类型: Journal Article
    目的:本研究旨在揭示SET结构域分叉1(SETDB1)在牙齿发育过程中对上皮细胞的影响。
    方法:我们产生了条件性敲除小鼠(Sedb1fl/fl,Keratin14-Cre+小鼠),其中Setdb1仅在上皮细胞中删除。在胚胎第14.5天(E14.5),进行免疫荧光染色以确认来自Setdb1fl/fl的牙齿胚胎上皮内不存在SETDB1,Keratin14-Cre+小鼠。在达到胚胎第13.5天(E13.5)后收获小鼠胚胎,并准备切片进行组织学分析。为了详细观察牙齿形态,在出生后1个月(P1M)和6个月(P6M)进行电子显微镜和显微CT分析。从出生后第7天(P7)小鼠中收获牙齿胚胎,分离牙齿胚胎的上皮成分,并使用定量RT-PCR检测牙齿发育相关基因的表达。
    结果:Setdb1fl/fl,Keratin14-Cre+小鼠表现出釉质发育不全,脆弱和脆弱的牙列,和显著的磨损。冠状切片显示出成釉细胞发育异常,包括不成熟的两极分化,以及在P7处从牙釉质交界处脱离的薄釉质层。电子显微镜分析显示了特征性的发现,例如不平坦的表面和没有搪瓷棱镜。表达Msx2,Amelogenin(Amelx),Ameloblastin(Ambn),在Setdb1fl/fl中,Enamelin(Enam)在牙胚的上皮成分中显著下调,Keratin14-Cre+小鼠。
    结论:这些结果表明,上皮细胞中的SETDB1对牙齿发育很重要,并首次阐明了SETDB1的表观遗传调控与牙釉质发育不全之间的关系。
    OBJECTIVE: This study aimed to reveal the effects of SET domain bifurcated 1 (SETDB1) on epithelial cells during tooth development.
    METHODS: We generated conditional knockout mice (Setdb1fl/fl,Keratin14-Cre+ mice), in which Setdb1 was deleted only in epithelial cells. At embryonic day 14.5 (E14.5), immunofluorescence staining was performed to confirm the absence of SETDB1 within the epithelium of tooth embryos from Setdb1fl/fl,Keratin14-Cre+ mice. Mouse embryos were harvested after reaching embryonic day 13.5 (E13.5), and sections were prepared for histological analysis. To observe tooth morphology in detail, electron microscopy and micro-CT analysis were performed at postnatal months 1 (P1M) and 6 (P6M). Tooth embryos were harvested from postnatal day 7 (P7) mice, and the epithelial components of the tooth embryos were isolated and examined using quantitative RT-PCR for the expression of genes involved in tooth development.
    RESULTS: Setdb1fl/fl,Keratin14-Cre+ mice exhibited enamel hypoplasia, brittle and fragile dentition, and significant abrasion. Coronal sections displayed abnormal ameloblast development, including immature polarization, and a thin enamel layer that detached from the dentinoenamel junction at P7. Electron microscopic analysis revealed characteristic findings such as an uneven surface and the absence of an enamel prism. The expression of Msx2, Amelogenin (Amelx), Ameloblastin (Ambn), and Enamelin (Enam) was significantly downregulated in the epithelial components of tooth germs in Setdb1fl/fl,Keratin14-Cre+ mice.
    CONCLUSIONS: These results indicate that SETDB1 in epithelial cells is important for tooth development and clarify the relationship between the epigenetic regulation of SETDB1 and amelogenesis imperfecta for the first time.
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  • 文章类型: Journal Article
    据报道,每个大陆都有翼龙遗骸;然而,翼龙骨骼仍然很少见。这里介绍了一种新的翼龙,HaliskiaPetersenigen.等sp.11月。,构成了来自澳大利亚的最完整的标本,该标本来自埃罗曼加盆地的上AlbianToolebuc组(昆士兰州,澳大利亚)。功能的组合,包括上颌前牙和弯曲的牙齿,和肩胛骨的形态,支持将其转介给安汉维亚。Haliskia可以根据两个牙齿特征与所有其他anhanguerian翼龙区分开来:第4和第5对牙齿比第3和第6对小,第2和第5肺泡小于3-4和6-8。此外,舌骨是下颌骨总长度的70%。此处提供的系统发育分析将Haliskia置于安汉吉利亚之内。在一项分析中,Haliskia和Ferrodraco被确定为姐妹类群,和长尾蛇妹妹一起去了那个进化枝。另一个解决了Haliskia,在Tropeophnathinae内的多发性切除术中的Mythunga和Ferrodraco。新的澳大利亚翼龙证明了白垩纪早期的成功,表明澳大利亚的形态在分类学上比以前认识到的更加多样化和古地理复杂。
    Pterosaur remains have been reported from every continent; however, pterosaur skeletons remain rare. A new pterosaur is presented here, Haliskia peterseni gen. et sp. nov., constituting the most complete specimen from Australia from the upper Albian Toolebuc Formation of the Eromanga Basin (Queensland, Australia). A combination of features, including the presence of a premaxillary crest and curved teeth, and the morphology of the scapulocoracoid, support its referral to Anhangueria. Haliskia can be distinguished from all other anhanguerian pterosaurs based on two dental characters: the 4th and 5th tooth pairs are smaller than the 3rd and 6th, and the 2nd and 5th alveoli are smaller than 3-4 and 6-8. Moreover, the hyoid is 70% the total length of the mandible. The phylogenetic analyses presented here place Haliskia within Anhangueria. In one analysis, Haliskia and Ferrodraco are resolved as sister taxa, with Tropeognathus mesembrinus sister to that clade. The other resolves Haliskia, Mythunga and Ferrodraco in a polytomy within Tropeognathinae. The new Australian pterosaur attests to the success of Anhangueria during the latest Early Cretaceous and suggests that the Australian forms were more taxonomically diverse and palaeobiogeographically complex than previously recognized.
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  • 文章类型: Journal Article
    利用间充质凝聚的发育事件来指导出生后的牙科干细胞聚集代表了一种尖端且有希望的牙齿再生方法。牙齿撕脱是最普遍和最严重的牙齿损伤之一,在临床试验中,由人脱落的乳牙(SHED)的干细胞组装的牙源性聚集体已被证明可以有效地恢复再生后的撕脱牙齿。然而,SHED聚集体(SA)是否以及如何与受体成分进行通信并促进协同组织再生以支持重新种植的牙齿仍然难以捉摸。这里,表明SA介导的撕脱牙再生涉及牙周修复和受体Gli1干细胞的恢复,动员并必然有助于牙齿-牙周膜-骨界面的重建。机械上,细胞外囊泡(EV)的释放对于植入的SA动员受体Gli1细胞并再生撕脱的牙齿是必不可少的。此外,SHED聚集体释放的EV(SA-EV)具有与组织再生有关的牙源性特性,这增强了迁移,扩散,和Gli1+细胞的分化。重要的是,SA-EV本身的局部应用增强了受体Gli1细胞的功能,并保护了撕脱牙齿的再生。总的来说,这些发现建立了一个范例,其中以牙齿发生为特征的电动汽车控制供体-受体干细胞相互作用以实现牙齿再生,鼓舞人心的无细胞翻译再生策略。
    Harnessing the developmental events of mesenchymal condensation to direct postnatal dental stem cell aggregation represents a cutting-edge and promising approach to tooth regeneration. Tooth avulsion is among the most prevalent and serious dental injuries, and odontogenic aggregates assembled by stem cells from human exfoliated deciduous teeth (SHED) have proven effective in revitalizing avulsed teeth after replantation in the clinical trial. However, whether and how SHED aggregates (SA) communicate with recipient components and promote synergistic tissue regeneration to support replanted teeth remains elusive. Here, it is shown that SA-mediated avulsed tooth regeneration involves periodontal restoration and recovery of recipient Gli1+ stem cells, which are mobilized and necessarily contribute to the reestablishment of the tooth-periodontal ligament-bone interface. Mechanistically, the release of extracellular vesicles (EVs) is revealed indispensable for the implanted SA to mobilize recipient Gli1+ cells and regenerate avulsed teeth. Furthermore, SHED aggregates-released EVs (SA-EVs) are featured with odontogenic properties linked to tissue regeneration, which enhance migration, proliferation, and differentiation of Gli1+ cells. Importantly, local application of SA-EVs per se empowers recipient Gli1+ cells and safeguards regeneration of avulsed teeth. Collectively, the findings establish a paradigm in which odontogenesis-featured EVs govern donor-recipient stem cell interplay to achieve tooth regeneration, inspiring cell-free translational regenerative strategies.
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