Prognosis and complications of mature teeth after lateral luxation: A systematic review

BackgroundDental trauma injuries are frequent in children and adolescents and can result in a sequela of future complications. Lateral luxation injuries are diagnosed when a tooth becomes displaced in a position other than axial and is often associated with alveolar bone fracture. Although the tooth is not immediately lost, pulp canal obliteration or pulpal necrosis can occur. The objective of this systematic review was to gather existing data on lateral luxation injuries to mature teeth to evaluate their overall prognosis and reported complications.Types of Studies ReviewedThe authors conducted a systematic search of the literature using MEDLINE, PubMed, Embase, and Cochrane databases in February 2019. They hand searched reference lists to identify additional literature. The authors included prospective and retrospective observational studies in the search. They screened a total of 291 articles, downloaded 28 articles, and included 4 articles in the study.ResultsThe most frequent complication reported for mature teeth with lateral luxation was pulpal necrosis (44.2%). Less frequent findings included surface resorption (14.0%), inflammatory resorption (8.5%), pulp canal obliteration (8.1%), and replacement resorption (0.9%). The included studies were cohort studies, which resulted in great heterogeneity, and the authors could not attempt a meta-analysis.Conclusions and Practical ImplicationsA large number of permanent teeth that experience lateral luxation are at risk of developing pulpal necrosis and other complications. Careful follow-up is required for these patients to treat complications as early as possible. Furthermore, the authors of this systematic review emphasize the importance of consistent reporting of dental trauma outcomes.     

复方氯己定含漱液预防干槽症临床观察

目的:评价复方氯己定含漱液预防下颌阻生智齿拔除术后干槽症的临床效果。方法:临床搜集需拔除下颌阻生智齿的342例患者,共342颗牙,随机分为复方氯己定含漱液组(A组)、口服抗生素组(B组)和消炎抗菌可溶止血纱布组(C组),比较3组术后干槽症的发病率。结果:A组干槽症发病率显著低于C组(P<0.05);A组与B组、B组与C组间比较,干槽症发病率均无显著性差异(均P>0.05)。结论:下颌阻生智齿拔除后,口腔应用复方氯己定含漱液可有效预防术后干槽症的发生。     

下颌第三阻生牙拔除术并发症回顾性分析

目的探讨下颌第三阻生智齿拔除术术中和术后并发症的原因和防治方法。方法对2008年1月到2012年3月拔除的482例下颌第三阻生齿临床资料进行回顾性分析,对术中并发症和术中并发症进行分析,寻找阻生齿拔除术并发症的有效防治手段。结果术中发生断根25例,舌侧牙槽骨板折裂30例,牙龈撕裂16例,邻牙损伤5例。术后早期并发症425例,其中同时具备疼痛、肿胀和张口受限症状的患者253例,单纯疼痛者22例,疼痛伴张口受限者80例,疼痛伴肿胀者70例,后期并发症中出血20例,干槽症30例。局部感觉异常12例,间隙感染10例。结论阻生牙术前应拍曲面断层片,正确评估拔牙难度和阻力分析,选用涡轮钻法,动作轻柔,缩短拔牙时间,减少创伤,能预防并发症的发生。     

超声洁牙机在乳牙窝洞预备上的实验研究

目的 探讨超声洁牙机在乳牙窝洞预备上的应用。 方法 采用快速涡轮机、低速涡轮机以及超声洁牙机分别在离体乳牙上进行窝洞预备,然后在洞形处片切。电镜下观察、对比3种方法预备后洞壁牙面的粗糙程度以及在分体式测振仪上观察3种器械在备洞时的振动频率。 结果 电镜显示,快速涡轮机预备后的牙面较光滑,低速涡轮机预备后的牙面较粗糙,超声洁牙机介于上述两者之间; 而在振动频率方面,超声洁牙机的平均振动频率介于快速涡轮机与低速涡轮机之间。 结论 超声洁牙机对乳牙的窝洞预备后牙面粗糙度适中,可保证充填材料与牙面接触的表面积和粘着强度,窝洞预备后的牙面不会影响充填材料的粘结固位。     

锥形束CT在阻生齿拔除术中的应用

目的:应用锥形束CT(CBCT)观测及分析阻生齿与邻近解剖结构的关系,为临床手术提供参考依据.方法:在第三磨牙拔除术前摄曲面断层X线片检查,对于与下牙槽神经管接触或部分重叠的病例35例,进行锥形束CT检查.结果:锥形束CT对阻生齿拔除术能更好的进行阻力分析.结论:锥形束CT检查对于第三磨牙拔除术手术方案的选定具有一定的指导意义.     

中国老年人群牙齿缺失与全因死亡风险关联的前瞻性队列研究

 目的 探讨中国老年人群余留牙齿数量与全因死亡的关联。方法 基于2011－2018年中国老年健康影响因素跟踪调查(CLHLS)纵向随访资料,通过调查问卷获取调查对象的基线特征、既往病史、余留牙齿数量等信息,采用Katz量表和简易智能状态检查量表评估日常活动能力和认知功能。采用多因素Cox等比例风险模型评估余留牙齿数量与全因死亡的关联。结果 共纳入8658例老年人,男3895例(45.0%),女4763例(55.0%),平均年龄为(85.7±11.2)岁,经7年随访,死亡4488例(51.8%),牙齿余留数量与年龄增长呈负相关(P<0.05)。多因素Cox回归结果显示,在调整年龄、性别、身体质量指数(body mass index,BMI)、吸烟、饮酒、锻炼、高血压、呼吸道疾病、心血管疾病、日常活动能力失能、认知功能受损等因素后,余留牙齿数量每增加一个,全因死亡风险下降1%,与余留牙齿数量为0的老年人相比,≥20颗余留牙齿的老年人的全因死亡风险下降22%。结论 中国老年人群余留牙齿数量的减少可能增加全因死亡风险,应预防老年人群牙齿脱落。     

Review: Extracellular Matrix Regulates Tooth Morphogenesis

Mineralized tissues are unique in that they use proteins to attract and organize calcium and phosphate ions into a structured mineral phase, thus precise knowledge of the expression and extracellular distribution of matrix proteins is very important to understand their function. Tooth development is regulated by sequential and reciprocal interactions between neural crest-derived mesenchymal cells and the oral environment. However, the precise molecular mechanisms that mediate interactions between epithelium and mesenchymal cells are not clear, although basement membrane (BM) components have been shown to play important roles in these regulatory events. In addition, the extracellular matrix layer, whose main components are laminin, collagen IV, nidogen, and sulfated proteoglycan, and the BM layer are both considered to be involved with cell proliferation and differentiation. During tooth morphogenesis, extracellular matrices are dramatically changed. Further, the BM components, laminin and collagen IV support dental epithelium; however, in the late stage, they begin the processes of enamel matrix secretion and calcification, after which the BM structure between the dental epithelium and mesenchyme disappears. In addition, tooth abnormalities associated with several kinds of human diseases that cause mutations in the extracellular matrix, as well as the molecular mechanisms of the basement membrane and enamel matrix during tooth morphogenesis, are not clearly understood. In our review, we discuss the role of the extracellular matrix, with focus on the BM and enamel matrix during tooth morphogenesis.     

The Structure of Mineralized Collagen Fibrils

A new model for the structure of mineralized bone collagen is presented which is compatible with neutron diffraction, electronmicroscopic, crosslinking, and composition-density data. Mineralized collagen fibrils are comprised of azimuthally oriented, flexible molecules laterally arranged on a superlattice. Four nearest neighbors are longitudinally staggered by 67 nm and two neighbors by 2* 67 nm. In early stages of mineralization the molecules are parallel to the fibril axis with an average interaxis distance of 1.8 nm. In later stages they become flexed away from the fibril axis by an anisotropic lateral compression of molecules to an interaxis distance of 1.3 nm. Three quarters of the mineral in bone is disposed within the fibrils with a symetry and habit reflecting the above organization of the collagen molecules.     

Evidence of Two Types of Odontoblasts during Dentinogenesis in Elasmobranchs

The fine structure of the odontoblasts in the sting rays, Dasyatis akajei Dasyatidae, and Urolophus aurantiacus Urolophidae, was examined using light and transmission electron microscopy. In the dentinogenesis stage, the odontoblasts have been classified into two types, that is, dark cells and light cells, based on differences in their fine structure. Many dark odontoblasts found along the predentine displayed well-developed organelles with secretory activity around the nuclei. They contained large amounts of expanded rER, widely distributed Golgi apparatus and secretory granules. In contrast, light odontoblasts showed a relatively clear cytoplasm and extended long processes which passed through the predentine and penetrated into the dentine. They contained large numbers of microtubules in the processes and many mitochondria around the nuclei. It is suggested that the light odontoblasts play an important part in material transport to the dentine and/or act as a sensory organ of the tooth. The dark odontoblasts seem to produce the organic matrix of the dentine and to prepare for mineralization in the dentine.