Clinical application of angiography of oral and maxillofacial hemangiomas. Clinical analysis of seventy cases

Angiographic findings in seventy cases of maxillofacial hemangioma are reported. The tumors have been divided into four types: (1) plexiform hemangioma, (2) cavernous hemangioma with venous drainage, (3) cavernous hemangioma without venous drainage, and (4) the so-called "diffuse type" of cavernous hemangioma. The angiographic features of the four types are described, and clinical application is evaluated. The angiograms demonstrate the location, extent, blood supply, and drainage of the tumors and show whether they communicate intracranially, thus providing valuable criteria for planning and determining the mode of treatment.     

热侧压充填法根尖封闭能力研究

本研究通过根尖渗漏试验和可见光分光光度法比较热侧压充填法和传统侧压充填法的根尖封闭能力。结果表明：加用封闭剂热侧压充填法的根尖封闭能力最佳，优于单纯热侧压充填法（Ｐ＜０．０５）及传统侧压充填法（Ｐ＜０．０１）。但由于国产牙胶尖易粘至热充填器上带出，操作不便，目前推广应用热侧压法尚有困难。     

异种脱细胞真皮基质修复膜在口腔黏膜下纤维性变手术治疗中的应用

目的:评价异种脱细胞真皮基质修复膜在口腔黏膜下纤维性变手术治疗中的应用效果。方法:8例重度口腔黏膜下纤维性变患者,经鼻腔气管插管全麻下切除双侧颊部翼下颌韧带前方区域纵行的纤维条索,术中被动开口度达正常范围后,剪取相应大小的异种脱细胞真皮基质修复膜覆盖黏膜缺损创面,间断缝合后,碘纺纱包加压固定。术后10～14d拆除纱包与缝线后开始开口训练,定期随访并进行类固醇皮质激素黏膜下局部注射等辅助治疗,通过伤口愈合、瘢痕软化及开口度改善等指标评价手术效果。采用SPSS16.0软件包对数据进行单因素方差分析。结果:8例患者双侧颊部纤维条索切除后形成的手术创面,采用异种脱细胞真皮基质修复膜进行修复均获得成功,无感染或排异等并发症发生。术后随访6～18个月,患者颊部原手术区黏膜红润,质地柔软,开口困难明显改善。术前开口度为(12.04±2.93)mm,术中开口度为(35.46±3.17)mm,术后6个月时的开口度为(29.33±4.28)mm,经统计学分析,差异具有显著性(P<0.05)。结论:应用异种脱细胞真皮基质修复膜修复重度口腔黏膜下纤维性变手术治疗中的黏膜缺损创面,能够起到促进创面早期愈合、减轻瘢痕形成与改善开口困难的作用,其操作简单易行,值得临床推广应用。     

Genome-wide association scan for childhood caries implicates novel genes

Dental caries is the most common chronic disease in children and a major public health concern due to its increasing incidence, serious health and social co-morbidities, and socio-demographic disparities in disease burden. We performed the first genome-wide association scan for dental caries to identify associated genetic loci and nominate candidate genes affecting tooth decay in 1305 US children ages 3-12 yrs. Affection status was defined as 1 or more primary teeth with evidence of decay based on intra-oral examination. No associations met strict criteria for genome-wide significance (p < 10E-7); however, several loci (ACTN2, MTR, and EDARADD, MPPED2, and LPO) with plausible biological roles in dental caries exhibited suggestive evidence for association. Analyses stratified by home fluoride level yielded additional suggestive loci, including TFIP11 in the low-fluoride group, and EPHA7 and ZMPSTE24 in the sufficient-fluoride group. Suggestive loci were tested but not significantly replicated in an independent sample (N = 1695, ages 2-7 yrs) after adjustment for multiple comparisons. This study reinforces the complexity of dental caries, suggesting that numerous loci, mostly having small effects, are involved in cariogenesis. Verification/replication of suggestive loci may highlight biological mechanisms and/or pathways leading to a fuller understanding of the genetic risks for dental caries.     

Effects of pH values of hydrogen peroxide bleaching agents on enamel surface properties

This study investigated the influence of pH values of bleaching agents on the properties of the enamel surface. Sixty freshly extracted premolars were embedded in epoxy resin and mesiodistally sectioned through the buccal aspect into two parts. The sectioned slabs were distributed among six groups (n=10) and treated using different solutions. Group HCl was treated with HCl solution (pH=3.0) and served as a positive control. Group DW, stored in distilled water (pH=7.0), served as a negative control. Four treatment groups were treated using 30% hydrogen peroxide solutions with different pH values: group HP3 (pH=3.0), group HP5 (pH=5.0), group HP7 (pH=7.0), and group HP8 (pH=8.0). The buccal slabs were subjected to spectrophotometric evaluations. Scanning electron microscopy investigation and Micro-Raman spectroscopy were used to evaluate enamel surface morphological and chemical composition alterations. pH value has a significant influence on the color changes after bleaching (p<0.001). Tukey's multiple comparisons revealed that the order of color changes was HP8, HP7>HP5, HP3>HCl>DW. No obvious morphological alterations were detected on the enamel surface in groups DW, HP7, and HP8. The enamel surface of groups HCl and HP3 showed significant alterations with an erosion appearance. No obvious chemical composition changes were detected with respect to Micro-Raman analysis. Within the limitations of this study, it was concluded that no obvious morphological or chemical composition alterations of enamel surface were detected in the neutral or alkaline bleaching solutions. Bleaching solutions with lower pH values could result in more significant erosion of enamel, which represented a slight whitening effect.     

Aggregatibacter actinomycetemcomitans leukotoxin is post-translationally modified by addition of either saturated or hydroxylated fatty acyl chains

Aggregatibacter actinomycetemcomitans, a common inhabitant of the human upper aerodigestive tract, produces a repeat in toxin (RTX), leukotoxin (LtxA). The LtxA is transcribed as a 114-kDa inactive protoxin with activation being achieved by attachment of short chain fatty acyl groups to internal lysine residues. Methyl esters of LtxA that were isolated from A. actinomycetemcomitans strains JP2 and HK1651 and subjected to gas chromatography/mass spectrometry contained palmitoyl (C16:0, 27-29%) and palmitolyl (C16:1 cis Δ9, 43-44%) fatty acyl groups with smaller quantities of myristic (C14:0, 14%) and stearic (C18:0, 12-14%) fatty acids. Liquid chromatography/mass spectrometry of tryptic peptides from acylated and unacylated recombinant LtxA confirmed that Lys(562) and Lys(687) are the sites of acyl group attachment. During analysis of recombinant LtxA peptides, we observed peptide spectra that were not observed as part of the RTX acylation schemes of either Escherichia coliα-hemolysin or Bordetella pertussis cyclolysin. Mass calculations of these spectra suggested that LtxA was also modified by the addition of monohydroxylated forms of C14 and C16 acyl groups. Multiple reaction monitoring mass spectrometry identified hydroxymyristic and hydroxypalmitic acids in wild-type LtxA methyl esters. Single or tandem replacement of Lys(562) and Lys(687) with Arg blocks acylation, resulting in a >75% decrease in cytotoxicity when compared with wild-type toxin, suggesting that these post-translational modifications are playing a critical role in LtxA-mediated target cell cytotoxicity.     

五倍子对口内菌斑生物膜活性影响的体外研究

目的应用口内菌斑生物膜模型观察五倍子水提取物对菌斑生物膜活性的影响。方法将牙釉质磨片粘结于两侧下颌第一恒磨牙颊侧获得24h口内菌斑生物膜模型,实验组和对照组分别用6mg/ml五倍子水提取物和生理盐水处理3min,应用溴化乙锭/荧光素双乙酸盐(ethidium bromide/fluorescein diacetate,EB/FDA)染色技术和激光共聚焦显微镜(confocal laser scan microscope,CLSM)观察五倍子水提取物对生物膜活性的影响。结果CLSM观察可见所有样本釉质表面均有细菌的定植,有早期的生物膜形成。对照组菌斑生物膜中细菌的活性明显高于实验组,两者相比具有显著差异(P<0.05)。结论五倍子水提取物在较短的时间内就能对生物膜中的细菌产生一定的杀伤效应,使其活性下降。