活动性矫治器早期治疗牙齿反的临床研究

目的：探讨活动性矫治器治疗早期牙齿反的临床疗效,为矫治前牙反提供有效办法。方法对60例牙齿反患儿采用佩戴活动性矫治器的方法进行早期治疗,分别比较这60例患儿治疗前后X线投影测量结果,判断治疗效果。结果60例牙齿反患儿中,矫治时间为2-9个月,其中10例矫治时间2-3个月,37例矫治时间3-7个月,13例矫治时间7-9个月,平均矫治时间（5.8±2.7）个月,所有研究患儿均按照医师要求完成治疗周期;对60例患儿的SNA角、颌凸角、SNB角、ANB角、U1-SN、SN-UIN、CV值治疗前后X线测量显示治疗后较治疗前均显著改善且差异均具有显著的统计学意义（P<0.05）;60例患儿在治疗后结束后1年进行复查,发现有4例儿童复发,均与年龄偏大、存在前牙反的家族史或不良的口腔习惯未破除等原因有密切关系,复发率为6.67%。结论活动性矫治器治疗早期牙齿反具有明显的正畸效果,但同时应该注意对儿童不良习惯的纠正以保持治疗效果。     

下颌前牙根管变异的锥形束CT研究

目的 运用锥形束CT(CBCT)研究下颌前牙的根管变异情况。方法收集250例患者的1352颗下颌前牙的CBCT资料,运用配套软件对牙齿的冠状面、矢状面以及横断面进行影像学分析,统计和分析牙根数目、根管数目、根管类型、对称性分布等。结果 下颌切牙均为单根,下颌尖牙双根发生率为1.45%。下颌中切牙、侧切牙、尖牙双根管发生率分别为17.34%、34.08%、9.05%。双根管的发生呈对称性分布,一侧出现双根管时,对侧同名牙也为双根管的概率下颌侧切牙最高,为77.78%,中切牙次之,为72.97%,尖牙为64.00%。按照Vertucci根管分型,共观察到除Ⅳ型和Ⅷ型外的6种根管类型,其中以Ⅰ型为主,为80.00%,其次为Ⅲ型,为16.51%。结论下颌前牙根管系统复杂多变,其中下颌侧切牙双根管发生率最高,双根管以Vertucci Ⅲ型为主,锥形束CT是诊断下颌前牙根管变异的有效手段。     

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.     

ProTaper机用锉在乳磨牙一次法根管治疗中的应用

探讨比较ProTaper机用锉结合根管测量仪与手持K型锉结合X线片在乳磨牙一次法根管治疗中的临床效果。选择5～8岁左右两侧下颌第2乳磨牙同患慢性牙髓炎的患儿50名,随机一侧应用ProTaper机用锉为观察组,对侧应用K锉为对照组。比较2组拔髓时间及疼痛情况、根管预备的时间和根充效果,并比较2组术后6 h、24 h、48 h和7 d时的VAS疼痛评分。观察组与对照组比较拔髓和根管预备时间短,疼痛少（P＜0.01）;根充效果观察,观察组根管糊剂的连贯性、致密性、恰填率高于对照组（P＜0.01）;术后6 h、24 h、48 h疼痛评分有显著性差异（P＜0.01）,术后7 d的疼痛评分无显著性差异（P＞0.05）。ProTaper机用锉应用于乳磨牙一次法根管治疗切实可行,可以缩短治疗时间,减少术后反应,提高工作效率和治疗效果。     

焦虑抑郁状态对智齿冠周炎复发的影响

 目的 探讨焦虑抑郁状态对非外科手术治疗的智齿冠周炎复发的影响。方法 选择就诊于中日友好医院口腔医学中心的首发非外科治疗的智齿冠周炎患者,通过发放电子问卷收集如下信息:人口学信息、焦虑量表(GAD-7)和抑郁量表(PHQ-9)。半年后对随访患者的复发情况进行统计,采用多因素logistic回归分析智齿冠周炎复发与患者发病时情绪状态的关系。结果 共收集568份有效问卷,其中7.0%患者存在焦虑状态(GAD-7≥10),13.7%存在抑郁状态(PHQ-9≥10),半年后随访智齿冠周炎的复发率为11.4%。分析智齿冠周炎6个月后复发情况发现,男性的风险低于女性(OR=0.416,P＜0.05),焦虑增加了智齿冠周炎的复发风险(OR=1.124,P＜0.05)。结论 口腔医师应关注患者焦虑抑郁情绪状态,有助于智齿冠周炎的预防和治疗。     

SEM Study of Apical Morphological Alterations in Primary Teeth with Vital and Necrotic Pulps

This study evaluated, by SEM, the morphology of human primary teeth roots. Twenty-four teeth were divided into 3 groups: pulp vitality (group I) and pulp necrosis without (group II) and with apical periodontitis (group III). Roots were analyzed by the presence of periodontal ligament (PDL) fibers and resorption areas. In groups I and II, presence of PDL fibers and absence of resorption were observed in all cases (100%), while all specimens (100%) of group III showed no PDL fibers and resorption areas. In conclusion, there are morphological differences in the apical region of primary teeth with different pulpal and periapical pathologies.     

Unravelling the blood supply to the zebrafish pharyngeal jaws and teeth

We describe the vascular supply to the pharyngeal jaws and teeth in zebrafish, from larval stages to juveniles, using serial high quality semithin sections and 3D reconstructions. We have identified that the arterial blood supply to the last pair of branchial arches, which carries the teeth, issues from the hypobranchial artery. Surprisingly, the arteries supplying the pharyngeal jaws show an asymmetric branching pattern that is modified over ontogeny. Moreover, the blood vessel pattern that serves each jaw can best be described as a sinusoidal cavity encircling the bases of both the functional and replacement teeth. Capillaries branching from this sinusoidal cavity enter the pulp and constitute the intrinsic blood supply to the attached teeth. The role of these blood vessels during tooth development (whether instructive or nutritive) remains to be determined and requires further study. However, we have provided a firm morphological basis that will aid in the interpretation of experiments addressing this question.     

Immunohistochemical Localization of Components of the Insulin-Like Growth Factor-System in Human Deciduous Teeth

To investigate the occurrence of components of the insulin-like growth factor (IGF) system during the resorption process of shedding human deciduous teeth, we investigated sections of 13 decalcified and paraffin-embedded deciduous teeth immunohistochemically with antibodies against IGF-I and -II, six IGF binding proteins (IGFBPs 1-6) and the IGF receptors IGFIR and IGF2R. The teeth were in different stages of resorption and all showed reparative cementum formation. It was found that acellular extrinsic fiber cementum, reversal lines and reparative cellular intrinsic fiber cementum were immunoreactive for both IGFs and various IGFBPs. Therefore, in human deciduous teeth, all subgroups of cementum, but not dentine, may represent sources of components of the IGF system. Odontoclasts did not carry IGFs or the IGF1R, but IGFBPs and the IGF2R. Therefore, these cells, in contrast to osteoclasts, may not respond to IGFs, but may be involved in the release and sequestration of IGFs from cementum during the resorption process. In contrast to odontoclasts, cementoblasts and periodontal ligament (PDL) fibroblasts carried IGF1R. The influence of the IGF system on the function of these cells with respect to periodontal matrix turnover and cementogenesis is discussed. On the behalf of the IGFBP immunoreactivities found, the PDL extracellular matrix can be considered to be a reservoir for IGF system components, where binding proteins may regulate IGF distribution and activity.     

A field-programmable gate array based system for high frame rate laser Doppler blood flow imaging

This paper presents a general embedded processing system implemented in a field-programmable gate array providing high frame rate and high accuracy for a laser Doppler blood flow imaging system. The proposed system can achieve a basic frame rate of flow images at 1 frame/second for 256×256 images with 1024 fast Fourier transform (FFT) points used in the processing algorithm. Mixed fixed-floating point calculations are utilized to achieve high accuracy but with a reasonable resource usage. The implementation has a root mean square deviation of the relative difference in flow values below 0.1% when compared with a double-precision floating point implementation. The system can contain from one or more processing units to obtain the required frame rate and accuracy. The performance of the system is significantly higher than other methods reported to date. Furthermore, a dedicated field-programmable gate array (FPGA) board has been designed to test the proposed processing system. The board is linked with a laser line scanning system, which uses a 64×1 photodetector array. Test results with various operating parameters show that the performance of the new system is better, in terms of noise and imaging speed, than has been previously achieved.