Dynamic magnetic resonance sialography as a new diagnostic technique for patients with Sjögren's syndrome

Objective: To evaluate the clinical utility of dynamic magnetic resonance (MR) sialographic images as a diagnostic tool for patients with Sjögren's syndrome. Methods: The morphological findings and various kinds of functional parameters in volunteers on dynamic MR sialographic images were compared with those in five patients with definite Sjögren's syndrome. Results: On the MR sialographs of all five patients with Sjögren's syndrome, the so‐called ‘apple‐tree appearance’ was seen. The difference in two functional parameters using the dynamic MR sialographic data was elucidated between the two groups. The maximum area of the detectable ducts in the group of patients was significantly smaller (P < 0.001) than that in the group of volunteers. The ratio of change in the detectable ducts in the group of patients was significantly lower (P = 0.011) than that in the group of volunteers. Conclusions: Our study suggests that dynamic MR sialographic data in addition to MR sialographic images might be useful for the diagnosis of Sjögren's syndrome.     

Association between food mixing ability and mandibular movements during chewing of a wax cube

The purpose of this study was to clarify whether masticatory movements during chewing of a wax cube associate with food mixing ability. Twenty-six dentate subjects (mean age 25.3 years) were directed to chew a two-coloured paraffin wax cube for 10 strokes on preferred chewing side. Mixing Ability Index (MAI) was determined from the colour mixture and shape of the chewed wax cube. MAI was employed as an estimate of food mixing ability. Mandibular movements during chewing of the wax cube were recorded using a six-degrees-of freedom jaw movements recording system, and motion of a lower incisal point of the mandible was computed. Twelve parameters of masticatory movements in relation to mandibular excursion, angle, velocity, cycle duration, duration of each phase were measured for each masticatory cycle. In addition, unilateral maximum biting was performed, and the maximum force during biting was measured using a force-transducer. A multiple regression analysis identified vertical amplitude, closing duration, closing angle and maximum bite force as significant predictors accounting for 63% of inter-subject variation (adjusted R(2)) in the MAI (P < 0.05). Only some parameters of masticatory movements seem to have an influence on the MAI in dentate subjects.     

Manometric evaluation of oral function with a hand-held balloon probe

Tongue pressure measured with a disposable hand-held balloon probe has been used for assessing tongue function; however, no diagnostic standard for assessing other oral functions exists currently. In this study, to develop a method for multifactorial manometric evaluation of oral functions, 20 men and 20 women (21-32 years of age) were instructed to apply 7-s maximal voluntary muscular effort on a hand-held balloon probe placed against the anterior and lateral parts of the palate, buccal surface of the molars on the habitual chewing side and labial surface of the anterior teeth for measuring anterior and posterior tongue, cheek and lip pressures (LPs), respectively. Intra-session reproducibility was determined by three repeated measurements, and associations between the obtained and the conventional data on oral diadochokinesis were tested. The men exhibited higher values of all the pressure types. Further, both genders showed a positive correlation between anterior and posterior tongue pressures (PTPs) (P < 0·05), but only the women exhibited positive correlations between anterior tongue and cheek pressures, cheek and PTPs, anterior tongue and LPs, and cheek and LPs (P < 0·05). No statistically significant correlation was found between the pressures and the number of syllabic articulations, except between LP and the number of /pa/ articulations in the women (r = 0·524, P < 0·05). In conclusion, the balloon probe method enables objective manometric evaluation of oral functions and could be an effective tool for clinical epidemiological studies and evidence-based decision-making in nursing care.     

Early function of splinted implants in maxillas and posterior mandibles, using Brånemark System Tiunite implants: an 18-month prospective clinical multicenter study

Background: Immediate or early loading of implants placed in maxillas and posterior mandibles has been a concern as bone density is often low in these areas, making it difficult to establish good initial implant stability. By adapting implant design and insertion protocols, however, high initial implant stability may be achieved in these regions. Further, a modified implant surface texture has been proved to help in maintaining stability during the initial healing period. Purpose: The aim of the present study was to investigate the clinical performance of oxidized titanium implants (TiUnite?, Nobel Biocare AB, Gothenburg, Sweden) when used for early function in the maxilla and in the posterior mandible, locations where the bone density often is low. A further aim was to evaluate the marginal bone level at oxidized implants and compare it with that of machined‐surface implants used in a previous study. Materials and Methods: Thirty‐one patients were consecutively included in the study, and 37 edentulous areas in maxillas and posterior mandibles were treated. Bruxism and uncontrolled periodontal disease were exclusion criteria. Temporary prostheses were generally placed within 9 days but not after 16 days from implant placement. A previous study applying the same study design and clinical protocol but using machined‐surface implants was used for comparisons. Results: Of the 111 implants installed, 1 failed, giving an overall survival rate of 99.1% after 18 months. The prosthesis survival was 100%. The marginal bone resorption was 0.8 mm (standard deviation ISD], 1.0), as opposed to 1.6 mm (SD, 1.3) in the previous study with machined‐surface implants, but was not statistically significantly different (p= .10). Conclusion: The present clinical protocol (aiming at high primary stability) and the use of oxidized titanium implants for early functional loading in the maxilla and the posterior mandible resulted in a high implant survival rate and a favorable marginal bone level during a follow‐up of 18 months. The difference in marginal bone resorption between the oxidized implants in the present study and the machined implants from a previous investigation with the same study design was not statistically significant.     

脑小血管病患者认知、睡眠和血浆标志物的研究进展

近年来随着神经影像技术的提高与普及,越来越多的脑小血管病被正确识别,脑小血管病在老年人群中已经成为一类常见病。脑小血管病能够引起一系列威胁患者健康的问题,尤其是认知功能损害,但由于疾病早期症状不突出,影像学检查滞后等原因,目前临床仍然缺乏有效的手段尽早识别此类疾病。本文阐述了脑小血管病的影像分型以及其特征性认知功能改变,探讨睡眠和血浆生物标志物与脑小血管病之间的关系,为临床早期鉴别诊断和个体化治疗提供有力依据。     

甜味觉的脑功能磁共振成像研究

目的：使用脑功能磁共振成像技术(fMRI)研究甜味觉刺激时的脑功能状态及脑激活模式。方法：对11例正常受试，依照事件相关结构(event-related structure)设计，给予甜味及无味对照的味觉刺激，采集全脑血氧水平依赖对比(BOLD)的fMRI扫描数据，用SPM99软件包进行t检验统计分析，以获取甜味刺激及无味对照刺激对比的脑功能图像。结果：在甜味刺激下最大范围的激活信号出现在左扣带回(24区)，其次为左侧脑岛、双侧顶上小叶(5／7区)、左丘脑腹后内侧核及左顶下小叶(40区)、左豆状核、额中回(6／9区)、前额皮质(10区)等脑区。结论：甜味觉引起兴奋的脑区，除传统的神经解剖及神经生理学研究已证明为味觉各级中枢的丘脑、脑岛、前额皮质等，还包括扣带回顶上二小叶、顶下小叶、豆状核、额中回等，反映味觉刺激时脑功能状态及其激活模式的复杂性。     

ERA全口覆盖义齿修复保留残根的半口牙列缺失患者的临床评估

目的：研究ERA附着体全口覆盖义齿的临床修复效果。方法：35例保留残根的半口牙列缺失患者，采用ERA全口覆盖义齿修复。结果：经过6个月至1年3个月时间随访，患者表示对该义齿的固位性能、咀嚼效能、舒适程度，以及装卸的方便程度感到满意。有1例出现ERA阳性部件老化，进行了即刻更换，其余无失败病例。结论：采用ERA全口覆盖义齿修复保留残根的半口牙列缺失病例，临床观察患者较满意，提示该方法是一种方便、可靠的修复方式。但ERA附着体的阳性部件需要根据老化情况，随时进行更换。     

自凝软衬处理对全口义齿咀嚼效率影响的临床观察

目的探讨自凝硅橡胶软衬材料（Sofreliner MS）对全口义齿患者咀嚼效率和最大咬合力的影响。方法在本院修复科选择因牙槽嵴条件差而导致下颌总义齿固位不良或压痛的惠者25例，使用Sofreliner MS自凝硅橡胶软衬材料在患者口内行义齿衬垫术，于衬垫前和衬垫后1周、1月、3月、6月用花生米比色法分别测定咀嚼效率、HL-Ⅱ型耠力仪测定最大咬合力，用SPSS统计软件进行数据分析。结果患者使用软衬义齿前和使用后1周、1月、3月、6月的咀嚼效率和最大咬合力均有显著差异（P〈0．05），软衬后明显高于软衬前；软衬后6月的咀嚼效率低于软村后3月（P〈0．05）；软村后1周、1月、3月、6月的最大咬合力没有显著差异（P〉0．05）。结论对因牙槽嵴条件差的无牙颌患者配戴的全口义齿，使用Sofreliner MS软衬后可以提高惠者的咀嚼效率，缩短患者对义齿的适应期，尽早发挥义齿的最大咀嚼功能。     

骨性III类错牙合畸形患者正颌手术前后咀嚼肌功能变化的初步研究

目的:应用肌电图仪评价骨性III类错牙合畸形患者正颌手术前后咀嚼肌功能的变化。方法:收集16例骨性III类错牙合畸形需正颌手术病例和20例正常牙合对照组,应用MedelecSynergy肌电图仪分别在静息放松、正中紧咬、前伸、开口、侧方和咀嚼运动时,测定双侧颞肌前束、咬肌和二腹肌前腹的表面募集电位,并计算其肌不对称指数运动。病例组在术后3个月和6个月时重复测定,采用t检验进行统计学分析,并与对照组进行比较。结果:手术前病例组咀嚼肌电位小于对照组,尤以紧咬和咀嚼时差异显著(P<0.05),肌不对称指数与对照组无差异。术后3个月时,部分肌功能恢复,但紧咬和咀嚼时募集电位下降显著(P<0.001),肌不对称指数也增大,提示此时肌功能尚未完全恢复。术后6个月各种功能运动时的募集电位均大于术前水平,肌不对称指数则基本小于术前水平,说明肌功能有所改善。结论:骨性III类错牙合畸形患者手术前咀嚼肌功能弱于对照组,正颌手术矫正了颌骨位置和咬合关系,改善了患者的咀嚼肌功能。     

Analysis of an impedance function of zinc anodic dissolution

Zinc anodic dissolution has been studied by means of electrochemical impedance spectroscopy (EIS). The kinetic study of the oxidation mechanism has allowed us to propose a theoretical impedance function for this system in deaerated sulphate medium. Relevant information on the faradaic process is provided by analysis of the theoretical impedance function. Kinetic parameters of this system can be calculated from the fitting of experimental data to the faradaic impedance function deduced theoretically. The physical measurements of this function are analysed by means of the dependence of simulated EIS spectra on kinetic parameters.