Mechanoreceptor activity from the human face and oral mucosa

Summary The feasibility of adopting the microneurography technique (Vallbo and Hagbarth 1968) as a tool to investigate the mechanoreceptive innervation of peri- and intra-oral tissues was explored. Multi-unit activity and impulses in single nerve fibers were recorded from the infraorbital nerve in healthy volunteers. The innervation territories of individual nerve fascicles were mapped. These varied considerably but most fascicle fields comprised the corner of the mouth. Twenty-four single mechanoreceptive units were recorded. Eighteen innervated the skin of the face, and six innervated the mucous membranes of the lips or cheeks. A majority of the mechanoreceptive afferent units were slowly adapting with small and well defined receptive fields. It is suggested that the various slowly adapting responses may originate from two different types of afferent units. No afferents showed response properties similar to typical Pacinian-corpuscle afferents.     

Tactile Sensibility of Single‐Tooth Implants and Natural Teeth Under Local Anesthesia of the Natural Antagonistic Teeth

Introduction and Aim: The term osseoperception describes the capability of developing a subtle tactile sensibility over dental implants. The present clinical study aims at clarifying the question of how far tactile sensibility is to be attributed to the periodontium of the natural opposing tooth of the implant. Material and Method: Thirty‐two subjects with single‐tooth implants with natural opposing teeth were included in this clinical, single‐blind, split‐mouth study. The natural antagonistic tooth of the implant and the corresponding natural contralateral tooth were anesthetized with a locally infiltrated articaine anesthetic. In a computer‐assisted and randomized way, copper foils of varying thickness (0–100 µm) were placed interocclusally between the single‐tooth implant and the natural opposing tooth, and between the contralateral pair of natural opposing teeth in order to investigate the active tactile sensibility according to the psychophysical method of constant stimuli and evaluate it statistically by the Weibull distribution. Results: The average tactile sensibility of the implants with anesthetized antagonists at the 50% value calculated by means of the Weibull distribution was 20 ± 11 µm with a support area (90%–10% value) of 77 ± 89 µm. For the pair of natural teeth, the tactile sensibility at the 50% value was 16 ± 9 µm with a support area of 48.4 ± 93 µm. This resulted in an average intraindividual difference of 3.5 ± 7 µm at the 50% value and 29 ± 93 µm in the support area. The statistical calculations demonstrated an equivalent tactile sensibility (50% value) of the single‐tooth implant and the contralateral natural control tooth with the natural antagonists being anesthetized in each case (double t‐test, equivalence limit ± 8 µm, P < 0.01, power >80%). Conclusion: Apparently, the active tactile sensibility of single‐tooth implants with natural opposing teeth is not only to be attributed to the periodontium of the opposing tooth but also to a perception over the implant itself. This could support the hypothesis according to which the implant may have a tactile sensibility of its own.     

Effects of short-term adaptation to new complete dentures on perception thresholds for interocclusal thickness in experienced and non-experienced denture wearers

Background The ability of patients to discriminate thickness can change with time after the insertion of new complete dentures, and this adaptation may differ according to the experiences of the patients. If so, an education program to reinforce the oral functions may be needed. This study was to evaluate patients’ ability to discriminate thickness by comparing experienced and non-experienced denture wearers after the insertion of new complete dentures. Methods Forty edentulous patients with a skeletal Class Ⅰ jaw relationship without any temporomandibular disturbances were in the study. After insertion of new complete dentures, all patients were tested for discrimination threshold for interocclusal thickness. The thickness perception test was repeated on days 1, 7, and 30 after the insertion of new dentures. The discriminatory ability was assessed with steel and aluminium foils placed between the upper and lower central incisor teeth. The records included the duration of wearing dentures. The data were subjected to statistical analysis of two-way ANOVA, multiple comparison test and Student’s t test.Results Discrimination of tactile ability significantly increased over 30 days in experienced denture wearers as compared with non-experienced patients (P&lt;0.001). The difference in thickness perception threshold was statistically significant between the two groups (P&lt;0.001). Conclusion Adaptation and denture experience can affect thickness discrimination of complete denture wearers.     

马鞍山市志贺菌福氏4c生物亚型生物学特性及感染分析

目的:了解马鞍山市志贺菌福氏4 c生物亚型(F4 c)的流行及分布特点、生物学特性、药物敏感性等。方法:采用常规分离、全自动微生物鉴定系统生化鉴定、血清学试验、刚果红侵袭力检测及Ep i info 2000统计软件分析,掌握福氏4 c生物亚型的生物学基本特性及人类感染统计学数据。结果:从428份标本分离的67株志贺菌中检出福氏4 c生物亚型37株,从45株赠送菌株中鉴定22株福氏4 c生物亚型,分别占检出菌株数的55.2%和48.9%;59株福氏4 c生物亚型的生物学特性与福氏其它血清型别的基本一致,完全符合志贺菌生化定义;侵袭力试验结果显示只有1株福氏4 c生物亚型为阴性,其余均为阳性;福氏4 c生物亚型耐药模式与其它志贺菌血清型存在一定差异;软件统计结果说明福氏4 c生物亚型感染人类具有普遍性,与年龄、性别无差异。结论:志贺菌福氏4 c生物亚型业已成为马鞍山地区志贺菌感染的主要流行株,为进一步掌握F4 c的流行动态,探讨其分子水平的流行状况,将通过分子流行病学方法追溯传染源,以达到将其消灭在初始阶段的目的。     

Directional sensibility of hairy skin and postural control

People can feel and report the direction of very small movements which cause changes in the tension of the forearm's hairy skin. This subjective sensory function may perhaps reflect more fundamental sensorimotor tasks. The hypothesis was investigated by measuring body sway and movement of six female and male volunteers who were performing the tandem-stance Romberg test with open and closed eyes. The increase in sway and movement after eye closure was reduced significantly when the subjects were allowed to use one forearm to touch a spatially fixed object from below. Three objects were used, a solid Perspex rod, an easily rotating steel ball, and a pointed metal peg whose tip was attached to the skin with a droplet of contact glue. Possible mechanical support could be excluded on basis of the objects' technical properties and the magnitudes of forearm movements. Movement of the forearm relative to an object could provide spatial information about changes of the forearm's position in space. Likewise, changes of skin tension that were caused by such movements could be useful. The Perspex rod and the steel ball might provide both types of information. However, the glued peg only caused changes of skin tension, but reduced sway and movement equally effectively. Therefore, information from tension receptors of the forearm's hairy skin underlying the accurate subjective directional sensibility also appears to participate in basic motor control.     

Areola-Nipple Perception Threshold to Faradic Electricity: A New Measure of Sensibility of the Breasts

Background  We describe a new method to study the sensibility of the nipple-areola complex of the breast with faradic electricity delivered through an electromyographic device used to monitor peripheral nerve conduction. Methods  The objective results of faradic pulses (2–50 mA per pulse) delivered to the nipple-areola complex of the breast through a Nihon-Kohden II machine (Evoked potential/Electromyographs, Nihon-Kohden Co., Japan) were evaluated in normal volunteers to get a basal measure that was defined by the patient as “a soft electric discharge.” The measures were recorded and their output discharges averaged (at least 5 to each complex). Results  Twenty-eight volunteers with normal breasts, 28 patients with breast hypertrophy before and after breast reduction, and 28 patients before and after breast augmentation were studied. The faradic pulses were perceived from 1.5 to 3.5 mA in the areola and from 3 to 5.5 mA in the nipple in the control group and from 4.5 to 7.0 mA in the areola and from 6.5 to 9.5 mA in the nipple in the breast hypertrophy group with no significant changes before and after surgery. In the breast augmentation group the faradic pulses were very similar to the volunteers that had normal breasts, but 13 months after breast augmentation with silicone gel prosthesis, a difference was found because all the patients had a higher threshold and three cases had lost sensibility of the nipple-areola complex. Conclusion  In normal breasts the areola had a lower threshold for faradic pulses compared to the nipple. Hypertrophic breasts had a higher threshold to the faradic stimulation than normal subjects in the pre- and postoperative period. Hypoplastic breasts before breast augmentation had a perception threshold similar to that of the normal volunteers but after breast augmentation this perception was much higher. This study received the Scientific Exhibit Award at the ASAPS/ASERF Annual Meeting in Vancouver, British Columbia, Canada, 2005.     

Subjectivity and vulnerability: reflections on the foundation of ethical sensibility

This paper investigates the possibility of understanding the rudimentary elements of clinical sensitivity by investigating the works of Edmund Husserl and Emmanuel Levinas on sensibility. Husserl's theory of intentionality offers significant reflections on the role of pre‐reflective and affective intuition as a condition for intentionality and reflective consciousness. These early works of Husserl, in particular his works on the constitution of phenomenological time and subjective time‐consciousness, prove to be an important basis for Levinas’ works on an ethics of alterity and infinite responsibility for the other person. In fact, it is difficult to understand the core of Levinasian ethics, of vulnerability as proximity, of ethical sensitivity as passivity and a suffering for the suffering of another, without understanding the influence from Husserl's work. Crucially, the paper will, on the basis of Levinasian ethics, establish an understanding of sensibility as vulnerability and receptivity that is fundamental also for understanding significant intuitions in clinical nursing. Clinical sensitivity and carefulness in nursing are shaped by the concrete and also bodily expressions of vulnerabilities in a receptivity that is pre‐reflective and pre‐ontological.     

Assessment of Regaining Pulp Sensibility in Mature Necrotic Teeth Using a Modified Revascularization Technique with Platelet-rich Fibrin: A Clinical Study

Introduction

The aim of the present study was to evaluate the possibility of regaining pulp sensibility in mature necrotic teeth using modified regenerative endodontic procedures by inducing bleeding in root canals and using platelet-rich fibrin (PRF).

Long-term Prognosis of Pulpal Status of Traumatized Teeth Exhibiting Contradictory Results between Pulp Sensibility Test and Ultrasound Doppler Flowmetry: A Retrospective Study

Introduction

In this retrospective study, we investigated long-term (over 3 years) follow-up results of teeth that exhibited contradictory results between the pulp sensibility test (thermal or electric pulp test) and ultrasound Doppler flowmetry (UDF) until 1 year after trauma to inspect the prognosis of the pulp.

原位PCR技术及其应用

目的：阐述原位PCR技术的基本原理，进展，应用及存在问题。方法：通过检索国内，外相关文献，归纳整理，结合实践操作经验，展开分析，结果：原位PCR技术是一种特异性，敏感性较高的靶序列检测定位技术，作为研究基因信息和细胞，染色体等的形态信息的有力工具，尤其是专用原位PCR仪在医学研究（医学检验，病理学领域）上的广泛应用，结论：原位PCR技术的应用推广及研究深入，也存在其技术应用不完善之处。