Diagnostic value of the 2017 McDonald criteria in patients with a first demyelinating event suggestive of relapsing-remitting multiple sclerosis.

BACKGROUND AND PURPOSE: For the diagnosis of relapsing-remitting multiple sclerosis (RRMS), the revised 2017 McDonald criteria include cerebrospinal fluid specific oligoclonal bands as a new criterion for dissemination in time. Amongst other things, one expectation of the new criteria is to marginalize the diagnosis of clinically isolated syndrome (CIS), thus allowing for a faster and at the same time still reliable diagnosis of RRMS. METHODS: In this study, data from an unselected patient cohort with a typical CIS and dissemination in space at a large German Multiple Sclerosis Center from 2013 to 2016 were re-analysed to compare differences in diagnosing RRMS with the 2017 versus 2010 McDonald criteria in everyday practice. RESULTS: Out of a cohort of 290 patients presenting with a typical first demyelinating event, 52% (152 patients) with the diagnosis of RRMS and 48% (138 patients) with the diagnosis of CIS according to the 2010 McDonald criteria were identified. The application of the 2017 McDonald criteria in the same patients increased the number of definite RRMS to 94% (273), thus leaving only 6% of patients with the diagnosis of CIS. The reason for this shift was the presence of cerebrospinal fluid specific oligoclonal bands which was found in 92.7% of the total population and in all patients with 2017 McDonald RRMS. Over a mean follow-up of 1.5 years, 50% of patients formerly diagnosed with CIS who are now RRMS also fulfilled the 2010 McDonald criteria. CONCLUSIONS: Our data support the use of the 2017 McDonald criteria for a more sensitive, but not that specific, diagnosis of RRMS in everyday practice.

Rotational coherent dot movement normalizes spatial disorientation of the subjective visual vertical in patients with rightsided stroke.

Studies in healthy individuals indicate a significant influence of rotating visual motion on judgments of the subjective visual vertical (SVV). Moreover, sensory stimulation manoeuvres like horizontal coherent dot movement significantly modulate horizontal spatial deficits in patients with rightsided stroke. Here, we investigated whether rotational coherent dot movement (RCDM) modulates spatial orientation deficits of the SVV in the roll plane in right hemispheric stroke. We tested the perceptual judgment of the SVV in 20 patients with right-hemispheric, first ever stroke (10 of them with a disorder of the SVV and 10 without a disorder), and 10 healthy, age-matched subjects under three experimental conditions: (1) with a static background of small white dots, (2) with slow clockwise or (3) counterclockwise circular RCDM of these background stimuli. In the baseline condition with static background, the impaired patient group showed a counterclockwise tilt of the SVV. Clockwise RCDM normalized this deficit completely, while with counterclockwise RCDM a slight aggravation was observed. Similar but quantitatively much smaller effects were obtained in the SVV-unimpaired patients and the healthy individuals. These results demonstrate a strong modulatory effect of RCDM on the SVV in patients with a tilt of the SVV due to right-sided stroke. RCDM thus appears to influence higher spatial representations devoted to visuospatial perception of the SVV. Possible mechanisms as well as clinical implications for therapy of visuospatial disorientation (self-orientation in space) after stroke are discussed.

The effect of rotating random dot motion on visuospatial line orientation in patients with right-sided stroke.

Spatial deficits are frequent after brain damage, particularly right hemisphere stroke. Visual judgments of line orientation (LINE) are often impaired after right parietal lesions. Perception of line orientation is an important visuoperceptual component of visuoconstructive capacities. Yet, little is known about modulating factors in LINE and effective treatments are rare for this disorder. Studies in patients with spatial neglect show that horizontal random dot motion (RDM) significantly modulates horizontal spatial disorders, both transiently and permanently after treatment. In the current study, we investigated whether rotational RDM modulates judgements in an oblique LINE task in 20 patients with right-hemispheric first ever stroke (10 of them with a disorder in LINE and 10 without such a disorder), and 10 healthy, age-matched subjects. Subjects were tested under three experimental conditions: (1) with a static background of small white dots, (2) with slow clockwise or (3) counterclockwise circular RDM of these background stimuli, while they performed the LINE task. In the baseline condition with static background, the impaired patient group showed a significant counterclockwise tilt. Clockwise rotating RDM normalized this deficit transiently but completely, while counterclockwise rotating RDM slightly aggravated it, though not significantly. Tilts in the LINE task were significantly correlated with left visuospatial neglect. Similar but much smaller effects were obtained in the spatially unimpaired patients and the normal controls. These results show that rotational RDM modulates deficits of line orientation in patients with right-sided stroke, possibly by influencing higher spatial representations devoted to the perception of oblique lines.

Complete denture displacement following open-mouth reline.

In 21 complete denture wearers, six upper and 15 lower denture relines were performed with the open-mouth technique. The centric relation (CR) was recorded with the Central-Bearing-Point (CBP) method three times before and three times after the reline. For each registration, the right and left condylar position was recorded in three dimensions using a custom-made measuring device. The average denture displacement from an initial reference position (CR) was calculated for each registration. An upper denture reline leads to a mean displacement of 2·5 mm, both in the right and left condylar area. With an average of 2·0 mm, this displacement was smaller following a lower denture reline (right and left mean, 1·6 mm). The precision of the CBP-registrations proved 0·5 mm before and 0·3 mm after reline; hence, the measured condylar displacement after reline could not attribute to a methodological bias. This clinical-experimental study demonstrates that relining complete dentures with the open-mouth technique may lead to a substantial denture shift and thus imply inevitably clinically relevant occlusal discrepancies. It is therefore important to carefully check the occlusion at denture delivery and remount the prostheses if necessary.

Multimodal and multispatial deficits of verticality perception in hemispatial neglect.

Recent evidence suggests that patients with left-sided visuospatial neglect often show deviations in their visual and haptic perception of verticality in the frontal and sagittal plane. However, little is known about the multimodality of these impairments and the relationship between deviations in the frontal and the sagittal plane. Moreover, no previous study has combined investigations of verticality judgments in both modalities and both spatial planes within the same sample of subjects using the same apparatus. Thus, the aim of the present study was to investigate both subjective visual vertical (SVV) and subjective haptic vertical (SHV) judgments in the frontal and the sagittal plane in right-brain-damaged patients with visuospatial neglect (n=16), right-brain-damaged patients without neglect (n=18) and age-matched healthy individuals (n=16) using the same testing device for all tasks. This allowed for direct comparisons of visual vs. haptic and frontal vs. sagittal verticality judgments. Neglect patients showed significant counterclockwise tilts in their SVV and SHV judgments in the frontal plane as well as marked backward (upper end of the rod towards the observer) tilts in the sagittal plane. In contrast, right-brain-damaged patients without neglect and healthy individuals showed no marked deviations in the frontal plane, but small forward (upper end of the rod away from the observer) tilts in the sagittal plane. Moreover, neglect patients showed significantly higher unsigned errors in all tasks. These results demonstrate multimodal and multispatial deficits in the judgment of verticality in patients with visuospatial neglect which are most likely due to an altered representation of verticality caused by lesions of brain areas related to multisensory integration and space representation in the right temporo-parietal cortex.

Visual context modulates the subjective vertical in neglect: evidence for an increased rod-and-frame-effect.

Patients with spatial hemi-neglect display systematic deviations of the subjective vertical. The magnitude of such deviations was shown to be modulated by internal factors mediating the perception of verticality, including head-orientation. The present study investigated whether and how spatial orientation deficits are modulated by external, contextual changes in neglect patients. In a classic rod-and-frame task, we analyzed effects of frame orientation on the subjective visual vertical (SVV) in neglect patients, control patients with left- or right-sided brain damage without neglect and healthy participants. We found that neglect patients, but not brain-damaged control patients, generally display a systematic counterclockwise (CCW) tilt in their SVV judgments. Furthermore, all participant groups displayed a typical rod-and-frame effect (RFE), that is, a modulation of the SVV as a function of frame tilt. However, in the control groups, this modulation was only moderate whereas in the neglect group SVV judgments were substantially and systematically modulated by frame orientation: with CCW frame tilts, the spatial bias of neglect patients increased as a function of the magnitude of the tilt whereas with clockwise (CW) frame tilts, the spatial bias was decreased in case of moderate frame tilts and even reversed in case of stronger frame tilts, resulting in a substantial CW spatial bias. This dramatically enhanced RFE might be caused by a pathologically increased influence of contextual cues on the subjective vertical in neglect patients as a consequence of impaired processing of gravitational information. The results indicate a systematic bias of the subjective vertical along with an impairment of spatial orientation constancy which leads to severe perturbations of subjective space as well as an increased reliance on internal and external cues mediating the perception of verticality in neglect.

The lateral leeway in the habitual intercuspation: experimental studies and literature review.

The habitual intercuspation is used ubiquitous for manufacturing small dental restorations. However, a little is known on its precision. The aim of the present study was therefore to investigate the unambiguity and accuracy of the habitual occlusion in mounted plaster casts from fully dentate persons. Eighty-one fully dentate volunteers, 36 women and 45 men aged 26.8 +/- 6.2 years (18-55 years), with minor fillings and no signs or symptoms of TMD took part in the experiments. Silicone impressions were taken, poured with stone plaster and the obtained casts mounted into Dentatus ARL(R)- articulators using an individual face bow transfer. Subsequently, the models were transferred to a custom-made measuring articulator where the lateral leeway and the accuracy of the hand-held habitual intercuspation were quantified in the condylar area. Measurements were repeated seven times with the upper cast pushed either to the maximum right or the maximum left intercuspation. The hand-held habitual intercuspation of upper and lower cast proved ambiguous in 57% of pairs of casts. The average lateral leeway of the habitual intercuspation in the condylar area was 0.10 +/- 0.05 mm (0-0.51 mm; median 0.07 mm) between the maximum right and left occlusal positions. The average accuracy of three repeated measurements was 0.22 +/- 0.09 mm (0.02-1.17 mm; median 0.16 mm). Natural occlusal surfaces in a full dentition do not guarantee an unambiguous habitual intercuspation of the plaster casts. The described leeway and technical limits might be possible causes for occlusal adjustments that are sometimes necessary when inserting restorations manufactured in habitual intercuspation.

[Design and testing of a novel measuring system for use in dental biomechanics--principles and examples of measurements with the hexapod measuring system]. / Aufbau und Erprobung eines neuartigen Messsystems für die dentale Biomechanik--Messprinzip und Beispielmessungen des Hexapod-Mess-Systems.

A novel measuring set-up based on a hexapod system for use in dental biomechanics is described. It was specially developed to measure force/deflection characteristics of different dental materials and devices. The functionability and suitability of the system for use in experimental biomechanics were investigated in two different studies. In a first study the micro mobility of prosthetic telescopic crowns prior to and after simulated wear was determined to investigate the influence of wear processes on the stability of the anchorage elements and thus of prostheses. This study investigated the ability of the setup to load a specimen with high forces or torques of up to 100 Newton. The second study looked at the force/deflection characteristics of orthodontic anchorage pins used in orthodontics to additionally stabilize the anchorage unit, for example during molar movement. In this study specimens were loaded with small forces of less than 10 Newton, as are typically used in orthodontics. Using the setup, the deflection behaviour of these devices under high and low loading was measured at a resolution of approximately one micrometer or one angular second.

Functional impression and jaw registration: a single session procedure for the construction of complete dentures.

The conventional fabrication of complete dentures involves two separate clinical sessions for functional impression making and jaw registration. The presented method combines both procedures in one session. The aim of this study was to survey the three-dimensional tooth positions in complete dentures with reference to the ridges to establish arbitrary guideline values that could be used for the manufacturing of tooth-position analogue plastic rims on functional impression trays. New complete dentures were fabricated by supervised undergraduate students in the conventional manner for 104 edentulous patients. The position of the maxillary teeth was surveyed in the horizontal plane using the Schmuth 'vizor-measuring plate'. The vertical dimension of occlusion, represented as the distance between opposing ridge areas of the dentures in maximum intercuspation, was measured at different sites by means of a Gutowski gauge. The tooth positions on the dentures varied widely, e.g. the horizontal distances between the incisive papilla and the maxillary incisors was 7.1 +/- 2.3 (3-14) mm. The vertical dimension of occlusion, which is most important in the jaw registration, varied equally with an anterior inter-alveolar distance between 12 and 33 (20.4 +/- 4.0) mm. Arbitrary moulding of the tooth position-analogue plastic rims does not seems to be an ideal method of pre-shaping functional impression trays, because the individual anatomical variation is considerable. Alternatively, the horizontal and vertical tooth positions of functionally and aesthetically pleasing dentures should be measured to pre-shape the rims of functional impression trays in the maxillary and the mandibular jaw. Such trays are a valuable tool for functional impressions and an immediate preliminary jaw registration in the fabrication of new complete dentures. This method allows a first try-in of the full set-up in the third clinical visit without loosing precision.

[Development of a periodontium-approximated specimen holder for attrition studies of telescopic crowns]. / Entwicklung eines parodontienadäquaten Probenhalters für Verschleissuntersuchungen von Teleskopkronen.

To enable attritional studies on telescopic crowns, a specimen holder has been constructed that is intended to simulate, in zero approximation, the biomechanical properties of abutments bearing telescopic crowns. The specimen holder consists essentially of a system with two metal "concertinas" with different elasticity constants reflecting the different biomechanical parameters for periodontium and bone. The biomechanical processes in the periodontium are too complex to be simulated accurately in vitro. Nevertheless, the specimen holder described here enables the forces acting during insertion and removal of a partial denture to be accommodated elastically in the angular and axial directions, to simulate the possible degrees of freedom of the abutments in situ. In this way, the unavoidable errors of specimen fixation are rendered tolerable, so that local preferential wear is decisively reduced.

Accuracy of check-bite registration and centric condylar position.

In a dentate subject a jaw relation can either be determined in maximum intercuspation and is as such given by the occlusal morphology, or the mandibular position can be allocated according to the centric position of the condyles. For comprehensive restorative treatment or analytic measures of the occlusion it is important to record the centric condylar position. Various registration methods have been described in the literature, but there is no consensus on which is the 'best'. The aim of the present study was therefore to assess the accuracy of various registration methods and evaluate a possible influence of the used materials. Four dentists were involved in the clinical part of the study, another was responsible for the measurements. Impressions were taken from 81 fully dentate volunteers. The casts were mounted by face-bow transfer and central-bearing-point (CBP) registration into Dentatus articulators. Subsequently the centric condylar position was determined with six different methods and materials, respectively. Each method was reproduced twice so that a total of 18 registrations was performed per patient. The mandibular positions which resulted from the individual registrations were then repeatedly compared in the condylar area using a computer supported specially modified measuring articulator. The accuracy was found best for the unrefined wax wafer registration (x=0.33 mm) and with an average of 0.44 mm worst when using acrylic wafers. The CBP and frontal jig methods as well as tin-foil and refined wax wafers showed an accuracy in-between these boundaries. The biggest measured mandibular displacement between any two registrations were considerably 2.0 mm. However, the described differences in accuracy between the various methods and materials proved statistically not significant. All investigated jaw registrations showed an accuracy of about 20 times the tactile fine sensibility of natural teeth which has to be taken into account when inserting fixed prosthetic restorations in centric condylar position. Despite meticulous clinical and technical procedures small occlusal adjustments are therefore almost unavoidable.

Studies of changes in occlusion after the insertion of complete dentures (part II).

The aim of this clinical experimental study was to investigate whether, and what, changes in occlusion occur between 3 weeks and 1 year after insertion of complete dentures. Twenty-six edentulous patients, who already had their jaw relation registered for part I of this study some 357 days before, were re-examined. The same special non-arcon measuring articulator was used for determination of any positional differences between the presently recorded central condylar position with inter-occlusal gap and the equilibrated intercuspal position, from approximately 1 year previous. Differences were recorded electronically in the condylar area in three dimensions. The position of the condylar balls of the measuring articulator in maximum intercuspation had shifted, since the previous recording, by about 0.62 +/- 0.04 mm (0.04-1.76 mm) in the sagittal and 0.89 +/- 0.72 mm (0.01-3.06 mm) in the vertical direction. Whereas the differences measured in maximum intercuspation scattered in the sagittal plane uniformly around the centric condylar position, in the vertical plane they were shifted cranially about an average of 0.77 +/- 0.85 mm (1.06 mm caudally to 3.06 mm cranially). The results indicate that in half of the patients from the present sample the occlusion did not remain stable, which is assumed to be mainly caused by resorption of alveolar bone and abrasion of the acrylic teeth. Therefore, at each check-up visit not only the health of the denture-bearing tissues and the fit of the dentures, but also the mandibular posture and the occlusion should be examined carefully.

Studies of changes in occlusion after the insertion of complete dentures. Part I.

The present study aims to investigate changes in the occlusion of complete dentures after their insertion. A total of 85 edentulous patients were provided with new complete dentures. Their individual hinge axes were determined using mechanical axiography and the upper finished dentures were transferred by facebows to Dentatus articulators. The lower dentures were mounted according to an intraoral central bearing point (CBP) registration and equilibrated in terminal hinge position. An articulator specially modified for measurements in the condylar area was used. The differences between the positions of the condylar balls with CBP registration and those after equilibrating the occlusion were determined. On average, 19 days after insertion, 71 patients took part in a follow-up examination. As in the first session, the terminal hinge position was registered with the CBP method using the apex of the Gothic arch. Thus, the positions of the condylar balls immediately after the new registration could be compared with those in equilibrated intercuspation 3 weeks earlier. The differences were found to be 0.5 +/- 0.4 mm (0-2.9 mm) in the three axes (sagittal, coronal and horizontal). They are thought to result from settling into the denture bearing tissues and also from neuromuscular adjustment of the masticatory system. Compulsory remounting of complete dentures after insertion is therefore recommended.

Studies on adaptation to complete dentures. Part II: Oral stereognosis and tactile sensibility.

High oral perception is thought to contribute to poor adaptation to new dentures. The aim of this study was to evaluate the oral stereognosis and tactile sensibility in edentate subjects and relate these to patient age and capability of adaptation to new prostheses. A total of 67 patients were provided with new complete dentures 2-3 weeks before the experiment. In 54 subjects, the oral stereognosis was evaluated by 12 different test-pieces, which were placed unseen on the tongue and had to be recognized. In 38 patients, the oral tactile sensibility was determined in the premolar area using copper foils. The capability of adaptation was evaluated by a questionnaire. Denture retention was assessed by clinical examination. The number of correctly identified test-pieces and the average identification time were related to the age, but no relation was found to patients' capability of adaptation. The tactile sensibility was found to be impaired with age and diminished capability of adaptation. Both adaptation and oral tactile sensibility were significantly lower in subjects with poor lower-denture retention. In conclusion, the results cannot support a relationship between high oral stereognosis and adaptation problems. However, good denture retention facilitates the adaptation process.

Comparative studies on check-bite and central-bearing-point method for the remounting of complete dentures.

Thirty-six complete dentures were remounted both with check-bite as well as central-bearing-point (CBP) registration. The mandibular or denture position was registered in the condylar area three times with each method. Two independent operators carried out the registrations. One half of patients had their occlusion equilibrated according to the check-bite registration, the other half in the central-bearing-point position. After individual determination of the hinge axis the upper dentures were mounted by a face-bow transfer into a Dentatus articulator. A total of six registrations was performed and repeatedly compared in the condylar area in three dimensions using a computer supported measuring device. The reproducibility of the check-bite registration was 0.37 +/- 0.33 mm, with a maximum of 1.77 mm. For the central-bearing-point method this was 0.29 +/- 0.26 mm with a maximum of 1.56 mm. The mean difference in condylar position between both methods was 0.66 +/- 0.55 mm with a maximum of 4.02 mm. A third independent operator re-examined 30 of the patients 2-3 weeks after the remounting and evaluated the adaptation to the new dentures. Those patients whose dentures were equilibrated with the central-bearing-point method tended to cope better with their dentures and suffered on average from fewer pressure spots.

[The intraoral determination of the sagittal condyle path inclination during face-bow recording]. / Intraorale Bestimmung der sagittalen Kondylenbahnneigung während der Gesichtsbogenübertragung.

In a clinical trial involving 40 fully dentate persons, three different intraoral procedures to determine the sagittal condyle path inclination were checked for accuracy. In each test person the condyle path inclination was determined three times, i.e. by the central bearing point method, the protrusive check-bite method and by a protrusive bite record integrated in the bite fork. At 5 mm of protrusion the reproducibility of the results obtained with the central bearing point method (mean value 2.1 +/- 2.0 degrees) were far better than that with either of the two other methods; the difference was statistically significant. The protrusive check-bite records and the protrusive bite fork records did not differ from each other as far as their accuracy was concerned (mean values 3.6 +/- 2.1 degrees and 3.4 +/- 1.6 degrees, respectively). The mean value of the condyle path inclination to the hinge axis infra-orbital plane in the sample was about 50 +/- 8 degrees regardless of the method used. Thus, protrusion records can be integrated in the face bow transfer.

[The reproducibility of the manual checkbite in the wearers of complete dentures]. / Reproduzierbarkeit der Handbissnahme bei Totalprothesenträgern.

Thirty-six new complete dentures were remounted by means of check bite records at the time of placement. The mandibular position was recorded three times in each patient by two clinicians using Bite Compound, a thermoplastic material, for the records. After individual transverse horizontal axis localization, the dentures were mounted in an articulator, and subsequently three-dimensional, electronic and computerized measurements were made with a special measuring instrument. In intraindividual comparison the reproducibility of the check bite records resulted in a mean value of 0.37 +/- 0.33 mm, whereby maximum deviations of up to 1.8 mm were observed. Repeated insertion of the maxillary dentures into the hardened impressions of the thermoplastic compound led to an error of 0.04 +/- 0.06 mm. The results of the two clinicians differed only slightly.

[The reproducibility of arrow-point registration in full-dentition subjects depending on the recording material]. / Reproduzierbarkeit der Pfeilwinkelregistrierung bei Vollbezahnten in Abhängigkeit vom Registratmaterial.

The reproducibility of the intraoral central bearing point method was measured in 46 dentate subjects with a healthy stomatognathic system. Nine complete registrations were carried out on each volunteer, while three different materials were used for fixing the upper to the lower jaw. The occlusal records were examined in the condylar area on a specially designed articulator. Two therapists took part in this study. The shifts of the condylar spheres in all three spatial directions were found as follows: Ramitec 0.14 +/- 0.16 mm, Super-Bite 0.15 +/- 0.14 mm and Bite Compound 0.15 +/- 0.16 mm. The movements of the condylar spheres in space were calculated. They amounted to 0.28 +/- 0.23 mm when using Ramitec, 0.28 +/- 0.20 mm when using Super Bite and 0.31 +/- 0.23 mm when using Bite Compound. Statistically, the differences between the data of the three materials were not significant. Also, the results of our random sample were independent of the therapist.

[The reproducibility of the abutment angle recording in the remounting of complete dentures]. / Reproduzierbarkeit der Pfeilwinkelregistrierung bei der Remontage von Total-Prothesen.

Upon insertion, 40 newly made full dentures could be remounted three times in succession by each of two therapists by means of the intraoral central bearing point method. The records were measured electronically and by computer in a special measuring articulator in the right and left condylar area. The shift of the condylar spheres in the three different records was smaller than about 0.3 +/- 0.2 mm in all three spatial directions. From this we calculated the movement of the spheres in space to be about 0.5 +/- 0.3 mm. The results of our random samples were independent of the therapist, the patients' age or sex, the period for which the patients had been edentulous, the sliding of the dental prostheses on the tegmentum or the anatomical shape of the alveolar ridges.

[Adhesive strengths of cast crowns with various types of cements]. / Haftkraft von Vollgusskronen in Abhängigkeit vom Befestigungszement.

In an in vitro study the adhesive strength of sand-blasted castings (gold alloy) was tested on human teeth prepared and finished in different ways. For cementation we used two glass ionomer and one phosphate cement. On the surfaces treated with carbide finishing instruments the force required for separating the crown from the tooth was about 1.9 N/mm2 for Ketac-cem, about 2 N/mm2 for Fuji Ionomer, and about 1.8 N/mm2 for Harvard (a zinc oxide phosphate cement). Compared with this, the values obtained for dentin surfaces pretreated with fine diamonds (red ring) were 1.5 N/mm2 for Ketac-cem, 1.6 N/mm2 for Fuji Ionomer, and 1.9 N/mm2 for Harvard. The measured differences between the various types of cement were statistically not significant.