P1574 Variation in myocardial work performance after surgical and transcather aortic valve replacement: A pilot echocardiographic study

Funding Acknowledgements

none

Objective

Perioperative myocardial injury occurs after surgical aortic valve replacement (SAVR) as well as after transcather aortic valve replacement (TAVR). The novel non-invasive method for regional LV pressure– strain corresponds well with invasively measured myocardial work (MW) and is independent of afterload compared to ejection fraction and global longitudinal strain (GLS) . In this pilot study, we aimed to compare changes of LV-MW index (MWI) between SAVR and TAVR in the early postoperative period.

Methods

25 TAVR (Corevalve & Symetis) and 25 SAVR (Perimount) patients, scheduled for elective procedures received transthoracic echocardiography studies pre- and 7 days postoperatively. Besides routine measurements the following parameters were analyzed: MWI, global MW efficiency (MWE), global wasted myocardial work (GWMW), GLS and global strain rate (GSR).

Results

In the TAVR group, 17 patients received transfermoral, 8 patients transapical TAVR. As expected, EuroSCORE II was significantly higher in the TAVR group (p = 0.015). GLS was significantly lower (better) in the SAVR group compared to the TAVR group preoperatively (-13.4 + 4.9 vs.-16.7 ± 4.2, p = 0.027). Postoperative GLS increased (worsened) in the SAVR group, though no significant difference was detected between the groups (-12.7 ± 5.1% vs. -10.4 ± 3.4%, p = 0.215) postoperatively. MWI was significantly lower in the TAVR group preoperatively (p = 0.033). Within the TAVR group MWI did not decrease significantly postoperatively (1242 mmHg% vs. 1108 mmHg%, p = 0.476). However, postoperative MWI decreased significantly in the SAVR group (1632 mmHg% vs. 1267mmHg%, p = 0.043). MWE and GWMW did not differ between the groups or within the groups comparing pre- and postoperative values.

Conclusion

Despite better GLS values in SAVR patients preoperatively, we could detect a better preservation of GMWI in TAVR Patients postoperatively. To evaluate the clinical impact of MWI, further studies with larger cohort and correlation with biomarkers of myocardial injury and follow-up assessments are required.

Abstract P1574 Figure. Myocardial work changes after TAVI

P312 Early changes of left ventricular myocardial work performance in patients undergoing coronary artery bypass surgery: off-pump vs. on-pump

Background

Coronary-artery bypass grafting (CABG) without the use of cardio-pulmonary bypass (CPB) was introduced to avoid the potential damaging effects of fpreign surfaces. Nevertheless, the value of off-pump CABG (OPCAB) remains controversial. Regional myocardial work has been shown to reflect regional metabolic demand and provide a more comprehensive assessment of myocardial function. Recently a novel non-invasive method for assessing regional MW by LV pressure–strain loop analysis has been described.

Purpose

To detect changes of MW after CABG comparing off- and on-pump techniques.

Methods

We prospectively evaluated 93 patients undergoing CABG (50 on- vs. 43 off-pump). Patients underwent transthoracic echocardiography exams prior to and one week after surgery as well as concurrently systolic arterial blood pressure measurements at rest. Besides conventional echocardiography parameters, wemeasured global longitudinal strain (GLS), global work index (GWI) and global work efficiency (GWE).

Results

All patients survived surgery. Patients in the OPCAB group had significantly higher EuroSCORE II (3.3% vs. 1.1%, p < 0.001). Preoperatively, OPCABgroup had significantly lower EF (50.1 vs. 55.7%, p = 0.004), lower GWI (1411 vs. 1650mmHg%, p = 0.039) and lower GWE (86.7 vs. 91.6%, p = 0.017). GLS did not differ significantly between off- and on-pump groupspreoperatively. However, postoperatively GLS, MWI, MWE and EF decreased significantly within the on-pump group (p < 0.001, p < 0.001, p < 0.001 and p = 0.002, respectively). In the OPCAB group only GWI and GLSdecreased significantly (p = 0.028 and p = 0.017, respectively). Due to the fact, that mean differences between all pre- and postoperative values were higher in the on-pump group, no significant differences in systolic LV-function (sLVF) could be detected between on- and off-pump patients postoperatively. During the early postoperative phase, no correlation between GWI and GWE and clinical outcomes could be detected, onlylower preoperative-GWI values showed a weak correlation with the incidence of postoperative cardiogenic shock (r= -0.27, p = 0.029).

Conclusion

Despite having worse preoperative sLVF in the off-pump group determined by EF, GLS, GWI and GWE, the decrease in sLVF parameters was significantly higher in the on-pump group, leading to an equal distribution of LV-function parameters between off- and on-pump patients postoperatively. Our results suggest that off-pump CABG provides a better preservation of LV-function.

The Central European GNSS Research Network (CEGRN) dataset

The Central European GNSS Research Network (CEGRN) collects GNSS data since 1994 from contributors which today include 42 Institutions in 33 Countries. CEGRN returns a dataset of coordinates and velocities computed according to international standards and the most recent processing procedures and recommendations. We provide a dataset of 1229 positions and velocities resulting from 3 or more repetitions of coordinate measurements of each site over 4 or more years. The velocity data result from a combination of eight multiyear, partially overlapping networks, using 234 stations of class A of the European Permanent Network (EPN) for alignment to the 'European Fixed' ETRF2000 Reference Frame. The rms (root mean square) of the 8 individual contributions to the combined solution, after a 7 - parameter Helmert transformation, is less than 5 mm in the observation period 1996-2017. This combined CEGRN network maintains the origin coincident with that of the ETRF2000 reference frame to within 1.8 mm rms for the entire period of analysis. The mean positions and velocities of common EPN Class A and CEGRN stations differ by 0.0 ± 1.1, 0.5 ± 1.0 and 0.1 ± 2.7 mm for the coordinates and 0.06 ± 0.13, -0.07 ± 0.12, 0.38 ± 0.28 mm/yr for the velocities respectively for the North, East and Up components at epoch 2010.0.

TAp73 is a central transcriptional regulator of airway multiciliogenesis

In this study, Nemajerova et al. identify TP73, a p53 homolog, as a key regulator of airway multiciliogenesis. They show that mice with TP73 deficiency suffer from chronic respiratory tract infections due to profound defects in ciliogenesis and complete loss of mucociliary clearance and identify the downstream components of TP73 during multiciliogenesis.

Motile multiciliated cells (MCCs) have critical roles in respiratory health and disease and are essential for cleaning inhaled pollutants and pathogens from airways. Despite their significance for human disease, the transcriptional control that governs multiciliogenesis remains poorly understood. Here we identify TP73, a p53 homolog, as governing the program for airway multiciliogenesis. Mice with TP73 deficiency suffer from chronic respiratory tract infections due to profound defects in ciliogenesis and complete loss of mucociliary clearance. Organotypic airway cultures pinpoint TAp73 as necessary and sufficient for basal body docking, axonemal extension, and motility during the differentiation of MCC progenitors. Mechanistically, cross-species genomic analyses and complete ciliary rescue of knockout MCCs identify TAp73 as the conserved central transcriptional integrator of multiciliogenesis. TAp73 directly activates the key regulators FoxJ1, Rfx2, Rfx3, and miR34bc plus nearly 50 structural and functional ciliary genes, some of which are associated with human ciliopathies. Our results position TAp73 as a novel central regulator of MCC differentiation.

[Eye muscle surgery]

Eye muscle surgery is as a rule surgery on healthy eyes. It therefore requires particularly high standards in terms of a lack of complications and predictability of surgical results. Misalignment of the eyes, binocular diplopia and ocular torticollis are all indications for eye muscle surgery as are enlargement of the binocular visual field, asthenopic complaints in heterophoria or the stabilization of binocular functions. Eye muscle surgery is binocular surgery and differs from monocular surgery. It has its own complications and requires specific skills.

Untersuchungen über die Größe, Struktur und Dynamik von Gallensäure/Lecithin-Mischmicellen / Size, Structure, and Dynamics of Bile Salt/Lecithin Mixed Micelles

The structure and size of lecithin/sodium glycocholate mixed micelles was investigated by quasi­ elastic laser light scattering and spin label techniques.

The investigations are in accordance with a bilayer model for these micelles. The order parameter and the phase transition enthalpy of the micellar bilayer were determined.

The lateral and rotational diffusion constants of label molecules are compared with the cor­ responding diffusion constants in liposomes.

[Optic nerve neuritis: from an ophthalmological perspective]

Optic nerve neuritis is one of the most important differential diagnoses of visual loss in young and middle aged adults. The prognosis in terms of functional outcome is generally good. The diagnosis of optic neuritis is clinical. Steroids can reduce the recovery time but do not affect the long-term functional outcome. Magnetic resonance imaging (MRI) is the most important investigation for assessing an associated risk of multiple sclerosis. Optical coherence tomography (OCT) contributes additional details on the course and functional outcome of optic neuritis. In the future OCT may additionally contribute to the relationship between optic neuritis and possible associated multiple sclerosis.

[Optic nerve neuritis]

Optic nerve neuritis is one of the most important differential diagnoses of visual loss in young and middle aged adults. The prognosis in terms of functional outcome is generally good. The diagnosis of optic neuritis is clinical. Steroids can reduce the recovery time but do not affect the long-term functional outcome. Magnetic resonance imaging (MRI) is the most important investigation for assessing an associated risk of multiple sclerosis. Optical coherence tomography (OCT) contributes additional details on the course and functional outcome of optic neuritis. In the future OCT may additionally contribute to the relationship between optic neuritis and possible associated multiple sclerosis.

Pure NOTES sigmoid resection in an animal survival model

INTRODUCTION

The potential to use single-site transluminal access to perform major surgical procedures is limited. In the current study, a pure natural orifice transluminal endoscopic surgery (NOTES) technique was developed for sigmoid resection, with combined transgastric and transvaginal access to the abdominal cavity and assisted by colonoscopy.

METHODS

This experimental study was conducted on a porcine model. Transgastric access was achieved by needle-knife incision and balloon dilation. Colonoscopy was used to maneuver the colon and expose the colic mesentery. Mesocolic dissection close to the bowel was carried out gastroscopically using a coagulating forceps. To prepare the anastomosis, a circular stapler anvil was introduced endoluminally. Subsequently, sigmoid resection was performed using a roticulating linear stapler inserted transvaginally. Bowel extraction was performed by invagination transrectally. After extracorporeal distal linear stapling of the sigmoid, colorectal anastomosis was completed by application of a circular stapling device transrectally. Gastric access closure was achieved using the over-the-scope clipping system (OTSC).

RESULTS

The procedure was successful in all animals, with the operation time ranging from 150 to 270 minutes. The first animal died at postoperative day 5 from peritonitis due to an infected hematoma following spleen injury by an observation trocar. All other animals gained weight postoperatively. Animals were sacrificed after postoperative day 35. The work-up showed complete anastomotic healing and healed gastric closure. The OTSC clip was still in situ in all animals.

CONCLUSION

The presented study shows that pure NOTES resection and anastomosis of the large bowel are feasible. Intraluminal organ manipulation provided excellent organ exposition and rendered one additional access site unnecessary. Transgastric preparation was shown to be safe and effective.

Diagnostic occlusion test in cases of unilateral strabismus sursoadductorius

PURPOSE

To investigate the diagnostic occlusion test (OT) according to Marlow in strabismus sursoadductorius (StS; also known as 'unilateral superior oblique palsy') and its implications for surgical treatment.

METHODS

In 67 cases of StS, angles of strabismus were measured before and after patching the affected eye for three days. Horizontal, vertical and torsional deviations were measured in front of the tangent screen of Harms in nine directions of gaze.

RESULTS

After OT, most cases of StS showed the following distribution of vertical deviation (VD) on horizontal versions: setting the VD in 30 degrees adduction to 100%, VD in primary position (PP) was 50%, VD in abduction 14%, excyclotropia in PP about 40% of the amount of VD. Those StS-cases showing the same distribution of VD on horizontal versions before and after OT were called 'typical' ones (27% of the patients). However, 73% of the patients showed a different distribution before OT: 68% VD in PP, 36% VD in abduction, excyclotropia of 20% in PP. After OT these cases converted to the normal pattern described above: VD in PP was 53 % and VD in 30 degrees abduction was 19%, excyclotropia in PP was 36%.

CONCLUSION

In 'typical' StS-cases, OT is not necessary. 'Atypical' cases, however, can be converted into 'typical' ones: they get more incomitant VD on horizontal versions and greater excyclotropia in PP. As VD in adduction remains almost the same in both groups after OT, surgery can be based on the angle in adduction. In individual 'atypical' patients the amount of oblique muscle surgery has to be modified after OT.

[Pulmonary nocardiosis with trimethoprime/sulphamethoxazole-resistant Nocardia paucivorans in a patient with no signs of immunosuppression]

This is so far the first published case report of a Nocardia paucivorans infection in an immunocompetent patient. A 54-year-old farmer was hospitalised with a history of coughing and fever for a period of five months. There was no indicator of either primary of secondary immunodeficiency in the prior medical history. A chest X-ray showed pneumonic infiltrates in the right middle und lower lobes, which progressed despite of antibiotic therapy with macrolides. A transbronchial biopsy revealed unspecific granulomatous inflammation of soft tissues. N. paucivorans - grew in cultures of sputum, bronchoalveolar lavage, and transbronchial biopsy. Oral antibiotic therapy was started with trimethoprime-sulphamethoxazole (TMP/SMX) and amoxicillin plus clavulanic acid. Susceptibility testing revealed high level resistance to TMP/SMX, which was consequently replaced by ciprofloxacin. Six months later, infiltrates had completely resolved and the patient did not report any residual clinical symptoms. The present case showed once again that nocardiosis is not limited to patients with immunodeficiencies. However, conservative combination therapy with oral antibiotics seems to be sufficiently effective for nocardiosis in the immunocompetent patient. For cases of suspected nocardiosis, a step-wise, risk-based diagnostic and therapeutic procedure is proposed.

[Diagnosis of supranuclear eye movement disorders. Part I: different types of eye movements]

The hallmark of a supranuclear eye movement disorder is a functional impairment of one or several types of different eye movements while other types of eye movements still work. All eye movement information is conveyed via the nuclei of the eye muscle nerves. However, the information for a specific type of eye movement is generated in prenuclear cortical and subcortical areas which are activated depending on the type of eye movement performed. Knowledge about the anatomy of these areas enables us to make a clinical diagnosis or to localize the pathological process to a specific area in many neurological conditions. Examination of eye movements are thus a valuable clinical tool in many neurological and neuroophthalmological diseases. The first part of this two-part contribution presents the different types of eye movements, the concept of neural integration, and prenuclear structures important for horizontal eye movement as well as the pertinent pathology. The second part will appear in the next issue and deals with the cerebral structures that are relevant for vertical eye movements including their pathology.

[Diagnosis of supranuclear eye movement disorders. Part II: Vertical and torsional oculomotoricity]

The hallmark of a supranuclear eye movement disorder is functional impairment of one or several types of different eye movements while other types of eye movement remain unchanged. All eye movement information is conveyed via the nuclei of the eye muscle nerves. However, the information for a specific type of eye movement is generated in prenuclear cortical and subcortical areas which are activated depending on the type of eye movement performed. The structures responsible for vertical and torsional oculomotoricity are described as well as the functional relationship between them. A summary of the development of saccades and movements arising from them is also given and the influence of the cerebellum on oculomotor processes is dealt with. In many neurological conditions knowledge about the areas of the brain relevant for eye movement enables a clinical diagnosis to be made or the pathological process to be localized to a specific anatomical area. Examination of eye movements is thus a valuable clinical tool in many neurological and neuro-ophthalmological diseases.

Naturally processed dermcidin-derived peptides do not permeabilize bacterial membranes and kill microorganisms irrespective of their charge

Dermcidin (DCD) is a recently described antimicrobial peptide, which is constitutively expressed in eccrine sweat glands and transported via sweat to the epidermal surface. By postsecretory proteolytic processing in sweat the dermcidin protein gives rise to several truncated DCD peptides which differ in length and net charge. In order to understand the mechanism of antimicrobial activity, we analyzed the spectrum of activity of several naturally processed dermcidin-derived peptides, the secondary structure in different solvents, and the ability of these peptides to interact with or permeabilize the bacterial membrane. Interestingly, although all naturally processed DCD peptides can adopt an alpha-helical conformation in solvents, they have a diverse and partially overlapping spectrum of activity against gram-positive and gram-negative bacteria. This indicates that the net charge and the secondary structure of the peptides are not important for the toxic activity. Furthermore, using carboxyfluorescein-loaded liposomes, membrane permeability studies and electron microscopy we investigated whether DCD peptides are able to permeabilize bacterial membranes. The data convincingly show that irrespective of charge the different DCD peptides are not able to permeabilize bacterial membranes. However, bacterial mutants lacking specific cell envelope modifications exhibited different susceptibilities to killing by DCD peptides than wild-type bacterial strains. Finally, immunoelectron microscopy studies indicated that DCD peptides are able to bind to the bacterial surface; however, signs of membrane perturbation were not observed. These studies indicate that DCD peptides do not exert their activity by permeabilizing bacterial membranes.

Chemo-mechanical dentine caries removal with Carisolv using a rotating brush

AIM

The aim of this study was to assess the efficacy of removing dentine caries using carbide burs, Carisolv with hand instruments and Carisolv in combination with a new mechanical excavation method using a rotating brush.

METHODS

36 extracted permanent teeth, with dentine caries, were assigned into 3 groups according to caries removal technique. Caries removal was monitored by checking the properties of the dentine with a dental explorer. After embedding and sectioning (400 microm), remaining caries was assessed by using a caries detector. In microscope images (7x) of the samples, the mean stain depth of the remaining carious tissue per tooth was calculated by AnalySIS computer software.

RESULTS

Four to 8 applications (mean time = 10.9 min) of Carisolv were necessary for caries removal with the new method using rotating brushes. The mean thickness of residual dentine caries by this procedure (226 microm, +/- 136) was higher than the one using Carisolv with hand instruments (57 microm, +/- 39) or carbide burs (32 microm, +/- 20). Even in areas with good access to the lesion, an unacceptable amount of residual caries was observed.

CONCLUSION

Thus, it seems that Carisolv using rotating brushes does not reach the degree of caries removal reached by additional mechanical abrasion of Carisolv using hand instruments or conventional rotating carbide burs.

Responder and Nonresponder Analysis for a Caries Prevention Program

To be able to generalize studies, it is important to know whether responders and nonresponders differ significantly. These data are usually not available. To assess whether responders and nonresponders differed significantly, 319 first and second graders in Greifswald, Germany took part in a compulsory dental school examination. Their parents completed a questionnaire on oral health topics and were asked to decide about their children's participation in a school-based caries prevention program plus anonymous scientific evaluation. The 91 children who were not allowed to participate (nonresponders) were older (mean 8.5 years) than the 228 responders (mean 8.1 years; p < 0.001), mostly because of a few older children having repeated a grade. In an age-adjusted analysis, nonresponders exhibited in 21 of 30 indices of higher caries and plaque values, less preventive measures and a lower rate of participation. The difference in caries in the permanent dentition and fluorosis reached statistical significance. This study suggests that nonresponders to caries prevention programs might comply less with preventive measures and exhibit poorer oral health than responders: a result which has to be taken into account in research and prevention programs in the community.

Single or combined oblique muscle surgery in acquired and congenital superior oblique palsy

Oblique muscle surgery with weakening of the inferior oblique muscle alone or in combination with a tuck of the superior oblique tendon reduces in a dose-dependent relationship the vertical deviation in patients with an acquired or congenital superior oblique palsy. Reduction of cyclotropia and the V-sign is less dose dependent.

[Laparoscopic treatment of small bowel obstruction with intussusception, volvulus and appendicitis caused by an inflammatory Meckel's diverticulum]

Indications and contraindications for diagnostic laparoscopy in cases of intestinal obstructions are discussed in connection with a 16-year-old patient's case report with small bowel obstruction including intussusception, volvulus and appendicitis caused by an inflammatory Meckel's diverticulum. The use of diagnostic laparoscopy in cases of intestinal obstructions is controversial. In the described case we performed completely laparoscopically the derevolving and desusception of the volvulus and intussusception, the appendectomy and resection of the diverticulum. The procedure itself and the postoperative course were uneventful.

Kinetic aspects of the formation of aluminium oxide by use of a microwave-induced plasma

The oxidation of thin aluminium layers in a microwave plasma has been investigated to determine the kinetics of oxide growth. Thin Al-coatings were oxidized by means of a variety of gas mixtures, characterized by different partial pressures of oxygen, in microwave-induced plasmas of different power. To study the whole kinetic process the Al-metal and the oxide formed were investigated by means of a combination of grazing incidence X-ray reflectometry (GIXR) and grazing incidence X-ray diffractometry (GIXRD). XPS and FTIR spectroscopy confirmed the formation of stoichiometric Al(2)O(3). The alumina formed is X-ray amorphous. Quantitative description of oxide formation was achieved indirectly by determination of the decrease in the integrated intensity of the Al(111)-peak and the total thickness of the whole coating. These values enabled calculation of kinetic data. It was found that oxide growth was a combination of two simultaneous processes - diffusion and sputter processes. The diffusion coefficient D (cm(2) s(-1)) and the sputter rate S (nm s(-1)) were determined. The effect of the composition of the gas mixture, microwave power, and concentration of activated oxygen species on the oxidation process will be discussed. For calculation of the activation energy, E(A), of this plasma-enhanced diffusion process the temperature-dependence of D was investigated.

Contribution of intraoperative cholangiography to incidence and outcome of common bile duct injuries during laparoscopic cholecystectomy

BACKGROUND

In the present study we examined, in a meta-analysis of the literature, the contribution of intraoperative cholangiography (IOC) to incidence, type, and time of diagnosis of common bile duct (CBD) injuries during laparoscopic cholecystectomy (LC).

MATERIALS AND METHODS

Forty of 2104 reports were enrolled for analysis. In 26 reports we found exact information on type, location and repair of 405 major injuries and in a subgroup examination we selected 103 major injuries with detailed information as to the event and size of CBD injury in association with IOC.

RESULTS

The main incidence of CBD injuries was 0.36%. Using the method of routine IOC the incidence was 0.21% and the rate of diagnosis at the time of cholecystectomy 87% in contrast to selective use of IOC with 0.43% and 44.5%. In 405 cases of major CBD injuries, severe injuries predominated in 83.9% of the cases. Reconstruction with the help of a bilio-digestive anastomosis was necessary in 45.7% of all patients. In 34.8% of the cases a second intervention had to be made in the follow-up of 4 years after LC. The analysis of type, severity, recognition, and follow-up of CBD injuries during LC w/wo IOC showed significant advantages for doing routine IOC.

CONCLUSIONS

The use of IOC can avoid severe types of CBD injuries during LC, increase the recognition at the time operation, and influence the success of repair and outcome of the patients.

[Orbital floor reconstruction. Comparison of a new perforated 0.15 mm thick PDS layer with established titanium dynamic mesh]

INTRODUCTION

For surgical reconstruction of the orbital floor after blow-out fractures, a new perforated PDS (poly-p-dioxanon) foil (0.15 mm thickness) has recently become available. The main target of this prospective and randomized interdisciplinary clinical study was to compare this new PDS foil with the proven titanium dynamic mesh (0.3 mm thickness).

PATIENTS/METHODS

Aside from the common diagnostic procedures, an extensive ophthalmologic examination was performed and documented preoperatively (U1), 4 days (U3), 1 month (U4), and 6 months (U5) postoperatively.

RESULTS

In both groups the surgical procedure was tolerated well. The new perforated PDS foil turned out to be easier to handle intraoperatively because of smooth and clean cutting edges. The surgical treatment was well tolerated in all randomized groups. In contrast to the control group, the PDS and TD groups showed postoperatively a slight increase of the preoperative exophthalmos (mean 0.5 mm).

CONCLUSION

The new perforated PDS foil is comparable concerning cosmetic and functional aspects. Especially with regard to stability after blow-out fractures, the new perforated PDS foil is equal to titanium dynamic mesh up to 20 mm in diameter. PDS foil is felt to be superior regarding bioresorption and due to the more convenient handling.

Effectiveness of a new perforated 0.15 mm poly-p-dioxanon-foil versus titanium-dynamic mesh in reconstruction of the orbital floor

INTRODUCTION

In recent years a new perforated PDS (poly-p-dioxanon) foil (0.15 mm) has become available and has not yet been proven to be successful in reconstruction of the orbital floor after blow-out-fractures in randomized studies. The main aim of this clinical trial is to compare this new PDS foil with titanium dynamic mesh (0.3 mm) (TD), which is well established in reconstruction of the orbital floor.

PATIENTS AND METHODS

In a prospective multicentre randomized trial, conducted between 1997 and 1998, out of 42 patients with fractures of the orbital floor, 28 patients needing material for reconstruction were randomized to receive either PDS foil or TD. In a comprehensive preoperative and postoperative protocol patients were monitored by the surgeon, radiologist and ophthalmologist with a postoperative follow-up of least 6 months.

RESULTS

Maximum defects of the orbital floor were comparable in both groups (PDS group: 13.3 mm, TD group: 13.9 mm). In both groups the surgical procedure was well tolerated, and functional and cosmetic results were evaluated as satisfactory by all patients. Ophthalmological evaluation, performed up to 6 months postoperatively, revealed double vision or vertical strabismus in nine patients (five PDS group, four titanium group). This was not confirmed subjectively in each single patient. Also ex- or enophthalmos, registered in seven patients of the PDS and four of the TD group (mainly + /- 1 mm) were not considered as relevant by the patients.

CONCLUSION

The new 0.15 mm perforated PDS foil was comparable to 0.3 mm titanium mesh concerning functional and cosmetic outcome. Obviously, persisting ophthalmometric disorders were compensated very well in both groups. PDS foil is felt to be the preferred material since it is bioresorbable and more convenient to handle.

The influence of surface configuration on the retention of posts designed for use with a cast-on technique

OBJECTIVES

The combination of an individually cast core and a prefabricated metal post is one of the many techniques to restore endodontically treated teeth. The surface characteristics of commercially available posts vary considerably and likely influence retention. In this study, the surface configuration of 11 castable prefabricated post systems and their retention at the post-cement interface were investigated.

METHOD AND MATERIALS

Scanning electron microscopic photos were made to assess surfaces of the posts. Etchant residues or applied surface layers were also analyzed with an electron beam microprobe. For the retention measurements, 6 posts from each system were cemented in artificial root canals with a zinc phosphate cement. Retention was measured on a universal testing machine.

RESULTS

Analysis of variance and the Ryan-Einot-Gabriel-Welsch F test revealed significant differences in retention between posts; these differences were related to the microstructure of the surfaces of the posts. In general, the coarser the surfaces, the better the retention. Gold plating of the etched surface for one manufacturer resulted in less retention compared to posts of the same type and size that were not plated.

CONCLUSION

The surface configuration of a post could be an important factor when selecting a prefabricated post system.

Caries prevention with chlorhexidine-thymol varnish in high risk schoolchildren

In a prospective, randomised and blinded cohort study, the acceptance and effectiveness of a 3-monthly chlorhexidine-thymol varnish application was assessed in 8- to 10-yr-old children (n=29) with high caries incidence after brushing with a 1.23% fluoride gel. The children of the control group (n=25) brushed with a fluoride gel only. The standardised interview showed good acceptance of the varnish applications in spite of the bitter taste. Caries incidence in one year was 1.2 DMFS (SD 1.5, median 1; 95% confidence interval 0-1) for the test group and 2.1 DMFS (SD 2.3, median 2; 95% confidence interval 0-3) for the control group. Due to a slightly lower reduction in caries incidence (42.3%) than in other studies and a higher standard deviation than in unselected study groups, the power of the present study was not high enough to prove this difference in caries incidence to be statistically significant in the Mann-Whitney test (P=0.11). This was also found for the difference of 0.4 initial lesions. The distribution patterns of caries incidence for tooth groups (70% in the first permanent molar) and surfaces (58% on occlusal surfaces) did not differ between the test and the control group. The reductions of caries incidence which have been found in highly caries active children of the present study should be evaluated further with a larger study sample.

Rotation of Listing's plane with convergence: independence from eye position

PURPOSE

To determine whether asymmetrical vergence results in a rotation of Listing's plane independent of vergence-associated changes of eye position in the orbit.

METHODS

Six normal subjects were required to fixate on a 3x3 array (40 degrees on a side) of light-emitting diodes arranged on a flat screen 124 cm from the subject. Disparity-induced vergence was elicited with a horizontal Fresnel prism (30 cm/m, approximately 17 degrees) placed in front of one eye. In four subjects accommodative vergence (10 degrees to 15 degrees) was produced by placing a minus spherical lens in front of one eye while the other eye was covered. Eye position was measured binocularly using three-axis search coils. Control data were collected without prisms during monocular and binocular viewing. For all data a planar regression was used to fit torsional eye position as a function of horizontal and vertical position to calculate the horizontal and vertical primary positions that define the orientation of Listing's plane.

RESULTS

In the prism experiment, the horizontal primary position of the eye not wearing the prism rotated temporally by 3.9 degrees +/-1.7 degrees compared with the both eyes viewing control condition. The rotation of the prism eye was in a similar range (3.4 degrees +/-2.0 degrees). With accommodation, the horizontal primary position of the viewing eye rotated temporally by 4.4 degrees +/-1.4 degrees compared with the monocular viewing control. In both the accommodation and the prism paradigms there was usually a rotation of vertical primary position downward.

CONCLUSIONS

Vergence-induced changes in Listing's plane can be independent of changes in orbital position associated with vergence. This finding supports a role for changes in central innervation in the elaboration of Listing's law.

[Motor and sensory responses in fusion of vertical disparities in different convergence places]

To study motor and sensory responses in vertical fusion at different angles of horizontal vergence in normal humans.

METHODS

The study included 12 normal subjects. A cross (+) extending 3.4 degrees x3.2 degrees was presented dichoptically. Vertical disparity was introduced by changing the vertical position of the cross in front of one eye. The disparity was incremented by 0.08 degrees every 8 s. Distance viewing was tested with 1 degrees of convergence demand, near vision with 6-15 degrees convergence demand. Eye movements were recorded using three-axis search coils.

RESULTS

Vertical fusion capability was larger at near vision than at distance in 9 of 12 subjects. For the entire group, total vertical fusion capability (motor plus sensory response) differed between distance (mean 1.68 degrees ) and near (mean 2.39 degrees ). The motor component differed significantly between distance (mean 1.42 degrees ) and near (mean 2.13 degrees ). No difference in the sensory component was seen between distance (mean 0.26 degrees ) and near (mean 0.27 degrees ).

CONCLUSIONS

Vertical fusion capability increases with convergence. This increase is mainly due to an increase of the motor response.