bluuebunny/crossref_metadata_2025 huggingface dataset:
Orbital space‐occupying lesions in Denmark 1974 –1997
Authors: Johansen Sven , Heegaard Steffen , Bøgeskov Lars , Prause Jan Ulrik
Published: March 2003

Purpose: To determine the frequency, distribution according to diagnosis and the recurrence frequency of orbital space‐occupying lesions in Denmark, to determine sex and age of the patients and to establish a national orbital data register.

Methods: All biopsied/surgically removed orbital lesions collected by Danish pathological departments during the period 1974–1997 were identified by SNOMED codes. In addition, in each case gender and age of the patients and number of recurrences were registered.

Results: 965 orbital lesions from 841 patients were identified during the 24‐year period. The incidence of orbital lesions increased significantly over the study period and at present about 80 cases/year are registered. The ratio benign/malignant lesion per year remained constant during the observation period. Lesions in children constituted a total of 152 (16%), the percentage of lesions in children being constant during the period. Malignant tumors comprised a total of 364 (45%) in adults and 34 (22%) in children. Malignant tumors were in adults distributed with 43% primary, 48% secondary invading and 9% metastatic tumors, and in children with 65% primary, 29% secondary invading and 6% metastatic tumors. Normal tissue was only found in 6% of the cases recorded.

Conclusion: A registration of all histologically evaluated orbital space‐occupying lesions in Denmark during a period of 24 years was performed and a national orbital database established. Orbital lesions are rare and primarily benign.
Visually impaired Swedish children. The 1980 cohort study; a 19‐year ophthalmological follow‐up
Authors: Blohmé Jonas , Tornqvist Kristina
Published: March 2003

Purpose: To assess the ophthalmological outcome in a cohort of visually impaired children in a geographically defined area.

Methods: A 19‐year follow‐up of medical records, interview and, if needed, re‐examination of the initial 128 patients, born 1962–1976.

Results and conclusion: Follow‐up was possible in 123 patients (96%); 76 (59%) were still visually impaired, 17 (13%) were deceased, while 30 (23%) had acquired a visual function ≥0.3. The chances of gaining a visual function outside the WHO limits for visual impairment was significantly higher for patients without additional impairments (p=0.0023). The initial ophthalmologic diagnosis remained unchanged in 88%. The diagnoses with improved visual development included albinism and congenital nystagmus, while retinal diseases showed poorer results. An increase in visual function could be seen even in the initially older age‐groups, indicating a maturation of visual function beyond what is usually considered the limit of plasticity of the visual system.
Central retinal vein occlusion and HELLP syndrome
Authors: Gonzalvo Francisco J. , Abecia Emilio , Pinilla Isabel , Izaguirre Lucía B. , Oliván José M.a , Honrubia Francisco M.
Published: March 2003

Purpose: To present a rare case of central retinal vein occlusion in conjunction with the HELLP syndrome.

Methods: A 30‐year‐old woman presented in the 28th week of her second pregnancy with severe pre‐eclampsia with HELLP syndrome; delivery by caesarean section was recommended. Ten days later, the patient complained of severely decreased visual acuity in her right eye.

Results: Ophthalmoscopy revealed a central retinal vein occlusion with venous engorgement and tortuosity, multiple flame hemorrhages, and disc and macular edema. Electroretinography revealed a reduction of b‐wave/a‐wave ratio. Fluorescein‐angiography showed a blockage due to extensive retinal hemorrhages with late mild staining of the walls of veins. The patient presented a spontaneous improvement in visual acuity (0.8 two months after) and a complete resolution of ophthalmoscopic findings.

Conclusion: Ophthalmic complications are possible during and soon after this syndrome. This is the first description of a patient suffering a central retinal vein occlusion during puerperium after the HELLP syndrome.
“With the rule” astigmatism is not the rule in the elderly
Authors: Gudmundsdottir Elinborg , Jonasson Fridbert , Jonsson Vesteinn , Stefánsson Einar , Sasaki Hiroshi , Sasaki Kazuyuki ,   the Iceland‐Japan Co‐Working Study Groups
Published: March 2003

Purpose: To study refractive state and visual acuity in citizens of Reykjavik 50 years and older.

Methods: 1700 persons were randomly selected from the national population census. 1379 could be located and qualified whereof 1045 participated. Evaluation of refraction was performed using Nidek ARK 900 autorefracto‐keratometer. Visual acuity was tested on a Snellen chart.

Results: The prevalence of hypermetropia increases with age by 0.3 D in five years. The prevalence of “against the rule” astigmatism increased on average 5.3% and oblique 3.9% in five years. Analysis of corneal astigmatism measured by keratometer shows an “against the rule” change with age.

Conclusions: Hypermetropia increases by age. The prevalence of astigmatism increases and the axis turns to “against the rule”. The changes in total astigmatism and corneal astigmatism is almost parallel which might indicate that the “against the rule” change is related to changes in the cornea.
Foreign body orbital cyst
Authors: Yazdanfard Younes , Heegaard Steffen , Fledelius Hans Callø , Prause Jan Ulrik
Published: March 2003

ABSTRACT. Purpose: To present the clinical and histopathological characteristics of a retained orbital foreign body.

Methods: A 34‐year‐old male was hit in his left eye by a flower stake. At first examination there was a massive haematoma of the left orbit and eyelids, reduced movement of the left eye and a small conjunctival lesion beneath the upper lid. There were no signs of deeper orbital or ocular lesions. During the subsequent months the haematoma disappeared, but increased proptosis and impaired eye movements with diplopia were noticed. One year after the injury, ultrasound and CT‐scan revealed an ovoid cystic tumour behind the globe. During surgery the content of the cyst appeared purulent and from the centre of the cyst a foreign body measuring 25×13×1 mm was removed.

Results: Microscopy of the foreign body showed the typical structure of a decidual leaf. The superficial cells were empty, whereas the centrally located cells contained remnants of cytoplasm. Confined to the border between the empty and the filled cells, a band of cells containing groups of Gram positive cocci was noted. Staining for immunoglobulins revealed traces of IgG in the superficial empty cells only.

Conclusion: The high degree of preservation of the leaf and the survival of the cocci may be due to a barrier function of the intact plant cell walls with their high content of cellulose.
The effect of systemic hypertension on pulsatile ocular blood flow in diabetic patients
Authors: Esgin Haluk , Alimgil Murat Levent , Erda Sait
Published: March 2003

ABSTRACT. Purpose: To determine the haemodynamics of the ciliary choroidal system in diabetics with or without systemic hypertension.

Methods: 90 eyes of 45 diabetic patients were included into the study. Patients were divided into two groups based on the presence of systemic hypertension. The pulsatile component of the total ocular blood flow in diabetics with or without hypertension was analyzed using ocular blood flow tonograph (OBF Labs, UK). The control group was comprised of 40 age‐matched eyes of 20 volunteers with no ocular or systemic disease. Results were compared with the control group.

Results: Pulse amplitude (PA), pulse volume (PV) and pulsatile ocular blood flow (POBF) were significantly lower (p<0.05) in diabetics without systemic hypertension than the controls. In diabetics with hypertension, although the systolic and diastolic blood pressures were significantly higher than the control group, there was not any statistically significant difference (p>0.05) between PA, PV and POBF results.

Conclusion: POBF was found to be lower in diabetics without hypertension compared to the controls. Such a presence of systemic hypertension may increase the choroidal blood flow in diabetics.
Vitreoretinal surgery in Behçet’s disease with severe ocular complications
Authors: Özertürk Yusuf , Bardak Yavuz , Durmuş Mustafa
Published: March 2003

ABSTRACT. Purpose: To investigate effects of vitreoretinal surgery in Behçet’s disease.

Materials and Method: Vitreoretinal surgery was applied to 26 eyes of 21 patients with Behçet’s disease. Preoperative and postoperative visual acuities, number and duration of attacks, anterior and posterior segment pathologies were evaluated.

Results: The mean age of the patients was 33 years and female/male ratio was 6/15. The mean follow‐up was 23 months. Visual acuity increased in 15 eyes (58%), did not change in 11 eyes (42%). In the postoperative period, there was a significant decrease in mean number of uveitis attacks compared to the preoperative period (p=0.001), as well as a significant decrease in the mean duration of uveitis attacks (p=0.001). In the postoperative follow‐up, intravitreal haemorrhage in 2 eyes (8%), posterior subcapsular cataract in 5 eyes (19%) and corticonuclear cataract in 2 eyes (8%) were observed. Posterior capsular opacification (PCO) developed in 5 of 16 eyes (31%) having ECLE‐IOL. CME continued in 3 eyes (12%).

Conclusion: Vitreoretinal surgery has favourable effect on the visual and anatomic prognosis in Behçet’s patients with severe ocular complications.
Costs of medical and surgical treatment of glaucoma
Authors: Calissendorff B. M.
Published: March 2003

ABSTRACT. Purpose: To compare county costs of medical and surgical glaucoma treatment.

Methods: Medical records of 470 patients who underwent trabeculectomies in 1992 were scrutinized for a period of 3 years before and 3 years after surgery (including the year of surgery). Treatment costs were based on DRG prices, and drug consumption costs on the “defined daily dose” (DDD).

Results: The costs rose steadily during the 3 years before surgery on account of more frequent visits and examinations and increased drug consumption. Mean total cost in the preoperative period was 13,355 SEK and that in the corresponding postoperative period, including surgery, was 23,684 SEK. The number of visits post‐surgery was only slightly reduced, but there was a marked decrease in medication. However, the cost of the drugs was not correspondingly lower. Thirty percent of the patients later underwent cataract extraction.

Conclusion: From a strictly economic point of view glaucoma surgery is not profitable within a 3‐year postoperative period.
Visual impairment in adult people with moderate, severe, and profound intellectual disability
Authors: Warburg Mette
Published: March 2003

Purpose:To assess visual impairment in adults with intellectual disability after de‐institutionalisation.

Patients:The county has a population of 385 483 persons of 18 years and older; 961 were moderately, severely or profoundly intellectually impaired (ID), 837 of them (87 %) participated in the investigation.

Methods:Visual acuity, VA: Østerberg picture charts and reduced copies for near vision could be used in 71% of the patients. Teller preferential looking procedure was applied to people who were unable to cooperate with the picture charts. When examined with picture wall chart VA 0.3‐≥0.10) was found in 10.8%, severe low vision in 1.2% (VA <0.10‐≥0.05), and blindness (VA<0.05) in 3.8%. Poor near vision (<0.3) was present in 19%. Those assessed with Teller acuity cards had poorer vision than the others. It is possible that the low values of assessment with Teller cards represent a combination of gnostic and resolution deficiences, which means that the results of grating VA and recognition VA are non‐comparable.Ophthalmic DisordersThe most widespread medical condition was cerebral visual impairment, the most frequent eye disorders were optic atrophy, high myopia, cataract, and keratoconus.Refraction:Refraction was assessed in 710 persons (85%), the most prevalent cause of visual impairment was uncorrected ametropia. Hypermetropia of >+1.50 was found in 151 of 710 subjects (21%), and spectacles were used by 106 (15%); myopia <−1.0 was present in 213 individuals (30%), 95 persons (13%) had lenses <−1.0.

Conclusion:Resettled adult people with intellectual disability have a high prevalence of treatable visual impairment. A structured scheme of referral to optometric and ophthalmological care is essential if these people are to be given the care to which they are entitled.
Genetic counseling in Leber hereditary optic neuropathy (LHON)
Authors: Huoponen Kirsi , Puomila Anu , Savontaus Marja‐Liisa , Mustonen Eila , Kronqvist Elina , Nikoskelainen Eeva
Published: March 2003

Purpose: To demonstrate the importance of mitochondrial DNA (mtDNA) analysis in the diagnosis of Leber hereditary optic neuropathy (LHON) and illustrate the difficulties in genetic counseling of the disease.

Participants and methods:  Ophthalmological and molecular genetic study of one affected and three unaffected members from a family with heteroplasmic ND1/3460 mtDNA mutation associated with LHON.

Results: The proband had variable amounts of mutant mtDNA in all his tissues studied, ranging from 58% in blood to 92% in subcutis. The mother had an extremely low amount of mutant mtDNA in her tissues, except for hair roots, which contained only normal mtDNA. No mutant mtDNA could be detected in the proband's unaffected sister and maternal aunt.

Conclusions: Despite her minimal mutation load, the mother of the proband has still transmitted a considerable amount of mutant mtDNA to her son, who is severely affected. Although proband's unaffected sister and maternal aunt had no mutant mtDNA, a theoretical risk that they may transmit the disease to their offspring cannot be excluded.
Intravitreal sustained‐release ganciclovir implants for severe bilateral cytomegalovirus retinitis after stem cell transplantation
Authors: Ghosh Fredrik , Hansson Lars‐Jörgen , Bynke Gunnel , Békássy Albert N.
Published: March 2003

Purpose:  To describe the treatment of cytomegalovirus (CMV) retinitis with intravitreal sustain‐release ganciclovir devices in a 16‐year‐old patient in third remission of acute lymphoblastic leukemia after stem cell transplantation.

Methods: The patient received a stem cell transplant from an unrelated bone marrow donor after which he contracted a serious CMV infection manifested in the lungs and retinae. His immune system at this time was almost completely depleted. Implantation of a sustained‐release ganciclovir device was performed in both eyes when retinitis progressed in spite of aggressive antiviral intravenous treatment.

Results: No per‐ or postoperative complications were noted. Infiltrates, hemorrhages and macular edema present preoperatively dissolved over a period of six months. The final visual acuity was 1.0 in both eyes. The patients immune system and lung function slowly recovered during the same time period.

Conclusions: The intravitreal ganciclovir implant provides safe and effective therapy against CMV retinitis, and should be considered in patients acquiring the infection after stem cell transplantation.
Optic nerve hypoplasia: Risk factors and epidemiology
Authors: Tornqvist Kristina , Ericsson Anders , Källén Bengt
Published: March 2003

Objectives: To study the epidemiology of optic nerve hypoplasia.

Design and Methods: Children with optic nerve hypoplasia and visual impairment were identified through the Swedish Register of Visually Impaired Children. Pre‐ and perinatal characteristics were obtained from the Medical Birth Registry and by scrutinizing pregnancy and delivery records. Clinical characteristics of children with optic nerve hypoplasia are described. The following risk factors were studied: maternal age, parity, maternal smoking, gestational duration, birth weight, delivery method, Apgar score, maternal disease during pregnancy, drugs used in early pregnancy.

Results: Young maternal age, first parity, maternal smoking, preterm birth and factors associated with preterm birth were risk factors for optic nerve hypoplasia. There was an indicated association with the use of fertility drugs and antidepressant drugs.

Conclusions: Optic nerve hypoplasia is apparently associated not only with other anomolies, notably of the central nervous system, but also with signs of general disturbance in fetal development.
Detection of retinal neovascularizations using 45 ° and 60 ° photographic fields with varying 45 ° fields simulated on a 60 ° photograph
Authors: Von Wendt Gunvor , Heikkilä Kauko , Summanen Paula
Published: March 2003

Purpose:  To compare the effectiveness of one‐ and two‐field 45 ° and 60 ° fundus photography for detection of retinal neovascularizations (NVEs); to compare the detection of NVEs in macular 45 ° fields centred on the fovea, between the fovea and the disc and with the nasal border along the nasal disc margin with that in standard 60 ° one‐ and two‐fields.

Methods:  Two ophthalmologists assessed red‐free, black and white screening and follow‐up photographs of 58 out of a total 72 patients referred for treatment for NVEs over the 3 year period 1997–99. The assessment included analysis of the numbers, sizes and locations of NVEs identified in different photographic fields defined by a transparent grid placed over two standard 60 ° fields.

Results:  Testing of 45 ° macular fields disclosed 59/81 (73%), 50/81 (62%) and 64/81 (79%), respectively, of NVEs detected in a 60 ° fovea‐centred photograph. Kappa values for detecting at least one NVE, when present, were 0.62 (95% CI 0.40–0.83), 0.38 (95% CI 0.19–0.57) and 0.83 (95% CI 0.62–0.99). The corresponding figures when compared with two‐field 60 ° photography were 59/111 (53%), 50/111 (45%) and 64/111 (58%), respectively. One macula‐centred 60 ° field disclosed 81/111 (73%) of NVEs detected by 60 ° two‐field photography with an additional optic disc‐centred field. Two‐field 45 ° photography disclosed 86/111 (77%) of NVEs detected by two‐field 60 ° photography. A total of 90% of NVEs detected in the optic disc‐centred 60 ° field only were also detected in the corresponding 45 ° field.

Conclusion:  One‐field 45 ° photography cannot be recommended as a screening method for diabetic retinopathy. Two‐field 45 ° photography (macula‐centred and disc‐centred fields) disclosed 77% of NVEs detected by the corresponding two‐field 60 ° photography.
Macular holes: classification, epidemiology, natural history and treatment
Authors: La Cour Morten , Friis Jakob
Published: March 2003

Background:  Macular hole is a retinal disease primarily affecting elderly women. Its overall prevalence in the Danish population is estimated to be 0.14%. The majority of cases are unilateral. The fully developed macular hole evolves through a series of stages starting with an impending hole. About half of impending macular holes regress spontaneously. The remaining half progress to full thickness macular holes. In a patient with a macular hole in one eye, the risk of development of a macular hole in the fellow eye is less than 2% if posterior vitreous detachment is present. If the posterior vitreous is attached, the risk is approximately 15%. If an impending hole is found in the other eye, the risk rises to 50%.

Treatment and outcomes:  Macular hole surgery is able to close full thickness macular holes in approximately 90% of cases. Visual acuity of 20/50 or better can be obtained in approximately half of patients with recent onset of symptoms. Complications include retinal detachment, endophthalmitis, late reopening of an initially successfully closed hole and retinal pigment epithelial abnormalities. Retinal detachment should be expected in less than 5% of cases.
Molecular heterogeneity of fluconazole‐resistant and ‐susceptible oral Candida albicans isolates within a single geographic locale
Authors: Dassanayake R. S. , Ellepola A. N. B. , Samaranayake Y. H. , Samaranayak L. P.
Published: March 2003

The emergence of drug‐resistant Candida albicans in immunocompromised patients is common. A disconcerting aspect of this phenomenon is the rapid emergence of C. albicans strains that are resistant to a widely used azole drug, fluconazole (FLZ). To understand the origin of FLZ‐resistant yeast isolates, we investigated molecular profiles of 20 geographically related oral C. albicans isolates using three genotyping methods: randomly amplified polymorphic DNA‐PCR, with six different primers (OBU1, OBU2, OBU3 RSD6, RSD11 and RSD12); electrophoretic karyotyping by pulsed‐field gel electrophoresis; and HinfI restriction fragment analysis. Of the 20 isolates studied, 10 were FLZ‐ resistant and originated from patients with oral candidosis with a history of FLZ therapy, and the remainder were FLZ susceptible from individuals with oral candidosis, but without a history of FLZ therapy. A composite genotype was generated for each strain by combining molecular types derived from the three independent molecular methods. The composite profiles indicated genetic diversity amongst both the FLZ‐resistant as well as ‐sensitive isolates, and no specific features emerged distinguishing the drug‐resistant and ‐sensitive groups. These observations cast doubt on the theory of a clonal origin of FLZ‐resistant C. albicans isolates.
Difference in neutrophil cytokine production induced by pathogenic and non‐pathogenic mycobacteria
Authors: Fäldt J. , Dahlgren C. , Ridell M.
Published: March 2003

This study shows differences between Mycobacterium tuberculosis and Mycobacterium avium (opportunistic) and Mycobacterium smegmatis (non‐pathogenic), with respect to their abilities to induce cytokine/chemokine release from human neutrophils. Neutrophils incubated with live cells of M. tuberculosis, M. avium, or M. smegmatis produced and released TNF‐α, IL‐6, and IL‐8. No or very small amounts of these cytokines/chemokines were found in resting neutrophils, suggesting that they were newly synthesised. The levels of TNF‐α, IL‐6, and IL‐8 produced/released from neutrophils incubated with M. tuberculosis were markedly lower than those of the opportunistic or non‐pathogenic bacterial species. The production of TNF‐α reached a maximum level at a time (4 h) when the production of IL‐8 had only just started, and this was true for all three mycobacteria tested. However, the time course for IL‐6 production differed between the species, reaching a peak value after 8 h for M. tuberculosis not seen with the other bacteria. It is likely that the relatively high levels of cytokines induced by opportunistic/non‐pathogenic mycobacteria are of importance for the induction of an innate immune response through which these organisms are eliminated, while the low levels of cytokines released by neutrophils interfering with M. tuberculosis might help the bacteria to persist.
GLUT4 expression at the plasma membrane is related to fibre volume in human skeletal muscle fibres
Authors: Gaster M. , Vach W. , Beck‐Nielsen H. , Schrøder H. D.
Published: March 2003

In this study we examined the relationship between GLUT4 expression at the plasma membrane and muscle fibre size in fibre‐typed human muscle fibres by immunocytochemistry and morphometry in order to gain further insight into the regulation of GLUT4 expression. At the site of the plasma membrane, GLUT4 was more abundantly expressed in slow as compared to fast fibres at the same fibre diameter (p<0.01) and the GLUT4 expression increased with increasing fibre radius independently of fibre type (p<0.01). The GLUT4 density at the surface of slow fibres of both diabetic and obese was reduced compared to control subjects at the same diameter (p<0.001). Fast fibres in obese and type 2 diabetic subjects expressed a fibre‐volume‐dependent GLUT4 expression (p<0.001), while this did not reach significance in slow fibres (obese p=0.18 and diabetic p=0.06). Our results show that increasing fibre volume is associated with increasing GLUT4 expression in both slow and fast fibres. Based on the possible dependency of GLUT4 expression on volume, we hypothesize that the reduced GLUT4 expression in obesity and type 2 diabetes may partly be compensated for by physical activity.
Histological examinations of bone and cartilage in the axial skeleton of human triploidy fetuses
Authors: Nolting Dorrit , Hansen Birgit Fischer , Keeling Jean W. , Kjær Inger
Published: March 2003

The aim of this study was to examine histologically bone and cartilage in vertebral corpora of axial skeletons of eight human triploid fetuses, gestational ages 14–25 weeks, CRL 100–200 mm. The results were compared to earlier studies on vertebral development in trisomies 21, 18, 13, and to normal corpora development. After radiography in frontal and lateral projections, the vertebral column was sectioned into cervical, thoracic and lumbar segments, decalcified, dehydrated, and embedded in paraffin. The blocks were serially sectioned in the vertical plane and stained with Toluidine blue and Alcian blue/van Gieson. The radiographic characteristics of the vertebral corpora observed in frontal and lateral projection varied from small cleft vertebral corpora to fusions between the individual corpora. Histological examination of the vertebral corpora confirmed the abnormal pattern of ossification seen radiographically. As a new finding abnormal metachromasia of the ground substance was observed in the cartilage. Marked borderlines were registered in the cartilage between regions with differences in metachromasia. These borderlines were similar but more extensive than borderlines observed previously in trisomies 21, 18 and 13.
Matrix vesicle enzyme activity in endosteal bone following implantation of bonding and non.‐bonding implant materials
Authors: Marshall T. S. , Schwartz Z. , Swain L. D. , Amir D. , Sela J. , Gross U. , Muller‐mai C. , Boyan B. D.
Published: March 2003

The effect of bone bonding (KGy‐Cera) and non‐bone bonding (KGy‐213) implant materials on primary mineralization was examined in endosteal bone repair following marrow ablation. Comparisons were made to determine implant effect on concentration and biochemical parameters of matrix vesicles, as contrasted to vesicles in normal bone healing. Matrix vesicle number was determined by high‐resolution computerized morphometric analysis, and implant effect on the specific activity of alkaline phosphatase and phospholipase AI was measured. Bone responses differed according to the composition of the implant material. The bone bonding implant in this study stimulated matrix vesicle formation, alkaline phosphatase specific activity, and, to a lesser extent, phospholipase A, activity. The effect of the non‐bonding implant on healing bone was of suppression of enzyme specific activities and reduced matrix vesicle production. The results indicate that the bone bonding implant material (KGy‐Cera) promotes the initiation of primary mineralization, whereas failure of the KGy‐213 to bond may be related to toxic materials that leach from the implant and inhibit the normal sequence of events in the mineralization cascade. The results also demonstrate that the implant materials alter the healing process distal to the injury site. Changes observed in the contralateral control limb mimic the changes observed in the injured limb, but at lower magnitude.
Functional adaptation to full‐arch fixed prosthesis supported by osseointegrated implants in the edentulous mandible
Authors: Book K. , KarIsson S. , Jemt T.
Published: March 2003

The objective of the present study was to assess possible adaptive functional changes in the masticatory system after insertion of fixed prostheses supported by osseointegrated implants in the edentulous mandible. Registrations of mandibular movement characteristics and maximal biteforce were performed at insertion and after 1 week, 3 months and 1 year after connection. The duration of the opening and closing phase decreased and maximal biteforce increased significantly (p≤0.05–0.001) from connection of the prostheses to the annual check‐up. However, the process of functional adaptation implied2 identified stages. An immediate phase that occurred within the 1st week, probably due to altered impact from mechano‐sensitive receptors and a later more time‐dependent phase, based on learning and new cortical engrams. Accordingly, the process of adaptation will continue over a long period of time.
Quantitative digital subtraction radiography for the assessment of peri‐implant bone change
Authors: Jeffcoat M. K. , Reddy M. S. , Van Den Berg H. R. , Bertens E.
Published: March 2003

The purpose of this study was to develop a digital subtraction technique to assess periimplant bone change. The method uses subtraction radiography to enhance visualization of the area of change that has occurred between radiographic examinations, and superimposes the area of change on the original radiographs. Furthermore, a reference wedge allows calculation of the mass of the lesion. The method was validated using 21 small bony chips placed on 3 different skulls prior to the first radiograph. The chips were removed, a second radiograph taken, and the images subtracted. A morphologic method was used to isolate the lesion and the change in bone mass calculated. Overall, there was excellent correlation between the calculated lesion mass (mg) and actual lesion mass (r²>0.90). The utility of the method was demonstrated using a case that experienced implant failure. These data indicate that quantitative digital subtraction radiography may be of value in measuring peri‐implant 1 bone change in root form implants.
The macroscopic, microscopic and spectrometric effects of various chemotherapeutic agents on the plasma‐sprayed hydroxyapatite‐coated implant surface
Authors: Zablotsky M. , Meffert R. , Mills O. , Burgess A. , Lancaster D.
Published: March 2003

The purpose of this research was to determine the nature of the residual hydroxyapatite (HA)‐coated implant surface after treatment with various chemotherapeutic modalities, including: citric acid, chlorhexidine gluconate, hydrogen peroxide, tetracycline HCl, stannous fluoride, polymyxin B and a prototype plastic Cavitron tip. Implant surfaces were evaluated macroscopically, microscopically (scanning electron microscopy (SEM)) and spectrometrically (energy‐dispersive spectrometry and X‐ray diffraction). HA‐substrate bond strength and dissolution testing was also performed for surfaces treated with a supersaturated citric acid solution. All treatments left either microscopic residues or a loss of surface roughness when viewed on SEM. A 30‐ to 60‐s application of citric acid left a significantly greater coating thickness than all other treatments, whereas a 3‐min application of citric acid removed significantly more HA than untreated controls. Significant changes in CaiP ratios were seen with most treatments. The clinical significance of this phenomenon is not known. No treatments altered the crystallinity of the residual HA coating. A l‐min application of citric acid did not significantly alter the tensile bond strength of the coating to the substrate. The clinical significance of these findings is not known at present. However. when taken with results from previous studies. it appears that in treating the infected HA‐coated implant surface, a 30‐ to 60‐s application of citric acid (pH 1) may be beneficial in detoxifying the HA coating prior to regenerative procedures. Further in vitvo and in viva studies are necessary to evaluate the biological response to citric acid when used to detoxify the infected implant surface.
Treatment of subgingival implant surfaces with Teflon®‐coated sonic and ultrasonic scaler tips and various implant curettes. An in vitro study.
Authors: Rühling A. , Kocher T. , Kreusch J. , Plagmann H.‐C.
Published: March 2003

Removal of plaque and calculus by means of sonic and ultrasonic scalers causes considerable damage to implants. With a view to avoiding the aggressive effects of these instruments, an experimental study was carried out for which conventional sonic and ultrasonic scalers were coated with Teflon®. The effects of these instruments on implant surfaces was then compared with that of plastic and metal implant curettes. Stereo‐microscopy, scanning electron microscopy and surface profilometry were used to detect and record damage to implant surfaces and changes in surface roughness. Generation and propagation of heat in subgingival simulation of use of sonic and ultrasonic scalers were also recorded by means of temperature measurements at the implant surface. The results revealed that no discernible damage was caused by Teflon‐coated sonic and ultrasonic scalers or implant curettes made of plastic on smooth titanium surfaces. Instrument material residues were found on rough implant surfaces. It was not the intention of this study to provide an analysis of the prerequisites for the cleaning of rough implant surfaces. but rather to determine what type of damage is to be expected when contact is made with smooth and rough surfaces unintentionally. Temperature measurements during the subgingival use of sonic and ultrasonic scalers indicated satisfactory functioning of the cooling system. Coating of sonic and ultrasonic scaler tips with Teflon thus facilitates the use of high‐frequency instruments to achieve professional cleaning of implants.
Digital image processing. II. In vitro quantitative evaluation of soft and hard peri‐implant tissue changes.
Authors: Fourmousis I. , Brägger U. , Bürgin W. , Tonetti M. , Lang N. P.
Published: March 2003

The aim of this study was to evaluate the ability of computer‐assisted densitometric image analysis (CADIA) to detect small changes in mineralized and nonmineralized tissues adjacent to dental implants and to correlate these changes with CADIA values. A section of a pig mandible including all soft tissues and in which a hollow cylinder ITI Bonefit® implant with an artificial mesial and a buccal infrabony defect was placed was used to obtain pairs of standardized radiographs. Series of radiographs were obtained with exposure times of 0.13. 0.20, 0.44. and 0.53 s. Specimens of mineralized or nonmineralized tissues were placed arbitrarily in the defects before each radiographic exposure. The radio‐graphs were captured through a video camera, digitized and stored in a personal computer. Every radiographic image was then subtracted from a baseline one without any change. The result of the subtraction was evaluated with CADIA. A linear correlation (r2=0.99) was found between the bone chips (1–5 mg of dry weight) placed in the mesial defect and the CADIA values. Bone chips in the buccal defect (behind the implant), however, were not detected unless their weight reached 14 mg or more. For conventionally exposed radiographs, it was not possible to recognize soft tissue specimens (1–6 mg), either in the buccal or the mesial defect. However, when “underexposed” radiographs (exposure time: 0.13 s) were obtained, a linear correlation (r2=0.80) was calculated for soft tissue specimens in the mesial defect and CADIA values. In normally exposed radiographs. the CADIA system could detect even the smallest change in bone density (bone chip of 1 mg of dry bone weight) and correlated almost linearly with these changes. Provided that the radiographic images are obtained with standardized geometry and normal exposure time. the tissue density changes detected by this system within bone defects represent only mineralized tissue changes. By underexposing radiographs, CADIA may even reveal soft tissue changes around dental implants.
The use of a connective tissue graft for closure over an immediate implant covered with an occlusive membrane
Authors: Edel A.
Published: March 2003

Complete wound closure over an immediate implant is considered to be a desirable goal. This case report describes for the first time the use of a connective tissue autograft placed under the existing flap margins of an extraction socket to successfully achieve closure over an immediate implant covered with an occlusive membrane. The rationale of the method is described. Healing was uneventful and epithelization of the graft surface from surrounding tissues was achieved. This technique created an increased width of keratinized tissue and avoided the need to disrupt the normal anatomical relationships of the surrounding buccal tissues, in contrast to current techniques. The advantages of the technique, together with factors that may influence healing and predictability, are discussed.
Bridges supported by free‐standing implants versus bridges supported by tooth and implant. A five‐year prospective study.
Authors: Olsson M. , Gunne J. , Ästrand P. , Borg K.
Published: March 2003

The clinical question at issue, whether it is possible to combine implants and natural teeth via fixed bridges, is of current interest. The treatment of the subjects of this prospective study was performed between June 1984 and December 1986. This article presents the 5‐year results of the study. The consecutive patient material comprised 23 patients with Applegate Kennedy Class I residual dentition in the mandible and a complete maxillary denture. All 23 patients were provided with implants ad modum Bråemark in each mandibular quadrant. One side was randomized to rehabilitation with fixed bridge between the distal tooth of the residual dentition and an implant; the other side received a free‐standang bridge on2 implants. The fixture survival rate was 88%. No difference was found between the two sides. Bridge stability was 89% for the implant bridges and 91% for the combination bridges. The change in marginal bone level at the implants was small during the 5‐year follow up period (on average 0.1–0.3 mm) and with no difference between the two sides. In conclusion, it was not possible to demonstrate any higher risk of implant or prosthetic failure for tooth‐implant fixed bridges compared with implant‐supported bridges.
Evaluation of bone density using cutting resistance measurements and microradiography. An in vitro study in pig ribs.
Authors: Friberg B. , Sennerby L. , Roos J. , Johansson P. , Strid C. G. , Lekholm U.
Published: March 2003

A method using cutting resistance measurements during low‐speed threading for identification of various bone densities has been evaluated with regard to its precision and potential. Pig ribs were used as test samples. Differing hand pressure, minor deviation (5") from a vertical tapping direction and individual threading did not reveal any significant differences in cutting resistance values. After implants were inserted into the threaded canals, the total bone as well as trabecular and compact bone areas surrounding the implants were calculated via a computer program and using microradiographs of the bone test samples. The outcome of the cutting resistance measurements was compared with that of the microradiographic technique, and good agreement was observed between the two procedures in the ability to identify bone density. Therefore, cutting resistance measurements may in the future also be used to clinically identify bone qualities in jaws
Evaluation of implant‐supported carbon/graphite fiber‐reinforced poly (methyl methacrylate) prostheses. A longitudinal multicenter study.
Authors: Bergendal T. , Ekstrand K. , Karlsson U.
Published: March 2003

Carbon/graphite fiber‐reinforced poly (methyl methacrylate)(CGFP) has been suggested as an alternative framework material for implant‐supported fixed prostheses. The aim of this study was to evaluate CGFP prostheses clinically over time in patients treated with titanium implants of the Brånemark type and to study the handling of the material in the technical production. Twenty‐five patients were fitted with 27 CGFP prostheses supported by 119 implants. Three implants, all in the upper jaw, were lost after loading. After a mean functioning time of 44 months (range 32–56(, 19 prostheses (70%) were still in situ. In all, 5 prostheses fractured, of which 3 were exchanged whereas 2 could be repaired. The fractures were discovered early after loading and located close to the end abutment cylinders. During the follow‐up period, the bone loss around the implants was about the same as earlier reported values for fixed prostheses with cast frameworks. It is concluded that a CGFP framework can be used to form the biocompatible superstructure of implant‐supported prostheses with high precision at a low material cost and with good aesthetic results. The mechanical properties are so far not satisfactory but the method has the potential to be further developed and standardized.
Supracrestal bone growth around partially inserted titantium implants in dogs. A pilot study.
Authors: Renvert Stefan , Claffey Noel , Orafi Hamed , Albrektsson Tomas
Published: March 2003

8 titanium implants (Nobel Biocare, Göteborg, Sweden) were inserted into edentulous lower premolar areas of 4 dogs so that 6 threads of the implant protruded from the bone crest. Newly‐developed perforated dome‐shaped titanium space maintainers were fixed to the implant with cover screws. Autogenous bone fragments were placed under the space maintainers. On one side of the arch, the space maintainer was covered with a non resorbable cell occluding barrier. The implant/space maintainers were submerged under coronally postitioned flaps. Following a 3‐month healing period, there was a mean gain of new bone amounting to 2.5mm for all specimems. A greater height of bone was found for those sites in which an e‐PTFE membrane was used; 3.1mm vs. 1.9mm (p<0.05). This study demonstrated the potential of coronal bone growth of the alveolar bone in a protected space around screw implants with exposed treads when placed in the dog.
Use of 5‐mm‐diameter implants: Periotest® values related to a clinical and radiographic evaluation
Authors: Aparicio Carlos , Orozco Paulina
Published: March 2003

A modified design of the original Brånemark implant consisting of a cp. Titanium 5.0‐mm‐diameter self‐tapping implant threaded up to the marginal platform has been proposed for specific indications. From February 1992 to November 1995, a total of 185 machined screw implants (Nobel Biocare, Gothenburg, Sweden) were installed in 45 patients to withstand 58 prostheses. Of these, 91 were 3.75mm diameter and 94 were 5.0mm wide. Most of the implants were placed in type B and C bone quantity and type 2 and 3 bone quality. A retrospective evaluation with regard to indications, marginal bone remodelling, Periotest® values (ID) and survival rate is presented. PTv and radiographic measurements were made at abutment connection and repeated 3, 6 and 12 months later and thereafter every year. The follow‐up ranged from 16 to 55 months (mean 32.9 months) post‐loading. Three patients with 8 5.0mm implants dropped‐out of the study at different stages. Out of the wide implants, 1 was expelled during the healing period; 3 were found mobile at the abutment connection; 1 lost its osseointegration suddenly after 2 years of function; 4 belonging to 1 patient did not meet the success criteria due to continuous marginal bone loss. The cumulative success rate of 5.0mm implants (CSR) after 1 year of function was 97.2% for upper jaws and 88.4% in mandibles, whereas the CSR in maxilla after 48 months was 97.2% and 83.4% in mandibles. The obtained PTv from 5.0mm‐wide fixtures in maxilla and mandibles were respectively 1.1 and 0.6 units lower than those obtained PTv for 3.75mm‐diameter implants in the same patients. The hypothesis that there are differences in the damping capacity of the bone surrounding a 5.0mm‐wide implant compared to the 3.75mm‐diameter implant is supported by the PTv results.
Blood‐filled spaces with and without filler materials in guided bone regeneration. A comparative experimental study in the rabbit using bioresorbable membranes.
Authors: Schmid J. , Hämmerle C. H. F. , Fliickiger L. , Winkler J. R. , Olah A. J. , Gogolewskiz S. , Lang N. P.
Published: March 2003

The aim of the present study was to evaluate the effect of natural deproteinized bone mineral on the temporal and spatial pattern of bone formation in a guided bone regeneration model system while using a bioresorbable membrane device. A periosteal skin flap was raised uncovering the calvaria of 20 rabbits. A stiff hemispherical dome made of polylactic acid was placed onto the roughened calvaria and anchored by screws. Prior to placement, the dome was either filled with peripheral blood (control group, 8 rabbits) or with blood and OsteoGraf/N‐300 (test group, 12 rabbits). At 1 month, histologic sections revealed bone regeneration in both test and control domes to various degrees. In the test domes, bone height reached 78%(67–83) and bone volume was 11%(&17), while in the control domes, bone height was 45%(1467) and bone volume 6%(1‐I 1). At 2 months, bone height was unchanged in the test group at 70%(67–83) and bone volume had only slightly increased to 16%(1 l‐2 1). In the controls, height increased to 86%(60–100) and volume to 20%(9–27). Thus, in this model system, natural bone mineral fill contributed to accelerate initial bone neogenesis, while it did not contribute to increasing bone volume or bone height at later observation stages.
Morphological and dimensional changes after barrier removal in bone formed beyond the skeletal borders at titanium implants. A kinetic study in the rabbit tibia.
Authors: Rasmusson Lars , Sennerby Lars , Lundgren Dan , Nyman Sture
Published: March 2003

The aim of the present experimental investigation was to study the morphological and dimensional changes of bone, augmented at titanium implants by a membrane technique, taking place after membrane removal. In 12 rabbits, screw‐shaped titanium implants were inserted in the tibia metaphyses in such a way that 5 threads became uncovered with bone. Surgery was performed on 2 occasions in order to retrieve specimens with different follow‐up times. An e‐FTFE barrier and a titanium device were used to provide space for bone formation. In 1 tibia of each rabbit, the membranes and spacers were removed after 8 weeks of healing, and the implants followed for 16 more weeks. Impressions were taken at day 0 and after 8 and 24 weeks of healing and plaster models were produced. In the contralateral tibiae, implants were inserted either 16 or 8 weeks prior to sacrifice. Measurements were made on the plaster models in 3 dimensions at 3.5 points around each implant in a coordinate measuring machine. Specimens taken 8, 16 and 24 weeks after insertion were analysed by means of light microscopical morphometry. The coordinate measurements showed that, in mean, 1.92 mm of bone had been formed during the first 8 weeks. A statistically significant loss of the height of the newly formed bone (0.70 mm) and thereby reduction of bone volume was found 24 weeks postoperatively. The volume decrease of the newly formed bone was more pronounced beside the implants than over the implant body. The histology showed that woven bone had been formed at the implants after 8 weeks. Further bone formation and remodelling and a net increase of mineralized bone were seen. The degree of bone‐implant contact and bone area in the threads increased with time. The present study showed that coordinate measurements on plaster models, obtained from the experimental areas, in combination with histology, form a useful technique to study long‐term changes of augmented bone. It was found that bone formed by a barrier membrane technique, decreased in volume during a 16‐week follow‐up period after barrier removal. Less dimensional changes were observed for the bone formed over the implant body. indicating that a solid surface may have a stabilizing effect on the augmented bone.