The aim of this study was to determine if edentulous persons could be identified using panoramic images by: I) investigating the possibility of matching two panoramic radiographs of the same person obtained on two different occasions, II) determining what anatomical features are used as the base for matching, III) investigating if oral and maxillofacial radiologists (OMR) and dentists who were not oral and maxillofacial radiologists (NOMR) differed in their ability to match the images, and IV) determining if the time elapsed between the images affected the results or the confidence of the match. Panoramic image pairs from 19 patients obtained on two different occasions were included, plus 10 images from other edentulous patients. The time elapsed between the image pairs varied between 4 months and 6 years. Four OMR and four NOMR were asked to match the image pairs depicting the same patient. The participants marked each match as "certain", "likely", or "possible" and what anatomical structure they used for matching. The OMR group correctly matched 100% of the images and the NOMR group correctly matched 96%. The anatomy of the mandible was most often used for matching. The OMR group was more certain in their decisions than the NOMR group. The time elapsed between the examinations did not affect the result. In conclusion, panoramic images can be used to identify edentulous patients. Both OMR and NOMR could identify edentulous individuals when only panoramic radiographic images were available and the OMR were especially confident in the identification process.

The aims of this study were; i) to determine the accuracy by which two intra-oral radiographic examinations performed on patients with edentulous mandibles treated with dental implants can be matched. ii) to determine whether prosthodontic supra-construction is important for matching. iii) to investigate whether there is a difference between oral and maxilla-facial radiologists (OMR) and dental practitioners, not specialized in oral and maxillofacial radiology (NOMR), regarding their ability to match. The specific features of the radiographs used by the operators to acquire a match were also investigated. Intra-oral radiographic examinations from 59 patients were utilized. Radiographic examinations from 47 patients carried out at placement of the supra-construction and at subsequent follow-up examinations were used as "ante-mortem" and "post-mortem" records respectively. Examinations from 12 patients were added to the "post-mortem" records without "ante-mortem" records being available. The study was divided into two parts. In Part One all "ante"- and "post-mortem" records had the supra-construction masked and in Part Two it was visible. Seven dentists (4 OMR, 3 NOMR) were instructed to specify on what basis each matching was made on the confidence of a three-graded scale OMR had 93.2 % and 98.5 % accuracy in Parts One and Two respectively. NOMR had 63.8 % and 87.9 %. Bone anatomy was the most commonly used feature by OMR to obtain a match. For NOMR it was the appearance of the fixtures. OMR reported higher confidence in their ability to match the examinations. This study indicates that OMR could be a valuable resource in cases of identification where dental implants are a feature of the post-mortem dental records.

Objectives: To investigate whether skill in the interpretation of three-dimensional (3D) information in radiographs utilizing the parallax phenomenon is associated with visual-spatial ability and whether development of this skill is related to visual-spatial ability.Methods: Eighty-six individuals with a median age of 25 years participated in the study. It was organized into three parts: (1) assessment before training, (2) training in object depth localization utilizing parallax and (3) assessment after training. Before training, visual-spatial ability was assessed with a mental rotation test, MRT-A; skill in interpreting 3D information was assessed with two specifically designed proficiency tests: a radiography test, which assessed the ability to interpret 3D information in radiographs utilizing motion parallax and a principle test which assessed understanding of the principles of motion parallax. After training, skill in interpreting 3D information was reassessed. Improvement was defined as the difference between test scores after training and before training. Multiple linear regression was used to analyse the effect of student and training characteristics on proficiency test results and improvement.Results: Radiography test results after training and improvement of radiography test results were significantly associated with MRT-A scores (P < 0.001 and P = 0.020, respectively). Principle test results were high before training and did not improve after training. The test results were associated with MRT-A both before (P = 0.009) and after training (P = 0.003).Conclusions: Understanding of the parallax phenomenon is associated with visual-spatial ability. Development of the skill to interpret 3D information in radiographs utilizing parallax is facilitated for individuals with high visual-spatial ability.

Henriksen [1] did not refute the belief [2] that lack of confidence in the filtration theory [3] may have contributed to the fact that Starling never received full recognition, nor the possibility that oscillating capillary pressure (Pc), capillary pulse pressure (CPP) of vasodilatation [4,5] may facilitate transport of plasma protein [2] by two-pore endothelia (Figure 1) of capillaries. Oddities of protein clearance from plasma (i) might be elucidated by CPP (ii, iii).

Thirty patients with extremely resorbed maxillae had reconstructive bone grafts from the ala iliaca and endosseous implants in a one-stage procedure. The first ten patients constituted a development group and the following 20 patients a routine group. The marginal bone level and implants success rate was evaluated in a prospective long-term follow-up for a minimum of 10 years (10-13 years). Clinical and radiographic examinations were performed at 6 months and then annually up to 5 years. The final examinations were performed at the 10-year follow-up. The bridges were removed at every clinical examination. Marginal bone loss was seen up to the 3-year examination, where it averaged 4.6 mm in the routine group. Between the 3- and 10-year follow-up no significant change was registered. The initial bone loss was probably due to the design of the 3.6 mm conical unthreaded marginal part of the implant. The implant success rate was 83.1% in the routine group. Failures mostly occurred during the first 2 years (14 out of 20). A substantial amount of bone can be gained in patients with extremely resorbed maxillae, when treated with bone graft according to the procedure described in this study.

Objective: To develop a software for virtual reality (VR) simulation of X-ray images based on perspective projections through a patient model derived from data from a CT examination and to evaluate the accuracy in the projection geometry obtained by the software.Methods: A VR software was developed on a personal computer, with models of a patient, an Xray machine and a detector. The model of the patient was derived from data from a CT examination of a dry skull. Simulated radiographic images of the patient model could be rendered as perspective projections based on the relative positions between the models. The projection geometry of the software was validated by developing an artificial CT data set containing high attenuation points as objects to be imaged. The accuracy in projection geometry was evaluated in a systematic way. The distances between two dots, representing the projected test points in the simulated radiographic images, were measured. They were compared with theoretical calculations of the corresponding distances using traditional mathematical tools.Results: The difference between the simulated and calculated projected distances never exceeded 0.5 mm. The error in simulated projected distances was in most cases within 1%. No systematic errors were revealed.Conclusion: The software, developed for personal computers, can produce simulated X-ray images with high. geometric accuracy based on perspective projections through a CT data set. The software can be used for simulation of radiographic examinations.

(2003). Ernest H. Starling and the Nobel Prize. Scandinavian Journal of Clinical and Laboratory Investigation: Vol. 63, No. 4, pp. 315-316.

A total of 30 patients, 10 in a developmental group and 20 in a routine group, with extremely resorbed maxillae were treated with bone grafting from the hip and implant placement in a one-stage procedure. All patients were followed for a minimum of 5 years and were examined regarding the long-term success rate of the implants and marginal bone level. The implant success rate was 74.6% for the whole patient group and 85.8% for the routine group, after 5 years. The marginal bone along the implant surface decreased continuously, up to 3 years and thereafter the bone level stabilized. In the routine group, changes in bone graft dimensions over time were also evaluated by computerized tomography. The mean height of the bone graft postoperatively at all implant sites was 8.3mm. The total mean bone height, including bone graft and residual alveolar crest, was 12.4mm. After 5 years the total bone height had decreased to a mean of 10mm. The mean width of the bone graft was 12mm postoperatively and 8.7mm at the 5-year examination. A substantial amount of bone can be gained in patients with extremely resorbed maxillae, when treated with bone graft according to the procedure described in this study.

Objectives: To identify those bony regions of the glenoid fossa where, due to the inclination, there is an increased risk of radiographic distortion in conventional and computed tomography (CT).Methods: The inclination of the roof and posterior wall of the glenoid fossa was determined relative to established imaging planes. Measurements were performed on 50 corrected coronal MR and 50 axial CT images and 200 sagittal cryosections of 50 temporomandibular joints (TMJs). The location of regions with unfavourable bone wall inclination was identified using the condyle as a reference.Results: The inclination of parts of the fossa roof exceeded the limit for reliable depiction in corrected sagittal and coronal planes in 40% and 8% of the joints respectively. The inclination of parts of the posterior wall of the fossa exceeded the limit for reliable depiction in corrected sagittal and in true sagittal planes in 100% and 84% of the joints respectively. In 84% of the joints the inclination exceeded the limit for reliable depiction in the axial plane. For both bone walls the regions with unfavourable inclination were in the medial part of the joint.Conclusions: The angulation of parts of the roof and posterior wall of the glenoid fossa in relation to established imaging planes makes them highly susceptible to distortion. The oblique coronal projection is well suited for depiction of the roof of the fossa and preferable to a sagittal projection. An oblique axial projection is required for the posterior wall.

Thirty patients with severely resorbed edentulous maxillae underwent combined treatment of iliac bone onlay graft and titanium implants. The patients were followed for 3 years. They were radiographically examined before surgery to evaluate the bone volume at the intended implant sites. Only 13/156 implant sites were suitable for implant insertion. The bone level at the implant surfaces was evaluated after 6 months and 1, 2, and 3 years, respectively. There was a continuing decrease of the bone level throughout the follow-up period with a mean loss of 4.9 mm after 3 years and with no difference between sexes. Twenty-six implants were radiographically examined before removal, and only three of these implant sites showed radiographic signs of failure. The soft-tissue profile was analyzed cephalometrically by the subtraction technique. The upper lip generally moved inward and the apex of the nose and the columella downward and inward. The anterior facial height increased in most of the patients, resulting in a downward and inward change of the lower lip, the mentolabial sulcus, the soft-tissue pogonion, and the soft-tissue gnathion.

Three out of the four Starling pressures were determined at arthroscopy of traumatic effusions of the knee. The range of the joint fluid hydrostatic pressure Pjoint was 5-83 cmH2O (0.5-8.1 kPa, 4-61 mmHg), that of the colloid osmotic pressure difference COPplasma-COPjoint 0-21.7 cmH2O. In 11 of 15 cases the sum Pjoint+COP difference exceeded 32.6 cmH2O (3.19 kPa, 24 mmHg), a high estimate of average capillary pressure at the level of the heart. The number of 'exceeding' cases was 8/15 if only 80% of the COP difference was considered effective. Pjoint and the COP difference oppose filtration of fluid from plasma into joints, indicating that mean capillary pressure, the only Starling pressure not determined, was elevated unless the effusions were being resorbed back into the blood. The findings can be explained by tamponade compensated by arteriolar vasodilatation, suspected to be metabolically mediated.

A new technique for intra-articular injection of a corticosteroid in the temporomandibular joint (TMJ) is presented. The corticosteroid is mixed with contrast medium and the administration visualized and controlled using fluoroscopy. When superior and inferior joint spaces have been filled and the soft tissues of the joint have been identified in the fluoroscopic image, additional corticosteroid can be administered to selected sites within the TMJ.

Cell clusters and tissue fragments in fine needle aspiration and mucosal brush specimens can be studied as paraffin sections by processing sediments in frustoconical cups closed with a fine-meshed net. A 20-microns-mesh nylon net welded into a net piece prevents fragments from escaping from the cups but has hydraulic conductance large enough to ensure proper fluid exchange, provided that during processing the net is kept vertical (cup axis horizontal) and that the shape of the cup promotes fluid exchange. At embedding the cup is turned vertical, and the specimen, in the melted paraffin, becomes enriched by sedimentation at the bottom of the cup. When hardened, the paraffin cone is twisted off the cup by means of the net piece, and the specimen in the top layer of the cone is sectioned.

Osseointegrated implants in 50 edentulous jaws were studied during a 2-year observation period. The implant survival rate was 89% in the maxillae and 97% in the mandibles. The marginal bone loss averaged 1.7 mm in the maxillae and 1.1 mm in the mandibles. Most of this bone loss occurred during the first year. The bone loss was greater in jaws with a preoperatively minor resorption of the alveolar ridge than in those with moderate or advanced resorption. The bone loss was also greater at the medially positioned implants than at those more posterior.

6 Dyck P J. Hypoxic neuropathy: Does hypoxia play a role in diabetic neuropathy ?-The 1988 Robert Wartenburg lecture. Neurology 1989; 39: 111-8. 7 Evans D J, Cashman S J, Walport M. Progressive systemic sclerosis: autoimmune arteriopathy. Lancet 1987; i: 480-2. 8 McLeod J G, Tuck R R. Disorders of the autonomic nervous system: Part I. Pathophysiology and clinical features. Ann Neurol 1987; 21: 419-30. 9 Gledhill R F, Dessein P H M C. Autonomic neuropathy in systemic lupus erythematosus. J Neurol Neurosurg Psychiatry 1988; 51: 1238-40.

In 10 patients referred to arthroscopy with traumatic effusions of the knee, the protein concentration of the synovial fluid (SF) correlated to its colloid osmotic pressure (pi SF). The pi SF did not correlate to the poorly determined hydrostatic pressure (PSF) in extended or slightly flexed joints or to the SF volume (VSF). SF hypoxia correlated to pi SF and to the number of intra-articular erythrocytes, but not to the determined PSF or VSF. SF hypoxia correlated to increase in lactate and decrease in pH, fitting enhanced anaerobic glycolysis. In addition, SF erythrocyte counts correlated to lactate increase. During a 5-min period of high PSF induced by flexion, the PSF decreased, and even more markedly so after the joints had been rinsed with saline. The results suggest that rinsing of joints in order to lower the pi SF and to remove erythrocytes is of benefit in cases of traumatic effusion.

In many types of arthropathy the synovial fluid (SF) oxygen tension and glucose levels often are low and associated with lactdosis which, unless joints are insensitive to the lack of fuel and oxygen, must contribute to joint damage. To such hypoxic-ischaemic changes can contribute quite a number of rheological and other mechanisms and synoial necroses, but also tamponade due to increased SF hydrostatic pressure caused by colloid osmotic forces (π) in SF with a high protein concentration. π in SF can be increased by numerous mechanisms, many of which are active in patients with rheumatoid and other arthropathies. The present compilation shows that the above in a dynamic fashion can be covered by equations elaborated by physiologists.

Analysis of rheumatoid factor (RF) effects according to physiological principles suggests that RF activity may decrease joint swelling by (i) decreasing synovial fluid (SF) colloid osmotic pressure, by increasing plasma viscosity and thereby decreasing (ii) fluid escape from the plasma and (iii) convective flux of proteins into joints, and by decreasing (iv) diffusion of proteins from capillaries (et cetera?). RF complexes raising whole blood viscosity might (v) decrease blood flow. A more significant cause of SF hypoxia and lactic acidosis may be tamponade of synovial circulation created by swelling-induced high SF hydrostatic pressures. Increase of non-RF IgG or monomeric IgM and possibly agammaglobulinaemia could contribute to swelling more strongly than RF's.

In inflammatory joint diseases the protein concentration often is high in the synovial fluid and, in rheumatoid arthritis at least, probably also in the extra-articular connective tissue. This alters the Starling equilibrium. Peculiarities of the circulation of blood and lymph in articular units and basic physiological principles might explain not only why this readily manifests as joint effusions, but also the influence of exercise, movement, immobilization and posture on the activity of non-bacterial synovitides.