1/42. Reactions and complications after the implantation of Endobon including morphological examination of explants.In the study described here, the integration of hydroxyapatite (HA) ceramic implants (Endobon) was investigated. These implants have an interconnecting system of pores and are free from foreign protein. The material is not toxic, genotoxic, nor zytotoxic, and it is biocompatible. The progress of integration was investigated by means of clinical and radiological check-ups. From 10 patients, it was possible to obtain samples for histological analysis during a second operation (e.g., metal explantation). Microscopic examination showed bony integration with newly formed bone in direct contact with the HA ceramic; it also showed osteoblasts and osteoid seams. No second operation took place earlier than 4 months after the first operation, yet even after this relatively short period, bony integration was already evident. Clinical observation (based on x-rays, reports of pain, signs of inflammation) showed that in most cases healing was taking place without complications. More general operational complications such as thrombosis or nerve injury were observed in 4 patients. If the implant is not sufficiently protected from mechanical stress, bony integation will not take place, and the implant may fracture. HA ceramic, with a porosity between 30% and 80%, is not comparable to cortical bone but only to spongy bone. This factor must be taken into account when deciding whether a HA ceramic implant is indicated.- - - - - - - - - - ranking = 1keywords = sample (Clic here for more details about this article) |
2/42. Multiple extraction patterns in severe discrepancy cases.Thirty-five cases have been collected from colleagues which illustrate that removal of additional maxillary teeth, following first bicuspid extractions, can allow the successful resolution of difficult discrepancy and anchorage cases. charts 1 and 2 describe the amounts of space that might be expected by removal of additional upper bicuspids, upper first molars, and upper second molars. The findings on upper second molars are admittedly limited. Anchorage values as expressed by an efficiency percentage were approximately what would be expected from a study of anchorage values of the roots of teeth. The removal of upper second bicuspids has a better anchorage efficiency potential than the upper first molar, but this may be overcome somewhat by the greater size of the molar. Clear guidance cannot be given as to which teeth to remove in a specific case, but it is the observation of the author that for cases that are still in full Class II following four bicuspid space closure, upper second bicuspid removal would be more helpful from an anchorage perspective, whereas for cases that are in end-to-end molar relationship or require only a few millimeters to move into Class I, the upper first molar might be the tooth of choice. Also, the supper first molar removal allows for a more "normal" appearing arch assuming normal alignment and size of the upper second and third molars. The comparison with the nonextraction control group showed an enormous difference in the amount of incisor retraction that extractions provide when related to the maxilla. The nonextraction control group, though experiencing dramatic correction of Class II relationships, showed no incisor movement within the maxilla. Some problems which appeared in the sample were described. Removal of upper teeth in addition to the four first bicuspids can be a solution to an occasional anchorage, skeletal, growth or cooperation problem.- - - - - - - - - - ranking = 1.5779856518391keywords = sample, size (Clic here for more details about this article) |
3/42. Higher osteoclastic demineralization and highly mineralized cement lines with osteocalcin deposition in a mandibular cortical bone of autosomal dominant osteopetrosis type II: ultrastructural and undecalcified histological investigations.In this study we report on histological and ultrastructural investigations of the mandibular cortical bone in a case of autosomal dominant osteopetrosis type II complicated by mandibular osteomyelitis. Histologically, there was a marked increase in the number and size of osteoclasts on the inner bone surface. An undecalcified preparation showed a pair of deeply stained (highly demineralized) and stain-phobic (highly mineralized) layers on the bone surface just beneath the osteoclasts. The layers were incorporated into the bone matrix during the remodeling process as thickened cement lines. A contact microradiogram of the cortical bone revealed highly mineralized layers at the cement lines, which were closely correlated with immunohistochemical evidence of deposition of osteocalcin at the thickened cement lines. Ultrastructural examination showed that the osteoclasts had a typical clear zone, but they were deficient in ruffled border formation and had numerous lysosomal vacuoles containing dense substances. An electron-dense amorphous material layer was present on the bone surface just beneath the osteoclasts as well as at the cement lines. The layer was partly composed of a short fibrillar material, and it partially revealed the lamellar structure. Consequently, an osteoclastic malfunction might be primarily involved in the process of bone matrix resorption rather than demineralization, resulting in higher demineralization and abnormal material deposition on the bone surface and at the cement lines. Furthermore, evidence of active osteoclastic bone resorption with a brush border formation at the bone involved in the inflammatory lesion in this case suggests that the osteoclastic malfunction is influenced and recovered by a microenvironment such as inflammatory cytokines.- - - - - - - - - - ranking = 0.28899282591954keywords = size (Clic here for more details about this article) |
4/42. hypercalcemia induced with the plasma levels of parathyroid hormone-related peptide in multiple myeloma.A 69-year-old man visited our department of neurology with symptoms of paresthesia on the lower extremities and lumbago. Biochemical examination of serum samples showed hypercalcemia (serum concentration 15.6 mg/dl). The levels of intact parathyroid hormone (i-PTH) and 1,25-dihydroxyvitamin D were suppressed, whereas parathyroid hormone-related peptide (PTHrP) was elevated up to 5.4 pM (normal range: below 0.6 pM). Additionally, bone survey revealed a punched-out lesion in radiological examinations of the skull. bone marrow aspiration demonstrated many atypical plasma cells suggesting multiple myeloma. Nephrogenous cyclic adenosine monophosphate (cAMP), urinary deoxypyridinoline, plasma interleukin 6 (IL-6) and transforming growth factor beta (TGF beta) concentrations were elevated, whereas % of renal tubular reabsorption of phosphate (%TRP) was decreased. The immunohistochemical results demonstrated the expression of PTHrP in atypical plasma cells. These data indicated that hypercalcemia complicating multiple myeloma causes an elevation of renal calcium reabsorption and an increase of bone resorption mediated by PTHrP action.- - - - - - - - - - ranking = 1keywords = sample (Clic here for more details about this article) |
5/42. Anterior open-bite malocclusion: stability of maxillary repositioning using rigid internal fixation.A retrospective cephalometric study was performed to investigate the stability of 37 non-growing anterior open-bite cases using mini-plate rigid fixation. The sample was divided into two groups: Group A: maxillary repositioning alone (17 cases) and Group B: bimaxillary surgery (20 cases). Tracings were performed pre-operatively (T1), immediately post-operatively (T2) and at a minimum of one year follow-up (T3) (12-90 months). In Group A, the maxilla was advanced (3.8 /- 2.8 mm, p < 0.01) and superiorly repositioned at PNS (2.8 /- 2.3 mm, p < 0.001). In Group B, the maxilla was advanced (3.5 /- 3.0 mm, p < 0.01) and superiorly repositioned at PNS (3.7 /- 1.8 mm, p < 0.001); and the mandible (11.7 /- 3.8 mm, p < 0.001), with no significant change in the vertical plane (p > 0.05). Late relapse due to condylar remodelling or resorption was found as a cause of large horizontal relapse (8.0 < x < 14.0 mm) in three cases (15%), the amount being associated with the amount of operative advancement (r = 0.7, r-sq = 40%, p < 0.01). It was concluded that the correction of anterior open bite by posterior repositioning of the maxilla using rigid fixation is a stable procedure during the follow-up period, and that in bimaxillary cases, post-operative stability depends largely on the stability of the mandibular advancement, which in turn relates to the amounts of advancement, the pre-operative anterior open bite and the mandibular plane angle.- - - - - - - - - - ranking = 1keywords = sample (Clic here for more details about this article) |
6/42. bone resorption of the mandible in progressive systemic sclerosis.Five of 16 patients with progressive systemic sclerosis were found to have bone resorption at the angle of the mandible. This finding appears to be closely related to the tightness of the skin of the face, atrophy of the masseter and pterygoid muscles, small size of the oral orifice, and a significantly high frequency in blacks. The mandible must therefore be added to the list of those bones that can be resorbed in progressive systemic sclerosis.- - - - - - - - - - ranking = 0.28899282591954keywords = size (Clic here for more details about this article) |
7/42. A concept for the treatment of various dental bone defects.Untreated dental bone defects usually lead to resorption of alveolar bone. Filling these defects with bone substitute material prevents resorption of bone, preserves the alveolar ridge, and provides sufficient bone for immediate or subsequent implant placement. A variety of bone substitutes is available. They differ in origin, consistency, particle size, porosity, and resorption characteristics. We have treated almost 1000 bony defect sites in 267 patients with the bone regeneration material Cerasorb. Being resorbed simultaneously with the formation of new bone, it is completely replaced by the patient's own vital bone within 6 to 12 months. The representative cases described in this paper demonstrate the successful use of the pure-phase beta-tricalcium phosphate ceramic in the treatment of all dental bone defects.- - - - - - - - - - ranking = 0.28899282591954keywords = size (Clic here for more details about this article) |
8/42. Central resorption in an iliac crest transplant with microvascular anastomosis--report of 2 cases.INTRODUCTION: The microvascular iliac crest flap is preferred for repair of segmental mandibular defects. Its viability and constant size are regarded as a great advantage for oral rehabilitation. patients: Two patients with oral cancer and recurrent keratocyst underwent mandibular reconstruction with an iliac crest transplant. wound healing was uneventful. RESULTS: Several years after reconstruction we noticed complete absence of cancellous bone in the transplants. The cortical aspect consisted of vital bone. CONCLUSION: Secondary to changes in the blood supply after tissue transfer, microvascular bone transplants may develop complete medullary resorption.Substitution of this central bone is variable and may not happen at all.- - - - - - - - - - ranking = 0.28899282591954keywords = size (Clic here for more details about this article) |
9/42. Posterior uveitis: an under-recognized adverse effect of pamidronate: 2 case reports.Ocular adverse effects of pamidronic acid are rare but well documented. Pamidronate, an inhibitor of bone resorption used primarily in the management of tumor-induced hypercalcemia and Paget's disease, is reported to cause conjunctivitis, anterior uveitis, and infrequently episcleritis and scleritis. It is hypothesized that an allergic or immunologic phenomenon caused by drug-indued immune complex formation is at fault. The reason why the uvea is a target organ is unclear. The acute inflammatory response seems unrelated to the dose of the drug, the way of administration, or the activity of Paget's disease or malignancy. We report two cases of pamidronate-induced posterior uveitis, following the WHO causality Assessment Guide of Suspected Adverse Reactions. uveitis and scleritis have been reported in association with a variety of topical, intraocular, periocular, and systemic medications. Seven criteria were proposed to establish causality of adverse events by drugs. Only systemically administered biphosphonates meet all seven criteria. Where pamidronate is currently considered as the drug of choice in diverse strategies, the adverse ocular effects should be well known to physicians in order to make rapid diagnosis and stop the drug causing adverse reaction.- - - - - - - - - - ranking = 0.28899282591954keywords = size (Clic here for more details about this article) |
10/42. A case of massive dystrophic cardiac calcinosis with increased bone resorption markers: a novel pathophysiologic link?We report a 72-year-old man who presented to our emergency room with congestive heart failure that was resistant to initial medical therapy. He had suffered from anterior myocardial infarction 20 years prior. echocardiography and computed tomography revealed marked cardiac calcification including myocardium, chordal structures, mitral annulus, and aortic valve. Neither chronic renal insufficiency nor hypercalcemia were present in our patient. bone resorption markers were increased and bone mineral density was consistent with severe osteoporosis. We suggested a novel mechanism, that increased bone resorption may lead to accumulation of calcium into avascular tissues in the heart (ie, chordal structures, mitral annulus, aortic valve, and fibronecrotic myocardium) especially in the setting of high left ventricular end-diastolic pressure. Dystrophic cardiac calcinosis, an age-related cardiomyopathy, is associated with elevated bone resorption markers and it may cause alterations in cellular calcium hemostasis with initiation of deleterious events leading to aggravate dilated and restrictive cardiomyopathy and may result in intractable congestive heart failure. The implication of this case report needs to be reemphasized.- - - - - - - - - - ranking = 0.28899282591954keywords = size (Clic here for more details about this article) |
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