970 resultados para Maxillary sinus augmentation


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This case report describes the diagnosis and treatment of a Ewing's sarcoma in the right maxillary sinus and alveolar bone of a 19-year-old female patient. The first clinical symptoms were a loss of sensitivity of the premolars and first molar in the right maxilla and acute pain located in the area of these teeth. Initially, the referring dentist had treated these findings as an acute apical periodontitis with root canal medication. Because swellings on the palatal and buccal aspects of the teeth occurred and could not be treated with incision and drainage, the dentist referred the patient. Cone-beam computed tomography revealed a proliferation of soft tissue in the right maxillary sinus, with a radiopaque material at the tip of the mesiobuccal root of the first molar and resorptive signs of the mesiobuccal and distobuccal roots of the first molar. The palatal cortical bone of the right alveolar process seemed to be intact. After explorative surgery with biopsies from the buccal, palatal, and sinus proliferation areas, the pathologist diagnosed the lesion as a Ewing's sarcoma. Treatment of the patient consisted of initial chemotherapy, hemimaxillectomy, and postsurgical chemoradiotherapy.

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OBJECTIVES: To evaluate the pattern of tissue remodeling after maxillary sinus floor elevation using the transalveolar osteotome technique with or without utilizing grafting materials. METHODS: During the period of 2000-2005, 252 Straumann dental implants were inserted using the transalveolar sinus floor elevation technique in a group of 181 patients. For 88 or 35% of those implants, deproteinized bovine bone mineral with a particle size of 0.25-1 mm was used as the grafting material, but for the remaining 164 implants, no grafting material was utilized. Periapical radiographs were obtained with a paralleling technique and digitized. Two investigators, who were blinded to whether grafting material was used or not, subsequently evaluated the pattern of tissue remodeling. RESULTS: The mean residual bone height was 7.5 mm (SD 2.2 mm), ranging from 2 to 12.7 mm. The mean residual bone height for implants placed with grafting material (6.4 mm) was significantly less compared with the implants installed without grafting material (8.1 mm). The implants penetrated on average 3.1 mm (SD 1.7 mm) into the sinus cavity. The measured mean radiographic bone gain using the transalveolar technique without grafting material was significantly less, 1.7 mm (SD 2 mm) compared with a mean bone gain of 4.1 mm (SD 2.4 mm), when grafting material was used. Furthermore, the probability of gaining 2 mm or more of new bone was 39.1% when no grafting material was used. The probability increased to 77.9% when the implants were installed with grafting material. CONCLUSION: When the transalveolar sinus floor elevation was performed without utilizing grafting material, only a moderate gain of new bone could be detected mesial and distal to the implants. On the other hand, when grafting material was used, a substantial gain of new bone was usually seen on the radiographs.

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OBJECTIVES: To analyze the survival and success rates of implants installed utilizing the (transalveolar) osteotome technique, to compare peri-implant soft tissue parameters and marginal bone levels of osteotome-installed implants with implants placed using standard surgical procedures, and to evaluate patient-centered outcomes. MATERIAL AND METHODS: During 2000 to 2005, 252 Straumann dental implants were inserted in 181 patients. The surgical technique was a modification of the original osteotome technique presented by Summers. In addition to the clinical examination, the patients were asked to give their perception of the surgical procedure, utilizing a visual analogue scale. RESULTS: The cumulative survival rate of the osteotome-installed implants after a mean follow-up time of 3.2 years, was 97.4% (95% confidence intervals: 94.4-98.8%). From the 252 implants inserted, three were lost before loading and another three were lost in the first and second year. According to residual bone height the survival was 91.3% for implant sites with < or =4 mm residual bone height, and 90% for sites with 4 mm and 5 mm, when compared with that of 100% in sites with bone height of above 5 mm. According to implant length the survival rates were 100% for 12 mm, 98.7% for 10 mm, 98.7% for 8 mm and only 47.6% for 6 mm implants. Soft tissue parameters (pocket probing depth, probing attachment level, bleeding on probing and marginal bone levels) did not yield any differences between the osteotome-installed and the conventionally placed implants. More than 90% of the patients were satisfied with the implant therapy and would undergo similar therapy again if necessary. The cost associated with implant therapy was considered to be justified. CONCLUSION: In conclusion, the osteotome technique was a reliable method for implant insertion in the posterior maxilla, especially at sites with 5 mm or more of preoperative residual bone height and a relatively flat sinus floor.

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Grafting of the maxillary sinus in both one- and two-stage protocols has become a highly predictable surgical technique for site development and for the placement of implants to support dentures. However, despite the predictability and high success rates reported for dental implants placed either simultaneously with or after a sinus floor elevation (SFE) procedure, complications have been reported. The aim of the following case report is to present an uncommon complication in a staged SFE procedure: the displacement of a dental implant into the maxillary sinus during insertion. As implant dentistry is becoming more and more popular among practitioners, and ever more demanding procedures for initial site development in jaws with bony deficiencies are being introduced into daily practice, the displacement of dental implants into the maxillary sinus during implant placement may become a more frequent complication. Management of this complication is presented, discussed, and evaluated in light of the current literature.

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INTRODUCTION Our objective was to investigate potential associations between maxillary sinus floor extension and inclination of maxillary second premolars and second molars in patients with Class II Division 1 malocclusion whose orthodontic treatment included maxillary first molar extractions. METHODS The records of 37 patients (18 boys, 19 girls; mean age, 13.2 years; SD, 1.62 years) treated between 1998 and 2004 by 1 orthodontist with full Begg appliances were used in this study. Inclusion criteria were white patients with Class II Division 1 malocclusion, sagittal overjet of ≥4 mm, treatment plan including extraction of the maxillary first permanent molars, no missing teeth, and no agenesis. Maxillary posterior tooth inclination and lower maxillary sinus area in relation to the palatal plane were measured on lateral cephalograms at 3 time points: at the start and end of treatment, and on average 2.5 years posttreatment. Data were analyzed for the second premolar and second molar inclinations by using mixed linear models. RESULTS The analysis showed that the second molar inclination angle decreased by 7° after orthodontic treatment, compared with pretreatment values, and by 11.5° at the latest follow-up, compared with pretreatment. There was evidence that maxillary sinus volume was negatively correlated with second molar inclination angle; the greater the volume, the smaller the inclination angle. For premolars, inclination increased by 15.4° after orthodontic treatment compared with pretreatment, and by 8.1° at the latest follow-up compared with baseline. The volume of the maxillary sinus was not associated with premolar inclination. CONCLUSIONS We found evidence of an association between maxillary second molar inclination and surface area of the lower sinus in patients treated with maxillary first molar extractions. Clinicians who undertake such an extraction scheme in Class II patients should be aware of this potential association and consider appropriate biomechanics to control root uprighting.

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Squamous cell carcinoma (SCC) of the maxillary sinus is a relatively rare disease. As the reported incidence of regional metastasis varies widely, controversy exists as to whether or not the N0 classified neck should be treated electively. In this review, the data from published series are analyzed to decide on a recommendation of elective treatment of the neck in maxillary SCC. The published series consist of heterogeneous populations of different subsites of the paranasal sinuses, different histological types, different staging and treatment modalities used and different ways of reporting the results. These factors do not allow for recommendations based on high levels of evidence. Given this fact, the relatively high incidence rate of regional metastasis at presentation or in follow-up in the untreated N0 neck, and the relatively low toxicity of elective neck irradiation, such irradiation in SCC of the maxillary sinus should be considered.

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The aim of this study was to evaluate in humans the amount of new bone after sinus floor elevation with a synthetic bone substitute material consisting of nanocrystalline hydroxyapatite embedded in a highly porous silica gel matrix. The lateral approach was applied in eight patients requiring sinus floor elevation to place dental implants. After elevation of the sinus membrane, the cavities were filled with 0.6-mm granules of nanocrystalline hydroxyapatite mixed with the patient's blood. A collagen membrane (group 1) or a platelet-rich fibrin (PRF) membrane (group 2) was placed over the bony window. After healing periods between 7 and 11 months (in one case after 24 months), 16 biopsy specimens were harvested with a trephine bur during implant bed preparation. The percentage of new bone, residual filler material, and soft tissue was determined histomorphometrically. Four specimens were excluded from the analysis because of incomplete biopsy removal. In all other specimens, new bone was observed in the augmented region. For group 1, the amount of new bone, residual graft material, and soft tissue was 28.7% ± 5.4%, 25.5% ± 7.6%, and 45.8% ± 3.2%, respectively. For group 2, the values were 28.6% ± 6.90%, 25.7% ± 8.8%, and 45.7% ± 9.3%, respectively. All differences between groups 1 and 2 were not statistically significant. The lowest and highest values of new bone were 21.2% and 34.1% for group 1 and 17.4% and 37.8% for group 2, respectively. The amount of new bone after the use of nanocrystalline hydroxyapatite for sinus floor elevation in humans is comparable to values found in the literature for other synthetic or xenogeneic bone substitute materials. There was no additional beneficial effect of the PRF membrane over the non-cross-linked collagen membrane.

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INTRODUCTION The proximity of the roots of the posterior maxillary teeth to the maxillary sinus is a constant challenge to the dental practitioner. Because the majority of studies have assessed the relationship regarding molars, the present study focused on premolars. METHODS Cone-beam computed tomographic images of 192 patients were reconstructed in sagittal, coronal, and axial planes to quantify the distances between the root apices of the maxillary premolars and the adjacent maxillary sinus. Measurements were taken for each root, and data were correlated with age, sex, side, and presence of both or absence of 1 of the 2 premolars. RESULTS A total of 296 teeth (177 first and 119 second premolars) were evaluated. The mean distances from buccal roots of the first premolars to the border of the maxillary sinus in the sagittal, coronal, and axial planes ranged from 5.15 ± 2.99 to 8.28 ± 6.27 mm. From palatal roots, the mean distances ranged from 4.20 ± 3.69 to 7.17 ± 6.14 mm. The mean distances of second premolars were markedly shorter in buccal roots between 2.32 ± 2.19 and 3.28 ± 3.17 mm and in palatal roots between 2.68 ± 3.58 and 3.80 ± 3.71 mm, respectively. The frequency of a premolar root protrusion into the maxillary sinus was very low in first premolars (0%-7.2%) but higher in second premolars (2.5%-13.6%). Sex, age, side, and presence/absence of premolars failed to significantly influence the mean distances between premolar roots and the maxillary sinus. CONCLUSIONS Based on the calculated mean distances of the present study, only few premolars (and if so second premolars) would present a risk of violating the border of the maxillary sinus during conventional or surgical endodontic treatment or in case of tooth extraction.

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Background: The aim of this study was to evaluate the validity and the inter- and intra-examiner reliability of panoramic-radiograph-driven findings of different maxillary sinus anatomic variations and pathologies, which had initially been prediagnosed by cone beam computed tomography (CBCT). Methods: After pairs of two-dimensional (2D) panoramic and three-dimensional (3D) CBCT images of patients having received treatment at the outpatient department had been screened, the predefinition of 54 selected maxillary sinus conditions was initially performed on CBCT images by two blinded consultants individually using a questionnaire that defined ten different clinically relevant findings. Using the identic questionnaire, these consultants performed the evaluation of the panoramic radiographs at a later time point. The results were analyzed for inter-imaging differences in the evaluation of the maxillary sinus between 2D and 3D imaging methods. Additionally, two resident groups (first year and last year of training) performed two diagnostic runs of the panoramic radiographs and results were analyzed for inter- and intra-observer reliability. Results: There is a moderate risk for false diagnosis of findings of the maxillary sinus if only panoramic radiography is used. Based on the ten predefined conditions, solely maxillary bone cysts penetrating into the sinus were frequently detected differently comparing 2D to 3D diagnostics. Additionally, on panoramic radiographs, the inter-observer comparison demonstrated that basal septa were significantly often rated differently and the intra-observer comparison showed a significant lack in reliability in detecting maxillary bone cysts penetrating into the sinus. Conclusions: Panoramic radiography provides the most information on the maxillary sinus, and it may be an adequate imaging method. However, particular findings of the maxillary sinus in panoramic imaging may be based on a rather examiner-dependent assessment. Therefore, a persistent and precise evaluation of specific conditions of the maxillary sinus may only be possible using CBCT because it provides additional information compared to panoramic radiography. This might be relevant for consecutive surgical procedures; consequently, we recommend CBCT if a precise preoperative evaluation is mandatory. However, higher radiation dose and costs of 3D imaging need to be considered. Keywords: Panoramic radiography; Cone beam computed tomography; Maxillary sinus; Inter-imaging method differences; Inter-examiner reliability; Intra-examiner reliability

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Monografia apresentada à Universidade Fernando Pessoa para obtenção do grau de Licenciada em Medicina Dentária.

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Objective: To compare new bone formation in maxillary sinus augmentation procedures using biomaterial associated with mesenchymal stem cells (MSCs) separated by two different isolation methods. Background: In regenerative medicine open cell concentration systems are only allowed for clinical application under good manufacturing practice conditions. Methods: Mononuclear cells, including MSCs, were concentrated with either the synthetic poylsaccharid (FICOLL) method (classic open system-control group, n = 6 sinus) or the bone marrow aspirate concentrate (BMAC) method (closed system-test group, n = 12 sinus) and transplanted in combination with biomaterial. A sample of the cells was characterized by their ability to differentiate. After 4.1 months (SD +/- 1.0) bone biopsies were obtained and analyzed. Results: The new bone formation in the BMAC group was 19.9% (90% confidence interval [CI], 10.9-29), and in the FICOLL group was 15.5% (90% CI, 8.6-22.4). The 4.4% difference was not significant (90% CI, -4.6-13.5; p = 0.39). MSCs could be differentiated into osteogenic, chondrogenic, and adipogenic lineages. Conclusion: MSCs harvested from bone marrow aspirate in combination with bovine bone matrix particles can form lamellar bone and provide a reliable base for dental implants. The closed BMAC system is suited to substitute the open FICOLL system in bone regeneration procedures.

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Background: Prosthetic rehabilitation of the posterior maxilla with dental implants is often difficult because of proximity to the maxillary sinus and insufficient bone height. Maxillary sinus floor augmentation procedures aim to obtain enough bone with an association between biomaterials and autogenous bone.Purpose: the purpose of this study was to evaluate histomorphometrically two grafting materials (calcium phosphate and Ricinus communis polymer) used in maxillary sinus floor augmentation associated with autogenous bone.Materials and Methods: Biopsies were taken from 10 consecutive subjects (mean age 45 years) 10 months after maxillary sinus floor augmentation. The sinus lift was performed with a mixture of autogenous bone and R. communis polymer or calcium phosphate in a 1:2 proportion. Routine histologic processing and staining with hernatoxylin and eosin were performed.Results: the histomorphometric analysis indicated satisfactory regenerative results in both groups for a mean of bone tissue in the grafted area (44.24 +/- 13.79% for the calcium phosphate group and 38.77 +/- 12.85% for the polymer group). Histologic evaluation revealed the presence of an inflammatory infiltrate of mononuclear prevalence that, on average, was nonsignificant. The histologic sections depicted mature bone with compact and cancellous areas in both groups.Conclusion: the results indicated that both graft materials associated with the autogenous bone were biocompatible, although both were still present after 10 months.

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Autogenous bone grafting is the gold-standard technique for bone augmentation procedures prior to implant placement. If the amount of available intraoral donor bone is insufficient, it is necessary to harvest bone graft from extraoral sites, such as calvaria. Although this technique is well established, only a few case reports show the histological analysis of the grafted bone at the moment of implant placement. This article reports the case of a 48-year-old female patient with a critical atrophic maxillary ridge reconstructed using autogenous calvarial bone graft prior to implant placement, with clinical and histological evaluation. Bone was collected under general anesthesia from the parietal bone. The outer cortical originated the bone blocks, and the medullar bone layer between was collected to be used in the sinus augmentation procedure, together with 5 of the bone blocks triturated. Six months after bone augmentation, 8 implants were placed in the grafted area and 2 biopsies were retrieved (anterior and the posterior regions), allowing the visualization of the bone-remodeling process in the grafted areas. The patient had a stable recovery. Our results showed that although necrotic bone could still be seen in the outer layer of the grafted area, the interface between this necrotic bone and the already remodeled bone was consistent with biocompatibility. Two-year radiographic evaluation showed success of the grafts and the implants in supporting an esthetic and functionally stable prosthesis. Summarizing, calvarial bone grafts are a viable alternative for the attainment of adequate bone volume prior to implant placement.