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- Abtahi, Jahan, 1965-
(författare)
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Bisphosphonates and implants in the jaw bone
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Insertion of metal implants in bone is one of the commonest of all surgical procedures. The success of these operations is dependent on the fixation of the implants, which, in turn, depends on the strength of the bone that holds them. If the quality of the bone holding the implant could be improved locally, surgical procedures would become simpler and rehabilitation would become faster. Bisphosphonates are anti-resorptive drugs that act specifically on osteoclasts, thereby maintaining bone density and strength. Once released from the surface of a coated implant, bisphosphonates reduce osteoclast activity, thereby changing the balance of bone turnover in favor of bone formation, leading to a net gain in local bone density. During the last decades, the effects of bisphosphonate treatment on the stability of implants have been tested in several clinical and animal studies, but not in human jaws. This may be because it has been suggested that there is a link between the use of bisphosphonates (especially those given intravenously) and a condition called osteonecrosis of the jaw (ONJ). The pathophysiology and treatment of ONJ is controversial. The difficulty in treating ONJ has highlighted the importance of prevention.The overall aim of the present thesis was to evaluate the effect of local and systemic use of bisphosphonates on bone tissue. Could a thin, bisphosphonate-eluting fibrinogen coating improve the fixation of metal implants in the human jaw? Would it be possible to reproduce ONJ and prevent the development of this condition in an animal model?In two clinical studies, a total number of 96 implants were inserted in 21 patients. In a randomized trial with a paired design, one implant in each pair was coated with a thin fibrinogen layer containing two bisphosphonates (pamidronate and ibandronate). The bisphosphonate-coated implants showed better stability as measured by resonancefrequency analysis. Radiographic intraoral films also showed less bone loss. Three animal models were developed. In a study comparing local and systemic effects of bisphosphonates, zoledronate-coated screws inserted in rats showed better fixation in spite of a drug treatment that is known to induce ONJ-like lesions when given systemically. In another rat model, ONJ-like lesions were reproducibly induced at sites of tooth extraction whereas there were no signs of bone cell death in uninjured sites. Finally, rat experiments showed that the development of ONJ-like lesions after tooth extraction could be prevented by early mucoperiosteal coverage.In conclusion, a thin, bisphosphonate-eluting fibrinogen coating can improve the fixation of dental implants in human bone. This may lead to new possibilities in orthopaedic surgery and dentistry. The pathophysiology of ONJ is strongly linked to bone exposure in combination with drugs that reduce resorption.
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| 2. |
- Abtahi, Jahan, 1965-, et al.
(författare)
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Ibandronate Reduces the Surface Bone Resorption of Mandibular Bone Grafts : A Randomized Trial With Internal Controls
- 2021
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Ingår i: JBMR Plus. - : Wiley. - 2473-4039. ; 5:3
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Tidskriftsartikel (refereegranskat)abstract
- Autologous bone grafts are considered the gold standard for reconstruction of the edentulous alveolar ridges. However, this procedure is associated with unpredictable bone loss caused by physiological bone resorption. Bisphosphonates are antiresorptive drugs that act specifically on osteoclasts, thereby maintaining bone density, volume, and strength. It was hypothesized that the resorption of bone grafts treated with an ibandronate solution would be less advanced than bone grafts treated with saline. Ten patients who underwent bilateral sagittal split osteotomy were included in a randomized double-blind trial with internal controls. Each patient received a bone graft treated with a solution of ibandronate on one side and a graft treated with saline (controls) contralaterally. Radiographs for the measurement of bone volume were obtained at 2 weeks and at 6 months after surgery. The primary endpoint was the difference in the change of bone volume between the control and the ibandronate bone grafts 6 months after surgery. All of the bone grafts healed without complications. One patient was excluded because of reoperation. In eight of the nine patients, the ibandronate bone grafts showed an increase in bone volume compared with baseline, with an average gain of 126 mm(3) (40% more than baseline) with a range of +27 to +218 mm(3). Only one ibandronate-treated graft had a decrease in bone volume (8%). In the controls, an average bone volume loss of -146 mm(3) (58% of baseline) with a range of -29 to -301 mm(3) was seen. In the maxillofacial field, the reconstructions of atrophic alveolar ridges, especially in the esthetical zones, are challenging. These results show that bone grafts locally treated with ibandronate solution increases the remaining bone volume. This might lead to new possibilities for the maxillofacial surgeons in the preservation of bone graft volumes and for dental implant installations.
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| 3. |
- Abtahi, Jahan, 1965-, et al.
(författare)
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Impact of a zoledronate coating on early post-surgical implant stability and marginal bone resorption in the maxilla-A split-mouth randomized clinical trial.
- 2019
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Ingår i: Clinical Oral Implants Research. - : John Wiley & Sons. - 0905-7161 .- 1600-0501. ; 30:1, s. 49-58
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: The objective of this clinical study was to evaluate the effect of a bisphosphonate coating on a titanium implant on the implant stability quotient (ISQ) and the radiographic marginal bone levels at implants during early healing (2-8 weeks).MATERIALS AND METHODS: In a randomized double-blind trial with internal controls, 16 patients received a dental implant coated with zoledronate and one uncoated implant as a control. The coated and uncoated implants which were visually indistinguishable were bone level titanium implants with a moderately rough surface and a microthreaded neck. ISQ values were obtained at insertion and at 2, 4, 6, and 8 weeks. Radiographs were obtained at insertion and at 8 weeks. The primary outcome was the difference in ISQ values between the coated implants and the control implants at 4 and 6 weeks, corrected for insertion values. The secondary outcome was loss of marginal bone level from insertion to 8 weeks.RESULTS: Implant stability quotient values remained largely constant over the 8 weeks, and there was no significant difference between coated and uncoated implants at any time point. There was 0.12 (SD 0.10) mm marginal bone loss at the control implants and 0.04 (SD 0.08) mm at the coated implants. The difference was 0.17 mm; SD 0.14; p < 0.006). On blind qualitative scoring, 13 of the 15 control implants and two of 15 coated implants showed small marginal bone defects (p = 0.003).CONCLUSIONS: There were no statistically significant differences observed in ISQ values between the coated and uncoated implants during the early healing. There was less marginal bone loss at the coated implants.
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| 4. |
- Abtahi, Jahan, 1965-, et al.
(författare)
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Malignant Transformation of Ossifying Fibroma into Parosteal Osteosarcoma with High-grade Component: Presentation of an Unusual Case and Review of the Literature
- 2018
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Ingår i: The Open Dentistry Journal. - : Bentham Open. - 1874-2106. ; 12, s. 1059-1068
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Tidskriftsartikel (refereegranskat)abstract
- Background: Parosteal Osteosarcoma of the Jaw (POSJ) is a rare entity that is associated with a high survival rate. Several case reports and case series of POSJ have been published in the literature, but few authors have described development of this tumor by possible transformation from a fibro-osseous neoplasm. Objective: We present a rare occurrence of parosteal osteosarcoma with involvement of the posterior maxilla, orbit floor, and infra-temporal fossa in a 20-year-old man. Furthermore, we performed a literature review regarding clinical, radiological, and histological features; treatment strategies; and etiology/pathophysiology. Methods: A PubMed search yielded a total of 74 articles and the articles were sorted according to their corresponding key area of focus. Results: This was a case of POSJ with high-grade component in the maxillofacial region of a 20-year old male. Co-expression of MDM2 and CDK4 was confirmed. At 2.5-year follow-up, the patient had died. The literature review revealed 18 articles including 20 cases of POSJ. Four cases represent the possible development of this tumor by transformation from a fibro-osseous neoplasm: Two cases of fibrous dysplasia, one case of cemento-ossifying fibroma, and the case of Ossifying Fibroma (OF) in the present study. Conclusion: In conclusion, we found an unusual case of POSJ of the midface in a patient with a previous diagnosis of OF in the same region. To our knowledge, there have been no previous reports of development of POSJ in OF. Furthermore, this is the first described case of high-grade surface osteosarcoma in the craniofacial region.
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| 5. |
- Abtahi, Jahan, 1965-, et al.
(författare)
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Surgical Management of Granular Cell Tumor of the Orbit : Case Report and Literature Review
- 2019
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Ingår i: The Open Dentistry Journal. - Sharjah, United Arab Emirates : Bentham Open. - 1874-2106. ; 13, s. 33-40
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Forskningsöversikt (refereegranskat)abstract
- Introduction: Granular Cell Tumors (GCTs) of the orbit are rare-entity soft-tissue tumors, and few reports have been published in the literature. The treatment of the choice is total excision. Early diagnosis prior to surgery is valuable for the distinction of malignant from benign tumor.Case presentation: We report a case of a 55-year-old woman with a solitary slow-growing mass in the right orbit with the involvement of the rectus inferior muscle, and present a review of the recent literature. The lesion had a diameter of 1 cm and was noticed 2 years before the examination. Excisional biopsy confirmed the diagnosis of GCT. The tumor was resected through a retroseptal transconjunctival approach. The final histological examination revealed findings characteristic of GCT, including positive reaction for protein S-100, SOX10, and calcitonin and negative reaction for desmin, myogenin, Smooth Muscle Antigen (SMA), Melan-A, and HMB-45. There were no signs of malignancy in this sample. Disturbance of motility was not noted by the patient after surgery.Conclusion: GCT should be included in the differential diagnosis of intraorbital lesions, particularly those that involve the orbit muscles. A biopsy is recommended before surgical resection, to exclude malignancy and prevent radical resection.
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| 6. |
- Alstad, V., et al.
(författare)
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Surgical removal of keratocystic odontogenic tumours via a Le Fort I osteotomy approach: a retrospective study of the recurrence rate
- 2017
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Ingår i: International Journal of Oral and Maxillofacial Surgery. - : Elsevier. - 0901-5027 .- 1399-0020. ; 46:4, s. 434-439
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Tidskriftsartikel (refereegranskat)abstract
- The keratocystic odontogenic tumour (KCOT) is one of the most aggressive odontogenic cysts and has a high recurrence rate. The treatment of these tumours is the subject of debate. A KCOT in the posterior maxilla with sinus involvement is rare. Few reports have been published in the literature. The purpose of this study was to evaluate the recurrence rate after surgical removal of maxillary KCOTs via a Le Fort I osteotomy. A search was performed to identify patients with a follow-up time of at least 5 years. Nine patients were included in the study. The following clinical variables were analyzed: age at surgery, sex, symptoms, site and size of the tumour, surgical approach, and recurrence rate. The surgical approaches were curettage (n=6) and enucleation (n=3). Recurrence was seen in three patients (33%); all had multilocular tumours. No recurrence was seen in patients with unilocular tumours. The Le Fort I osteotomy approach allows direct visualization and ensures wide excision, minimizing the risk of recurrence. In this series, cases with a multilocular KCOT showed a higher risk of recurrence due to the difficulty of removing the tumour in total. All recurrences took place within 2 years of the intervention; a 5-year follow-up is recommended.
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| 7. |
- Stålhand, Gudrun, et al.
(författare)
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Distribution of orthognathic surgery among the Swedish population: a retrospective register-based study
- 2023
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Ingår i: Acta Odontologica Scandinavica. - : Informa UK Limited. - 0001-6357 .- 1502-3850. ; 81:5, s. 414-421
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveThe aim of this study was to provide a nationally representative assessment of orthognathic procedures performed in hospitalised patients in Sweden and study regional differences in prevalence, demographic parameters and hospitalisation time.Material and methodsFrom the Swedish National Board of Health and Welfare's register, all the patients undergoing orthognathic surgery between 2010 and 2014 were identified. Outcome variables were categorised into: (1) Surgical methods and regional distribution (2) Demographic variations (3) Hospitalisation time.ResultsThe population-prevalence-rate of orthognathic procedures over the 5-year period was 6.3 (SD 0.4) per 100,000 persons, a regional difference in the prevalence was found. Most common were Le Fort I osteotomies (43.4%) and bilateral sagittal split osteotomies (41.6%), 39% of the patients had bimaxillary surgery. The majority of the surgery was performed in the age group 19-29 (68.8%). The mean hospital stay was 2.2 days (SD = 0.9, range 1.7-3.4). A significant regional difference (p <= 0.001) was found in hospitalisation time for single-jaw versus bimaxillary surgery.ConclusionsRegional differences in the distribution of orthognathic surgery and demographic variations were found in Sweden in 2010-2014. The underlying causes of variations are still unknown and request further investigation.
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