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1.
Br J Oral Maxillofac Surg ; 58(7): 812-818, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32409131

RESUMO

Is there a variation in facial ideals depending on ethnic background that affects judgements of outcome in orthognathic surgery? How does the evaluation correlate with patient-reported outcome measures? Two evaluation panels, Singaporean and Swedish, judged photographs of patients undergoing orthognathic surgery taken before and after operation. Improvement in facial aesthetics was calculated between the two ratings. The result was compared between the panels and correlated with health-related quality of life (QoL) measures. Thirty male and 27 female patients aged between 18 and 28 years (mean 21) were included, and 52 subjects were eligible for comparison of health-related QoL. The photographic evaluation showed that both panels judged there to be significant improvement in facial aesthetics after treatment (p<0.001). The Singaporean panel rated the overall facial appearance higher than the Swedish panel when evaluating photographs both before (p=0.025) and after (p=0.032) operation. Improvement of the overall facial appearance showed no significant difference between the panels (p>0.30). No correlation between health-related QoL and improvement of facial appearance was found by either panel. Subjective evaluation of facial aesthetics in orthognathic surgery is unaffected by the observer's ethnic origin. Independently of their ethnicity, the evaluation juries found that facial aesthetics improved after orthognathic surgery. Improvement reported by the juries corresponded to that reported by patients.


Assuntos
Cirurgia Ortognática , Procedimentos Cirúrgicos Ortognáticos , Adolescente , Adulto , Estética Dentária , Etnicidade , Feminino , Humanos , Masculino , Qualidade de Vida , Adulto Jovem
2.
Br J Oral Maxillofac Surg ; 57(4): 345-351, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31000205

RESUMO

The outcome of treatment in orthognathic surgery is dependent on preoperative surgical planning. The main purpose of the present study was to evaluate from photographs the improvement in facial appearance after orthognathic surgery. In addition, the outcomes of two different planning techniques, 2-dimensional and 3-dimensional, were compared and the correlation between the outcome and health-related quality of life (HRQoL) assessed. The study was a randomised controlled trial with the intervention being either 2-dimensional or 3-dimensional treatment planning. An evaluation panel compared photographs taken before and after operation on patients with severe class III malocclusion. The change in facial appearance was rated, the two planning techniques compared, and the result correlated with previously published findings on cephalometric accuracy and HRQoL in the same group. Completed 12-month follow-up resulted in the inclusion of 57 subjects aged between 18 and 28 years at the time of operation (mean 21 years). We found significant differences between the two evaluations (p = 4.4E-9) but no significant difference in facial improvement between the planning techniques (p = 0.54). However, there was a correlation between cephalometric measurement of accuracy in the anterior maxilla and evaluation of improvement of facial appearance (p = 0.024, r = 0.30), but we found no correlation +between HRQoL and the evaluation of facial appearance (p = 0.31, r = -0.14). We conclude that there was an improvement in facial aesthetics after orthognathic surgery that was independent of the planning technique used.


Assuntos
Cirurgia Ortognática , Procedimentos Cirúrgicos Ortognáticos , Adolescente , Adulto , Cefalometria , Estética Dentária , Humanos , Imageamento Tridimensional , Má Oclusão Classe III de Angle , Medidas de Resultados Relatados pelo Paciente , Qualidade de Vida , Resultado do Tratamento , Adulto Jovem
3.
Br J Oral Maxillofac Surg ; 57(4): 352-358, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30962030

RESUMO

The aim of this randomised controlled trial was to compare the costs and benefits of computer-based 2-dimensional and 3-dimensional predictions in orthognathic surgery. Subjects aged 18-30 years with severe class III malocclusion had their treatment planned with both 2- and 3-dimensional techniques. They were randomised in a 1:1 ratio for one or other planning technique. Costs (financial, time, and dose of radiation) were compared with benefits (accuracy and health-related quality of life (HRQoL)). In total, 57 subjects (27 women and 30 men, mean (range) age 21 (18-28) years) completed the study. Comparisons showed no significant difference in total time spent, but a large advantage for the 2-dimensional technique in financial costs (p < 0.001); it also required a significantly lower dose of radiation (p < 0.001). The cost-effectiveness analysis showed a reduction in time of 0.53 minutes/HRQoL-point gained, and an increased economic cost of US$15/HRQoL point gained for the 3-dimensional technique. It also showed that the two techniques consumed an equal amount of time, but that the 2-dimensional technique had lower financial costs, and the 3-dimensional technique a larger dose of radiation.


Assuntos
Cirurgia Ortognática , Procedimentos Cirúrgicos Ortognáticos , Adolescente , Adulto , Análise Custo-Benefício , Feminino , Humanos , Masculino , Técnicas de Planejamento , Qualidade de Vida , Cirurgia Assistida por Computador , Adulto Jovem
4.
J Dent Res ; 98(1): 84-90, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30205020

RESUMO

The impact of osteoporosis on implant treatment is still a matter of debate in the scientific community, as it may possibly lead to higher failure rates. As long-term controlled trials are missing, the aim of this study was to verify the long-term outcome of implants placed in patients with systemic osteoporosis. Postmenopausal women in need of implants underwent bone mineral density measurements in hip and spine, using dual X-ray absorptiometry scans. Based on T-scores, they were divided into 2 groups: group O (osteoporosis group) with a T-score ≤-2 or group C (control group) with a T-score of ≥-1. Implants were placed in a 2-stage manner and loaded 4 to 8 wk after abutment surgery. Six months after loading and thereafter yearly, clinical and radiographical parameters were assessed. In total, 148 implants were placed in 48 patients (mean age: 67 y [range, 59-83]). Sixty-three implants were placed in 20 patients (group O) and 85 implants in 28 patients (group C). After 5 y, 117 implants (38 in group O and 79 in the group C) in 37 patients were assessed. Cumulative survival rate on an implant level was 96.5% (group O: 91.5%; group C: 100.0% [ P < 0.05]) and 95.7% (group O: 89.2%; group C: 100.0% [ P > 0.05]) on a patient level. The overall marginal bone-level alterations, after 5 y of loading, were -0.09 ± 0.78 mm (group O: -0.15 ± 0.50 mm; group C: -0.06 ± 0.89 mm) on an implant level and -0.09 ± 0.54 mm (group O: -0.18 ± 0.43 mm; group C: 0.06 ± 0.58 mm) on a patient level ( P > 0.05). Oral implant therapy in osteoporotic patients is a reliable treatment option with comparable osseointegration rates, implant survival, and marginal bone-level alterations after 5 y of functional loading (ClinicalTrials.gov NCT00745121).


Assuntos
Implantação Dentária Endóssea , Implantes Dentários , Falha de Restauração Dentária , Carga Imediata em Implante Dentário , Osteoporose Pós-Menopausa/complicações , Pós-Menopausa , Idoso , Perda do Osso Alveolar , Prótese Dentária Fixada por Implante , Feminino , Humanos , Estimativa de Kaplan-Meier , Pessoa de Meia-Idade , Osseointegração , Estudos Prospectivos , Resultado do Tratamento
5.
J Craniomaxillofac Surg ; 44(8): 973-8, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27240820

RESUMO

AIM: Surgical corrections of dentofacial deformities have both physical and psychological impact on quality of life (QoL). The objectives of the present study were to evaluate the impact of oral health related problems on QoL before and after a combination of orthodontic treatment and orthognathic surgery. Additionally, the study aimed to identify correlations between different dentofacial patterns and possible improvements due to treatment. MATERIAL AND METHODS: In a prospective study, we evaluated fifty patients before start of treatment, 6 weeks and 6 months postoperatively. The questionnaires used were: OHIP-14 (Short Form Oral Health Impact Profile), a condition-specific QOL approach (Orthognathic Quality of Life Questionnaires; OQLQ) and a social-demographic questionnaire. RESULTS: There was a statistically significant improvement in the OHIP domains from baseline to 6 months follow-up and for the OQLQ, the improvement was significant both at 6 weeks and 6 months in relation to the baseline data. CONCLUSION: Significant improvement of quality of life over time is proved by both OHIP-14 and OQLQ in the present study. Socio-demographic and holistic considerations are important when evaluating treatment outcome after combined orthodontic and orthognatic surgery. However, longer follow-up would be beneficial.


Assuntos
Deformidades Dentofaciais/cirurgia , Procedimentos Cirúrgicos Ortognáticos , Qualidade de Vida , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Ortognáticos/psicologia , Estudos Prospectivos , Inquéritos e Questionários , Suécia , Adulto Jovem
6.
Int J Oral Maxillofac Surg ; 44(2): 252-8, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25304755

RESUMO

A randomized, prospective, controlled trial was conducted to determine the efficacy of single and repeated betamethasone doses on facial oedema, pain, and neurosensory disturbances after bilateral sagittal split osteotomy. Thirty-seven patients (mean age 23.62 years, range 17-62 years) with either mandibular prognathism or retrognathism were enrolled consecutively into the study and divided into three groups: control (n=12), repeated dose 4+8+4mg betamethasone (n=14), single dose 16mg betamethasone (n=11). The intake of diclofenac and paracetamol was assessed individually. Measurements of facial oedema, pain, and sensitivity in the lower lip/chin were obtained 1 day, 7 days, 2 months, and 6 months postoperatively. Furthermore, we investigated the possible influences of gender, age, total operating time, amount of bleeding, postoperative hospitalization, and advancement versus setback of the mandible. A significant difference (P=0.017) was observed in percentage change between the two test groups and the control group regarding facial oedema (1 day postoperatively). Less bleeding was associated with improved pain recovery over time (P=0.043). Patients who required higher postoperative dosages of analgesics due to pain had significantly delayed recovery of the inferior alveolar nerve at 6 months postoperatively (P<0.001). Betamethasone did not reduce neurosensory disturbances over time.


Assuntos
Betametasona/uso terapêutico , Traumatismos dos Nervos Cranianos/prevenção & controle , Edema/prevenção & controle , Dor Facial/prevenção & controle , Glucocorticoides/uso terapêutico , Doenças Mandibulares/cirurgia , Osteotomia Sagital do Ramo Mandibular , Adolescente , Adulto , Betametasona/administração & dosagem , Cefalometria , Traumatismos dos Nervos Cranianos/etiologia , Método Duplo-Cego , Edema/etiologia , Dor Facial/etiologia , Feminino , Glucocorticoides/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Estudos Prospectivos
7.
Front Plant Sci ; 4: 38, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23515425

RESUMO

A complete understanding of the mechanistic basis of marine ecosystem functioning is only possible through integrative and interdisciplinary research. This enables the prediction of change and possibly the mitigation of the consequences of anthropogenic impacts. One major aim of the European Cooperation in Science and Technology (COST) Action ES0609 "Seagrasses productivity. From genes to ecosystem management," is the calibration and synthesis of various methods and the development of innovative techniques and protocols for studying seagrass ecosystems. During 10 days, 20 researchers representing a range of disciplines (molecular biology, physiology, botany, ecology, oceanography, and underwater acoustics) gathered at The Station de Recherches Sous-marines et Océanographiques (STARESO, Corsica) to study together the nearby Posidonia oceanica meadow. STARESO is located in an oligotrophic area classified as "pristine site" where environmental disturbances caused by anthropogenic pressure are exceptionally low. The healthy P. oceanica meadow, which grows in front of the research station, colonizes the sea bottom from the surface to 37 m depth. During the study, genomic and proteomic approaches were integrated with ecophysiological and physical approaches with the aim of understanding changes in seagrass productivity and metabolism at different depths and along daily cycles. In this paper we report details on the approaches utilized and we forecast the potential of the data that will come from this synergistic approach not only for P. oceanica but for seagrasses in general.

8.
Clin Oral Implants Res ; 22(12): 1404-8, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21435007

RESUMO

OBJECTIVES: The purpose of this study was to histologically examine the responses of intramembraneous bone to calcium sulfate (CaS) and evaluate the resorption and replacement process. MATERIAL AND METHODS: Fourteen rabbits were used in this study. Defect healing without any filling material was compared with CaS. Five millimetres wide and 4 mm deep defects were drilled with a trephine bur on both sides of the edentulous space between the incisors and the molars. Test vs. control sites were randomly selected and thereby compared in each animal. The animals were killed after 2, 4 and 8 weeks for histological examination. RESULTS: After 2 weeks, the specimens showed a great extent of degradation of CaS. No signs of the material could be seen after 4 and 8 weeks. There were no statistically significant differences in bone regeneration between the test and control sites within the 8 weeks group in this study. However, there was tendency of more blood vessels in the test sites after 4 weeks of healing. CONCLUSION: The present study showed that CaS does not interfere with intramembraneous bone healing. In this animal model, the CaS exhibited resorption/degradation early in the healing process while seemingly stimulating angiogenesis. However, there was no significant increase in bone regeneration in the sites treated with CaS during an 8 week period of healing and observation time, as compared with a control defect.


Assuntos
Aumento do Rebordo Alveolar/métodos , Regeneração Óssea/efeitos dos fármacos , Sulfato de Cálcio/farmacologia , Maxila/cirurgia , Animais , Reabsorção Óssea , Coelhos , Estatísticas não Paramétricas , Fatores de Tempo , Cicatrização
9.
Int J Oral Maxillofac Surg ; 36(12): 1164-71, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17855054

RESUMO

The aim of this study was to evaluate the effect of platelet-rich plasma (PRP) on early and late bone healing after autogenous maxillary sinus grafting. Eleven patients were subjected to sinus augmentation with particulated autogenous bone bilaterally with the addition of PRP in one side. Platelet counts in baseline whole blood and PRP were registered. Biopsies were taken in the grafted bone of the sinus area with trephine at 3 months (nine patients) and simultaneously a micro-implant was installed in the same region. The micro-implants with surrounding bone were retrieved by biopsy at 6 months (seven patients). Undecalcified cut and ground sections were histomorphometrically analysed. Quantification of new and old bone in all biopsies was performed. The results of this histological study showed that significantly more new bone was formed at PRP-treated sites compared to controls after 3 months of healing. After 6 months, this effect could no longer be observed. This is in accordance with previous studies showing that PRP has a rather low regenerative capacity but may influence the early phase of bone healing. The additional value of PRP in autogenous bone grafts in the maxillary sinus is questionable.


Assuntos
Regeneração Óssea/efeitos dos fármacos , Transplante Ósseo/métodos , Seio Maxilar/cirurgia , Plasma Rico em Plaquetas , Próteses e Implantes , Adulto , Idoso , Feminino , Humanos , Ílio/transplante , Masculino , Seio Maxilar/diagnóstico por imagem , Seio Maxilar/ultraestrutura , Pessoa de Meia-Idade , Radiografia , Estatísticas não Paramétricas
10.
Int J Oral Maxillofac Surg ; 36(1): 62-71, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17027235

RESUMO

The aim of the study was to compare the integration and implant stability of turned and oxidized titanium implants when placed in experimental bone defects with autogenous bone graft, BMP-2 or without adjunctive therapy. Four defects were prepared on each side of the mandible of 12 mongrel dogs five months after tooth extractions. Implants with turned and oxidized surfaces were placed in the defects. The circumferential gaps were filled with either autogenous bone grafts, a BMP-allogeneic dog mixture in a thermoplastic carrier, carrier alone or left without any treatment (control). There were no statistically significant differences between control and treated sites, neither for turned nor for oxidized implants with regard to histomorphometric measurements in ground sections and to implant stability as measured with resonance frequency analysis (RFA) after 4 and 12 weeks of healing. However, oxidized implants showed a significantly higher stability after 4 weeks and a tendency (p < 0.1) of that after 12 weeks. Histomorphometry showed more bone contacts for oxidized than for turned implants. It is concluded that oxidized implants gain stability more rapidly and integrate with more bone contacts than implants with a turned surface when placed in bone defects.


Assuntos
Proteínas Morfogenéticas Ósseas/farmacologia , Materiais Revestidos Biocompatíveis , Implantes Dentários , Planejamento de Prótese Dentária , Osseointegração/fisiologia , Fator de Crescimento Transformador beta/farmacologia , Animais , Proteína Morfogenética Óssea 2 , Regeneração Óssea/efeitos dos fármacos , Transplante Ósseo , Implantação Dentária Endóssea , Polimento Dentário , Retenção em Prótese Dentária , Cães , Implantes Experimentais , Masculino , Mandíbula/cirurgia , Osseointegração/efeitos dos fármacos , Óxidos , Estatísticas não Paramétricas , Propriedades de Superfície , Titânio , Vibração
11.
Int J Oral Maxillofac Surg ; 34(5): 495-8, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16053867

RESUMO

The aim of the present study was to report the incidence of neurosensory dysfunction in the lower lip and chin after bilateral sagittal split osteotomy at four postoperative time points, and the relation of impairment to factors connected with the operation. Sixty-eight patients who had undergone the procedure (at 136 operated sites) were reviewed, and neurosensory recovery was studied at 2, 6, 18 and finally 30 months postoperatively. A change in neurosensory recovery was seen over this period of time. Two months postoperatively, 84 sites had reduced sensitivity (62%). The incidence of disorder decreased to 52 sites (38%) at 6 months, 43 sites (32%) at 1.5 years and 32 sites (24%) at the final 2.5-year check up. The patient age at the time of surgery, the type of osteosynthesis and the perioperative position of the inferior alveolar nerve were variables that influenced the neurosensory outcome. In conclusion, this retrospective study shows that the most important factors influencing postoperative nerve function are patient age, fixation method and the perioperative position of the inferior alveolar nerve.


Assuntos
Mandíbula/cirurgia , Nervo Mandibular/fisiopatologia , Osteotomia/métodos , Transtornos de Sensação/etiologia , Adolescente , Adulto , Fatores Etários , Placas Ósseas/efeitos adversos , Parafusos Ósseos/efeitos adversos , Fios Ortopédicos/efeitos adversos , Queixo/inervação , Feminino , Seguimentos , Humanos , Lábio/inervação , Masculino , Mandíbula/inervação , Nervo Mandibular/patologia , Pessoa de Meia-Idade , Osteotomia/efeitos adversos , Recuperação de Função Fisiológica/fisiologia , Estudos Retrospectivos , Resultado do Tratamento
12.
Artigo em Inglês | MEDLINE | ID: mdl-11441539

RESUMO

BACKGROUND: Previous experimental studies have shown a higher degree of bone-implant contact for surface-enlarged implants compared with machined implants. Yet, there is insufficient evidence that such implants show higher stability and an increased survival rate. PURPOSE: The purpose of this investigation was to study the integration and stability of grit-blasted implants with retention elements on the implant neck, with and without marginal bone defects, compared with machined implants without retention elements. MATERIALS AND METHODS: After tooth extraction of the mandibular premolars in six dogs, two grit-blasted, partly microthreaded Astra Tech implants and one standard Brånemark implant were bilaterally placed in each dog. On one side, 3 x 3 mm large buccal defects were created, to expose three to four implant threads. The contralateral side served as control, and no defects were made. The animals were sacrificed after 4 months of healing. Implant stability was measured using resonance frequency analysis at implant installation and after 4 months of healing. Histologic and histomorphometric evaluation was made after 4 months of healing. RESULTS: Resonance frequency analysis indicated that all implants in the test and control groups were osseointegrated after 4 months, with a tendency toward higher implant stability for the Astra Tech implants. There was a statistically significant higher increase in resonance frequency for the Astra test implants compared with their corresponding controls. Histology and histomorphometry showed well-integrated implants with varying degrees of bone repair at the defect sites. The greater bone-implant contact for the Astra implants was statistically significant. No significant difference between the implants in amount of bone filling the threads was recorded. CONCLUSIONS: The Astra Tech implants tested showed a higher degree of bone-implant contact and higher level of bone regenerated at defect sites compared with the Brånemark implants. Resonance frequency analysis demonstrated a significantly higher increase in the Astra test implants compared with their control groups than did the Brånemark test implants versus their controls.


Assuntos
Regeneração Óssea , Implantes Dentários , Planejamento de Prótese Dentária , Retenção em Prótese Dentária , Mandíbula/cirurgia , Perda do Osso Alveolar/fisiopatologia , Perda do Osso Alveolar/cirurgia , Animais , Cães , Feminino , Seguimentos , Masculino , Mandíbula/patologia , Mandíbula/fisiopatologia , Osseointegração , Estatísticas não Paramétricas , Propriedades de Superfície , Alvéolo Dental/fisiopatologia , Alvéolo Dental/cirurgia , Transdutores , Vibração , Cicatrização
13.
Clin Implant Dent Relat Res ; 3(3): 120-4, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11799701

RESUMO

BACKGROUND: To date, clinical studies have mainly focused on early loading of mandibular implants. Recently, there has also been considerable interest in early loading of maxillary implants. PURPOSE: The purpose of this article is to report the outcome of maxillary implants loaded after a 3-month healing period and followed up to 5 years. MATERIALS AND METHODS: Seventeen patients (11 males and 6 females) received 44 Astra Tech implants (Mölndal, Sweden) for treatment of single-tooth (13 cases) and partial edentulism (9 cases). The patients were followed up to 5 years after implant placement: 50% of the implants were followed for 3 years and 16% have been followed throughout the observation period. Preoperatively, bone height and width were assessed on radiographs. Marginal bone loss was recorded on intraoral radiographs annually. RESULTS: No implant was lost during the observation period. The average marginal bone loss was 0.5 +/- 0.7 mm after 1 year, 0.6 +/- 0.7 mm after 3 years, and 0.9 +/- 1.6 mm after 5 years. There were no soft-tissue or prosthetic failures recorded during the observation period. CONCLUSION: Early loading of Astra Tech implants was highly successful in maxillary partial and single-tooth cases followed up to 5 years in function.


Assuntos
Dente Suporte , Implantes Dentários , Prótese Dentária Fixada por Implante , Maxila/cirurgia , Adulto , Idoso , Reabsorção Óssea/diagnóstico por imagem , Coroas , Implantes Dentários para Um Único Dente , Planejamento de Prótese Dentária , Prótese Parcial Fixa , Feminino , Seguimentos , Humanos , Arcada Parcialmente Edêntula/diagnóstico por imagem , Arcada Parcialmente Edêntula/reabilitação , Arcada Parcialmente Edêntula/cirurgia , Masculino , Maxila/diagnóstico por imagem , Pessoa de Meia-Idade , Radiografia , Resultado do Tratamento , Cicatrização
14.
J Mater Sci Mater Med ; 11(2): 83-9, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15348051

RESUMO

An experimental rabbit bone graft model for the study of bone formation and remodeling around titanium implants is described. A 2.5-cm long radius bone segment served as an onlay graft. Two commercially pure (c.p.) titanium implants were inserted into the bone graft prior to fixation to the inferior border of the mandibular base with osteosynthesis titanium screws. Each animal was operated twice, allowing follow-up periods of 6 weeks on one side and 6 months on the contralateral side. In order to study bone remodeling by means of fluoroscopy the animals received single injections of tetracyclin and alizarine complexone 2 weeks and 1 week, respectively, prior to sacrifice by perfusion fixation with glutaraldehyde. The bone and implants were excized en bloc, postfixed and embedded in plastic resin. Stained and unstained thin ground sections as well as microradiographed thick sections were produced for light microscopic morphometry and fluoroscopy. After 6 weeks, osteoclastic/osteoblastic activity was primarily observed in the graft-recipient contact area and in the intracortical compartment of the graft bone. New bone formation observed on the implant surface originated from the recipient site. The bone formation was evident also in the implant-graft interface. At 6 weeks the average bone fill of the implant threads was 28.4% which increased to 36.4% after 6 months as measured by morphometry. An average of 17.6% bony contact was measured after 6 weeks which increased to 29.7% 6 months after surgery. The graft bone had reduced in size from an average of 39.5% after 6 weeks down to 24.8% after 6 months (P \lt 0.05). It is concluded that the described experimental model can serve as a useful method for the study of implant healing in onlay grafts.

15.
Clin Oral Implants Res ; 10(4): 267-77, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10551069

RESUMO

The objective of the present report was to study the effects of barrier membranes on bone resorption and implant stability in a rabbit onlay bone graft model, using resonance frequency analysis, coordinate measurements on plaster models, removal torque measurements and histology. Disc-shaped bone grafts were harvested from the calvarium and placed with titanium implants in the proximal tibial metaphyses of 9 rabbits. On one side (test) the bone graft/implant was covered by an e-PTFE barrier, while the contralateral side was not covered by a membrane and served as control. Three animals were sacrificed after 8 weeks for histology. In 6 animals the membranes were removed after 8 weeks and the animals were followed for an additional period of 16 weeks. Implant stability and bone height around the implants was assessed for the test and control sides at Day 0 and 8, 16 and 24 weeks postoperatively. Removal torque tests were performed after 24 weeks. The results showed an increase in volume of the bone graft on the test side as long as the barrier membrane was in place. However, after removal of the membrane at 8 weeks the resorption rate was higher on the test side compared to the control side, resulting in a similar bone height after 24 weeks. There were no statistically significant differences in implant stability between the test and control sides at any time point, as measured with resonance frequency analysis. Additionally, no statistically significant differences were found between the test and control sides after 24 weeks, using removal torque measurements, coordinate measurements and histomorphometric evaluation. Thus, in this experimental model, the use of non-resorbable barrier membranes did not improve the stability of implants simultaneously placed with onlay bone grafts. Moreover, extensive resorption of the grafted bone was seen after barrier removal, which resulted in similar bone graft volume for the test and control sides at the end of the observation period.


Assuntos
Reabsorção Óssea/etiologia , Transplante Ósseo/efeitos adversos , Implantes Experimentais , Membranas Artificiais , Animais , Reabsorção Óssea/prevenção & controle , Implantação Dentária Endóssea , Remoção de Dispositivo , Feminino , Osseointegração , Politetrafluoretileno , Coelhos , Estatísticas não Paramétricas , Tíbia , Torque , Transdutores , Vibração
16.
Int J Oral Maxillofac Implants ; 14(4): 571-8, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10453674

RESUMO

A surgical procedure for the rehabilitation of severely resorbed maxillae is described. Twenty-five patients, made up of a development group of 5 and a routine group of 20, were treated with Le Fort I osteotomy using interpositional bone grafts from the iliac crest and, in a second stage, titanium implants. Altogether, 181 Brånemark implants were placed, and the patients were followed for up to 5 years. The implant survival rate for the development group was 60.0% after 5 years. Life table analysis for the routine group showed a 5-year survival rate of 85.6%. Twenty-two patients received fixed prostheses and 2 received overdentures. One patient lost all implants and was rehabilitated with a prong denture.


Assuntos
Reabsorção Óssea/cirurgia , Transplante Ósseo , Implantação Dentária Endóssea , Implantes Dentários , Maxila/cirurgia , Doenças Maxilares/cirurgia , Osteotomia de Le Fort , Adulto , Idoso , Transplante Ósseo/métodos , Implantação Dentária Endóssea/métodos , Planejamento de Prótese Dentária , Prótese Dentária Fixada por Implante , Falha de Restauração Dentária , Revestimento de Dentadura , Feminino , Seguimentos , Humanos , Tábuas de Vida , Masculino , Pessoa de Meia-Idade , Osteotomia de Le Fort/métodos , Estudos Prospectivos , Análise de Sobrevida , Titânio
17.
Int J Oral Maxillofac Surg ; 28(3): 224-31, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10355947

RESUMO

A rabbit model was used to study the healing and stability of titanium implants in free bone grafts, placed simultaneously or after 8 weeks of healing and followed for 24 weeks. The skull bone was used as donor site and the tibial metaphysis as recipient site. Stability measurements were performed by using resonance frequency analysis (RFA) at implant placement and after 4, 8, 16 and 24 weeks of healing. Statistically significant higher resonance frequencies were measured at all time points for the delayed approach implants. Removal torque tests after 24 weeks revealed no differences between the two procedures. Histologic ground sections were prepared on specimens taken after 8, 16 and 24 weeks of healing. More bone-implant contacts were observed in the bone graft for the implants inserted in a delayed fashion, while there was no statistically significant difference in the degree of total bone-implant contact between the two groups. It is concluded that delayed implant placement in autogenous onlay bone grafts results in a better integration and stability of the implants.


Assuntos
Transplante Ósseo , Implantes Experimentais , Osseointegração , Implantação de Prótese/métodos , Animais , Fenômenos Biomecânicos , Feminino , Percussão , Coelhos , Crânio , Estatísticas não Paramétricas , Tíbia , Fatores de Tempo , Titânio , Torque , Transdutores , Vibração
18.
Int J Oral Maxillofac Surg ; 28(1): 31-7, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10065646

RESUMO

The aim of the present study was to histologically analyse the bone graft-titanium implant interface after six and twelve months of healing for a simultaneous approach and after six months for a delayed approach. For this purpose, screw-shaped c.p. titanium microimplants, 2 mm in diameter and 5 mm long, were placed and retrieved at different time intervals in ten consecutive patients with severely resorbed maxillae and treated with iliac cortico-cancellous bone grafts and titanium implants in a two-stage procedure. The histomorphometrical analyses of ground sections of the specimens showed a higher degree of bone-implant contact and more bone filling the implant threads in the delayed approach microimplants. This was probably due to the partly revascularized grafted bone in the delayed approach being able to respond to the surgical trauma, resulting in interfacial bone formation. It is concluded that the results from the present study favour the use of a delayed approach when using free autogenous bone grafts and titanium implants for reconstruction of the severely atrophied maxilla.


Assuntos
Aumento do Rebordo Alveolar/métodos , Transplante Ósseo/métodos , Implantação Dentária Endóssea/métodos , Osseointegração , Processo Alveolar/irrigação sanguínea , Transplante Ósseo/fisiologia , Implantes Dentários , Feminino , Humanos , Ílio , Masculino , Pessoa de Meia-Idade , Osteogênese , Estatísticas não Paramétricas , Fatores de Tempo , Titânio
19.
Clin Implant Dent Relat Res ; 1(2): 70-4, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-11359300

RESUMO

BACKGROUND: High failure rates have been presented for implants placed in grafted bone. The bone graft-implant interface constitutes a most complex healing situation, where the time scale for osseointegration and development of implant stability currently is not known. PURPOSE: The aim of the study was to measure the stability of implants placed in grafted bone after various follow-up periods. METHODS: Implant stability measurements by means of resonance frequency analysis were performed in 10 patients previously treated with a Le Fort I osteotomy and interpositional bone grafts. The implants were placed 3 to 4 months after the grafting procedure. Sixty-seven Brånemark implants were subjected to resonance frequency analysis measurements at fixture placement and up to 5.5 years after implant surgery. Periapical radiographs were used for assessment of marginal bone levels. RESULTS: The radiographic examinations showed marginal bone loss with time during the 5.5-year follow-up. The resonance frequencies varied from 5860 to 8440 Hz. When accounting for abutment length and marginal bone level, there was a tendency of increasing resonance frequency with time. Two implants with low resonance frequencies failed during the prosthetic phase. CONCLUSION: The results indicate an increased implant stability with time, which may reflect bone formation, remodeling, and maturation at the implant interface.


Assuntos
Transplante Ósseo , Implantação Dentária Endóssea/métodos , Implantes Dentários , Retenção em Prótese Dentária , Maxila/cirurgia , Osseointegração , Idoso , Estudos Transversais , Falha de Restauração Dentária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteotomia de Le Fort , Projetos Piloto , Processamento de Sinais Assistido por Computador , Estatísticas não Paramétricas , Fatores de Tempo , Transdutores , Vibração
20.
Clin Oral Implants Res ; 9(5): 343-7, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9835814

RESUMO

A specially designed, TiO2-blasted titanium fixture, partially conical and microthreaded, the Astra Tech Fixture ST, was used for rehabilitation of partial edentulism in the posterior mandible. Superior to the mandibular canal 25 fixtures were placed in 10 patients. Fixed metal-ceramic bridges were then performed. After 1-year follow-up, all bridges were found to be clinically stable. The implant survival rate was 100% and the mean marginal bone resorption was 0.05 +/- 0.11 mm.


Assuntos
Implantes Dentários , Planejamento de Prótese Dentária , Prótese Dentária Fixada por Implante , Prótese Parcial Fixa , Arcada Parcialmente Edêntula/reabilitação , Idoso , Perda do Osso Alveolar/etiologia , Dente Pré-Molar , Implantação Dentária Endóssea , Implantes Dentários/efeitos adversos , Estudos de Avaliação como Assunto , Feminino , Seguimentos , Humanos , Masculino , Mandíbula , Pessoa de Meia-Idade , Dente Molar
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