Displacement of a dental implant into the maxillary sinus: report of an unusual complication when performing staged sinus floor elevation procedures

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.

Ridge augmentation and maxillary sinus grafting with a biphasic calcium phosphate: histologic and histomorphometric observations

OBJECTIVES: This retrospective study reports on histologic and histomorphometric observations performed on human biopsies harvested from sites augmented exclusively by biphasic calcium phosphate [BCP: hydroxyapatite (HA)/ tricalcium phosphate (TCP) 60/40] and healed for a minimum of 6 months. MATERIALS AND METHODS: Five patients benefited from three augmentation regimens (i.e.: one-stage lateral augmentation; two-stage lateral augmentation; and two-stage sinus grafting). In all patients, a degradable collagen membrane served as a cell-occlusive barrier. Core biopsies were obtained from lateral as from crestal aspects 6-10 months after augmentation surgeries. For histologic and histomorphometric evaluations, the non-decalcified tissue processing was performed. RESULTS: The histological examination of 11 biopsies showed graft particles frequently being bridged by the new bone, and a close contact between the graft particles and newly formed bone was seen in all samples. The mean percentages of newly formed bone, soft tissue compartment, and graft material were 38.8% (+/-5.89%), 41.75% (+/-6.08%), and 19.63% (+/-4.85%), respectively. Regarding bone-to-graft contact values, the percentage of bone coverage of graft particles for all biopsies ranged from 27.83% to 80.17%. The mean percentage of bone coverage was 55.39% (+/-13.03%). CONCLUSIONS: Data from the present study demonstrated osteoconductivity scores for the BCP material (HA/TCP 60/40) in patients resembling those previously shown for grafting materials of xenogenic and alloplastic origin.

Maxillary sinus floor extension and posterior tooth inclination in adolescent patients with Class II Division 1 malocclusion treated with maxillary first molar extractions

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.

The controversy in the management of the N0 neck for squamous cell carcinoma of the maxillary sinus

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.

Maxillary sinus grafting with a synthetic, nanocrystalline hydroxyapatite-silica gel in humans: histologic and histomorphometric results.

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.

Proximity of premolar roots to maxillary sinus: a radiographic survey using cone-beam computed tomography.

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.

Evaluation of the maxillary sinus in panoramic radiography—a comparative study

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

Piezosurgery Applied to Implant Dentistry: Clinical and Biological Aspects

Piezosurgery is a new and modern technique of bone surgery in implantology. Selective cutting is possible for different ultrasonic frequencies acting only in hard tissues (mineralized), saving vital anatomical structures. With the piezoelectric osteotomy technique, receptor site preparation for implants, autogenous bone graft acquistition (particles and blocks), osteotomy for alveolar bone crest expansion, maxillary sinus lifting, and dental implant removal can be performed accurately and safely, providing excellent clinical and biological results, especially for osteocyte viability. The aim of this review was, through literature review, to present clinical applications of piezosurgery in implant dentistry and outline their advantages and disadvantages over conventional surgical systems. Moreover, this study addressed the biological aspects related to piezosurgery that differentiate it from those of bone tissue approaches. Overall, piezosurgery enables critical operations in simple and fully executable procedures; and effectively, areas that are difficult to access have less risk of soft tissue and neurovascular tissue damage via piezosurgery.

Imunomarcação da OPG e RANKL no reparo ósseo após a cirurgia de elevação do seio maxilar com Bio-Oss

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aplicação de engenharia tecidual na elevação de seio maxilar: uma revisão sistemática da literatura

The purpose of this literature review is to present the state-of-the-art on the application of tissue engineering techniques in sinus lifts procedures, reporting the influence of these techniques in increasing bone height and volume in the maxillary sinus, and the osseointegration of the implants installed in the grafted areas. PubMed and Scopus databases were searched using the keywords “scaffold” OR “engineered tissue” AND “sinus augmention” OR “sinus floor elevation”. In the initial search 463 articles were selected, of which 19 were selected abstracts reading, with nine papers selected by the end, for evaluation of the application of tissue engineering techniques in sinus lift procedures. Despite the positive results of tissue engineering procedures in sinus floor elevation reported in the selected articles, further studies are still needed, for a better standardization of experimental models and materials used, leading to definitive conclusions about the effects of the application of tissue engineering procedures on bone formation in maxillary sinus lifting procedures.

Avaliação clínica e radiográfica de pacientes submetidos ao levantamento da membrana do seio maxilar

Implant dentistry is a dental specialty which presents great predictability in the rehabilitation at posterior, partially edentulous maxillary areas. Early tooth loss results in significant jaw remodeling. The maxillary sinus lifting followed by implant placement is a predictable technique initially described in 1980. Since then, several different techniques have been investigated varying filling materials and the management of complications in order to provide effective guidance in the rehabilitation of these patients. The current study evaluated ten patients who underwent sinus lifting before implant placement and crown installation. First, a retrospective analysis of the medical records was conducted to obtain information about possible postoperative complications. Clinical and radiographic analyses were performed at baseline and 180 days after surgeries. The sinus lifting with immediate implant placement provided satisfactory outcomes and can be considered a safe procedure. Treatment predictability was demonstrated in 90% of patients and for 86.96% of implants placed. It is important to highlight knowledge of anatomical structures at this area, the use of delicate surgical techniques, and strict patient follow-up.

Avaliação do índice de sucesso dos enxertos autógenos e dos implantes instalados em região de seio maxilar

Maxillary sinus lifting surgery is considered an excellent option for patient rehabilitation in cases of maxillary sinus pneumatization. This longitudinal study was performed in 41 patients to evaluate 51 maxillary sinus lifting procedures concomitant to autogenous bone grafted from mandibular ramus. Of the 107 implants installed, 28 were immediate fixations. Success index achieved regarding to bone graft was of 98.04%. The implants installed immediately or after bone grafting resulted in success rates of 92.86% and 94.59% respectively, with no statistically significant differences between them. Surgeries for bone grafting and immediate installation are considered a reliable treatment alternative provided that both anatomical structures and tissue physiology are kept in good conditions, with appropriate indication and techniques for good implant stability.

A aplicação de plasma rico em plaquetas na regeneração dos tecidos periodontais

O periodonto é uma unidade biológica e funcional, constituída pela gengiva, pelo cemento, pelo ligamento periodontal e pelo osso alveolar. O seu processo de cicatrização envolve mecanismos fisiológicos complexos que requerem a ação dos fatores de crescimento, péptidos oriundos da desgranulação das plaquetas. Neste sentido surge o Plasma Rico em Plaquetas como um produto autólogo, obtido a partir da centrifugação do sangue do próprio paciente e que visa melhorar a cicatrização dos tecidos após procedimentos enquadrados na Medicina Dentária. Esta revisão bibliográfica baseou-se numa pesquisa realizada na base de dados MEDLINE, via pubmed. Foram utilizadas as palavras-chave “plasma rich in growth factors”, “platelet-rich plasma”, “oral surgery”, “dental implants”, “sinus lift”, “third molar surgery” e “bone regeneration”. Após leitura de 40 artigos, foram descartados 9 pela sua pouca relevância no contexto. O objetivo é avaliar a efetividade da aplicação de plasma rico em plaquetas na regeneração dos tecidos periodontais em situações clínicas como alvéolos pós-extracionais, cirurgias de implantes, cirurgias de elevação do seio maxilar e na regeneração óssea. A efetividade em tecidos moles parece ser consensual. A efetividade no tecido ósseo é alvo de contradição entre os diversos autores, concluindo-se que há necessidade de mais estudos randomizados e controlados para que se possa responder à questão com evidência científica suficiente.

Mesenchymal Stem Cells and Bovine Bone Mineral in Sinus Lift Procedures-An Experimental Study in Sheep

Introduction: New reconstructive and less invasive methods have been searched to optimize bone formation and osseointegration of dental implants in maxillary sinus augmentation. Purpose: The aim of the presented ovine split-mouth study was to compare bovine bone mineral (BBM) alone and in combination with mesenchymal stem cells (MSCs) regarding their potential in sinus augmentation. Material and Methods: Bilateral sinus floor augmentations were performed in six adult sheep. BBM and MSCs were placed into the test side and only BBM in the contra-lateral control side of each sheep. Animals were sacrificed after 8 and 16 weeks. Augmentation sites were analyzed by computed tomography, histology, and histomorphometry. Results: The initial volumes of both sides were similar and did not change significantly with time. A tight connection between the particles of BBM and the new bone was observed histologically. Bone formation was significantly (p = 0.027) faster by 49% in the test sides. Conclusion: The combination of BBM and MSCs accelerated new bone formation in this model of maxillary sinus augmentation. This could allow early placement of implants.