Kinetical analysis of tumor cell death-inducing mechanism by polymorphonuclear leukocyte-derived calprotectin: involvement of protein synthesis and generation of reactive oxygen species in target cells

Nasal reconstruction presents a significant challenge to the facial plastic surgeon. Reestablishment of the desired aesthetic nasal contour and restoration of respiratory function are the dual goals of this endeavor. While autologous cartilage or bone is considered optimal grafting material, the supply is often limited and harvesting entails additional morbidity. Many synthetic materials have been introduced for use in nasal reconstruction, but high infection and extrusion rates have left most surgeons dissatisfied with conventional implants. Porous polyethylene (Medpor) implants were used for nasal reconstruction in 187 patients; 66 (35.3%) patients underwent primary rhinoplasty, while revision surgery was performed in 121 (64.7%) patients. Most patients required multiple implants, including columella struts, plumper grafts, dorsal tip implants, and nasal valve battens. Postoperative follow-up ranged from 6 months to 3.5 years. Complications occurred in five (2.6%) patients. Three early and two delayed infections necessitated implant removal in five patients, all of whom had compromised skin-soft tissue envelopes secondary to heavy smoking, cocaine abuse, or prior surgery. One case of an overly augmented nasal dorsum and tip required implant removal, reduction, and reinsertion. All implants were easily removed. No other complications including implant extrusion or skin erosion have been noted. Porous polyethylene (Medpor) implants allow for fibrovascular ingrowth, which lends stability to the implant. Porous polyethylene implants are well tolerated and provide an ideal material for nasal reconstruction.     

Long-term evaluation of the use of coralline hydroxyapatite in orthognathic surgery

PURPOSE: This prospective study was designed to evaluate the long-term clinical and radiographic results of porous block hydroxyapatite (PBHA) used as a synthetic bone graft in orthognathic surgery and craniofacial augmentation. PATIENTS AND MATERIALS: A total of 245 consecutive patients were treated initially. Inclusion criteria for this study included a minimum clinical and radiographic follow-up of 5 years. In addition, all patients with known implant failures were included regardless of whether they met the study criteria. There were 111 patients that met the criteria for inclusion in this study. All patients had undergone orthognathic surgery with rigid fixation and had had inlay or onlay PBHA implants placed. Ninety-six percent of the implants were placed through an intraoral approach. Long-term postoperative radiographs were visually compared with immediate postoperative radiographs for implant position, stability, resorption, and other significant radiographic changes. The clinical examination evaluated for signs and symptoms of infection, wound dehiscence, implant exposure, implant displacement, changes in the overlying mucosa, and development of oronasal or oroantral fistulae. RESULTS: Four hundred seventy-one implants were placed: 403 in the maxilla, 44 in the mandible, and 24 in the periorbital region. There were 289 implants placed in direct communication with the maxillary sinus. The average follow-up time was 7.2 years (range, 5.0 to 10.3 years). Twenty-three implants (4.9%) were removed during the evaluation period. Lateral maxillary wall grafting had 95.7% success, with nine implants being lost in three patients. One chin implant was removed because of dissatisfaction with the aesthetics. Seven (14%) midpalatal implants used for maxillary expansion were lost, primarily because of exposure of the implant to the oral or nasal cavity at the time of surgery. When PBHA was used for alveolar cleft grafting, there was a 100% failure rate. CONCLUSION: The use of PBHA as a bone graft substitute in orthognathic surgery and for facial augmentation showed a high percentage of success and efficacy. However, adequate soft tissue coverage in the nasal floor and on the palate are paramount for success of midpalatal implants. PBHA should not be used for alveolar cleft grafting. Rigid fixation for inlay implants in the maxilla is important to provide stress shielding of the material and minimize micromovement during the initial healing phase.     

Maxillary sinus augmentation using different grafting materials and dental implants in monkeys. Part I. Evaluation of anorganic bovine-derived bone matrix

The aim of this study was to evaluate clinically, histologically and histometrically the use of anorganic bovine bone matrix (i.e. Bio-oss) as a grafting material for maxillary sinus augmentation procedures. In 4 adult male rhesus monkeys (i.e. Macaca mulatta) the 1st, 2nd and 3rd maxillary molars on one side of the jaws were extracted. The remaining bone between the alveolar crest and the bottom of the sinus was then reduced to 3-4 mm. After 3 months, maxillary sinus augmentation procedures were performed on one side of the jaws in each monkey and the sinuses were grafted with the bovine bone matrix. At that time, 2 IMZ pure titanium plasma coated implants were immediately placed into the augmented sinuses (i.e. simultaneous implants-loaded group). After 4 months, 2 additional similar implants were placed into these previously augmented sinuses (i.e. delayed implants-loaded group). Four months later, the abutment connection was performed and all 4 implants were loaded with a gold-alloy bridge for 6 months (i.e. until sacrifice of the animals). The contralateral side of each monkey received the same treatment with the exception that the extractions were performed 7 months after those in the opposite side and that the implants in this side were not loaded. Thus, 2 additional study groups (i.e. simultaneous implants-unloaded group and delayed implants-unloaded group) were obtained. Clinically, all loaded implants were stable at the day of sacrifice. Histologically, the grafted sinuses exhibited significant bone formation with integration of the bovine bone matrix particles to the new bone. Direct mineralized bone-to-implant contact was greater for the delayed implant placement groups than for the implants installed simultaneously with the sinus augmentation. Furthermore, the percentage of direct mineralized bone-to-implant contact was greater in the residual bone than in the augmented area. It was concluded that the anorganic bovine bone matrix facilitated bone formation and implant osseointegration in the augmented sinuses and that the delayed implant placement in combination with the sinus augmentation procedure seemed to be preferable.     

Clinical use of a bioactive glass particulate in the treatment of human osseous defects

The dental practitioner has a wide choice of materials available for use in bone grafting procedures. A bioactive glass particulate possesses many favorable qualities not often found in other materials, including the ability to remain where placed even with adjacent suctioning; hemostasis; and incorporation into the host bone without the fibrous encapsulation encountered with most other synthetic materials. It is also quick and easy to prepare. This article reviews clinical experiences with PerioGlas in the setting of private practice periodontics, in which this material was used as the grafting material for periodontal defects, apicoectomies, cysts, and ridge augmentation and maintenance procedures, as well as for implant repairs. Several cases detail the advantages of this grafting material.     

Short-term healing following the use of calcium sulfate as a grafting material for sinus augmentation: a clinical report

Because of the frequent lack of bone in the posterior maxilla, sinus augmentation has become a commonly practiced treatment modality. Many different materials have been used for augmenting the sinus, and the ideal graft is yet to be found. The present article reports the results of sinuses grafted with calcium sulfate in 2 patients. Bone biopsies were harvested 9 months after the augmentation procedure. In the first patient, 3 titanium threaded-cylinder implants were placed in the grafted area after 9 months, while in the second, 1 acid-etched, screw-shaped titanium implant was placed simultaneously with the graft. Light microscopic evaluation revealed new bone formation with ongoing remodeling and progressive lamellar maturation in the specimens. No remnants of the alloplastic material were detectable in any section, either within the bone or in the medullary tissue. When reevaluated at the uncovering procedure, the implants were radiographically and clinically judged to be osseointegrated. These observations suggest that, when used in the appropriate form and with the proper technique, calcium sulfate is a promising graft material for sinus augmentation, producing adequate quantity and quality of new bone for implant placement.     

Reconstruction of alveolar defects before implant placement

Guided bone regeneration and bone grafting have been used to reconstruct defective alveolar ridges in preparation for implant placement. This phase of implant treatment is critical to a successful overall result. Remarkable advances that have occurred in techniques and materials enable us to place and restore implants in cases where previously it was not feasible. Three case reports are presented to illustrate successful management of different alveolar defects.     

Bone grafting materials for dental applications: a practical guide

A variety of grafting materials are available for use in dental applications. Autogenous bone is the material of choice because of its osteogenic properties, which allow bone to form rapidly and under conditions where significant bone augmentation or repair is required. For other dental applications, allografts and alloplasts are appropriate. Knowing the physical and chemical properties of these materials and their mechanism of action, the correct graft or combination of grafts can be selected for each situation encountered. This article discusses current bone grafting options as reported in the literature since 1984. It emphasizes acquainting the reader with currently available materials and their properties.     

Problems associated with the atrophic mandible

A range of treatment options has been presented regarding the use of dental implants to rehabilitate patients who otherwise have compromised function using conventional tissue-borne prostheses. This patient population offers significant challenges to both the surgeon and the prosthodontist. Generally speaking, IODs retained on two or more endosteal osseointegrated implants; transosteal, subperiosteal, ramus frame implant-supported and implant-retained prostheses, and a totally implant-supported design offer options to treat the severely atrophic mandible. When bone support or volume is so lacking that augmentation procedures are required, bone grafting can be considered as a treatment option. The state-of-the-art of implant treatment for the atrophic mandible offers to the dental professional and patient a variety of options. Thus far, it is too early to make specific recommendations as to which treatment offers the best option for each patient. It is fair to say that the ISP remains the gold standard against which other treatments can be compared.     

Coralline hydroxyapatite: a bone graft alternative in foot and ankle surgery

The use of coralline hydroxyapatite has become a viable bone grafting alternative. Its efficacy has been well established through multiple human and animal studies. Coralline hydroxyapatite enhances osteogenesis by providing a biocompatible lattice for the passage and assembly of vascular, fibroblastic, and osteoblastic tissues. It also provides support for surrounding osseous structures. The uses of this material are expanding into the realm of foot and ankle surgery. Its consideration as an appropriate bone graft substitute as well as multiple case studies demonstrating its surgical applicability are discussed. The implants utilized at Thorek Hospital and Medical Center over the past eight years, with an average follow-up of three and one-half years, have proven to be a valuable resource for augmentation where an osseous defect has occurred.     

Chondroid syringoma of the orbit

Augmentation of lips is a common aesthetic procedure that is mostly performed with alloplastic materials or autologous tissue. Various alloplastic injectable implants have been developed for soft tissue augmentation without surgery. Most biologic materials are resorbed within a few months, fluid silicone may migrate, and autologous fat is not ideal for fine contouring of the lips. The search for a biocompatible, permanent, nontoxic, and biologically inert filler material led to the development of some new materials for subdermal or intradermal implantation. Recently Bioplastique, Artecoll, and Gore-Tex have been well established and recommended by many authors. Although these materials meet most of the characteristics that constitute an ideal injectable prosthetic material, we describe 3 examples of adverse reactions after their implantation into lips.     

Elaboration of an alternative, segmental, cartilage-sparing tip graft technique: experience in 405 cases

Despite the value of tip grafting in many rhinoplasty patients, adequate donor cartilage may be unavailable in secondary and even primary patients whose donor sites have been harvested previously or whose septal cartilage is calcified. Furthermore, by enlarging the lobule, tip grafts can create undesirable postoperative disproportions in some patients. These two observations have stimulated the elaboration of a tip graft method (which evolved from the Sheen technique) that uses small amounts of autogenous donor material to augment only those lobular segments that require increased contour or support, without necessarily increasing overall lobular volume. This article reports experience with; the technique in a 405-patient study group. Segmental tip grafting is performed endonasally through access incisions along the caudal edge of one alar cartilage. Grafts augment each third of the tip lobule and anterior columella (corresponding to each of the alar cartilage crura) depending on the aesthetic objective; multiple grafts are always placed. Selective augmentation limits the overall increase in lobular size. The method is not suitable for those patients needing substantial augmentation (58 of 463 tip-grafted patients in the 6-year study period), in which case the author still prefers the Sheen technique. The records of the 405-patient study group (40 percent primary rhinoplasty, 60 percent secondary rhinoplasty) indicate a total nasal revision rate of 14 percent; 6 percent were tip revisions. Tip revisions were more frequent in secondary patients but not in patients with thin skin. Reoperation percentages decreased during the study term, so that the tip revision rate was 12 percent in the first 12 months of study but only 4 percent in the last 12 months (p < 0.0008). The primary indication for tip grafting has evolved since the author's earlier practice experience: in the past 3 years of the study, 77 percent of primary patients and 80 percent of secondary patients underwent grafting principally to improve lobular contour, not tip projection (p < 0.0005). A segmental, cartilage-sparing tip graft technique can provide both projection and contour for primary and secondary rhinoplasty patients. Nevertheless, tip imperfections remain the most common reason for revision in the author's practice.     

Indirect sinus augmentation procedures using one-stage anatomically shaped root-form implants

Sinus augmentation procedures are a standard part of implant dentistry. Indirect sinus augmentation procedures reduce the magnitude of the surgery when sinus lift procedures are necessary. This article describes a variation of the indirect augmentation of maxillary sinuses. The surgery is performed through small diameter surgical access openings. This modified indirect sinus augmentation procedure is combined with the immediate placement of one-stage dental implants that effectively seal the surgical access openings and have an anatomical exit profile for easier restoration.     

Predictors of underlying coronary artery disease in cocaine associated myocardial infarction: a meta-analysis of case reports

A preliminary report presenting the results of fibular strut grafting in the severely resorbed mandibular and maxillary region is presented. Thirteen patients were treated due to severe resorption of alveolar and basilar bone of 49 segments of the mandible and the maxilla. Two patients additionally had pathological fractures of the mandible. In 10 cases the strut graft was harvested by means of a new minimally invasive technique. After modelling the fibular bone it was fixed to the recipient site by miniscrews or implants. After a mean follow-up period of 20 months (max. 31, min. 11 months) a retrospective analysis of clinical and radiological findings was carried out. It showed that a mean augmentation of 16 mm was achieved. Compared to other studies the fibular strut graft was resorbed less, and due to the primary stability it could be used for the treatment of fractures of the mandible. No more than natural resorption was observed when the patients received their prostheses fixed to dental implants.     

Evaluation of expanded polytetrafluoroethylene as a soft-tissue filling substance: an analysis of design-related implant behavior using the porcine skin model

Soft-tissue augmentation using the synthetic nonfluid biomaterial expanded polytetrafluoroethylene (ePTFE) has been supported by number of recent reports citing the favorable characteristics of biocompatibility, soft and natural feel, ease of use, and permanent augmentation. Concern has been expressed about this application for ePTFE material because of the proximity of the implants to the skin surface and potential problems with infection and extrusion. We evaluated the behavior of a series of specific ePTFE implant designs using a long-term subcutaneous augmentation model. By using a porcine model, 466 implants of ePTFE in the form of strips, rolls, or tubes were placed using a percutaneous insertion device subcutaneously over the dorsum and face. The animals were divided into three study groups by length of implantation (3 weeks, control; 6 months, intermediate term; and 12 months, long-term) and en-bloc tissue specimens, including skin, implants, and underlying soft tissue, were harvested for gross and histologic examination. Implants were removed at the earliest sign of infection, exposure, or extrusion and the difficulty of removal was ascertained and recorded. These data reveal that ePTFE material elicits acceptable levels of tissue activity with low extrusion rates over the short and long term supporting its use for soft-tissue augmentation. The data show a clear difference, however, in the host response and behavior of the implants for this application based on shape or design. A statistically significant difference in the low, but measurable, extrusion rates was observed amongst these implant designs. ePTFE tubes showed greater stability and predictable augmentation over other implant designs for soft-tissue augmentation and seem to represent a substantial improvement for this application.     

The use of osteotomes for sinus augmentation at the time of implant placement

The placement of endosseous dental implants is often hampered by the loss of alveolar bone. In the posterior maxilla, the presence of the maxillary sinus and less-dense bone present additional obstacles to successful implant placement. Existing methods of subantral augmentation require extensive surgical manipulation, often including a second surgical site for harvesting autogenous bone. The development of surgical osteotomes has facilitated the placement of implants in areas of minimal alveolar bone height in the posterior maxilla. This article describes the osteotome technique for sinus augmentation at the time of implant placement and presents a short-term evaluation of 34 implants placed in 18 patients.     

Hereditary angio-oedema: new clinical observations and autoimmune screening, complement and kallikrein-kinin analyses

Sinus cavities are often a major obstacle to the placement of dental implants in the posterior maxilla, especially when early tooth loss has occurred. Several grafting procedures aimed at reducing the expanded volume of these pneumatic cavities have been routinely utilized since 1979. Essentially, these techniques have consisted of recreating the necessary viable bone volume at the floor of sinus cavities by placing different bone substitute materials to allow for the insertion of endosseous implant devices. The progress achieved in the refinement of the surgical procedures and the knowledge acquired in the field of patient screening and selection, choice of biomaterials, management of complications, etc., have made sinus graft surgery highly codified and predictable. A comprehensive statistical study by multifactorial procedures was carried out to establish a Burt Contingency Chart. This chart visualizes the frequencies of all the "modality combinations" among the selected "qualitative parameters" and, by a " factorial analysis", the "multiple correlations", so that the "statistical affinities" that may exist among the same variables can be determined. This critical study endeavors to search for and reveal the favorable clinical, biologic and scientific parameters necessary for the success of sinus graft surgery on short-, medium-, and long-term bases (more than nine years). It is a particularly homogenous study, since all the operative procedures have been carried out exclusively by the author under standardized conditions. The wide variety of biomaterials utilized by the author since 1979 shows the development of bone substitute biomaterials as they have been introduced into the market during the past 15 years. The large number of patients treated, the variety of grafting materials, the important success rate obtained, and the long duration of patient follow-up have been instrumental in enabling us to establish scientifically significant results. Autogenous bone and its combinations with calcium- and phosphorus-containing biomaterials remain undoubtedly the best all-purpose biomaterials. The synthetic biomaterials have their own specific indications according to their stable (non-resorbable) or unstable (resorbable) nature and their rates of metabolic "turnover". Differently treated bones from the tissue bank (if not contaminated or immunologically questionable) behave in a fashion not unlike autogenous bone. Root-form implants are by far the best implants in the reconstructed sinus sites, while other implant types (subperiosteal implants, etc.) inserted beneath the reinforced osseous sinus floor, buccal wall, and pyramidal process, also have their indications.     

Case report. Dental Class I and skeletal Class III with unilateral right crossbite

Different forms of bone grafting materials are alluded to in this paper. Autogenous graft is superior to other bone grafting materials but is many times not available or the patient is not willing to utilize cranial or iliac crest bone. Allografts, Xenografts and bone substitute materials are the most widely used today in dentistry and especially those patients wishing to use dental implants as abutment support. The technique discussed utilizing surgical tissue design, tissue closure over the graft material and the tissue barrier can be used to produce a successful final result using a graft material of choice. It is quite certain that in the near future, the use of bone graft enhancement materials (bone morphogenic protein-like substances) will be used to enhance a quicker result. It is anticipated that growth factors, stimulating factors, bone morphogenetic proteins, and osteogenetic proteins will cause a bone graft to vascularize, solidify, incorporate, and function optimally in a shorter period of time. These materials will reduce the disability time and enhance the outcome of bone grafting in the dental profession. It is also anticipated that advanced tissue surgical techniques will give better vascularization to the new graft. The described technique is predictable and should give the operator the desired result.     

Effect of magnesium on calcium responses to vasopressin in vascular smooth muscle cells of spontaneously hypertensive rats

PURPOSE: We discuss conventional intestinal cystoplasty and show how concern about potential complications has led to an interest in alternative methods for cystoplasty. Techniques such as gastrocystoplasty, ureterocystoplasty, vesicomyomectomy (autoaugmentation), seromuscular augmentation, alloplastic replacement and bioprosthetic materials are reviewed. Laboratory and clinical results of these techniques are examined critically to compare advantages, disadvantages and potential applications. MATERIALS AND METHODS: Computer searches of available medical data bases were used to generate a list of relevant publications, including original contributions and review articles, which were then reviewed, compared and summarized. RESULTS: Augmentation cystoplasty is used routinely for treatment of reduced bladder compliance and capacity secondary to infectious, inflammatory, neurogenic and congenital disorders. Sigmoidocystoplasty and ileocystoplasty have become standard techniques but there is renewed interest in alternative techniques due to the relatively high morbidity of intestinal cystoplasty. Alternative techniques have been described to avoid inclusion of intestinal mucosa in the urinary tract while creating a compliant bladder of adequate capacity. These techniques include gastrocystoplasty, vesicomyotomy, seromuscular augmentation, various alloplastic or biodegradable scaffolds and in vitro culture with subsequent grafting of autologous urothelium. Although encouraging animal and human results have been reported, each technique is associated with its own limitations and disadvantages. CONCLUSIONS: While intestinal cystoplasty remains the standard, several alternative techniques show promise. At present only gastrocystoplasty, ureterocystoplasty and seromuscular augmentation should be considered clinically useful.     

The use of high-density polyethylene implants in facial deformities

OBJECTIVE: To determine the usefulness of porous high-density polyethylene implants (Medpor) in a variety of facial skeletal deformities and subcutaneous defects, excluding those associated with acute maxillofacial trauma. DESIGN: Case series. SETTING: Academic tertiary care referral center in Baltimore, Md. PATIENTS: Thirty-four patients (age range, 20-74 years) with facial deformities requiring skeletal defect reconstruction or augmentation (38 cases), treated between January 1, 1992, and January 1, 1997. Follow-up ranged from 6 months to 40 months. MAIN OUTCOME MEASURES: Age, type and origin of the deformity treated, type of treatment, and complications. RESULTS: Types of deformities and defects treated include 7 patients with orbital defects (secondary traumatic or oncologic deformities), 8 with temporal fossa defects, 8 with frontocranial defects, 4 with maxillary or malar defects, 7 with calvarial bone graft donor site defects, 2 with microtia, and 2 with chin deficiency. Forty implants were placed. Complications included implant exposure in 4 patients and inappropriate augmentation in 1 patient (chin implantation). CONCLUSIONS: High-density polyethylene implants offer an excellent alternative to autogenous and other alloplastic materials in reconstruction of many facial defects and deformities. Advantages include its versatility and relatively ideal pore size that allows for excellent soft tissue ingrowth and coverage. Disadvantages include its rigid nature and difficulty in contouring to the surface of complex skeletal structures.     

Guided bone regeneration for immediate non-submerged implant placement using bioabsorbable materials in Beagle dogs

The aim of the present study was to evaluate the combined application of different bioabsorbable materials for healing of residual peri-implant defects after placement of non-submerged implants into fresh extraction sockets. Second and third mandibular premolars were extracted from 10 Beagle dogs, the coronal part of the distal sockets were surgically enlarged and this was followed by immediate placement of specially designed hollow-screw non-submerged dental implants. For each animal, the coronal peri-implant defects were further treated with one of the 4 following procedures: 1) no treatment, control site; 2) grafting with porous hydroxyapatite (HA); 3) collagen membrane tightly secured around the implant and over the defect and 4) grafting with HA covered with a collagen membrane. After 16 weeks of healing, specimens were removed from the mandibule and prepared for a histomorphometric evaluation. The bone-to-implant contact length (BIC) was measured and compared amongst the different treatment modalities. In the defect area, the irregular bone regeneration was similar between all the treatment procedures (P > 0.10). In the sites covered with a collagen membrane alone, the total BIC (47%) was greater than in control sites (28.7%, P < 0.05) or sites grafted with HA (22.2%, P < 0.02). Total BIC in sites treated with the HA-membrane combination (43%) was only significantly different from sites treated with HA (P < 0.05). It is concluded that the use of bioabsorbable materials results in a limited increase of osseointegration when used in conjunction with immediate placement of non-submerged implants, although the principle of the one stage surgical approach can be maintained.