Zonal expression of angiotensin II-AT1-receptor genes in rat kidneys

The trapezius osseomyocutaneous flap is the only pedicled flap that is able to transfer vascularized bone for mandibular reconstruction as well as skin for intra-extra oral reconstruction. The trapezius muscle also helps to fill the defect created by the neck dissection and covers the vessels of the neck. This flap has been used in our maxillofacial surgery service during the past 14 years. In spite of having incorporated microvascular flaps in our reconstructive techniques it continues to be one of the flaps we use in selected patients for bone and soft tissue compound defects of the oral cavity. We describe in this article our experience using this flap with dental implants in order to achieve a functional reconstruction. We also discuss when we use this flap for mandibular reconstruction and when a free vascularized flap is used.     

The expression of regenerative growth factors in chronic liver injury and repair

The outcomes of surgical reconstruction for patients who have undergone extensive tumor resection of the mandible and associated soft tissue have been less than desirable for many reasons: lack of cancer cure, radiation problems, as well as inadequate functional reconstructive results. These patients traditionally have undergone multiple surgical procedures for restoration of the surgical deformity. With the advent of new donor sites and successful transfer of microvascular hard and soft tissue, one can restore the largest defects created during cancer excision. Combining these techniques with biocompatible dental implants and reconstructive bone plates, technology has advanced to the point of predictable outcomes. The restoration of appearance, mandibular function, and mastication is mandated by patients. Dental implants are now placed in vascularized bone reconstruction of the mandible immediately at the time of ablative surgery. This obviates the need for additional surgical reconstructive procedures, adjunctive hyperbaric oxygen therapy, and problems associated with the placement of dental implants in irradiated tissue.     

Endosseous implant and autogenous bone graft reconstruction of mandibular discontinuity: a 12-year longitudinal study of 31 patients

Surgical, medical, and prosthodontic records of 61 consecutively treated patients with mandibular discontinuity were reviewed retrospectively. All 61 patients had undergone discontinuity reconstruction with autogenous bone grafts; 31 of 61 had also received endosseous dental implants and a dental osseoprosthesis. Of these 31 implant-reconstructed patients, 23 had free autogenous nonvascularized and 8 had vascularized bone grafts. The surgical-prosthetic protocol consisted primarily of secondary, free autogenous nonvascularized bone graft reconstruction and secondary root-form endosseous implant and fixed prosthesis dental reconstruction. Vascularized bone (8 patients) or soft tissue (4 patients) grafts were utilized selectively for severely compromised patients after extensive oncologic resection, avulsive trauma, or after previous radiation treatment. Endosseous implant survival (95.5% in 31 patients), autogenous bone graft success (98.4% in 61 patients), and dental osseoprosthesis success (100% in 31 patients) were favorable. A high incidence (9.1%) of nonfunctioning (sleeping) implants was recorded for this patient population. The need to remove the titanium mesh tray for various reasons (17.6%) and the need to reconstruct soft tissue in the irradiated patient (12%) were noteworthy.     

Reconstruction of the jaw and oral cavity with free vascularized grafts

59 microvascular graft transfers performed in 50 patients in our department since 1985 have been studied retrospectively. The indications for microvascular reconstruction were sequelae after tumour surgery in 38 patients, gunshot injury in seven, chronic osteomyelitis of the mandible in three, complication after jaw fracture in one patient, and atrophy of the alveolar ridge also in one patient. Transplants from the iliac crest, fibula, radius, radial forearm skin and jejunum were used. Three transplants were lost because of arterial thrombosis, giving a success rate of 94.9%. Complications were registered in 19 cases, the largest group being wound infections. 21 of the 50 patients have been treated with dental implants for total rehabilitation of masticatory function. Transfer of free vascularized bone and soft tissue grafts has greatly improved the functional and cosmetic results obtained in reconstructive surgery of the orofacial region.     

Overview of quality measurement and improvement

BACKGROUND: Oro-mandibular reconstruction using vascularized bone-containing free-flaps can be accomplished with flap survival rates in the range of 95%. Primary reconstruction offers the best opportunity to achieve the optimal aesthetic and functional results. Patients presenting for secondary oro-mandibular reconstruction have a unique set of problems; these include the presence of soft tissue contracture displacing the mandibular segments in malposition and soft tissue deficiencies, that makes surgical correction more difficult and potentially more hazardous. Vascularized bone-containing free-flaps are indicated in secondary oro-mandibular reconstruction where both hard and soft tissues replacement is needed or when the recipient bed is unfavourable due to previous surgery and/or radiation. METHODS: Authors presents personal experience in ten cases of secondary oro-mandibular reconstruction treated at Maxillofacial Department of Parma from September 1995 to September 1996 with secondary oro-mandibular reconstruction using bone containing free flaps. Two different donor sites were used to harvest bone-containing free flaps: iliac crest in 2 cases and fibula in the others. In 4 cases the flap was only osseous while in the other 6 cases it was osteocutaneous. RESULTS: All flaps were transplanted successfully; in 1 case necrosis of the skin component of the flap was observed. CONCLUSIONS: The introduction of vascularized bone containing free flaps transferred from distant sites by microvascular techniques has changed mandibular reconstruction. Vascularized bone transferred into tissue beds compromised by salivary contamination and previous irradiation and the rational use of the soft tissutal components of the flap permit also the restoration of articulation, deglutition and mastication with quality of life better than non-vascularized alternatives.     

A comparison of vascularized and nonvascularized bone grafts for reconstruction of mandibular continuity defects

PURPOSE: This study compared vascularized and nonvascularized bone grafts for the reconstruction of segmental defects of the mandible. PATIENTS AND METHODS: The results in 39 patients having vascularized bone grafts (38 fibulas and one iliac crest) and 29 patients having nonvascularized bone grafts (26 iliac crest [22 corticocancellous block grafts, four cancellous bone grafts in a tray] and three rib grafts) for segmental mandibular reconstruction were evaluated in terms of overall success rate, total number of surgeries performed, total blood loss, total number of hospital days, and total number of hours in the operating room. RESULTS: Of 39 vascularized bone grafts, two failed (95% success rate), whereas of 29 nonvascularized bone grafts, seven failed (76% success rate). Failure for the nonvascularized bone grafts was closely correlated to the length of the defect. Nonvascularized bone graft patients underwent an average of one more surgical procedure for total reconstruction than vascularized bone graft patients, including osseointegrated implants. However, vascularized bone graft patients spent a mean of over 14 additional days in the hospital for all of their reconstructive procedures and an additional 3 hours in the operating room as compared with nonvascularized bone graft patients. Blood loss was similar in both groups (1,100 mL). Only 20% to 24% of patients in each treatment group have completed reconstruction to include osseointegrated implants. CONCLUSIONS: The success rate for vascularized bone grafting is high and is the treatment of choice when primary reconstruction is required, when the patient has been previously irradiated, or when simultaneous replacement of soft tissue is required. Vascularized bone grafts are also the treatment of choice for mandibular replacements over 9 cm in length. Nonvascularized bone grafts create a better contour and bone volume for facial esthetics and subsequent implant insertion, and may be the treatment of choice for secondary reconstruction of defects less than 9 cm in length.     

Omental transfer for salvage of the moribund lower extremity

Use of omental flaps is well documented in soft tissue reconstruction of the head and neck, chest wall, and abdomen. Three cases of omental transfer for soft tissue reconstruction of the lower extremities are presented. In two patients, free vascularized omental flaps were used to cover deep soft tissue defects over the lower leg and in one patient, a pedicle flap was used to cover a deep groin defect extending into the hip joint. In all patients, use of an omental graft allowed revascularization and subsequent wound healing with good cosmetic results.     

Primary insertion of osseointegrated dental implants into fibula osteoseptocutaneous free flap for mandible reconstruction

Twelve patients with segmental mandibular defects were reconstructed with fibula osteoseptocutaneous flaps and simultaneous placement of osseointegrated implants. Decision to perform this procedure was based on the facts that all patients had benign diseases, did not require postoperative radiotherapy, were in good general and oral conditions, and were psychologically motivated. A total of 34 fixtures was inserted in the first stage. Eight patients underwent second stage surgery, which consisted of connection of the implant abutments to the fixtures and the use of palatal mucosal grafts around the implants. Final dental prostheses were fixed 1 month later in seven patients, at this time. All flaps survived after surgery, and no implant failure was observed after a mean follow-up period of 25 months. Only one fixture was not used during the subsequent stage and was left as a sleeper. Fixed dental prostheses were used in five patients and removable overlay prostheses in the other two. Chewing function was recovered between 4 and 6 weeks after the start using the definitive dental prosthesis. In contrast to previous results, we conclude that excellent results can be achieved when this combined procedure is used in carefully selected patients. In addition, it is confirmed that the fibula osteoseptocutaneous flap is a versatile, reliable composite tissue that facilitates primary placement of osseointegrated dental implants during mandible reconstruction, thus allowing full oral rehabilitation in a shorter period of time.     

Epinephrine in digital blocks: revisited

STATEMENT OF PROBLEM: Implant treatment in the United Kingdom has been provided mainly in specialist, regional dental hospitals. However, increasingly, general dentists are providing implant-supported prostheses in a private office setting. PURPOSE: This study investigated the nature, timing, and frequency of complications associated with single tooth implant therapy in a dental hospital and two dental offices. METHODS: The dental records of 58 patients provided with 76 implants during the period of 1989-95 were reviewed retrospectively. Fifty-three single tooth crowns on implants were placed by general dentists and 23 by specialists in the dental hospital. RESULTS: Implant survival rate was 96%. Twenty-eight guided bone regeneration procedures were required, including 13 unplanned ones. Prosthodontic complications included the need for recontouring of three crowns and the recementation of three crowns. Only two abutment screws required retightening. Peri-implant soft tissue inflammation occurred around six crowns and recession around two. CONCLUSION: The single tooth implant-supported crown appears to be an effective and durable restorative treatment with a relatively low prevalence of postoperative complications.     

The pectoralis major myocutaneous flap in oral and maxillofacial reconstruction: a retrospective analysis of 50 cases

PURPOSE: This article retrospectively reviews 50 consecutive pectoralis major flaps used in oral and maxillofacial reconstruction with respect to reliability and complications. PATIENTS AND METHODS: Fifty patients had reconstruction of postcancer resection defects of the oral cavity and maxillofacial region. The age and sex of the patients and site of defect were analyzed. The design of the pectoralis major flap and complications encountered were documented. RESULTS: There were three cases (6%) of flap failure and an additional three cases (6%) in which 40% or more of the skin paddle sloughed. Orocutaneous fistula was rare. The use of an osteomyocutaneous flap with a rib gave poor results for mandibular reconstruction. CONCLUSION: The pectoralis major flap is reliable, and the complications seen in this series were comparable to other large series in the literature. Despite the increased use of microvascular flaps, the pectoralis major flap remains an excellent reconstructive choice for large soft tissue defects in the oral cavity.     

Clinical evaluations of a porous-surfaced endosseous implant system

Clinical evaluations of a new porous-surfaced implant concept (Endopore) in a large population of fully and partially edentulous patients are reported, and a technique of spreading buccal and lingual plates with osteotomes to place these implants in proximity to the sinus of the posterior maxilla is described. Three-dimensional, interconnecting pores on this implant's bone interface surface give a great surface area for bone engagement. When the maxilla is prepared by this spreading procedure, these implants can be successfully placed in areas having limited available bone. Our success rates are 97.0% for implants stabilizing a mandibular overdenture and 94.8% for implants placed in partially edentulous patients. Many times, sinus lift or other augmentation procedures can be avoided in the maxilla and mandible, allowing for less patient morbidity and for an implant reconstruction that is more affordable for the patient.     

The relationship between myenteric neuronal denervation, smooth muscle thickening and epithelial cell proliferation in the rat colon

The aim of the present experiment was to (i) study the healing after 3 and 7 months of bone defects filled with cancellous bovine bone mineral and (ii) compare the healing around implants placed in normal bone and in defects filled with bovine bone mineral. 5 beagle dogs, about 1-year-old, were used. At baseline, extractions of all mandibular left and right premolars were performed. Bone defects were prepared in the left mandibular quadrant. The defect was immediately filled with natural bovine cancellous bone mineral particles (Bio-Oss, Geistlich Sons Ltd. Wolhusen, Switzerland). No resective surgery was performed in the right jaw quadrant. In both quadrants the flaps were adjusted to allow full coverage of the edentulous ridge and sutured. 3 months later, 2 dogs (group I) were euthanized and biopsies from the premolar regions obtained and prepared for histologic analysis. The 3 remaining dogs (group II) were at this time interval (3 months) subjected to implant installation in the premolar region of both the right and left mandibular jaw quadrants. 2 fixtures of the ITI Dental Implant System (Straumann, Waldenburg, Switzerland; solid-screw; 8 x 3.3 mm) were installed in each side. The fixtures in the test side were placed within the previously grafted defect area, while the fixtures in the control side were placed in normally healed extraction sites. A 4 month period of plaque control was initiated. At the end of this period, a clinical examination including assessment of plaque and soft tissue inflammation was performed and radiographs obtained from the implant sites. Biopsies were harvested and 4 tissue samples were yielded per dog, each including the implant and the surrounding soft and hard peri-implant tissues. The biopsies were processed for ground sectioning or "fracture technique" and the sections produced were subjected to histological examination. The volume of the hard tissue that was occupied by clearly identified Bio-Oss particles was reduced between the 3- and 7-month intervals. This indicates that with time, Bio-Oss becomes integrated and subsequently replaced by newly formed bone. In other words, this xenograft fulfils the criteria of an osteoconductive material. It was also observed that 4 months after implant installation, the titanium/hard tissue interface at test and control sites exhibited, from both a quantitative and qualitative aspect, a similar degree of "osseointegration".     

Functional alveolar ridge reconstruction with prefabricated iliac crest free flap and osseointegrated implants after hemimaxillectomy

We achieved functional alveolar ridge reconstruction after hemimaxillectomy using a prefabricated iliac crest flap. The iliac crest was vascularized secondarily by a long rectus abdominis muscle flap with its inferior epigastric vessels intact to obtain an ideal anatomic location between the maxillary defect and microvascular anastomosis site. The iliac crest was tightly resurfaced with a split-thickness skin graft as well. After a bony surgical delay, the prefabricated iliac crest flap was microsurgically transferred to the face. Three osseointegrated implants were placed in the prefabricated iliac crest, and a dental prosthesis was worn with immobilization and stability. Our procedure enabled recovery of a satisfactory facial appearance and excellent masticatory function.     

Surgical treatment of induced peri-implantitis in the micro pig: clinical and histological analysis

The purpose of this pilot study was to determine if lost osseous support adjacent to root form implants could be regenerated using a guided tissue regeneration technique. Three fixtures were placed in each edentulous mandibular bicuspid region of two micro pigs. A total of 6 fixtures were placed in each pig. Due to the presence of a pathologic condition, which was in no way related to the research, the results of one pig were not evaluated. Following osseointegration, peri-implantitis were induced by the use of ligatures and a soft diet. Three modalities of treatment were performed. Utilizing a surgical flap approach, one third of the fixtures (one per quadrant) were covered with expanded polytetrafluoroethylene (ePTFE) membrane and submerged under the soft tissue complex. The second group of fixtures were submerged under the soft tissue complex with no ePTFE membrane. The control fixtures along with their abutments were debrided and remained non-submerged. All fixtures were debrided using an air-abrasive polishing system. The osseous defects around the fixtures were measured from a fixed reference point at the time of surgery and after obtaining block sections.(ABSTRACT TRUNCATED AT 250 WORDS)     

Second free flaps in head and neck reconstruction

Over the past decade, free-tissue transfer has greatly improved the quality of oncology-related head and neck reconstruction. As this technique has developed, second free flaps have been performed for aesthetic improvement of the reconstructed site. This study evaluated the indications for and the success of second free flaps. Medical files for patients who underwent second free flaps for head and neck reconstruction at the University of Texas M.D. Anderson Cancer Center, from May 1, 1988 to November 30, 1996, were reviewed. The flaps were classified as being either immediate (done within 72 hr) or delayed (done within 2 years) reconstructions. Indications, risk factors, recipient vessels, outcome, and complications were analyzed. Of the 28 patients included in this study, 12 had immediate (nine as salvage after primary free flap failure, and three for reconstruction of a soft-tissue defect), and 16 had delayed second free flaps (two for reconstruction of a defect resulting from excision of recurrent tumors, and 14 for aesthetic improvement). Reconstruction sites included the oral cavity in 18 patients; the midface in six; the skull base in two; and the scalp in two. The success rate for the second free flaps was 96 percent. Five patients had significant wound complications. In a substantial number of cases, identical recipient vessels were used for both the first and second free flaps. The authors conclude that second free flaps can play an important role in salvaging or improving head and neck reconstruction in selected patients. In many cases, the same recipient vessels can be used for both the first and second flaps.     

Clinical morphology of pneumoconiosis]

Different methods of primary mandibular reconstruction carried out at the Tata Memorial Cancer Hospital range from the pectoralis major myocutaneous or osteomyocutaneous composite flap, which is the most frequently performed procedure, to a free vascularised composite tissue transfer with microvascular anastomosis, including, iliac crest free vascularised bone grafts or radial artery forearm flap free vascularised radius bone grafts, free vascularised fibular bone grafts and silastic mandibular implants. The clinical results of immediate mandibular reconstruction with a silastic mandibular implant (SMI) in 69 patients is presented. Out of the 69 cases, 2 patients died in the early post-operative period. Twenty (30%) SMI were retained for a period of 1 year to 5 years. Forty seven (70%) SMI were retained for a period of less than 1 year. These implants have been used in a variety of cases, with or without major flap reconstruction, where a skeletal support was indicated, especially after mandibular arch resection. The results of this series indicates the importance of these implants as a short term spacer, even in advanced, fungating lesions of head and neck cancer where the risk of infection, haematoma and salivary leak is very high. Bone replacements were undertaken at a later date in suitable cases. The effects of preoperative chemotherapy and radiotherapy on the retention of these implants has also been studied.     

Fate of free flap microanastomosis distal to the zone of injury in lower extremity trauma

The decision to perform free flap microanastomosis to clearly uninjured vessels proximal to the zone of injury for lower extremity reconstruction must be weighed against the anatomic and technical difficulties of performing such an anastomosis. Preserved blood flow through vessels traversing the zone of injury has been shown. The records of all patients who underwent lower extremity reconstruction with microvascular free flaps at NYU Medical Center and Bellevue Hospital Center from January 1979 through August 1995 were reviewed. Patients with free flap microanastomoses distal to the zone of injury were compared with those with proximally based anastomoses. The group of patients was subdivided further into acute (1-21 days), subacute (22-60 days), and chronic (greater than 60 days) reconstruction groups. Of 451 microvascular free flaps, 35 were performed with recipient vessels distal to the zone of injury. Time interval from injury to coverage ranged from 24 hours to 57 years. Of 35 distally based flaps, 33 (94 percent) were successful and 5 required reoperation (14 percent). There was a similar incidence of thrombotic complications throughout all after-injury phases. Of 416 free flaps performed with microanastomoses to vessels proximal to the zone of injury, 388 (93 percent) were successful and 62 (15 percent) required reoperation. There was no significant difference (p > 0.05) in outcome between distal and proximal anastomoses and no significant difference (p > 0.05) in rates of reoperation. Timing of operation after injury had no bearing on outcome. Distally based microvascular free flaps anastomoses may be technically less difficult with rates of survival equal to those of proximally based flaps. The consideration and use of microanastomoses distal to the zone of injury are encouraged in selected patients.     

Tissue preparation in combined scapula flap for microsurgical reconstruction of defects of the oromaxillofacial area]

Nowadays, in congenital or acquired large oro-maxillofacial defects microsurgical reconstruction is mainly performed by revascularized osseous, osteocutaneous, or osteomyocutaneous distant flaps. The aim of reconstruction includes not only restoration of stable continuity and esthetic contour, but also the restoration of a functioning "chewing organ". For reconstruction in maxillary and midface defects, we prefer the scapular flap for a single-step reconstruction. Tissue prefabrication results in osseointegrated implants and thin mucosal linings with stable soft tissue conditions at the time of microsurgical reconstruction. Following dental restoration, full oral function is given. This single-stage procedure improves the psychosocial situation of the patient considerably when compared with conventional multi-stage reconstruction.     

Soft tissue coverage for the upper extremity

Soft tissue coverage of the upper extremity continues to be a challenging and evolving field. The expeditious and reliable methods of soft tissue coverage currently in use are discussed with reference to their shortcomings and advantages. For soft tissue coverage of fingertip injuries, open treatment or local flaps from the hand remain the mainstay of treatment. For dorsal and volar hand defects, distal axial flaps, such as the groin flap or microvascular tissue transfer, are utilized most commonly. For large defects proximal to the wrist, trunk axial pattern flaps, microvascular transfer, or the radial forearm flap have the greatest utility. Finally, technical points necessary for the success of some of the flaps are discussed.     

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.