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.     

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.     

Reconstruction of residual alveolar cleft defects with one-stage mandibular bone grafts and osseointegrated implants

PURPOSE: This study evaluates a treatment regimen for reconstruction of residual maxillary alveolar cleft defects consisting of mandibular bone grafting and immediate implant installation. PATIENTS AND METHODS: Sixteen cleft patients (five female and 11 male) had residual cleft defects of the alveolar ridge reconstructed with bone grafts from the mandibular symphyseal region. The bone graft was pretapped at the donor site before fixation in the residual ridge with Br?nemark implants. Twenty implants were installed according to this concept. The period of observation ranged from 36 to 69 months, with a mean of 48 months after implant installation. RESULTS: Five patients developed wound dehiscenses that resulted in total or partial bone graft sequestration. Two implants were lost, one due to sequestration and the other due to mobility at the abutment procedure; 18 implants were still well functioning at the end of the observation period. However, all patients showed significant periimplant bone resorption after this one-stage treatment. CONCLUSION: Because of the observed complication rate, the one-stage procedure may not be optimal for reconstructing residual cleft defects.     

Interposed bone grafts to accommodate endosteal implants for retaining mandibular overdentures. A 1-7 year follow-up study

STUDY OBJECTIVES: To examine the effect of timing of an intravenous (i.v.) dose (intraoperative vs. postoperative) of ketorolac tromethamine on pain scores and overall outcome after total abdominal hysterectomy (TAH) and myomectomy. DESIGN: Prospective, randomized, placebo-controlled study. PATIENTS: 248 ASA physical status I and II adult female patients scheduled for elective hysterectomy or myomectomy. INTERVENTIONS: General anesthesia was administered that consisted of thiopental sodium for induction, enflurane or isoflurane in nitrous oxide-oxygen for maintenance, and small doses of fentanyl and midazolam. Patients were randomized into three groups to receive toradol/placebo on a dosing schedule of dose 1 given one-half hour prior to expected end of surgery, dose 2 given on awakening in the postanesthesia care unit, and doses 3, 4, and 5 given at 6, 12, and 18 hours, respectively, after dose 2; Group 1 patients received placebo (saline) for dose 1, ketorolac 60 mg i.v. for dose 2, and ketorolac 30 mg i.v. for doses 3, 4, and 5. Group 2 patients received ketorolac 60 mg i.v. for dose 1, placebo for dose 2, and ketorolac 30 mg i.v. for doses 3, 4, and 5. Group 3 patients received placebo for all doses. All patients were given i.v. morphine PCA postoperatively, and morphine usages, visual analog pain intensity (VAS) scores, as well as adverse events and median times to recovery milestones were recorded. MEASUREMENTS AND MAIN RESULTS: VAS scores (mean) before dose 2 were significantly lower in Group 2 than Group 1, as were at-rest evaluations at 15 minutes and one hour. Group 2 patients also had decreased morphine requirements as compared to placebo. Both ketorolac groups (Groups 1 and 2) had significantly higher values for patient and observer overall ratings, case of nursing care, and tolerability as compared to placebo (Group 3). There were no significant differences among groups in adverse events or median times to recovery milestones. CONCLUSIONS: Although it is possible to demonstrate an improvement in early postoperative pain scores with intraoperative ketorolac and better overall ratings of ketorolac both intraoperatively and postoperatively as compared with placebo, the lack of clinically significant differences in analgesic efficacy in the two active study groups indicates the need for a careful consideration by the clinician of the risks versus benefits involved in the administration of antiplatelet medication in the perioperative period.     

Vascularized bone flaps versus nonvascularized bone grafts for mandibular reconstruction: an outcome analysis of primary bony union and endosseous implant success

We present a patient with a lesion of the mesial frontal cortex, including the supplementary motor areas bilaterally, who on clinical examination revealed no spontaneous movements, although neurophysiological examination indicated integrity of the corticospinal tract to thenar and tibialis anterior muscles bilaterally. The patient was alert, speech was hesitant, and he was able to move his hands only on command. The role of the supplementary motor areas in planning, setting, and execution of skillful voluntary movements has been previously established by direct cortical electrical stimulation and studies of regional cerebral blood flow. The findings in our patient support the role of the supplementary motor areas in initiating movements. The presence of motor evoked potentials after acute insults to the brain is considered to be associated with a good functional outcome. This is in contrast to our patient who did not show improvement in motor performance, despite preserved motor evoked potentials. Hence, in the case of bilateral lesions to the supplementary motor areas sparing the corticospinal tract, the presence of motor evoked potentials may not predict functional recovery.     

Vascularized fibular grafts for the reconstruction of segmental tibial bone defects

Free vascularized fibular grafts were employed in seven patients with large tibial defects following trauma or resection of tumour. All patients were followed for more than 5 years. Tibial union and excellent functional results were achieved in all seven patients. Free vascularized fibular transfer seems to be an effective method of treatment for massive segmental bone defects.     

Biomechanical and histologic alteration of facial recipient bone after reconstruction with autogenous bone grafts and alloplastic implants: a 1-year study

Potential alteration of the underlying recipient bone resulting from a graft or implant has significant clinical relevance. The present study was designed to evaluate the biomechanical and histologic alteration of facial recipient bone with autogenous bone graft and alloplastic implants over a 1-year period. The bilateral arches of 15 rabbits were randomized between four groups: (1) control (n = 6), subperiosteal exposure of the zygomatic arch was made; (2) onlay (n = 12), bone graft was placed as an onlay to the zygomatic arch; (3) inlay (n = 6), bone graft was placed as an inlay within the zygomatic arch; (4) implant (n = 6), a stainless steel plate was placed as an onlay to the zygomatic arch. Animals were killed 1 year after grafting. In the onlay groups, all steel implants and half of the onlay bone grafts (n = 6) were separated from the zygomatic arch; the remaining onlay bone grafts (n = 6) were left on the zygomatic arch. Three-point breaking strength was measured through the center of the graft/implant site on the zygomatic arch, followed by histologic evaluation and histometric assessment of residual bone density. The findings demonstrated no difference in the breaking strength per unit bone area between the control zygomatic arch group and the onlay group in which the bone graft was left in place. Breaking strength of the zygomatic arch in the former two groups was significantly greater than that in either group in which the onlay bone graft or implant had been removed, and was also greater than the breaking strength in that group in which inlay bone had been placed (p < 0.05). Histologic assessment showed full-thickness conversion in architecture of the zygomatic arch from compact to woven bone beneath onlays of either autogenous bone graft or steel implant; histometric assessment demonstrated an accompanying decrease in bone density in the latter groups relative to the control zygoma (p < 0.05). We conclude that onlay autogenous bone graft and alloplastic implants to the facial skeleton induce transformation of both graft and recipient bone from compact to woven architecture, accompanied by a reduction in bone density. The biomechanical strength of recipient facial bone is significantly weakened if an onlay bone graft or implant is removed. Weakening occurs per unit area of remaining bone, and is therefore independent of any thinning that may occur within the recipient bone because of graft/implant placement. These findings may impact upon decisions to augment stress-bearing regions of the facial skeleton with bone graft or implants, particularly if the graft/implant may eventually require removal.     

Dental prosthetic reconstruction of osseointegrated implants placed in irradiated bone

Deficiency of the sixth component of human complement (C6) has been reported in a number of families from the western Cape, South Africa. Meningococcal disease is endemic in the Cape and almost all pedigrees of total C6 deficiency (C6Q0) have been ascertained because of recurrent disease. We have sequenced the expressed exons of the C6 gene from selected cases and have found three molecular defects leading to total deficiency: 879delG, which is the common defect in the Cape and hitherto unreported, and 1195delC and 1936delG, which have been previously reported in African-Americans. We also show that the 879delG and 1195delC defects are associated with characteristic C6/C7 region DNA marker haplotypes, although small variations were observed. The 1936delG defect was observed only once in the Cape, but its associated haplotype could be deduced. The data from the haplotypes indicate that these three molecular defects account for the defects in all the 38 unrelated C6Q0 individuals we have studied from the Cape. We have also observed the 879delG defect in two Dutch C6-deficient kindreds, but the 879delG defect in the Cape probably did not come from The Netherlands.     

Available bone is the foremost criterion in the insertion of endosteal implants

The foremost criterion in the insertion of endosteal implants is bone availability. Implant dentists should consider first the amount of available bone of the edentulous ridge where the endosteal implant will be inserted. A common error and cause of many implant failures is the dentist's use of an implant modality which is not indicated for the density and morphology of the available bone in the edentulous ridge. Implant modality/system is not the primary criterion in the insertion of endosteal implants. Before the dentist inserts an endosteal implant, he should gauge or measure the amount of bone where the implant is intended to be placed. It should be measured in width, height, length, trajectory, and implant-crown ratio. After recording the measurements of the available bone, these should be placed in different categories to serve as guides in implant selection. If there is not enough bone for the endosteal implant, bone modification should be performed. This can be done either by osteoplasty or ridge augmentation with the use of bone grafting materials. Aside from the amount of available bone in the edentulous ridge, another very, very important thing that should be considered is the quality or its density. Any biocompatible implant demonstrates some osseointegrated surfaces depending upon the bone type into which it is placed and the loads placed upon it. Implant body must exhibit a macrogeometry suitable for acceptable levels of force transfer to the surrounding tissues as well as for implantation into a bony site of a particular anatomic size.     

Radiographic assessment of changes in marginal bone around endosseous implants supporting mandibular overdentures

We report a case of primary iliopsoas abscess successfully treated by ultrasonographically guided percutaneous drainage. A 56-year-old man presented at our hospital with lumbago, right-sided back pain, fever (temperature 38.5 degrees C) and chills. On physical examination, we found dark red skin, swelling, and tenderness localized at the right side at the back of his waist. Laboratory examination showed leukocytosis (white blood cell count 9700/mm3) with a leftward shift and elevated C-reactive protein (5.2 mg/dl). Ultrasonography (US), computed tomography (CT), and magnetic resonance imaging revealed a hypodense lesion in the right iliopsoas muscle extending to the subcutaneous tissue. About 50 ml of thick yellow pus was obtained by ultrasonographically guided aspiration drainage. A drain catheter was inserted in the abscess cavity. Laboratory findings improved and clinical symptoms abated rapidly after drainage. On the twenty-first day after drainage, US and CT showed that the abscess was no longer present. The patient was discharged after 32 days of hospitalization. As possible primary diseases causing iliopsoas abscess, such as digestive tract disease, tuberculosis, and osteomyelitis, were not found, we diagnosed the disease as primary iliopsoas abscess. Although surgical drainage has been performed in most reported cases of iliopsoas abscess, this case report shows that ultrasonographically guided percutaneous drainage is also effective for treating primary iliopsoas abscess if it is diagnosed early enough.     

A comparative study of osseointegration of titanium implants in autogenous and freeze-dried bone grafts

PURPOSE: This study was undertaken to compare the rate and degree of osseointegration of dental implants when placed into either autogenous corticocancellous chip or freeze-dried corticocancellous chip bone grafts. MATERIALS AND METHODS: The canine ilium was used as the model site. Thirty experimental and 15 control implants were placed in 15 dogs: autogenous versus freeze-dried corticocancellous chip bone grafts around the exposed implant surfaces. In addition to the placement of control implants, the apical portion of the grafted implants acted as their own control. The implants were harvested at 1, 2, and 3 months. The evaluation of the integration process was performed by means of light microscopy, microradiography, and histomorphometry. RESULTS: Using this model, the results indicate that at 1 month there was no statistical difference in the degree of osseointegration in the two bone grafts. At 2 months, there was a statistically greater degree of osseointegration noted in the autogenous corticocancellous chip sites than in the freeze-dried bone grafts. At 3 months, the degree of osseointegration in the two groups was 70% and 33%, respectively. At 3 months, there was virtually 100% integration with trabecular bone at the control implant sites. CONCLUSION: The results indicate that at 2 months postoperatively implants placed in an autogenous bone chip graft osseointegrate to a significantly greater degree than implants placed in a freeze-dried bone chip graft, and this difference remains at 3 months.     

Revascularization of calvarial, mandibular, tibial, and iliac bone grafts in rats

The development of approaches to screening of hospital patients for harmful drinking frequently encounters resistance from both patients and hospital staff. A contributing factor could be the discomfort both feel about talking specifically about drinking. One approach to reducing this discomfort has been to mask concern about alcohol consumption into a general focus on other health and lifestyle issues. One-hundred and eighty-two patients admitted to an emergency department were presented randomly with either a straight alcohol screening questionnaire or a general health and lifestyle questionnaire with alcohol questions embedded amongst items on smoking exercise and diet. The number of returns was equal for both questionnaires which suggests the masked questionnaire does not improve the acceptability of alcohol screening in hospital environments.     

The Ranawat Award. Histology of nine structural bone grafts used in total knee arthroplasty

The cross section radiographs and histology of nine bone grafts were examined to determine whether grafts are durable enough to support a total knee implant when the load is shared by host bone, graft bone, and a stemmed component. All cases had cemented total knee arthroplasties with stemmed components adjacent to bulk grafts. The cases included autografts and allografts, which had been in situ for an average of 41 months (range, 20-62 months). Seven of the grafts were retrieved postmortem from three patients (four knees), and two were retrieved at revision surgery from one patient. The allografts all were intact, but had not revascularized. The autografts were viable bone. New bone was being laid down on the dead graft bone at the periphery of the allografts. No change in the bone to cement interface, no graft collapse, no development of radiolucent lines, and no component loosening occurred in these cases. The promising clinical results of bone grafts in total knee arthroplasties were confirmed by the examination of these grafts at the cellular level. Using stemmed components in bone grafted knee reconstructions may have increased graft durability and protected the grafts from fatigue failure.     

Use of demineralized bone implants in orbital and craniofacial reconstruction and a review of the literature

A retrospective study and review of the literature was performed on the use of demineralized bone implants for the correction of orbital and craniofacial defects. Demineralized bone implants heal by endochondral osteogenesis, inducing a transformation of local cells, as well as by osteoconduction, similar to autogenous grafts. They induce the chemotaxis and transformation of mesenchymal cells into chondroblasts, followed by ossification. They also act as a scaffold, with bone resorption taking place simultaneous with bone formation. This study reviewed 21 patients and 31 orbits, in which demineralized bone was used for orbitocranial reconstruction for congenital deformities (nine patients), after surgery for orbital fractures (seven patients: four floor, three roof), and orbital tumors (five patients). The surgical technique is described, and the results are discussed. The follow-up period averaged 15 months (6 months to 33 months). The overall resorption rate of the demineralized bone implants was estimated based on follow-up radiologic studies (facial films, computed tomography scans, and magnetic resonance imaging scans), as well as clinical examinations. All patients had a satisfactory to excellent result. The demineralized bone and Grafton (Osteotech, Shrewsbury, NJ, U.S.A.) was obtained from the Musculoskeletal Transplant Foundation of Holmdel, New Jersey, and it was all processed and reconstituted in a standard manner with Alloprep System. Surgical complications were cerebrospinal fluid leaks (one patient) with infection, transient chemosis, enophthalmos, and hypophthalmos. There were no complications related to demineralized bone alone. Properly prepared demineralized bone is a safe material for orbital reconstruction that eliminates the need for a second operative site to harvest a bone graft.     

Placement of endosteal implants combined with chin bone onlay graft for dental reconstruction in patients with grafted alveolar clefts

CONTEXT: Physical activity and fitness are believed to reduce premature mortality, but whether genetic factors modify this effect is not known. OBJECTIVE: To investigate leisure physical activity and mortality with respect to familial aggregation of health habits during childhood and factors that may enable some individuals to achieve higher levels of fitness. DESIGN: Prospective twin cohort study. SETTING: Finland. SUBJECTS: In 1975, at baseline, 7925 healthy men and 7977 healthy women of the Finnish Twin Cohort aged 25 to 64 years who responded to a questionnaire on physical activity habits and known predictors of mortality. Those who reported exercising at least 6 times per month with an intensity corresponding to at least vigorous walking for a mean duration of 30 minutes were classified as conditioning exercisers, those who reported no leisure physical activity were classified as sedentary, and other subjects were classified as occasional exercisers. MAIN OUTCOME MEASURES: All-cause mortality and discordant deaths among same-sex twin pairs from 1977 through 1994. RESULTS: Among the entire cohort, 1253 subjects died. The hazard ratio for death adjusted for age and sex was 0.71 (95% confidence interval [CI], 0.62-0.81) in occasional exercisers and 0.57 (95% CI, 0.45-0.74) in conditioning exercisers, compared with those who were sedentary (Pfor trend <.001). Among the twin pairs who were healthy at baseline and discordant for death (n=434), the odds ratio for death was 0.66 (95% CI, 0.46-0.94) in occasional exercisers and 0.44 (95% CI, 0.23-0.83) in conditioning exercisers compared with those who were sedentary (P for trend, .005). The beneficial effect of physical activity remained after controlling for other predictors of mortality. CONCLUSION: Leisure-time physical activity is associated with reduced mortality, even after genetic and other familial factors are taken into account.     

Transplantation of vascularized allogeneic skeletal muscle for scalp reconstruction in a renal transplant patient

We studied the effect of complete spinal cord transection (SCT) on gastric emptying (GE) and on gastrointestinal (GI) and intestinal transits of liquid in awake rats using the phenol red method. Male Wistar rats (N = 65) weighing 180-200 g were fasted for 24 h and complete SCT was performed between C7 and T1 vertebrae after a careful midline dorsal incision. GE and GI and intestinal transits were measured 15 min, 6 h or 24 h after recovery from anesthesia. A test meal (0.5 mg/ml phenol red in 5% glucose solution) was administered intragastrically (1.5 ml) and the animals were sacrificed by an i.v. thiopental overdose 10 min later to evaluate GE and GI transit. For intestinal transit measurements, 1 ml of the test meal was administered into the proximal duodenum through a cannula inserted into a gastric fistula. GE was inhibited (P < 0.05) by 34.3, 23.4 and 22.7%, respectively, at 15 min, 6 h and 24 h after SCT. GI transit was inhibited (P < 0.05) by 42.5, 19.8 and 18.4%, respectively, at 15 min, 6 h and 24 h after SCT. Intestinal transit was also inhibited (P < 0.05) by 48.8, 47.2 and 40.1%, respectively, at 15 min, 6 h and 24 h after SCT. Mean arterial pressure was significantly decreased (P < 0.05) by 48.5, 46.8 and 41.5%, respectively, at 15 min, 6 h and 24 h after SCT. In summary, our report describes a decreased GE and GI and intestinal transits in awake rats within the first 24 h after high SCT.     

Comparison of life of two types of decay heat exchangers used in prototype fast breeder reactor

The decay heat generated by radioactive decay of fission products in the core after reactor is shut down is to be removed for limiting of temperatures of various components. In prototype fast breeder reactor (PFBR), a dedicated safety grade decay heat removal (SGDHR) system consisting of four independent loops of each 8 MW_t heat removal capacity is used for removing decay heat. Each loop consists of a sodium to sodium heat exchanger (DHX) and sodium to air heat exchanger (AHX). While DHX transfers heat from the radioactive primary sodium to intermediate sodium, AHX dissipates the heat to atmospheric air. Diversity in the design is adopted from reliability consideration. This paper compares the design life of two types of DHX (Type-A & B). Both DHX are shell and tube type with primary sodium on shell side and intermediate sodium on tube side. While Type-A has the tubesheet design similar to IHX, Type-B is a U ‘ tube two-pass heat exchanger. In this tubes are supported at the top by two separate tube sheets (split tubesheets). The tubesheets along with attached shells are analysed using CAST 3M, issued by CEA, France. The creep-fatigue damage is evaluated as per RCC-MR (2002). For the specified design life of 40 years, the fatigue damage is small and the creep damage evaluated is 0.26 in the type-A and 0.32 in the type-B, thus meeting design code limits. Two types of DHX are found to have 121y and 154y as allowable life after considering appropriate factor of safety given in design code RCC-MR.     

Size estimation method for patch used in reconstruction of LV cavity

The reconstruction of LV cavity is accomplished by suturing a patch to the viable myocardium to exclude the infarcted area from the high LV pressures. However, there is no clear guideline to estimate the size of patch used for LV reconstruction. We have designed a new method to determine the correct patch size, and applied it in 5 cases. The suture line of the patch is at the junction of contractile (functional) and infarcted portions of LV. The patch size is determined by the length of AB, termed "a", as the base, where "point A" represents the junction on the LV anterior wall side, and "point B" the junction of the LV posterior wall side, from RAO 30 degrees projection of the left ventriculogram obtained by cardiac catheterization. In LV aneurysm, we designed the patch in the range of a/2 < l < or = pi a/2, where patch length on RAO 30 degrees is considered "l". An effort was made to reconstruct to normalize LV volume and contour by designing the patch size to be a/2 < l < a, particularly when the contractile portion was enlarged by aneurysm. On the other hand, in post AMI VSD, LV contractile portion is not enlarged in early stage. Therefore, the patch was designed in the range of a < l < or = pi a/2 to maintain LV volume. Postoperative LV volume can be calculated prior to surgery, by using the lengths of the designed patch. Postoperative analysis indicated that the actual LV volume and contour were almost identical to our estimation. This method is very useful in planning the patch size for LV reconstruction.