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.     

Immediate insertion of two types of implants into vascularized bone grafts used for mandibular reconstruction in miniature pigs

Genomic DNAs of metallothionein I and II in Caenorhabditis elegans (CeMT-I and CeMT-II) were isolated by YAC library/polytene filter hybridization followed by subcloning of corresponding cosmid clones. Both genes are mapped at chromosome V. Although the similarities of 5'-flanking regions and coding regions have shown only 55-58%, the introns are split at the same position in both genes, indicating that these two genes are originally from the same gene. While several metal responsive elements are conserved among eukaryotes, only one metal responsive element was found in the promoter region in CeMT-II and not in CeMT-I. Indeed, neither of 5'-flanking regions of CeMT-I nor CeMT-II connected to chloramphenicol acetyltransferase reporter gene is responsive to heavy metals in mammalian culture cells by transient transfection analysis. These results would suggest that the metal regulatory factors in C. elegans might be different from those conserved in invertebrates and vertebrates, although the MTs in C. elegans revealed the similarities to mammalian MTs in several points.     

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.     

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.     

Pelvic ring reconstruction with a vascularized bone flap of femur

Three patients developed acute colitis, either de novo, or as an exacerbation of pre-existing colitis, following the use of oral acyclovir, prescribed for Herpes zoster or Herpes simplex infection. Rechallenge with oral acyclovir was performed in one patient, and resulted in a recurrence of colitic symptoms. It is speculated that acyclovir can have a direct irritant effect on large bowel mucosa.     

Possibilities in the reconstruction of bone defects

The importance of the functional unit "bone-soft-tissue" for the treatment of bone defects is discussed. A division is made between non-vascular and vascular bone transport. The individual methods are explained and their clinical significance is illustrated partly using case material. In general, the best way to fill small defects in vital soft tissue is to use cancellous autografts. For bridging longer bone defects callus distraction is the method of first choice, but in individual cases vascularized bone transfer can be taken from the iliac crest or the fibula. Homo- or heterografts should only be used in cases where no autologic bone material is available or when there is not enough.     

Reconstruction of mandibular continuity defects in dogs using poly (L-lactide) mesh and autogenic particulate cancellous bone and marrow: preliminary report

PURPOSE: This study evaluated the reconstruction of continuity defects in the canine mandible using a poly [L-lactide] (PLLA) mesh tray and particulate cancellous bone and marrow (PCBM). MATERIALS AND METHODS: Eight adult dogs were divided into two groups of four dogs each. In group A, each dog had a tray fixed with stainless steel wires on each side of the mandibular stumps with the concave surface of the tray attached to the inferior border of the mandible (U-fixation). In group B, the concave surface was attached to the superior border (inverted U-fixation). Each tray was filled with PCBM from the ilium. After the operation, the dogs were radiographed, and specimens were examined histologically at 3-, 6-, and 12-month intervals. RESULTS: All of group A showed good clinical healing and the continuity of the mandibular bone was regained within 3 months postoperatively. However, fibrous tissue had invaded through the area above the tray, resulting in a poorly shaped alveolar ridges. In group B, the dogs showed good bony regeneration with well-shaped alveolar ridges. However, two animals in this group had partial exposure of the PLLA mesh tray into the oral cavity. CONCLUSION: It is suggested that a combination of the PLLA mesh and PCBM grafts might be a useful technique for functional reconstruction of the jaw bone, specifically using method A (U-fixation) as a technique to reconstruct continuity defects of the mandible, and method B (inverted, U-fixation) as a promising method for alveolar reconstruction to make wearing dentures possible.     

Late fracture of vascularized fibular grafts

There are several causes of erosion - acidic foods and drinks have been implicated and reducing their erosive potential would seem an important area of research. Calcium-citrate-malate (CCM) appeared to have potentially useful properties as an anti-erosion additive. The study aims were to test the ability of an intra-oral enamel slab system to measure erosion and to compare the erosive potential of a citric acid-based orange juice drink either with or without added CCM and a positive and negative control. Eleven adults wore an upper removable appliance for four periods each of 6 days. Each appliance held two enamel slabs which were inserted into the test drinks for 15 min 4 times a day for 6 days. Loss of enamel was quantified by profiling casts of the enamel slabs taken before and after the test period. Loss of enamal was greatest during exposure to a diet phosphoric acid-based cola drink (p < 0.001) but was similar during exposure to the two citric acid-based orange drinks, with or without CCM, and distilled water. The loss of surface enamel measured from a scanning electron micrograph agreed well with the measurement obtained by profilometry. It can be concluded that (a) the intra-oral enamel slab system was able to discriminate between drinks in their erosive potential, and (b) it was not possible to determine if CCM had any potential for reduction in erosion in an acid beverage as the level of erosion observed for both the critic acid-based orange drinks was not statistically significantly different from that observed with distilled water.     

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.     

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.     

Autologous fibrin adhesive in mandibular reconstruction with particulate cancellous bone and marrow

Displacement of bone graft particles during their placement, neck flap closure, and insertion of the freeze-dried mandibular crib housing the graft to the glenoid fossa is a commonly encountered problem during major mandibular reconstruction with autogenous particulate cancellous bone and marrow. Autologous fibrin adhesive proved to be a solution as demonstrated in a series of 33 cases. In addition to adhesive and hemostatic properties, it helped the remodeling process begin about 50% earlier by providing the substratum for migration of mesenchymal cells, accelerating revascularization and migration of fibroblasts, stimulating the growth of both fibroblasts and osteoblasts, and slowing the multiplication of microorganisms. Bony incorporation and remodeling were detected radiographically at the fourth postoperative week compared with the eighth week in bone grafts without autologous fibrin adhesive.     

Classification of mandibular defects

A classification of mandibular defects based on functional as well as aesthetic factors is presented. By taking into account the difficulties in restoring form and function and not simply relying on traditional anatomic landmarks, it is hoped that this method will allow different types of reconstructions to be fairly evaluated. It also should help surgeons to tailor individual reconstructive techniques to specific clinical situations. Major difficulties in mandibular reconstruction arise when a condyle requires replacement, when there is a mucosal and/or skin component to the defect, and when the area to be reconstructed involves the anterior arch. The classification is based on three upper-case and three lower-case characters: H, C, L and o, m, s. H defects are lateral defects of any length, including the condyle but not significantly crossing the midline; L defects are the same only without the condyle; C defects consist of the entire central segment containing the four incisors and the two canines. Combinations of these letters are possible (an angle-to-angle defect, for example, is represented as LCL). Thus H and L defects may reach or even extend slightly beyond the midline but are not referred to as LC or HC unless they contain the entire central segment. The letters o (neither a skin nor a mucosal component), s (skin), m (mucosa), and sm (skin plus mucosa) are added to denote the epithelial requirement.     

Reconstruction of mandibular discontinuity defects using autogenous grafting and a mandibular reconstruction plate: a prospective evaluation of nine consecutive cases

This article presents the clinical results of a prospective evaluation of nine cases of mandibular discontinuity that were reconstructed using autogenous grafting and a reconstruction plate. All patients were allowed to function immediately postsurgery. Acceptable esthetic and functional results were obtained with minimal donor and recipient site complications. All cases showed complete graft incorporation and restoration of osseous continuity.     

The use of autogenous fat, fascia, and nonvascularized muscle grafts in the head and neck

We have reviewed the transplantation of autogenous fat, fascia, and nonvascularized muscle. Although none of these tissues satisfies all of the requirements for an ideal transplantation material, understanding the indications and each material's limitations will broaden the surgeon's armamentarium when soft-tissue grafting is desired. Although the use of autogenous fat grafts in head and neck surgery has been associated with some unpredictability, fat remains an excellent choice for obliteration of frontal sinuses, for myringoplasty, and for limited soft-tissue augmentation. In most applications, significant resorption of the transplanted fat can be expected, and it should be compensated for accordingly by initial overcorrection. Future research endeavors, including development of preadipocyte transplants and hormonal manipulation of fat grafts, will perhaps improve results of transplantation. The grafting of fascia has been shown to be a very reliable technique, especially when tensile strength is required of the transplant material. In grafts, fascia is much more predictable than fat, in that the majority of the fascia survives as living tissue that retains its original characteristics. A relative lack of three-dimensional bulk, however, limits the use of fascia in soft-tissue augmentation. The transplantation of nonvascularized muscle, because of its enormous metabolic requirements, almost always results in death of the muscle cells and subsequent partial replacement by fibrous tissue. Free muscle grafts therefore have very limited application, except in circumstances in which fibrous tissue obliteration of small defects (such as the nasofrontal duct or eustachian tube) is the desired result. In clinical situations in which maintenance of the substance or bulk of the transplanted material is of paramount importance, consideration should be given instead to the transfer of vascularized tissue. For this purpose, numerous simple and composite flaps of fascia, fat, muscle, and other tissues are now available. Vascularized tissue transfers are certainly not the solution to every reconstructive problem, however. When properly selected and applied, the transplantation of fat, fascia, and occasionally muscle remains an important option for soft-tissue replacement in head and neck surgery.     

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.     

PCL reconstruction. In vitro biomechanical comparison of ''isometric'' versus single and double-bundled ''anatomic'' grafts

The analgesic tramadol inhibits the neuronal reuptake of norepinephrine and 5-hydroxytryptamine, facilitates 5-hydroxytryptamine release, and activates mu-opioid receptors. Each of these actions is likely to influence thermoregulatory control. We therefore tested the hypothesis that tramadol inhibits thermoregulatory control. Eight volunteers were evaluated on four study days, on which they received no drugs, tramadol 125 mg, tramadol 250 mg, and tramadol 250 mg with naloxone, respectively. Skin and core temperatures were gradually increased until sweating was observed and then decreased until vasoconstriction and shivering were detected. The core temperature triggering each response defined its threshold. Tramadol decreased the sweating threshold by -1.03 +/- 0.67 degrees C microgram-1.mL (r2 = 0.90 +/- 0.12). Tramadol also decreased the vasoconstriction threshold by -3.0 +/- 4.0 degrees C microgram-1.mL (r2 = 0.94 +/- 0.98) and the shivering threshold by -4.2 +/- 4.0 degrees C microgram-1.mL(r2 = 0.98 +/- 0.98). The sweating to vasoconstriction interthreshold range nearly doubled from 0.3 +/- 0.4 degree C to 0.7 +/- 0.6 degree C during the administration of large-dose tramadol (P = 0.04). The addition of naloxone only partially reversed the thermoregulatory effects of tramadol. The thermoregulatory effects of tramadol thus most resemble those of midazolam, another drug that slightly decreases the thresholds triggering all three major autonomic thermoregulatory defenses. In this respect, both drugs reduce the "setpoint" rather than produce a generalized impairment of thermoregulatory control. Nonetheless, tramadol nearly doubled the interthreshold range at a concentration near 200 ng/mL. This indicates that tramadol slightly decreases the precision of thermoregulatory control in addition to reducing the setpoint. IMPLICATIONS: The authors evaluated the effects of the analgesic tramadol on the three major thermoregulatory responses: sweating, vasoconstriction, and shivering. Tramadol had only slight thermoregulatory effects. Its use is thus unlikely to provoke hypothermia or to facilitate fever.     

Regeneration of defects in articular cartilage with callus and cortical bone grafts. An experimental study

Luteal-phase estrogen and progesterone concentrations were measured every other day and used to monitor the corpus luteum activity. The patterns of estrogen and progesterone concentrations were compared relative to the day of endogenous human chorionic gonadotropin (hCG) detection (defined as the day of implantation). The relationship between estrogen and progesterone and hCG concentrations was studied in 71 viable pregnancies, 12 clinical abortions, five preclinical abortions and 84 non-pregnant cycles after IVF/ET. Although all patients received luteal-phase progesterone support (25-50 mg/ml), low late luteal-phase progesterone concentrations of < 30 ng/ml from day + 11 to day + 15 were found in 64 patients (17% of viable pregnancies, 33.3% of clinical abortions, 60% of preclinical abortions and 53.6% of non-pregnant cycles) day + 1 was the day of retrieval). Implantation always occurred before or on day + 13 and 86% of pregnant cycles implanted on day + 8 to day + 11. Viable pregnancies had significantly higher mean progesterone concentrations on day + 3 to day + 7 (pre-implantation) and on day + 9 to day + 15 (postimplantation) than those of non-pregnant cycles or abortions. On the day of implantation, the mean +/- standard of deviation of estrogen (pg/ml) and progesterone (ng/ml) levels for viable pregnancies, clinical abortion and preclinical abortions were 314 +/- 210, 40.5 +/- 25; 226.7 +/- 246, 48.7 +/- 31; and 39.6 +/- 24.5, 28.6 +/- 24.5, respectively. On the same day, 73.2% of viable pregnancies, 41.7% of clinical abortions, and 20% preclinical abortions had a progesterone concentration > 30 ng/ml; 73.2% of viable pregnancies, 41.7% of clinical abortions and 20% of preclinical abortions had an estrogen concentration > 100 pg/ml. Although not precluding implantation completely, late luteal-phase hormonal deficiencies may impair endometrial growth and might ultimately lead to failure or abnormal implantation. A viable pregnancy requires not only a functional corpus luteum in the early luteal phase to develop a receptive endometrium, but also a responsive corpus luteum in the late luteal phase to support pregnancy. The time of implantation is critical. Implantation that occurs before the demise of the corpus luteum will facilitate a normal pregnancy.