Faculty Bibliography

OBJECTIVES: This study aims to evaluate bone response to an implant surface modified by 1alpha,25-dihydroxyvitamin D3 [1.25-(OH)2D3] in vivo and the potential link between 1.25-(OH) 2D3 surface concentration and bone response. MATERIAL AND METHODS: Twenty-eight implants were divided into 4 groups (1 uncoated control, 3 groups coated with 1.25-(OH)2D3 in concentrations of 10(-8), 10(-7) and 10(-6) M respectively), placed in the rabbit tibia for 6 weeks. Topographical analyses were carried out on coated and uncoated discs using interferometer and atomic-force-microscope (AFM). Twenty-eight implants were histologically observed (bone-to-implant-contact [BIC] and new-bone-area [NBA]). RESULTS: The results showed that the 1.25-(OH)2D3 coated implants presented a tendency to osseointegrate better than the non-coated surfaces, the differences were not significant (P > 0.05). CONCLUSIONS: The effect of 1.25-(OH)2D3 coating to implants suggested possible dose dependent effects, however no statistical differences could be found. It is thought that the base substrate topography (turned) could not sustain sufficient amount of 1.25-(OH)2D3 enough to present significant biologic responses. Thus, development a base substrate that can sustain 1.25-(OH)2D3 for a long period is necessary in future studies.

BACKGROUND: Prior studies report a high incidence of airway complications in patients with Robin sequence following palatoplasty. The authors' institution uses polysomnography to assess risk of airway compromise before palatoplasty in Robin sequence. This study compares airway complications in Robin sequence to cleft palate only using this screening airway protocol and identifies risk factors for airway complications after palatoplasty. METHODS: A 12-year retrospective review of patients with Robin sequence undergoing palatoplasty was performed. Robin sequence patients were divided into nonoperative management and mandibular distraction osteogenesis subgroups. Preoperative variables including comorbidities were recorded. The primary outcome was postoperative airway complication, defined as reintubation, emergency room visit, or hospital admission within 3 months of palatoplasty. RESULTS: One hundred thirteen patients met inclusion criteria: polysomnography, 34.5 percent; Robin sequence, 65.5 percent; and Robin sequence treated with mandibular distraction osteogenesis, 30.1 percent. Screening polysomnography was used to indicate patients for palatoplasty or other airway interventions. The total airway complication rate was 7.1 percent; this was similar in Robin sequence (5.8 percent) and cleft palate only (7.7 percent). In isolated Robin sequence, the reintubation rate was 0 percent. Lower airway anomalies were associated with airway complications (p = 0.03). Significant variables for reintubation were cardiac (p = 0.046), gastrointestinal (p = 0.04), and lower airway anomalies (p = 0.025) and syndromic diagnosis (p = 0.05). CONCLUSION: Screening polysomnography can control airway complications following palatoplasty in Robin sequence patients to a rate that is comparable to that of patients with cleft palate only.

BACKGROUND: Understanding normal volume asymmetry is essential for accurate assessment of limb volume changes following breast cancer (BC) treatment in which lymphatic function is disrupted. The purposes of this study were to evaluate for differences in dominant and nondominant limb volumes and to evaluate for interactions between the effects of dominance and side of cancer on limb volume. METHODS AND RESULTS: This study evaluated preoperative limb volumes of 397 women enrolled in a prospective, longitudinal study of neuropathic pain and lymphedema. Volume was calculated from circumference. Limb resistance was measured with bioimpedance. Women were dichotomized into two groups: those whose cancer was on their dominant side and those whose cancer was on their nondominant side. Analyses of variance were used to evaluate for differences. In 47%, BC occurred on the side of the dominant limb. Except for the 30 to 40 centimeter (cm) limb volume segment, a main effect of dominance was found for all measures. The volume of the dominant limb was significantly greater than that of the nondominant limb. No main effects were found for side of cancer. A statistically significant interaction was found only at the 0 to 10 cm limb volume segment. CONCLUSIONS: Prior to BC treatment, the dominant limb demonstrated lower bioimpedance resistance (-2.09%) and greater total limb volume (1.12%) than the nondominant limb. Segmental volume differences were greatest at the proximal forearm segment (2.31%) and least at the proximal arm segment (0.21%). This study provides evidence that preoperative volume assessment is important due to normal variability associated with limb dominance.

Since the first facial transplantation in 2005, 28 have been done worldwide with encouraging immunological, functional, psychological, and aesthetic outcomes. Unlike solid organ transplantation, which is potentially life-saving, facial transplantation is life-changing. This difference has generated ethical concerns about the exposure of otherwise young and healthy individuals to the sequelae of lifelong, high-dose, multidrug immunosuppression. Nevertheless, advances in immunomodulatory and immunosuppressive protocols, microsurgical techniques, and computer-aided surgical planning have enabled broader clinical application of this procedure to patients. Although episodes of acute skin rejection continue to pose a serious threat to face transplant recipients, all cases have been controlled with conventional immunosuppressive regimens, and no cases of chronic rejection have been reported.

Bone graft materials are utilized to stimulate healing of bone defects or enhance osseointegration of implants. In order to augment these capabilities, various surface modification techniques, including atmospheric pressure plasma (APP) surface treatment, have been developed. This in vivo study sought to assess the effect of APP surface treatment on degradation and osseointegration of Synthograft, a beta-tricalcium phosphate (beta-TCP) synthetic bone graft. The experimental (APP-treated) grafts were subjected to APP treatment with argon for a period of 60s. Physicochemical characterization was performed by environmental scanning electron microscopy, surface energy (SE), and x-ray photoelectron spectroscopy analyses both before and after APP treatment. Two APP-treated and two untreated grafts were surgically implanted into four critical-size calvarial defects in each of ten New Zealand white rabbits. The defect samples were explanted after four weeks, underwent histological analysis, and the percentages of bone, soft tissue, and remaining graft material were quantified by image thresholding. Material characterization showed no differences in particle surface morphology and that the APP-treated group presented significantly higher SE along with higher amounts of the base material chemical elements on it surface. Review of defect composition showed that APP treatment did not increase bone formation or reduce the amount of soft tissue filling the defect when compared to untreated material. Histologic cross-sections demonstrated osteoblastic cell lines, osteoid deposition, and neovascularization in both groups. Ultimately, argon-based APP treatment did not enhance the osseointegration or degradation of the beta-TCP graft. Future investigations should evaluate the utility of gases other than argon to enhance osseointegration through APP treatment.

We report a versatile method for the fabrication of nanowires and hierarchical porous materials from a wide variety of ceramic materials such as CaCO3, ZnO, CuO, Co3O4, Co-doped ZnO, and Ag2O. The method consists of evaporation of CO2-enriched water microdroplets (diameter approximately 3 mum) deposited from an aerosol onto heated substrates (T = 120 degrees C). A variety of porous scaffolds with 1-3 mum sized pores can be generated by tuning the process conditions. Subsequent sintering of the scaffolds is shown to generate nanosized pores in the walls of the porous scaffold creating a dual hierarchy of pore sizes ( approximately 50 nm and 1-3 mum). We propose a mechanism for the formation of scaffolds based on the coffee-ring effect during the evaporation of microdroplets. Ostwald-ripening of CaCO3 scaffolds prepared without sintering yields scaffold structures consisting of two-dimensional crystals of CaCO3 that are one unit cell thick. The favorable application of CaCO3 scaffolds for the enhancement of bone healing around titanium implants with improved biocompatibility is also demonstrated.

This study investigated whether the use of a dual-layer polytetrafluoroethylene (PTFE)/porcine-derived bioresorbable pericardium membrane enhances the osseointegration around implants compared to a single-layer porcine-derived bioresorbable pericardium membrane and a no-membrane control group. Endosseous implants were placed in the fresh extraction sockets of beagles. At 6 weeks, bone loss and apical soft tissue migration occurred in the control group, whereas bone successfully formed to the neck of the implant for the single-layer porcine-derived bioresorbable pericardium membrane group. The dual-layer PTFE/ porcine-derived bioresorbable pericardium membrane showed bone growth coronal to the neck of the implant. Bone-to-implant contact and buccal bone loss were respectively higher and lower relative to the single-layer but not statistically different.

Subungual melanoma is a rare but lethal form of melanoma. Amputation at the level of the interphalangeal joint or proximal has been described as appropriate surgical management for all stages of subungal melanoma. In cases of subungual melanoma in situ (SMIS), wide local excision can improve functional and aesthetic outcomes. We reviewed our experience of wide local excision for the treatment of SMIS. Between 2003 and 2010, we treated 9 cases of SMIS. We performed a retrospective review of this series looking at the primary outcomes of recurrence or metastasis. Average age was 40 years (range, 5-65 years). Presenting lesions were on the thumb (5) and index finger (4). All patients underwent definitive reconstruction with a combination of full-thickness skin graft (8) and paronychial advancement flap (6). Reexcision was performed when disease-free margins could not be confirmed. To date, there have been no cases of metastasis or local recurrence in any of our 9 patients (mean follow-up time of more than 4 years). Wide local excision can improve functional and aesthetic outcomes with similar success in rates of local recurrence and metastasis when compared to treatment by amputation in SMIS.