Faculty Bibliography

A 28-year-old otherwise healthy man was admitted to the burn center for treatment of toxic epidermal necrolysis (TEN) involving 90% of the TBSA and oropharynx. On hospital day 8, his cutaneous lesions were healing well, but he developed respiratory distress, fever, and abdominal distension. Computerized tomography demonstrated distended bowel, pneumatosis intestinalis, and portal venous gas. He underwent emergent celiotomy. Patchy areas of nonperforated necrosis along the jejunum and ileum were present. No mechanical or embolic source of ischemia could be identified. A 120-cm segment of ischemic small bowel was resected and the abdomen was closed temporarily. On planned "second look" the following day, no further disease was encountered and intestinal continuity was restored. Tube feeds were then initiated and the patient's recovery was uneventful thereafter. Although traditionally considered a skin disorder, TEN may be more accurately described as a disorder affecting the junction of an epithelium and its supporting tissue. It is most prominently manifested at the epidermal-dermal junction, but epithelial-submucosal junctions are also affected. The ocular, respiratory, genitourinary, and gastrointestinal manifestations of TEN are variable and incompletely understood. This disease is rooted in immunological dysfunction and the small bowel is rich in immunologically active tissue; Peyer patches and lymph nodes abound. Clinicians should be vigilant for gastrointestinal tract involvement, which is potentially treatable with resection of the ischemic bowel. The authors suspect that, given the critical condition of many TEN patients, bowel symptoms may be incorrectly attributed to global hypoperfusion and sepsis.

Micro- and nanoscale surface modifications have been the focus of multiple studies in the pursuit of accelerating bone apposition or osseointegration at the implant surface. Here, we evaluated histological and nanomechanical properties, and gene expression, for a microblasted surface presenting nanometer-scale texture within a micrometer-scale texture (MB) (Ossean Surface, Intra-Lock International, Boca Raton, FL) versus a dual-acid etched surface presenting texture at the micrometer-scale only (AA), in a rodent femur model for 1, 2, 4, and 8weeks in vivo. Following animal sacrifice, samples were evaluated in terms of histomorphometry, biomechanical properties through nanoindentation, and gene expression by real-time quantitative reverse transcription polymerase chain reaction analysis. Although the histomorphometric, and gene expression analysis results were not significantly different between MB and AA at 4 and 8weeks, significant differences were seen at 1 and 2weeks. The expression of the genes encoding collagen type I (COL-1), and osteopontin (OPN) was significantly higher for MB than for AA at 1week, indicating upregulated osteoprogenitor and osteoblast differentiation. At 2weeks, significantly upregulated expression of the genes for COL-1, runt-related transcription factor 2 (RUNX-2), osterix, and osteocalcin (OCN) indicated progressive mineralization in newly formed bone. The nanomechanical properties tested by the nanoindentation presented significantly higher rank hardness and elastic modulus for the MB compared to AA at all time points tested. In conclusion, the nanotopographical featured surfaces presented an overall higher host-to-implant response compared to the microtextured only surfaces. The statistical differences observed in some of the osteogenic gene expression between the two groups may shed some insight into the role of surface texture and its extent in the observed bone healing mechanisms.

PURPOSE:: This clinical and histological study evaluated the healing of extraction sockets after implantation of a biphasic calcium sulfate (CS) alone or in combination with a gamma-radiated human mineralized allograft. MATERIALS AND METHODS:: Ten healthy adult patients participated in the study. A minimum of 2 teeth, per patient, extracted for different reasons were evaluated. Each socket was randomly filled to the crest with either (a) a biphasic CS or (b) large particulate gamma-radiated human mineralized allograft in combination with a biphasic CS. RESULTS:: No complications during reentry of the socket site during bone core retrieval, such as inflammation/immunogenic response, were observed. Histological findings showed a mean new bone (NB) of 33% for sockets filled with biphasic CS and 31% for sockets filled with biphasic CS in combination with allograft material. There was no statistically significant difference in the percentage of NB and the presence of soft tissue between graft materials. CONCLUSION:: Biphasic CS used alone or in combination with an allograft resulted in the same amount of NB formation in alveolar ridge preservation procedures.

AIMS: It has been accepted that bone damage and subsequent resorption occurs in cases of adverse interfacial bone strain. Fractured implants represents an important opportunity for evaluating the bone response to overstrain. The objective of the study was to analyze the bone morphology and morphometry around retrieved fractured implants in humans. Five fractured implants retrieved after 22.4 (+/- 2.8) years were used in the present study. The investigation was conducted in a transmitted brightfield and circularly polarized light Microscope. The parameters considered were the total bone area, total bone remodeling area, bone-remodeling rate (BRR), and bone transverse collagen fibers orientation (CFO). FINDINGS: For grouped samples, the BRR was 51.9% (+/- 10) while the transverse CFO was 13.0% (+/- 9.7). The interthread BRR was 58.1% (+/- 4.0) for level 1 and 40.4% (+/- 12.8) for level 2 with a significant decrease in BRR (p = 0.019) as a function of depth along the implant length. CONCLUSIONS: Both bone level and bone quality attains stability to a certain level with respect to implant neck fracture following physiologic interaction between mechanical and biological inputs. The BRR significantly decrease as function of threads depth. (c) 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 1342-1352, 2014.

Recent advances in surgery and orthodontics have resulted in improvements in the management of patients with a cleft lip or palate. Early surgical intervention and bone-grafting procedures have frequently been used to ensure closure of the cleft and continuity of the alveolar bone. However, a need for the prosthodontic management of patients with a cleft palate still exists. Most frequently, the indication is to restore the edentulous spaces located anteriorly in the vicinity of the residual cleft defect. In addition to improving the esthetic outcome, prosthodontic management also is required to restore function, especially occlusion and speech. This clinical report illustrates the management of an adult patient with a unilateral cleft of the lip and palate who required prosthodontic rehabilitation after surgery. The patient had previously undergone multiple surgeries and did not want to consider implant therapy as a treatment option. Thus, the patient was managed with fixed and removable prosthodontics with a maxillary overdenture prosthesis retained by microextracoronal resilient attachments, which were laser welded onto crowns on abutment teeth to obtain a functionally and esthetically acceptable result.

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.

PURPOSE: Local anesthetic is often used for perioperative pain control. Thrombin serves as a carrying medium for sustained release of antibiotics, chemotherapy, and growth factors. We tested the hypothesis that local anesthetic pain relief can be prolonged with the adjunct use of thrombin. METHODS: A prospective single-blinded clinical study was performed. Patients undergoing elective hand surgery inclusive of carpal tunnel release, excision of ganglion cyst, trigger finger release, and excision of mucous cyst under local block were enlisted. Before closure, patients received 1 of the following combinations: (1) control with oral analgesics, (2) 5 mL of 2% xylocaine, (3) 5 mL of 0.5% bupivacaine, (4) 2.5 mL of 2% xylocaine with 2.5 mL of 0.5% bupivacaine (XB), (5) thrombin with 5 mL of 2% xylocaine (XT), (6) thrombin with 5 mL of 0.5% bupivacaine (BT), and (7) thrombin with 2.5 mL of 2% xylocaine and 2.5 mL of 0.5% bupivacaine (XBT). There were 7 patients in each group, and patient demographics were similar between groups. Outcome measures included postanesthesia care unit (PACU) time, pain level, and number of pain pills required. RESULTS: Compared with oral analgesics alone, mean (SD) postoperative pain levels were reduced by 33.3% (8.9%) by xylocaine, 69.1% (8.7%) by bupivacaine, and 45.7% (9.4%) by XB. When thrombin was added, pain levels were further reduced by 69.9% by XT (P < 0.001), 23.1% by BT (P = 0.071), and 50.5% by XBT (P < 0.001) compared with their nonthrombin counterparts. In addition, PACU time was decreased by 34.8% by XT (P = 0.003) and 19.7% by XBT (P = 0.013) compared with xylocaine and XB, respectively. However, there was no difference in total pain pills needed between xylocaine, bupivacaine, and XB when administered with and without thrombin. CONCLUSIONS: The addition of topical thrombin to local anesthetic at the end of elective hand surgery provides for sustained postoperative pain control. Patients in this study who received thrombin and local anesthetic before wound closure had lower pain levels and were discharged from the PACU sooner than those who received local anesthetic alone. LEVEL OF EVIDENCE: Therapeutic level 2.

BACKGROUND: Vascularized composite tissue allotransplant recipients are often highly sensitized to human leukocyte antigens because of multiple prior blood transfusions and other reconstructive operations. The use of peripheral blood obtained from dead donors for crossmatching may be insufficient because of life support measures taken for the donor before donation. No study has been published investigating human leukocyte antigen matching practices in this field. METHODS: A survey addressing human leukocyte antigen crossmatching methods was generated and sent to 22 vascularized composite tissue allotransplantation centers with active protocols worldwide. Results were compiled by center and compared using two-tailed t tests. RESULTS: Twenty of 22 centers (91 percent) responded to the survey. Peripheral blood was the most commonly reported donor sample for vascularized composite tissue allotransplant crossmatching [78 percent of centers (n=14)], with only 22 percent (n=4) using lymph nodes. However, 56 percent of the 18 centers (n=10) that had performed vascularized composite tissue allotransplantation reported that they harvested lymph nodes for crossmatching. Of responding individuals, 62.5 percent (10 of 16 individuals) felt that lymph nodes were the best donor sample for crossmatching. CONCLUSIONS: A slight majority of vascularized composite tissue allotransplant centers that have performed clinical transplants have used lymph nodes for human leukocyte antigen matching, and centers appear to be divided on the utility of lymph node harvest. The use of lymph nodes may offer a number of potential benefits. This study highlights the need for institutional review board-approved crossmatching protocols specific to vascularized composite tissue allotransplantation, and the need for global databases for sharing of vascularized composite tissue allotransplantation experiences.