Faculty Bibliography

Posterior tongue defects present a unique reconstructive challenge. The various reconstructive options available for treating the defect created by a posterior hemiglossectomy frequently result in a distorted tongue and functional impairment. This paper describes a novel sliding anterior hemitongue flap to allow reconstruction of moderate resection defects (i.e. for T1-T2 tongue squamous cell carcinomas) of the posterior tongue. By mobilizing the anterior tongue, near normal mobility and tongue length are maintained. This surgical technique may be performed alone intraorally or in combination with a neck dissection.

Bone remodeling, along with tissue biomechanics, is critical for the clinical success of endosseous implants. This study evaluated the long-term evolution of the elastic modulus (GPa) and hardness (GPa) of cortical bone around human retrieved plateau root form implants. Thirty implant-in-bone specimens showing no clinical failure were retrieved from patients at different in-vivo times (0.3 to approximately 24 years) due to retreatment needs. After dehydration, specimens were embedded in methacrylate-based resin, sectioned along the bucco-lingual long axis and fixed to acrylic plates and nondecalcified processed to slides with approximately 50 mum in thickness. Nanoindentation testing was carried out under wet conditions on bone areas within the first three plateaus. Indentations (n = 120 per implant total) were performed with a maximum load of 300 muN (loading rate: 60 muN/s) followed by a holding and unloading time of 10 s and 2 s, respectively. Elastic modulus (E, GPa) and hardness (H, GPa) were computed. Both E and H values presented increased values as time in vivo elapsed (E: r = 0.84; H: r = 0.78). Significantly higher values for E and H were found after 5 years in vivo (p < 0.001). Maxillary or mandibulary arches or positioning did not affect mechanical properties, nor did implant surface treatment on the long-term bone biomechanical response (E: p >/= 0.09; H: p >/= 0.3). This work suggests that human cortical bone around plateau root form implants presents an increase in elastic modulus and hardness during the first 5 years following implantation and presents stable mechanical properties thereafter. (c) 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.

BACKGROUND:Impaired wound healing remains a major clinical problem with many etiologies. Altering gene expression to enhance healing is an innovative therapeutic approach. In recent years, we have developed a means to topically silence genes at the post-transcriptional level to locally alter wounds and improve the healing process. THE PROBLEM/OBJECTIVE:Many types of chronic wounds have been associated with alterations in the expression of genes that mediate healing. Targeting the expression of these genes in a way that can improve healing while limiting systemic side effects has been very challenging. BASIC/CLINICAL SCIENCE ADVANCES/UNASSIGNED:Our laboratory's recent work has focused on the use of topically applied small interfering ribonucleic acid (siRNA) to inhibit messenger RNA expression of certain mediators involved in healing in two different types of cutaneous injury-radiation-induced cutaneous injury and the diabetic excisional wound. By successfully inhibiting specific gene mediators with topical siRNA, we reversed downstream signaling pathways, which led to expedited wound healing in diabetic wounds and restoration to a more normal phenotype in radiation-induced skin injuries. CLINICAL CARE RELEVANCE/UNASSIGNED:The signaling pathways and gene mediators that we targeted and inhibited in murine models are present in humans. Applying parallel treatment strategies in humans may provide novel means of treating these burdensome and costly conditions. CONCLUSION/CONCLUSIONS:Our novel method for local gene silencing is effective in treating various types of cutaneous murine wounds. Topical gene silencing with siRNA obviates the side effects of systemic medication and has the potential to be effective in healing or preventing a wide array of cutaneous human conditions.

OBJECTIVE: This study aims to use the evidenced-based approach to better understand the surgical management and treatment of pressure ulcers. SUMMARY OF BACKGROUND DATA: Pressure sores are a cause of significant morbidity in the medical community. Although there are a multitude of preventative and treatment options, there remains some degree of uncertainty in the literature in defining the best way to treat and manage pressure sores. METHODS: An exhaustive literature search was performed using several electronic databases. The search revealed several identified modalities for treatment of pressure ulcers. We then assessed each modality individually for the level of evidence that exists in the most current literature, with preference given to more recent studies (2005-present). RESULTS: Here, we reviewed the most relevant, high-level evidence that exists for the following modalities for managing pressure ulcers from a surgical perspective: wound cleansers, repositioning, negative pressure therapy, enteral and parenteral feeding, vitamin and mineral supplementation, specialized mattresses, ultrasound therapy, honey, cellular therapy, debridement, ostectomy, and musculocutaneous and fasciocutaneous flap closure. CONCLUSIONS: Although many of the previously mentioned modalities are used, we encourage clinicians and health care providers to consider the evidence-based data when deciding how to most appropriately manage their patient's pressure sores.

BACKGROUND: With the transplantation of more extensive facial vascularized composite allografts, fundamental craniofacial and aesthetic principles become increasingly important. In addition, computer-assisted planning and intraoperative navigation may improve precision and efficiency in these complex procedures. METHODS: Ten mock face transplants were performed in 20 cadavers. The vascularized composite allograft consisted of all facial skin, mimetic muscles, the tongue, the midface by means of a Le Fort III osteotomy, and the mandible by means of sagittal split osteotomies. Craniofacial computed tomographic scans were obtained before and after the mock transplants. Surgical planning software was used to virtually plan the osteotomies, and a surgical navigation system guided the osteotomies intraoperatively. Cephalometric analyses were compared between the virtually planned transplants and the actual postoperative results. RESULTS: The combination of preoperative computerized planning and intraoperative guidance consistently produced a vascularized composite allograft that could be easily fixated to the prepared recipient, with only minimal burring of osteotomy sites necessary. Satisfactory occlusion was maintained, and postoperative computed tomography confirmed accurate skeletal fixation. Insignificant differences with regard to cephalometric analyses were noted when predicted and actual postoperative data were compared. CONCLUSIONS: The authors' experience treating severe craniofacial injury allowed consistent transfer of facial vascularized composite allografts, maintaining proper occlusion. Preoperative computer planning and intraoperative navigation ensured precise osteotomies and a good donor-recipient skeletal match, which greatly reduced the need for intraoperative adjustments and manipulation. This total facial vascularized composite allograft represents one of the most extensive described and is intended to represent a typical central facial demolition pattern.

BACKGROUND: Abdominal fascia plication using a simple continuous suture can sometimes cause tears in the fascia. This problem can be circumvented when the continuous horizontal mattress suture is used. No data exist from comparing the two suturing techniques. The aim of this study was to examine which technique can potentially cause greater tissue damage. The time required to perform each type of suture was also recorded. METHODS: Wound closure pads were plicated using the simple continuous and continuous horizontal mattress techniques performed by a single operator using Ethilon 2-0 nylon sutures. To verify their resilience, plastic bags were inflated beneath the pads to 30, 60, and 120 mmHg and tears were recorded. The time needed to perform the procedures was recorded using a stopwatch. RESULTS: Mean time for the continuous vertical mattress suture was 87 s and for the simple continuous suture 116 s. Tears in the pad that was plicated with the simple continuous pattern were significantly longer than those in the pad plicated with the continuous horizontal mattress pattern (fissure mean length +/- SD = 3.958 +/- 0.157 vs. 2.736 +/- 0.157, respectively, p < 0.001). This finding was true for each of the three measured pressures (fissure mean length for 30 mmHg was 3.40 +/- 1.807 vs. 2.12 +/- 1.709 cm; for 60 mmHg, 3.94 +/- 2.90 vs. 2.90 +/- 1.893 cm; and for 120 mmHg, 4.54 +/- 1.924 vs. 3.19 +/- 2.110 cm; p < 0.001). CONCLUSIONS: Continuous horizontal mattress pattern sutures were found to be superior to simple continuous pattern sutures in the suggested model, in terms of suturing time and damage to the pad. Further research in human subjects is still required. LEVEL OF EVIDENCE II: This journal requires that authors assign a level of evidence to each article.

OBJECTIVE: The aim of this study was to evaluate the use of a collagen-based membrane compared with no treatment on guided bone regeneration by 3-dimensional computerized microtomography (muCT). STUDY DESIGN: Defects were created between the mesial and distal premolar roots of the second and third premolars (beagle dogs; n = 8). A collagen-based membrane (Vitala; Osteogenics Biomedical Inc., TX, USA) was placed in one of the defects (membrane group; n = 16), and the other was left untreated (no-membrane group; n = 16). Left and right sides provided healing samples for 2 and 16 weeks. Three-dimensional bone architecture was acquired by muCT and categorized as fully regenerated (F, bone height and width) or nonregenerated (N). RESULTS: Chi-square tests (95% level of significance) showed that tooth did not have an effect on outcome (P = .5). Significantly higher F outcomes were observed at 16 weeks than 2 weeks (P = .008) and in membrane group than in no-membrane group (P = .008). CONCLUSIONS: The collagen-based membrane influenced bone regeneration at the furcation.