Faculty Bibliography

Introduction: The profunda artery perforator (PAP) flap is a new addition to our reconstructive armamentarium. In effort to better understand patient candidacy for the PAP flap we characterized the profunda artery perforators on preoperative imaging. Methods: A retrospective review was completed of 40 preoperative posterior thigh computed tomography angiographies and magnetic resonance angiographies by four plastic surgeons. The positioning of the patient, type of study, number of perforators, and size of perforators were documented. The location was documented on an x-y-axis. Perforator course and surrounding musculature was documented. Results: In 98.8% of posterior thighs suitable profunda artery perforators were identified. The average number and size of perforators was 3.3 and 1.9 mm. The most common perforator was medial (present in 85.6% of thighs); found near the adductor magnus at 3.8 cm from midline and 5.0 cm below the gluteal fold. The second most common perforator was lateral (present in 65.4% of thighs); found near the biceps femoris and vastus lateralis at 12.0 cm from midline and 5.0 cm below the gluteal fold. Nearly 48.3% were purely septocutaneous. And 51.7% had an intramuscular course (average length 5.7 cm). Preoperative imaging corresponded to suitable perforators at the time of dissection of all PAP flaps. Thirty five PAP flaps (18 patients) were performed with 100% flap survival. Conclusion: Analysis of preoperative posterior thigh imaging confirms our intraoperative findings that a considerable number of suitable posterior thigh profunda perforators are present, emerge from the fascia in a common pattern, and are of sufficient caliber to provide adequate flap perfusion and recipient vessel size match. (c) 2012 Wiley Periodicals, Inc. Microsurgery, 2012.

OBJECTIVES: The aim of this study was to assess the effect of abutment's diameter shifting on reliability and stress distribution within the implant-abutment connection for internal and external hexagon implants. The postulated hypothesis was that platform-switched implants would result in increased stress concentration within the implant-abutment connection, leading to the systems' lower reliability. METHODS: Eighty-four implants were divided in four groups (n=21): REG-EH and SWT-EH (regular and switched-platform implants with external connection, respectively); REG-IH and SWT-IH (regular and switched-platform implants with internal connection, respectively). The corresponding abutments were screwed to the implants and standardized maxillary central incisor metal crowns were cemented and subjected to step-stress accelerated life testing. Use-level probability Weibull curves and reliability were calculated. Four finite element models reproducing the characteristics of specimens used in laboratory testing were created. The models were full constrained on the bottom and lateral surface of the cylinder of acrylic resin and one 30 degrees off-axis load (300N) was applied on the lingual side of the crown (close to the incisal edge) in order to evaluate the stress distribution (s(vM)) within the implant-abutment complex. RESULTS: The Beta values for groups SWT-EH (1.31), REG-EH (1.55), SWT-IH (1.83) and REG-IH (1.82) indicated that fatigue accelerated the failure of all groups. The higher levels of sigma(vM) within the implant-abutment connection observed for platform-switched implants (groups SWT-EH and SWT-IH) were in agreement with the lower reliability observed for the external hex implants, but not for the internal hex implants. The reliability 90% confidence intervals (50,000 cycles at 300N) were 0.53(0.33-0.70), 0.93(0.80-0.97), 0.99(0.93-0.99) and 0.99(0.99-1.00), for the SWT-EH, REG-EH, SWT-IH, and REH-IH, respectively. SIGNIFICANCE: The postulated hypothesis was partially accepted. The higher levels of stress observed within implant-abutment connection when reducing abutment diameter (cross-sectional area) resulted in lower reliability for external hex implants, but not for internal hex implants.

BACKGROUND: Isolated nonsyndromic bicoronal synostosis is a relatively rare entity that produces a characteristic turribrachycephalic skull shape. The purpose of this study was to evaluate the long-term outcomes of the isolated nonsyndromic bicoronal synostosis patients treated at the authors' institution. METHODS: A retrospective chart review of all patients who underwent cranial vault remodeling for nonsyndromic bicoronal synostosis was performed at the Children's Hospital of Philadelphia from 1991 to 2011. Fifteen patients were identified for this study, and information regarding their demographic, perioperative, and postoperative details were analyzed. RESULTS: Four boys and 11 girls were identified for inclusion in this study. The average age at the time of the initial surgery was 9 months, with an average follow-up of 13.4 years. There were no reported complications. Six patients with at least a 10-year follow-up (six of 10 patients) underwent revision for contour improvement in the forehead and temporal regions, and two patients required a repeated fronto-orbital advancement. Four patients underwent subsequent strabismus surgery. No patients were documented to have midface hypoplasia requiring orthognathic surgery. One patient with an associated diagnosis of autism was noted to have significant developmental delay. CONCLUSIONS: Isolated nonsyndromic bicoronal synostosis confers a high rate of revisions for contour deformities but is associated with a low risk of complications. Overall, nonsyndromic patients require less secondary fronto-orbital advancement when compared with syndromic patients. In contrast to the syndromic population, there were no instances of midface hypoplasia necessitating surgery. There did not appear to be significant correlation between bicoronal synostosis and developmental abnormalities or delays.

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.

BACKGROUND: Breast reconstruction rates continue to slowly rise in large part because of patients and physicians becoming more knowledgeable about postmastectomy options. Overall satisfaction with breast reconstruction after mastectomy has traditionally been high, only adding to the popularity of this choice. Prior research has demonstrated that race, age, and socioeconomic status are important determinants in whether a patient undergoes breast reconstruction; specifically, indigent women have a lower rate of breast reconstruction when compared to the national average. METHODS: All records of patients who received mastectomies between January 2001 and December 2009 were examined. The PubMed database was used to search for reference articles. RESULTS: Between January 2001 and December 2009, 309 patients underwent mastectomy, and 134 (43.4%) elected reconstruction. Patients in age ranges 20 to 39 and 40 to 59 were both significantly more likely to undergo reconstruction than patients older than 60 years. Disease stage was not significantly related to rates of breast reconstruction. Reconstruction rates by race and ethnicity were analyzed and demonstrated a significantly lower rate of breast reconstruction in Asian women (34%) compared with Hispanic women (48%), despite the same access to available services. CONCLUSIONS: Our data demonstrate breast reconstruction rates significantly higher than prior studies for women in this public hospital demographic, rivaling the reported numbers from dedicated cancer centers where breast reconstruction is expected to be at the highest range. Types of reconstruction were based mainly on patient choice after full discussion regarding individual options. These data suggest that patients considered to be financially indigent are more likely to have breast reconstruction when their care is delivered at a university-based public hospital where immediate and consistent patient education is practiced in a multidisciplinary setting.

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.

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.

This study evaluated the early biomechanical fixation and bone-to-implant contact (BIC) of an alumina-blasted/acid-etched (AB/AE) compared with an experimental resorbable blasting media (RBM) surface in a canine model. Higher texturization was observed for the RBM than for the AB/AE surface, and the presence of calcium and phosphorus was only observed for the RBM surface. Time in vivo and implant surface did not influence torque. For both surfaces, BIC significantly increased from 2 to 4 weeks.