Faculty Bibliography

The pathophysiology of diabetic wound healing and the identification of new agents to improve clinical outcomes continue to be areas of intense research. There currently exist more than 10 different murine models of diabetes. The degree to which wound healing is impaired in these different mouse models has never been directly compared. We determined whether differences in wound impairment exist between diabetic models in order to elucidate which model would be the best to evaluate new treatment strategies. Three well-accepted mouse models of diabetes were used in this study: db/db, Akita, and streptozocin (STZ)-induced C57BL/6J. Using an excisional model of wound healing, we demonstrated that db/db mice exhibit severe impairments in wound healing compared with STZ and Akita mice. Excisional wounds in db/db mice show a statistically significant delay in wound closure, decreased granulation tissue formation, decreased wound bed vascularity, and markedly diminished proliferation compared with STZ, Akita, and control mice. There was no difference in the rate of epithelialization of the full-thickness wounds between the diabetic or control mice. Our results suggest that splinted db/db mice may be the most appropriate model for studying diabetic wound-healing interventions as they demonstrate the most significant impairment in wound healing. This study utilized a novel model of wound healing developed in our laboratory that stents wounds open using silicone splints to minimize the effects of wound contraction. As such, it was not possible to directly compare the results of this study with other studies that did not use this wound model

The role of expert witnesses in medical malpractice litigation is often misunderstood. Much maligned, the expert has been the subject of castigation by a range of people, from his professional colleagues to the jurists who preside over his testimony. From an academic perspective, the expert witness is a necessary evil, and his denigration is his own doing; for the expert is a neutral character who creates his own professional persona. This purpose of this article is to serve as a primer for those interested in understanding the role that the expert is supposed to play in litigation, and the factors surrounding his activities.

BACKGROUND: Treatment of macrogenia can be a challenging problem. In this article, the authors provide novel insights for treatment of a previously poorly treated problem. The authors have developed anatomical insights that facilitate the subtly difficult preoperative evaluation of the large chin and, when applied appropriately, will provide uniformly pleasing results. METHODS: A retrospective review of the senior author's (B.M.Z.) patient records was performed. More than 50 cases of macrogenia were identified. As previously described, almost all of the cases were performed under local anesthesia with oral premedication only. RESULTS: This article demonstrates why prior modalities such as intraoral burring and lower border setback failed to treat the variety of large chins properly. The nine critical factors the surgeon must consider in developing a successful surgical plan are outlined. The surgical plan is not primarily based on radiographs as much as on direct tactile and visual analysis of the sublabial structures both in repose and while smiling. Crucial aspects of the operative technique are highlighted. CONCLUSIONS: The large chin can be approached with confidence if nine parameters are appreciated. The authors have outlined these key variables that facilitate proper preoperative topographic analysis of the large chin. Once these variables are appreciated, an appropriate surgical plan can be formulated

BACKGROUND: Perforator flaps represent the latest in the evolution of soft-tissue flaps. They allow the transfer of the patient's own skin and fat in a reliable manner, with minimal donor-site morbidity. The powerful perforator flap concept allows transfer of tissue from numerous, well-described donor sites to almost any distant site with suitable recipient vessels. Large-volume flaps can be supported reliably with perforators from areas such as the abdomen, buttock, or flank and transferred microsurgically for breast reconstruction. INDICATIONS: The ideal tissue for breast reconstruction is fat with or without skin, not implants or muscle. Absolute contraindications specific to perforator flaps in the authors' practice include history of previous liposuction of the donor site, some previous donor-site surgery, or active smoking (within 1 month before surgery). TECHNIQUE: Perforator flaps are supplied by blood vessels that arise from named, axial vessels and perforate through or around overlying muscles and septa to vascularize the overlying skin and fat. During flap harvest, these perforators are meticulously dissected free from the surrounding muscle, which is spread in the direction of the muscle fibers and preserved intact. The pedicle is anastomosed to recipient vessels in the chest, and the donor site is closed without the use of mesh. CONCLUSION: Perforator flaps allow for safe, reliable tissue transfer from a variety of sites and provide ideal tissue for breast reconstruction, with minimal donor-site morbidity

OBJECTIVE: To describe a frameless stereotactic technique used to resect cerebral arteriovenous malformations (AVMs) and to determine whether frameless stereotaxy during AVM resection could decrease operative times, minimize intraoperative blood losses, reduce postoperative complications, and improve surgical outcomes. METHODS: Data for 44 consecutive patients with surgically resected cerebral AVMs were retrospectively reviewed. The first 22 patients underwent resection without stereotaxy (Group 1), whereas the next 22 patients underwent resection with the assistance of a frameless stereotaxy system (Group 2). RESULTS: The patient characteristics, AVM morphological features, and percentages of preoperatively embolized cases were statistically similar for the two treatment groups. The mean operative time for Group 1 was 497 minutes, compared with 290 minutes for Group 2 (P = 0.0005). The estimated blood loss for Group 1 was 657 ml, compared with 311 ml for Group 2 (P = 0.0008). Complication rates, residual AVM incidences, and clinical outcomes were similar for the two groups. CONCLUSION: Frameless stereotaxy allows surgeons to 1) plan the optimal trajectory to an AVM, 2) minimize the skin incision and craniotomy sizes, and 3) confirm the AVM margins and identify deep vascular components during resection. These benefits of stereotaxy were most apparent for small, deep AVMs that were not visible on the surface of the brain. Frameless stereotaxy reduces the operative time and blood loss during AVM resection

The purpose of this study was to develop a technique to evaluate the implant-abutment gap of an external hexagon implant system as a function of radius. Six implants of 3.75 mm in diameter (Conexao Sistema de Protese Ltda, Sao Paulo, Brazil) and their respective abutments were screw connected and torqued to 20 N cm(-1). The implants were mounted in epoxy assuring an implant long-axis position perpendicular to the vertical axis. Each implant was grounded through its thickness parallel to implant long-axis at six different distance interval. Implant-abutment gap distances were recorded along the implant-abutment region for each section. Individual measurements were related to their radial position through trigonometric inferences. A sixth degree polynomial line fit approach determined radial adaptation patterns for each implant. Micrographs along implant sections showed a approximately 300 mum length implant-abutment engagement region. All implants presented communication between external and internal regions through connection gaps and inaccurate implant-abutment alignment. Average gap distances were not significantly different between implants (P > 0.086). Polynomial lines showed implant-abutment gap values below 10 mum from 0 mum to approximately 250 mum of the implant-abutment engagement region. Gap distances significantly increased from approximately 250 mum to the outer radius of the implant-abutment engagement region. The technique described provided a broader scenario of the implant-abutment gap adaptation compared with previous work concerning implant-abutment gap determination, and should be considered for better understanding mechanical aspects or biological effects of implant-abutment adaptation on peri-implant tissues.

A patient with Apert syndrome who underwent a monobloc osteotomy with distraction advancement sustained partial unilateral vision loss as a complication from a direct carotid-cavernous fistula. Successful embolization was used to treat the fistula. Precaution should be taken by craniofacial surgeons in performing similar procedures in patients with Apert syndrome because of their unique skull abnormalities.

OBJECTIVE: We report the incidence and clinical evolution of postoperative deficits and supplementary motor area (SMA) syndrome after volumetric stereotactic resection of glial neoplasms involving the posterior one-third of the superior frontal convolution. We investigated variables that may be associated with the occurrence of SMA syndrome. METHODS: The postoperative clinical status of 27 consecutive patients who underwent resection of SMA gliomas was retrospectively reviewed. Neurological examination results were recorded 1 day, 1 week, 1 month, and 6 months postoperatively. The extent of tumor resection, the percentage of SMA resection, violation of the cingulate gyrus, and operative complications were tabulated. RESULTS: The overall incidence of SMA-related deficits was 26% (7 of 27 patients), with 3 patients having complete SMA syndrome and 4 patients having partial SMA syndrome. Two additional patients (7.5%) had other postoperative deficits, including one with mild facial weakness and one with transient aphasia. The resection of low-grade gliomas was associated with a higher incidence of SMA syndrome, an outcome that likely reflects more complete removal of functional SMA cortex in this subset of patients. Intraoperative monitoring localized the precentral sulcus within the preoperatively defined tumor volume in 6 (22%) of 27 patients, thereby precluding gross total resection. All 27 patients had excellent outcomes at the 6-month follow-up examination. CONCLUSION: When the resection of SMA gliomas is limited to the radiographic tumor boundaries, the incidence and severity of SMA syndrome may be minimized. With the use of these resection parameters, patients with high-grade SMA gliomas are unlikely to experience SMA syndrome. These findings are helpful in the preoperative counseling of patients who are to undergo cytoreductive resection of SMA gliomas

BACKGROUND: Patients with craniofacial anomalies can have hard and soft tissue deficiencies. In some cases, distraction osteogenesis can restore the bony deficiencies, but the soft tissue contour defect remains problematic. For these patients, the union of distraction osteogenesis and microvascular free flaps (MVFF) can restore bone and soft tissue form and function. PATIENTS AND METHODS: A retrospective review of all patients treated with mandibular distraction osteogenesis between 1989 and 2005 was performed. A similar review of all patients treated with MVFFs was performed. These 2 cohorts were cross-referenced to identify all patients treated with both procedures. The indications, choices, safety, and efficacy of MVFF reconstruction of facial soft tissues following mandibular reconstruction are reviewed. RESULTS: Over a 16-year period, 141 patients underwent mandibular distraction osteogenesis; 8 patients treated with mandibular distraction osteogenesis subsequently underwent 12 MVFFs. Patient diagnoses included unilateral craniofacial microsomia (n = 2), bilateral craniofacial microsomia (n = 3), Goldenhar syndrome (n = 1), Nager syndrome (n = 1), and Treacher-Collins syndrome (n = 1). Free flap choices included 10 parascapular fasciocutaneous, 1 parascapular osteofasciocutaneous, and 1 fibular osteocutaneous flap. Four patients underwent staged bilateral free flaps. A single case of partial flap loss was the only complication. In all cases, facial contour was improved following MVFF transfer. CONCLUSIONS: In certain circumstances, facial rehabilitation may require the marriage of craniofacial and microsurgical techniques to restore both form and function. In these cases, mandibular distraction osteogenesis and MVFFs can be safely and effectively combined