Faculty Bibliography

INTRODUCTION: Methyl methacrylate is a biologically inert alloplastic material that is commonly used to rebuild the calvarial vault. Since methyl methacrylate does not permit tissue incorporation it is susceptible to displacement and/or fracture. In order to increase the tensile strength of methyl methacrylate onlay cranioplasties, we use wire reinforced masonry techniques. PATIENT: A 56-year-old female presents with forehead asymmetry due to displacement and fracture of a silicone alloplastic implant. This patient, treated with onlay wire reinforced methyl methacrylate, demonstrates the utility of this novel technique. RESULTS: Wire is passed through 2-mm outer cortex tunnels like spokes on a wheel, around the perimeter of the defect to form a rebar grid. Methyl methacrylate is poured onto the rebar grid and contoured after it solidifies. CONCLUSIONS: Wire reinforced methyl methacrylate is a simple technique to improve the tensile strength of calvarial alloplastic reconstructions

BACKGROUND: Gluteal augmentation is increasingly common. However, few studies have quantitatively reported postoperative gluteal projection. This study compared three different standardized instruments (i.e., radiographic, sonographic, and anthropometric) for quantifying gluteal projection after lumbar-hip dermal fat rotational flap to identify a simple, cost-efficient valid instrument. METHODS: A total of 10 women ages 35 to 68 years (mean, 47.3 years) with skin flaccidity and gluteal ptosis underwent bilateral lumbar-hip dermal fat rotation flap gluteal augmentation (20 procedures). Gluteal projection was measured 1 week preoperatively and 8 months postoperatively using computerized axial tomography (CAT) scan, ultrasound, and anthropometry. RESULTS: The CAT scan measured 1.40 cm of projection on the left (p < 0.001) and 1.43 cm on the right (p = 0.001). Ultrasound measured 2.16 cm of projection on the left (p < 0.001) and 1.88 cm on the right (p = 0.001). Anthropometry measured 1.75 cm of projection on the left (p < 0.01) and 1.35 cm on the right (p < 0.05). Repeated measures analysis of variance (ANOVA) comparing the CAT scan, ultrasound, and anthropometry demonstrated statistically similar results on the left (p = 0.43) and right (p = 0.62). CONCLUSIONS: All three instruments were sufficiently sensitive to measure a statistically significant increase in postoperative gluteal projection. Moreover, all three instruments were statistically similar in accuracy of measurement. Therefore, the authors conclude that ultrasound or anthropometry are satisfactory, inexpensive instruments for accurately quantifying postoperative gluteal projection

BACKGROUND: Free tissue transfer for adult mandibular reconstruction is a well-established technique; however, there are few reports of pediatric microvascular lower jaw reconstruction. METHODS: This retrospective study was undertaken to review the range of indications, choices, safety, and efficacy of pediatric free tissue transfer to the lower jaw. All patients underwent a parascapular, scapular, or fibula free tissue transfer. Flap choice was based on preoperative clinical examination, radiographic findings, need for linear or multiplanar mandibular reconstruction, need for dental restoration, severity of soft-tissue deficit, and peroneal artery anatomy. RESULTS: Over a 10-year period (1989 to 1999), we performed eight free tissue transfers to reconstruct the mandibles of seven children, aged 6 to 17 years. Indications included radiation-induced hypoplasia (n = 1), postsurgical resection of fibrous dysplasia (n = 1), hemifacial microsomia (n = 3), Robin sequence with severe micrognathia (n = 1), and osteomyelitis (n = 1). The authors transferred four parascapular osseocutaneous, two scapular osseocutaneous, one fibular osseocutaneous, and one fibular osseous flap to reconstruct five ramus, four condyle, and two subtotal mandibular defects. All bony defects were successfully bridged and all osseous flaps successfully integrated. Postoperatively, mandibular symmetry and Angle class I occlusion were restored in all patients throughout the 10.5-year follow-up period (range, 9 to 14 years). Two patients received osseointegrated dental implants. Our only complication was the partial loss of a skin paddle. CONCLUSION: Microvascular reconstruction of the pediatric mandible, in selected patients, is a safe, reliable procedure that provides the bone stock and soft tissue necessary to restore normal maxillomandibular growth and dental rehabilitation.

BACKGROUND: Correction of the long, nonprojecting chin requires both vertical reduction and sagittal augmentation. Wedge excision-based therapy reduces chin height and allows for advancement of the distal segment, but it is associated with at least a 10 percent incidence of mental nerve injury. The authors propose two innovative ways to correct the long, nonprojecting chin. METHODS: There are two approaches, intraoral and extraoral. With the intraoral approach, following a gingivobuccal incision, a single horizontally oblique osteotomy is made at least 6 mm beneath the mental nerve foramina. The vertically long genial segment is freed and the posterior edge is contoured with a side-cutting burr. The contoured jumping genial segment is secured to the mandible with countersunk screws and contoured in situ to preserve the lower 8 to 10 mm. With the extraoral approach, following a submental incision, the anterior and posterior surfaces of the symphysis are cleared (a double-armed suture is placed through the posterior musculature). A reciprocating saw is used to remove the lower border of the symphysis to reduce the vertical excess. The tagged musculature is resuspended, and a tapered, textured implant is secured to the new symphysis. RESULTS: Aesthetic outcomes using these two techniques were good and there were no complications. Representative patients, operated on by the senior author, illustrate these techniques. CONCLUSIONS: Both the intraoral one-cut in situ contoured jumping genioplasty and the extraoral vertical reduction/sagittal augmentation genioplasty reduce excess chin height, control sagittal advancement, provide pogonion projection, and avoid the risks of a standard wedge. Both techniques provide custom projection at the lower pole of the new symphysis

The ability to affect gene expression via topical therapy has profound therapeutic implications for conditions characterized by open wounds including cutaneous neoplasms, thermal injury, skin disorders and dysfunctional wound healing. Specifically targeting local gene expression avoids systemic toxicity and simplifies treatment. We have developed a new method of topical matrix-based short interfering RNA application to precisely and effectively silence local gene expression in nondelimited wounds

Cherubism is an autosomal-dominant syndrome characterized by excessive bilateral maxillomandibular bony degeneration followed by fibrous tissue hyperplasia. Eight patients (age, 6-15 years; mean, 11 years) with severe cherubism were treated with a 2-stage operation by the same senior surgeon (C.M.R.-A.) over an 18-year period, 1987 through 2005. Severity was based on a modified Motamedi classification system. The diagnosis was established clinically, radiographically, and histologically. Postoperative follow up ranged from 2 to 18 years (mean, 5.1 years). All patients underwent 2-stage surgical treatment. In the first stage, the anterior wall of the maxilla was osteotomized and removed (n = 5). The cherubic lesion was curetted from the maxilla and orbits. The maxilla was recontoured on the back table and then fixed orthotopically with wires. Alternatively, cortical bone windows were created, the maxillary and orbital lesions were curetted, and the maxilla was infractured and recontoured in situ with manual pressure (n = 3). Six months after the maxillary/orbital procedure, all patients underwent second-stage curettage and recontouring of the mandible using bony access windows and manual infracture. Satisfactory esthetic results were achieved in all patients. The patients remained clinically and radiographically disease-free throughout the follow-up period. The most profoundly affected patient sustained bilateral lower eyelid ectropion that resolved with full-thickness skin grafting. Although cherubism tends to abate by the fourth decade of life, early 2-stage surgical curettage provides a simple and reliable treatment that not only delivers immediate results, but also seems to arrest the growth of any remaining cherubic tissue

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: Silicone chin augmentation remains a popular treatment for microgenia because its placement appears deceptively simple. However, when extrusion, displacement, capsular contracture following implant removal, overaugmentation, or malposition occurs, a revision operation may be required. Secondary chin surgery is challenging because (1) implant removal alone may produce a disfigured chin; and (2) placement of a new implant in an oversized misshapen pocket demands precision, control, and reliability. METHODS: The textured implant may be placed by means of an intraoral or extraoral route. The extraoral route is usually chosen except when transoral procedures (e.g., mentalis suspension) are required. The superior 30 to 50 percent of a standard textured implant is always removed and then tapered anteriorly at a 45-degree angle to reduce its sharp front edge. The lateral wings are also reduced and tapered. Two pilot holes are drilled in each half of the implant and then it is divided in the midline. Each half is inserted and secured individually. The medial screw is placed first and nearly fully tightened. Then, holding the implant exactly along the inferior border of the mandible, the distal screw is placed and both screws are tightened completely. The lower border of the implant should be exactly along the lower border of the mandible. The soft tissues are closed in three layers over a drain. RESULTS: This technique has been used to treat more than 100 patients. Selected photographs illustrate this technique. CONCLUSION: This article explains how to place a textured implant efficiently and effectively under light premedication and local anesthesia

BACKGROUND: Distraction osteogenesis is a valuable clinical tool; however the molecular mechanisms governing successful distraction remain unknown. We have used a uniaxial in vitro strain device to simulate the uniaxial mechanical environment of the interfragmentary distraction gap. MATERIALS AND METHODS: Using the Flexcell system, normal human osteoblasts were subjected to different levels of cyclical uniaxial mechanical strain. Cellular morphology, proliferation, migration, and the expression of angiogenic (vascular endothelial growth factor [VEGF] and fibroblast growth factor-2 [FGF-2]) and osteogenic (osteonectin, osteopontin, and osteocalcin) proteins and extracellular matrix molecules (collagen IalphaII) were analyzed in response to uniaxial cyclic strain. RESULTS: Osteoblasts exposed to strain assumed a fusiform spindle-shaped morphology aligning parallel to the axis of uniaxial strain and osteoblasts exposed to strain or conditioned media had a 3-fold increase in proliferation. Osteoblast migration was maximal (5-fold) in response to 9% strain. Angiogenic cytokine, VEGF, and FGF-2, increased 32-fold and 2.6-fold (P < 0.05), respectively. Osteoblasts expressed greater amounts of osteonectin, osteopontin, and osteocalcin (2.1-fold, 1.8-fold, 1.5-fold respectively, P < 0.01) at lower levels of strain (3%). Bone morphogenic protein-2 production increased maximally at 9% strain (1.6-fold, P < 0.01). Collagen I expression increased 13-, 66-, and 153-fold in response to 3, 6, and 9% strain, respectively. CONCLUSIONS: Uniaxial cyclic strain using the Flexcell device under appropriate strain parameters provides a novel in vitro model that induces osteoblast cellular and molecular expression patterns that simulate patterns observed in the in vivo distraction gap