Faculty Bibliography

Bony defects in the craniomaxillofacial skeleton remain a major and challenging health concern. Surgeons have been trying for centuries to restore functionality and aesthetic appearance using autografts, allografts, and even xenografts without entirely satisfactory results. As a result, physicians, scientists, and engineers have been trying for the past few decades to develop new techniques to improve bone growth and bone healing. In this review, the authors summarize the advantages and limitations of current animal models; describe current materials used as scaffolds, cell-based, and protein-based therapies; and lastly highlight areas for future investigation. The purpose of this review is to highlight the major scaffold-, cell-, and protein-based preclinical tools that are currently being developed to repair cranial defects

Objective:This study aimed (1) to investigate the relationship between the presence of lymph node central necrosis, viewed on pre-operative computed tomography imaging, and the occurrence of histopathologically determined metastatic lymph node extracapsular spread and (2) to determine whether a larger scale study would be valuable.Materials and methods:Pre-operative computed tomography scans, surgical records and post-operative histopathological analysis results were reviewed for 19 consecutive neck dissections performed in 17 patients with head and neck squamous cell carcinoma.Results:A total of 20/26 (77 per cent) lymph nodes with central necrosis had extracapsular spread on histopathological analysis. Twenty of 21 (95 per cent) lymph nodes with extracapsular spread had central necrosis on pre-operative computed tomography. Thirty-four of 40 (85 per cent) lymph nodes without extracapsular spread had no evidence of central necrosis on computed tomography. Only three of 12 (25 per cent) patients with lymph node central necrosis identified on pre-operative computed tomography were found to have actual necrosis on final histopathological analysis.Conclusions:Lymph node central necrosis viewed on pre-operative computed tomography scans is a useful indicator of metastatic lymph node extracapsular spread, with a sensitivity of 95 per cent, a specificity of 85 per cent, a positive predictive value of 69 per cent and a negative predictive value of 98 per cent. Lymph node diameter is not a sensitive indicator of extracapsular spread

BACKGROUND: The authors sought to review the various types of patients with psychological abnormalities who may present to the plastic surgeon and the psychological impact of various plastic surgery procedures on these patients. METHODS: After systematically searching the Embase and PubMed databases and following further refinement (based on the authors' inclusion and exclusion criteria), the authors identified 65 studies. In addition, the authors felt that important information was contained in four textbooks, two press releases, and one Internet database. The inclusion criteria were studies that investigated the psychological outcomes, background, and personality types of patients seeking specific plastic surgery procedures. In addition, studies that addressed the impact of plastic surgery on patients' psychological status and quality of life were also included. The authors excluded studies with fewer than 30 patients, studies that did not pertain to the particular plastic surgery procedures, and studies that addressed psychological sequelae of revision operations. RESULTS: Narcissistic and histrionic personality disorders and body dysmorphic disorder are the three most common psychiatric conditions encountered in patients seeking cosmetic surgery. Overall, plastic surgery not only restores the appearance and function of the disfigured body unit but also alleviates psychological distress. CONCLUSION: Identifying the psychologically challenging patient before surgical intervention will allow the patient to obtain the appropriate psychological assistance and may result in a healthier individual with or without associated plastic surgery procedures.

BACKGROUND:: Three-dimensional digital animation can enable surgeons to create anatomically accurate, virtual models of normal and pathologic human anatomy. From these models, surgical procedures can be digitally performed, recorded, and distributed as a teaching tool or as a virtual surgical atlas. The idea of a virtual surgical atlas has recently become a part of contemporary surgical teaching. In the field of craniofacial surgery, no such educational tool exists. Presented is the first part of the creation of a virtual atlas of craniofacial surgical procedures: the three-dimensional digital modeling of pathologic deformities commonly treated by craniofacial surgeons. METHODS:: Three-dimensional craniofacial models were constructed using Maya 8.5. A skeletally 'normal' craniofacial skeleton was first produced from a preexisting digital skull using Bolton tracings as a reference. The remaining soft-tissue elements were then added to create an anatomically complete three-dimensional face. The 'normal' model was then deformed in Maya to produce specific craniofacial deformities using computed tomographic scans, cephalograms, and photographs as a reference. One of the craniofacial deformity models was created directly from computed tomographic data. RESULTS:: One model of the normal face and eight pathologic models of craniofacial deformities were created: microgenia, micrognathia, prognathia, temporomandibular joint ankylosis, maxillary hypoplasia, Crouzon syndrome with and without the need for cranial vault expansion, and bicoronal craniosynostosis. CONCLUSIONS:: For the first time, anatomically accurate three-dimensional digital models of craniofacial deformities have been created. The models are the first step in the creation of a virtual surgical atlas of craniofacial procedures

BACKGROUND:: Craniofacial surgery can be challenging to teach and learn. To augment the intraoperative learning experience for surgical trainees and to provide a resource for practicing craniofacial surgeons to review uncommonly performed procedures before entering the operating room, a series of three-dimensional animations were created encompassing the most commonly performed craniofacial procedures. METHODS:: Previously created three-dimensional craniofacial digital models were used to create digital animations of craniofacial surgical procedures using Maya 8.5. Digital models were altered systematically within Maya to recreate the ordered steps of each craniofacial procedure. Surgical tools were imported into Maya for use in the animations using computer-aided manufacturing files obtained directly from the manufacturer. RESULTS:: Nine craniofacial procedures were animated: genioplasty, bilateral sagittal split osteotomy, intraoral vertical ramus osteotomy, Le Fort I osteotomy, unifocal mandibular distraction, mandibular transport distraction, fronto-orbital advancement with cranial vault remodeling, Le Fort III advancement/distraction, and monobloc advancement/distraction. All major surgical steps are demonstrated, including exposure, execution of the osteotomy, displacement of the bone composite, and the predicted morphologic changes to the craniofacial contour. Throughout the surgical animation, the view of the surgeon in the operating room is incorporated to reproduce the vantage of the surgeon, and the overlying tissue is rendered transparent to illustrate critical underlying anatomical relationships. CONCLUSIONS:: The first virtual surgical atlas of craniofacial procedures is presented. These animations should serve as a resource for trainees and practicing surgeons in preparation for craniofacial surgical procedures

BACKGROUND: Mandibular distraction has evolved from the use of external to the use of intraoral and semiburied devices. The authors highlight the evolution of the semiburied technique. The authors evaluate advantages and limitations, and report perioperative events for external and semiburied techniques to establish the indications for selection of the different devices. METHODS: A retrospective review was conducted of patients undergoing mandibular distraction at the New York University Langone Medical Center from the authors' introduction of mandibular distraction in May of 1989 to June 30, 2009. Perioperative events were stratified into three groups: minor incidents, moderate incidents, and major incidents. RESULTS: A total of 211 mandibular distraction procedures were performed: 129 external procedures on native bone, 37 external procedures on grafted bone, and 45 semiburied procedures on native bone. Minor incidents were more common with the semiburied device (62 percent) compared with external devices on native (26 percent) and grafted (38 percent) bone. There were fewer moderate incidents with the semiburied device (18 percent) than with the external device on native (22 percent) and grafted (30 percent) bone. In contrast to the external technique, no major incidents were seen with semiburied distraction. CONCLUSIONS: The semiburied device reduces scarring and has the mechanical advantages of being applied directly to the bone, less vulnerable to dislodgment, and more favorable for a vertical vector. However, its use requires more bone stock and it has the disadvantage of requiring a second operation for removal. Semiburied distraction is safe, reliable, and indicated for lengthening of the hypoplastic mandible where there is adequate bone stock for its attachment

BACKGROUND: Physical and bioceramic incorporation surface treatments at the nanometer scale showed higher means of bone-to-implant contact (BIC) and torque values compared with surface topography at the micrometer scale; however, the literature concerning the effect of nanometer scale parameters is sparse. PURPOSE: The aim of this study was to evaluate the influence of two different implant surfaces on the percentage bone-to-implant contact (BIC%) and bone osteocyte density in the human posterior maxilla after 2 months of unloaded healing. MATERIALS AND METHODS: The implants utilized presented dual acid-etched (DAE) surface and a bioceramic molecular impregnated treatment (Ossean(R), Intra-Lock International, Boca Raton, FL, USA) serving as control and test, respectively. Ten subjects (59 +/- 9 years of age) received two implants (one of each surface) during conventional implant surgery in the posterior maxilla. After the non-loaded period of 2 months, the implants and the surrounding tissue were removed by means of a trephine and were non-decalcified processed for ground sectioning and analysis of BIC%, bone density in threaded area (BA%), and osteocyte index (Oi). RESULTS: Two DAE implants were found to be clinically unstable at time of retrieval. Histometric evaluation showed significantly higher BIC% and Oi for the test compared to the control surface (p < .05), and that BA% was not significantly different between groups. Wilcoxon matched pairs test was used to compare the differences of histomorphometric variables between implant surfaces. The significance test was conducted at a 5% level of significance. CONCLUSION: The histological data suggest that the bioceramic molecular impregnated surface-treated implants positively modulated bone healing at early implantation times compared to the DAE surface.

Strain rate dependence of the mechanical response of hard tissues has led to a keen interest in their dynamic properties. The current study attempts to understand the high strain rate characteristics of rabbit femur bones. The testing was conducted using a split-Hopkinson pressure bar equipped with a high speed imaging system to capture the fracture patterns. The bones were also characterized under quasi-static compression to enable comparison with the high strain rate results. The quasi-static compressive moduli of the epiphyseal and diaphyseal regions were measured to be in the range of 2-3 and 5-7GPa, respectively. Under high strain rate loading conditions the modulus is observed to increase with strain rate and attains values as high as 15GPa for epiphyseal and 30GPa for diaphyseal regions of the femur. The strength at high strain rate was measured to be about twice the quasi-static strength value. A large number of small cracks initiated on the specimen surface close to the incident bar. Coalescence of crack branches leading to fewer large cracks resulted in specimen fragmentation. In comparison, the quasi-static failure was due to shear cracking.