Faculty Bibliography

Statement of Problem: Reconstruction of maxillectomy defects is challenging due to the complex 3-dimensional anatomy of the region. It is diverse with multiple effective techniques that appear to functionally aid patients in speech and mastication. Defects can be secondary to benign or malignant pathology, craniofacial or post-traumatic deformities, and infection. Interocclusal and orthognathic relationships are tantamount to successful reconstruction. Rehabilitation must provide adequate upper lip support and maintain symmetrical alar bases as well as create an adequate seal from the oral cavity to nasal cavity to prevent regurgitation of fluids. Many different classification schemes have been discussed at length within the literature.¹ At our institution we utilize the maxillectomy classification system set forth by Brown et al.² The classification of the vertical component is as follows: Class 1, maxillectomy without an oro-antral fistula; Class 2, low maxillectomy not including orbital floor or contents; Class 3, high maxillectomy involving orbital contents; and Class 4, radical maxillectomy includes orbital exenteration. The horizontal component is classified as follows: a, unilateral alveolar maxillectomy; b, bilateral alveolar maxillectomy; and c, total alveolar maxillary resection. Methods: A retrospective review was performed of case records at Bellevue Hospital Center/New York University Langone Medical Center during a 6-year period from June 2006 to February 2012. In addition to patient demographics the charts were reviewed for Brown classification, tumor pathology, type of reconstruction, timing of feeding by mouth, and patient satisfaction. Methods of Data Analysis: This was a retrospective chart review from June 2006 to February 2012. Descriptive statistics were used to analyze the data. Results: Fifty patients were identified, the average age was 49. The lowest Brown classification was 1A; there were no orbital exenterations thus our highest Brown class was 3C. The pathology was reviewed; 40% of the lesions were malignant and 60% of lesions were benign. 24% of patients were treated with microvascular free tissue transfer: 38% osteocutaneous and 62% myofasciocutaneous. 18% were treated with obturators, 16% were treated with local flaps, 16% were treated with nonvascularized bone grafts, 14% were treated zygomatic implants, and 12% were treated using a combination of local flaps, obturators, zygomatic implants, and free tissue transfer. 34% of patients fell into Brown class one, 48% of patients were Brown class two, and 18% of patients were Brown class three. Postoperatively patients were fed immediately unless treated with free tissue transfer. Subjectively, all but one patient was satisfied with their maxillary reconstruction. This patient had an obturator placed after resection of squamous cell carcinoma of the maxilla, and was unable to tolerate the obturator. She was later reconstructed using a microvascular radial forearm free flap and is now able to function, phonate, and is content with her current status. Conclusion: All methods described above are viable surgical options and decisions for reconstruction must be on a patient specific basis. However, one can extrapolate that the higher the Brown class the larger the defect and thus the need for microvascular free tissue transfer increases. An algorithm for our reconstruction protocol will be presented

PURPOSE: Posterior vault expansion using distraction osteogenesis has become a vital instrument in our institution, particularly as a first-line treatment in syndromic craniosynostosis. In this review, we highlight the several advantages, diverse utility, and technicalities of the operative procedure. METHODS: A review of the literature and explanation of the technical details of the procedures were described in this manuscript. RESULTS/CONCLUSION: Posterior cranial vault distraction offers several benefits over traditional expansion procedures.

The purpose of this study was to describe our technique of bilateral mandibular distraction for micrognathia and to highlight the ultrasonic scalpel as an alternative to conventional saws in performing osteotomies for mandibular distraction osteogenesis. To do so, we retrospectively reviewed all patients who underwent mandibular distraction with an ultrasonic scalpel for tongue-based upper airway obstruction due to micrognathia between 2010 and 2011. Study outcome measures include operative blood loss, length of surgery, postoperative complications, and avoidance of a tracheostomy. Excel (Microsoft) was used to calculate averages, P values (2-tailed Student t test), and SDs for operative data, sleep studies, and cephalometric analysis. Nine patients--7 females and 2 males--were distracted for a mean distance of 17 +/- 6 mm. Mean blood loss was 15 +/- 7 mL, and the average length of surgery was 111 +/- 27 minutes. One patient returned to the operating room for debridement/washout of a wound infection, but distraction was continued without sequelae. There were no other postoperative complications. Resolution of airway obstruction was evidenced by clinical examination and avoidance of a tracheostomy in all cases. Based on these data, we feel that mandibular distraction with univector, internal distractors, and ultrasonic osteotomies at the mandibular angle is safe and efficacious at relieving tongue-based upper airway obstruction and avoiding a tracheostomy.

INTRODUCTION: Beginning in 2004, we modified our surgical technique for a cranial vault remodeling in sagittal and lambdoid synostosis. Beginning in the early 1990s, we started using a calvarial vault remodeling technique in sagittal and lambdoid synostosis that involves removing the posterior two thirds of the skull, extending from the coronal suture to below the lambdoid suture to within 1-1.5 cm of the foramen magnum. Up until 2004, the bone fixation evolved from wire fixation, then micro-metallic fixation plates and resorbable sutures. DISCUSSION: Over the last 9 years, we have used a novel technique of absorbable fixation plates and a polydioxanone suture trellis or lattice network, which has reduced operating times significantly and continued to give excellent results. Additional advantages include the absence of a need for molding or protective helmets, the absence of bony defects at the completion of the procedure, the absence of age limitation, and the ability to correct the tightly constricted occiput. CONCLUSION: To date, we have had no significant complications, no return to operating room, and the aesthetics have held up well since its introduction.

BACKGROUND: In the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST), the composite primary endpoint of stroke, myocardial infarction, or death during the periprocedural period or ipsilateral stroke thereafter did not differ between carotid artery stenting and carotid endarterectomy for symptomatic or asymptomatic carotid stenosis. A secondary aim of this randomised trial was to compare the composite endpoint of restenosis or occlusion. METHODS: Patients with stenosis of the carotid artery who were asymptomatic or had had a transient ischaemic attack, amaurosis fugax, or a minor stroke were eligible for CREST and were enrolled at 117 clinical centres in the USA and Canada between Dec 21, 2000, and July 18, 2008. In this secondary analysis, the main endpoint was a composite of restenosis or occlusion at 2 years. Restenosis and occlusion were assessed by duplex ultrasonography at 1, 6, 12, 24, and 48 months and were defined as a reduction in diameter of the target artery of at least 70%, diagnosed by a peak systolic velocity of at least 3.0 m/s. Studies were done in CREST-certified laboratories and interpreted at the Ultrasound Core Laboratory (University of Washington). The frequency of restenosis was calculated by Kaplan-Meier survival estimates and was compared during a 2-year follow-up period. We used proportional hazards models to assess the association between baseline characteristics and risk of restenosis. Analyses were per protocol. CREST is registered with ClinicalTrials.gov, number NCT00004732. FINDINGS: 2191 patients received their assigned treatment within 30 days of randomisation and had eligible ultrasonography (1086 who had carotid artery stenting, 1105 who had carotid endarterectomy). In 2 years, 58 patients who underwent carotid artery stenting (Kaplan-Meier rate 6.0%) and 62 who had carotid endarterectomy (6.3%) had restenosis or occlusion (hazard ratio [HR] 0.90, 95% CI 0.63-1.29; p=0.58). Female sex (1.79, 1.25-2.56), diabetes (2.31, 1.61-3.31), and dyslipidaemia (2.07, 1.01-4.26) were independent predictors of restenosis or occlusion after the two procedures. Smoking predicted an increased rate of restenosis after carotid endarterectomy (2.26, 1.34-3.77) but not after carotid artery stenting (0.77, 0.41-1.42). INTERPRETATION: Restenosis and occlusion were infrequent and rates were similar up to 2 years after carotid endarterectomy and carotid artery stenting. Subsets of patients could benefit from early and frequent monitoring after revascularisation. FUNDING: National Institute of Neurological Disorders and Stroke and Abbott Vascular Solutions.

OBJECTIVES: To evaluate the reliability and failure modes of regular and horizontal mismatched platforms for implant-abutment connection varying the implant diameter. MATERIAL AND METHODS: Regular (REG, n = 21, 4.0-mm-diameter implant) and horizontal mismatched (HM, n = 21, 4.6-mm-diameter implant) platform Ti-6Al-4V implants were restored with proprietary identical Ti-6Al-4V abutments and metal crowns (cobalt-chrome, Wirobond((R)) 280, BEGO, Bremen, Germany) cemented. Mechanical testing comprised step-stress accelerated-life testing, where crowns were distributed in three loading profiles for fatigue in water, producing timely and clinically relevant fractures. The probability of failure vs. cycles (95% two-sided confidence intervals) was calculated and plotted using a powerlaw relationship for damage accumulation, Weibull modulus (95% two-sided confidence intervals) and then the reliability for a mission of 50,000 cycles at 125 N load (95% two-sided confidence interval) were calculated. Fractography was performed in the scanning electron microscope. RESULTS: The beta-value for group REG (beta = 1.37) indicated that fatigue was a factor accelerating the failure, whereas load alone dictated the failure for group HM (beta = 0.71). The Weibull parameter contour plot showed no significantly different Weibull modulus for REG (10.24) compared to HM (10.20) and characteristic strength of 162.6 and 166.8 N, respectively (P > 0.91). The calculated reliability for a mission of 50,000 cycles at 125 N load was not significantly different (0.71 for REG and 0.73 for HM). Abutment screw failure was the chief failure mode. CONCLUSIONS: Reliability was not significantly different between groups and failure modes were similar