Faculty Bibliography

BACKGROUND: Resident duty hours have been restricted to 80 per week, a limitation thought to increase patient safety by allowing adequate sleep. Yet decreasing work hours increases the number of patient exchanges (so-called 'handoff') at the end of shifts. WHERE ARE WE NOW?: A greater frequency of handoff leads to an increased risk of physician error. Information technology can be used to minimize that risk. WHERE DO WE NEED TO GO?: A computer-based expert system can alleviate the problems of data omissions and data overload and minimize asynchrony and asymmetry. A smart system can further prompt departing physicians for information that improves their understanding of the patient's condition. Likewise, such a system can take full advantage of multimedia; generate a study record for self-improvement; and strengthen the interaction between specialists jointly managing patients. HOW DO WE GET THERE?: There are impediments to implementation, notably requirements of the Health Insurance Portability and Accountability Act; medical-legal ramifications, and computer programming costs. Nonetheless, the use of smart systems, not to supplant physicians' rational facilities but to supplement them, promises to mitigate the risks of frequent patient handoff and advance patient care. Thus, a concerted effort to promote such smart systems on the part of the Accreditation Council for Graduate Medical Education (the source of the duty hour restrictions) and the Association of American Medical Colleges (representing medical schools and teaching hospitals) may be effective. We propose that these organizations host a contest for the best smart handoff systems and vigorously promote the winners

BACKGROUND AND OBJECTIVE: The most common risk factor for bisphosphonate-related osteonecrosis of the jaws (BRONJ) is dentoalveolar surgery. It has been suggested that reduced serum C-terminal telopeptide (CTX) can determine the degree of osteoclast suppression and may predict the development of BRONJ after dentoalveolar surgery. Although there are many radiographic appearances associated with BRONJ, there are little data that describes changes preceding dentoalveolar surgery. The objective of this retrospective study was: 1) to investigate if reduced serum CTX values (i.e., <150 pg/mL) were associated with BRONJ after dentoalveolar surgery; and 2) to determine if specific radiographic changes are associated with teeth that develop BRONJ after extraction. STUDY DESIGN: A retrospective review of radiographic and/or serum CTX data was performed for 68 patients with a history of bisphosphonate therapy who either underwent dental extraction or were diagnosed with BRONJ in the Department of Oral and Maxillofacial Surgery during the period 2007-2009. Postoperative healing was assessed for 26 patients with reduced serum CTX levels (<150 pg/mL) who either underwent dental extraction or treatment for BRONJ. Preoperative radiographs were evaluated for 55 patients who either healed normally or developed BRONJ after dental extraction. RESULTS: All 26 patients (100%) who had serum CTX levels <150 pg/mL healed successfully after dentoalveolar surgery (20 patients) or after treatment for BRONJ (6 patients). Among the 55 patients who underwent radiographic evaluation, 24 patients (83%) with BRONJ exhibited periodontal ligament (PDL) widening associated with extracted teeth, whereas only 3 patients (11%) who healed normally demonstrated PDL widening. CONCLUSION: These data suggest that radiographic PDL widening may be a more sensitive indicator than CTX testing in predicting risk of BRONJ. Current guidelines that recommend minimal surgical intervention may need to be revised to include alternative strategies for the elimination or management of this pathology.

OBJECTIVES: To observe the extent of nasal polyposis endoscopically in a cystic fibrosis population before the first surgical intervention and to grade the extent using a modified Malm scale, to observe patients prospectively and record the need for revision endoscopic sinus surgery (ESS), and to compare this among the individual polyp grading groupings. DESIGN: Retrospective medical record review of data collected prospectively. SETTING: Tertiary care hospital. PATIENTS: Forty-nine consecutive patients with a clinical preoperative diagnosis of cystic fibrosis and sinusitis. MAIN OUTCOME MEASURES: Using a modified Malm scale, the extent of polyps was prospectively graded into 3 groups before the first surgical intervention. The number of patients needing revision ESS and the mean time to revision ESS were compared among the 3 groups. RESULTS: Forty-nine consecutive patients underwent ESS between 1992 and 2007. We used a 3-stage system for extent of polyposis: 16 patients were noted to have no polyps (grade A), 14 had mild polyposis (grade B), and 19 had extensive polyposis (grade C). During the study, 14 patients required revision surgery: 3 with mild polyps and 11 with extensive polyps. Mean time to revision surgery was 39.7 months for those with grade B and 23.8 months for those with grade C. In the overall statistical analysis, the rate of revision ESS was significantly different among the 3 groups (P < .001). In pairwise comparisons, there were significant differences between those with grades A and C (P < .001) and between those with grades B and C (P = .04) and a trend toward significance between those with grades A and B (P = .052). There were no complications from ESS. CONCLUSION: Preoperative grading of nasal polyposis in patients with cystic fibrosis can help assess the future likelihood of revision ESS

Despite the increasing utilization of all-ceramic crown systems, their mechanical performance relative to that of metal ceramic restorations (MCR) has yet to be determined. This investigation tested the hypothesis that MCR present higher reliability over two Y-TZP all-ceramic crown systems under mouth-motion fatigue conditions. A CAD-based tooth preparation with the average dimensions of a mandibular first molar was used as a master die to fabricate all restorations. One 0.5-mm Pd-Ag and two Y-TZP system cores were veneered with 1.5 mm porcelain. Crowns were cemented onto aged (60 days in water) composite (Z100, 3M/ESPE) reproductions of the die. Mouth-motion fatigue was performed, and use level probability Weibull curves were determined. Failure modes of all systems included chipping or fracture of the porcelain veneer initiating at the indentation site. Fatigue was an acceleration factor for all-ceramic systems, but not for the MCR system. The latter presented significantly higher reliability under mouth-motion cyclic mechanical testing

BACKGROUND: The aim of this study was to calculate and analyze the cost of treatment for stage IV pressure ulcers. METHODS: A retrospective chart analysis of patients with stage IV pressure ulcers was conducted. Hospital records and treatment outcomes of these patients were followed up for a maximum of 29 months and analyzed. Costs directly related to the treatment of pressure ulcers and their associated complications were calculated. RESULTS: Nineteen patients with stage IV pressure ulcers (11 hospital-acquired and 8 community-acquired) were identified and their charts were reviewed. The average hospital treatment cost associated with stage IV pressure ulcers and related complications was $129,248 for hospital-acquired ulcers during 1 admission, and $124,327 for community-acquired ulcers over an average of 4 admissions. CONCLUSIONS: The costs incurred from stage IV pressure ulcers are much greater than previously estimated. Halting the progression of early stage pressure ulcers has the potential to eradicate enormous pain and suffering, save thousands of lives, and reduce health care expenditures by millions of dollars

OBJECTIVE: Radiotherapy, an essential modality in cancer treatment, frequently induces fibrotic processes in the skin, including accumulation of extracellular matrix. Transforming growth factor-beta is essential in regulating extracellular matrix gene expression and is dependent on Smad3, an intracellular mediator/transcription factor. Our study characterized the genetic expression involved in extracellular matrix accumulation during radiation-induced fibrosis. We performed Smad3 gene silencing in an attempt to abrogate the effects of radiation. STUDY DESIGN: Laboratory research. SETTING: University laboratory. SUBJECTS AND METHODS: C57 murine dermal fibroblasts were irradiated with 20 Gy RNA isolated (0, 6, 12, 24, 48, 72 hours postirradiation) and mRNA analyzed (reverse transcriptase polymerase chain reaction) for known regulators (Smad3, interleukin-13 [IL-13]), tumor necrosis factor-alpha [TNF-alpha]) and mediators of fibrosis (collagen 1A1 [Col1A1]), TGF-beta, matrix metalloprotease-1 and -2 (MMP-1, MMP-2), and tissue inhibitor of metalloprotease-1 (TIMP-1). Smad3 gene expression was silenced using siRNA in an effort to restore an unirradiated gene profile. RESULTS: Following irradiation, there was a steady increase in mRNA expression of Smad3, IL-13, TGF-beta, Col1A1, MMP-2, TIMP-1, with peak at 12 to 24 hours and subsequent decline by 72 hours. TNF-alpha expression remained elevated throughout. MMP-1 showed minimal expression initially, which decreased to negligible by 72 hours. Inhibition of Smad3 significantly decreased expression of Col1A1, TGF-beta, MMP-2, and TIMP-1. IL-13 and TNF-alpha expression was not affected by Smad3 silencing. CONCLUSION: We have characterized the early-phase mRNA expression profiles of the major mediators of radiation-induced fibrosis. Smad3 siRNA effectively abrogated the elevation of Col1A1, TGF-beta, TIMP-1, and MMP-2. IL-13 and TNF-alpha were unaffected by Smad3 silencing and appear to be minor regulators in fibrosis. These findings suggest a therapeutic rationale for Smad3 silencing in vivo

BACKGROUND:: Pediatric temporomandibular joint (TMJ) dysfunction, resulting from either soft tissue or skeletal disorders, may be congenital or acquired. Congenital TMJ disorders are uncommon. Here we review our experience with pediatric TMJ disorders and propose a new classification system. METHOD:: Clinical records, cephalograms, computed tomography, magnetic resonance images, and pathologic specimens of all pediatric patients (< 18 years) with trismus or restricted mandibular excursion from 1976-2008 were reviewed. Cases were stratified according to soft tissue or skeletal pathology; skeletal abnormalities were further characterized as intra- or extra-capsular. RESULTS:: 38 patients, ranging in age from 1 day to 18 years of age at diagnosis, were identified with TMJ disorders. Ten cases (26.3%) were due to soft tissue pathology. The remaining 28 cases (73.7%) were due to skeletal pathology, consisting of 14 congenital and 14 acquired cases (50% each). Acquired skeletal deformities included 12 (85.7%) intracapsular ankyloses and 2 (16.7%) extracapsular ankylosis (extra-articular bone blocks). Congenital skeletal deformities accounted for 5 (35.7%) intracapsular ankyloses and 9 (64.3%) extracapsular ankyloses. CONCLUSION:: On initial survey, the data are consistent with published reports that attribute TMJ dysfunction to acquired pathology (i.e., trauma and infection). However, we observed a significantly higher percentage (50%) of congenital TMJ skeletal disorders than previously reported. Most congenital cases involved extracapsular pathology (i.e., coronoid hypertrophy); only a minority of cases had glenocondylar fibro-osseous fusion (i.e., intracapsular ankyloses). Since the diagnosis and classification of TMJ disorders determines treatment options, we provide a new classification that characterizes the extent of capsular involvement

The present study focused on determining the effect of high strain rate loading on the deformation and fracture characteristics of syntactic foams and relating them with the initial foam microstructure. The high strain rate testing was carried out using a split-Hopkinson pressure bar system and the damage evaluation was carried out using microCT-scan and scanning electron microscope. The strength was found to be 50-150% higher at high strain rates when compared to quasi-static values for various grades of syntactic foams. Damage evaluation revealed crushing of particles in the surface layer, shear cracking, and propagation of longitudinal cracks as the main fracture modes at different strain rates and material compositions. Wall thickness and volume fraction of hollow particles used in syntactic foams played an important role in determining the failure mechanism. At low strain rates shear cracking of specimens was prominent, whereas at high strain rates longitudinal cracks were the main failure mode. Understanding the strain rate dependence of failure mechanisms is important for aerospace applications of these lightweight composites. (C) 2010 Elsevier B.V. All rights reserved.