Faculty Bibliography

The human vocal fold is a complex structure made up of distinct layers that vary in cellular and extracellular matrix composition. Elucidating the mechanical properties of vocal fold tissues is critical for the study of both acoustics and biomechanics of voice production, and essential in the context of vocal fold injury and repair. Both quasistatic and dynamic behavior in the 10-300Hz range was explored in this preliminary investigation. The resultant properties of the lamina propria were compared to that of the nearby thyroarytenoid muscle. Er, quantified via quasistatic testing of the lamina propria, was 609+/-138MPa and 758+/-142MPa in the muscle (p=0.001). E' of the lamina propria as determined by dynamic testing was 790+/-526MPa compared to 1061+/-928MPa in the muscle. Differences in E' did not achieve statistical significance via linear mixed effect modeling between the tissue types (p=0.95). In addition, frequency dependence was not significant (p=0.18).

BACKGROUND: The study of biomechanics of deformation and fracture of hard biological tissues involving organic matrix remains a challenge as variations in mechanical properties and fracture mode may have time-dependency. Finite element analysis (FEA) has been widely used but the shortcomings of FEA such as the long computation time owing to re-meshing in simulating fracture mechanics have warranted the development of alternative computational methods with higher throughput. The aim of this study was to compare dynamic two-dimensional FEA and moving particle simulation (MPS) when assuming a plane strain condition in the modeling of human enamel on a reduced scale. METHODS: Two-dimensional models with the same geometry were developed for MPS and FEA and tested in tension generated with a single step of displacement. The displacement, velocity, pressure, and stress levels were compared and Spearmans rank-correlation coefficients R were calculated (p<0.001). RESULTS: The MPS and FEA were significantly correlated for displacement, velocity, pressure, and Y-stress. CONCLUSIONS: The MPS may be further developed as an alternative approach without mesh generation to simulate deformation and fracture phenomena of dental and potentially other hard tissues with complex microstructure.

Interindividual variability exists in persistent breast pain following breast cancer surgery. Recently, we used growth mixture modeling to identify 3 subgroups of women (N = 398) with distinct persistent breast pain trajectories (ie, mild, moderate, severe) over 6 months following surgery. The purposes of this study were to identify demographic and clinical characteristics that differed among the breast pain classes and, using linear mixed effects modeling, to examine how changes over time and in sensitivity in the breast scar area, pain qualities, pain interference, and hand and arm function differed among these classes. Several demographic and clinical characteristics differentiated the breast pain classes. Of note, 60 to 80% of breast scar sites tested were much less sensitive than the unaffected breast. Significant group effects were observed for pain qualities and interference scores, such that, on average, women in the severe pain class reported higher scores than women in the moderate pain class. In addition, women in the moderate pain class reported higher scores than women in the mild pain class. Compared to women in the mild pain class, women in the severe pain class had significantly impaired grip strength, and women in the moderate and severe pain classes had impaired flexion and abduction. PERSPECTIVE: Subgroups of women with persistent postsurgical breast pain differed primarily with respect to the severity rather than the nature or underlying mechanisms of breast pain. Pervasive sensory loss and the association between persistent breast pain and sustained interference with function suggest the need for long-term clinical follow-up.

Background/Purpose: Pediatric cleft lip and palate surgery can be stressful for both the child and the parents. Limited pain knowledge and certain parent psychological traits are associated with increased parental anxiety around surgery in older children. Increased parental anxiety has been associated with increased child pain, decreased ability of the child to cope with pain and worse outcomes in other surgical settings. Little is known about parental anxiety and child pain in preverbal children undergoing cleft lip and palate repair. The objectives of this study were to explore possible sociodemographic factors contributing to parental anxiety in the immediate postoperative period and to determine if there is a relationship between parental postoperative anxiety and infant postoperative pain. Methods/Description: Cross-sectional pilot study, semi-structured interview. Eight mothers of children under 18 months of age undergoing cleft lip/palate (CL/P) repair at an urban craniofacial center were recruited. Semi-structured interviews about their experience with their infant's surgery were conducted. Demographics were collected at a preoperative visit, while maternal anxiety scores, measured using the Hospital Anxiety and Depression Scale (HADS), and nurse-recorded child pain scores (Face, Legs, Activity, Cry, Consolability scale), were collected on postoperative day (POD) 1. Fisher's exact tests were used to compare demographics and Student's t-tests were used to analyze pain medication and doses given. Results: Mothers who were healthcare workers were more likely to have borderline/abnormal anxiety scores (HADS > 7) than mothers who were non-healthcare workers (p = .035) on POD1. Mothers of infants undergoing a bilateral CL/P repair tended to be more anxious than mothers of infants undergoing a unilateral CL/P repair (p=.090). Infants of anxious mothers tended to have more variation in pain scores, more pain scores recorded (95% CI -1.74, 4.0) (p = .19) and more pain medication given (95% CI 2.!

Background: The reported incidence of peripartum cardiomyopathy (PPCM) in the United States varies widely. Furthermore, limited information is available on the temporal trends in incidence and outcomes of PPCM. Objectives: To determine the overall incidence and complication rates of PPCM, and to analyze temporal trends in incidence and outcomes of PPCM in the United States. Methods: We queried the 2004 to 2011 Nationwide Inpatient Sample databases to identify all women aged 15 to 54 years with the diagnosis of PPCM using ICD-9-CM codes 674.5x. Temporal trends in incidence (per 10,000 live births), maternal major adverse events (MAE defined as in-hospital mortality, cardiac arrest, heart transplant, mechanical circulatory support, acute pulmonary edema, thromboembolism or implantable cardioverter defibrillator/permanent pacemaker implantation), cardiogenic shock, and length of stay were analyzed. Results: From 2004 to 2011, we identified 34,219 women aged 15 to 54 years with PPCM. The overall PPCM rate was 10.3 per 10,000 (or 1 in 968) live births. PPCM incidence increased from 8.5 to 11.8 per 10,000 live births (ptrend<0.001) during the study period. MAE occurred in 13.5% of patients. The most common complication in women with PPCM was thromboembolism (6.6%). The incidence of other complications was - in-hospital mortality in 1.3%, cardiac arrest in 2.1%, heart transplant in 0.5%, use of mechanical circulatory support in 1.5%, acute pulmonary edema in 1.8%, ICD/PPM placement in 2.9%, and cardiogenic shock in 2.6% There was no temporal change in MAE rate, except a small increase in in-hospital mortality [0.7% in 2004 to 1.8% in 2011, adjusted OR (per year) 1.08, 95% CI 1.02-1.14, ptrend=0.006] and use of mechanical circulatory support [0.9% in 2004 to 2.2% in 2011, adjusted OR (per year) 1.08, 95% CI 1.03-1.14, ptrend=0.002]. Cardiogenic shock increased from 1.0% in 2004 to 4.0% in 2011 [adjusted OR (per year) 1.16, 95% CI 1.11-1.21, ptrend<0.001]. Mean length of stay decreased during the study !

BACKGROUND: Over the past decade, facial vascularized composite allotransplantation has earned its place at the top of the reconstructive ladder. However, as in free tissue transfer, postoperative revisions are necessary to achieve optimal functional and aesthetic results. Although revising a facial vascularized composite allotransplantation may potentially risk the integrity of the graft, the authors believe that the advantages of appropriately chosen revisions may provide great benefit. METHODS: Following the most extensive face transplant performed to date, revisions were performed in two surgical procedures. The first included a Le Fort III osteotomy for malocclusion correction, midface tissue resuspension and coronal eyebrow lift to correct soft-tissue ptosis, and submental lipectomy. Bilateral blepharoplasty to minimize tissue excess and scar revision were performed at a subsequent operation. Cephalometric analysis and angiography were performed and blink data collected. RESULTS: Before transplantation, the patient was in class III malocclusion. After transplantation, class I occlusion was obtained; however, the patient subsequently returned to class III occlusion. After skeletal revision, class I occlusion was obtained; however, a corneal blink deficit was noted. Eight months after skeletal revision, blink had improved spontaneously. Angiography revealed collateralization providing retrograde flow from the flap to the recipient. CONCLUSIONS: Although the necessity for revisions is clear, determining which revisions to safely perform and their timing and execution have not been explored. The authors address four distinct categories of revisions, including soft-tissue revision, hard-tissue mismatch, and craniofacial skeleton and dental occlusion. The authors illustrate the success of these revisions and assess their advantages, disadvantages, and relative risk. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

BACKGROUND: Fat necrosis is a well-known complication of free tissue transfer and fat grafting that is becoming increasingly reported in the literature. However, there is no clear consensus on how fat necrosis is defined and classified in the plastic surgery literature. METHODS: A systematic review of the literature was performed using the PubMed database of the National Library of Medicine and National Institutes of Health and Google Scholar from January 1, 2003, to November 1, 2013. The keywords used in the search included "fat necrosis" and "plastic surgery." RESULTS: Sixty-nine articles were chosen that met the authors' criteria and were included in this review. There was wide variation on the size requirements and postoperative timing when defining fat necrosis. In addition, the workup sought after clinical examination to confirm a diagnosis of fat necrosis varied, including radiographic studies, histopathologic examination, or a series of studies. CONCLUSIONS: Based on the articles reviewed in this article, a more uniform definition needs to exist that is clearly defined in all articles that report on fat necrosis. The authors suggest defining fat necrosis as a palpable, discrete, and persistent subcutaneous firmness found postoperatively that measures at least 1 cm during physical examination. Fat necrosis can be identified and confirmed by imaging and histopathology or through intraoperative findings. The authors provide a classification system for fat necrosis that can be used by clinicians to describe fat necrosis into varying grades of severity to ultimately help guide clinical decision-making.

BACKGROUND: The authors report the cause of and risk factors for mortality in infants with Robin sequence and identify characteristics associated with quality-of-life outcomes. METHODS: The authors performed an 11-year retrospective review of all infants with Robin sequence treated at a neonatal intensive care unit. Patient characteristics were correlated to mortality and quality-of-life measures. Emergency room visits and hospital admissions were used to assess quality-of-life outcomes. Significant variables were identified by means of univariate analysis. RESULTS: One hundred eighty-one consecutive infants were identified. Patient characteristics included the following: isolated, 32.6 percent; syndromic, 31.5 percent; gastrointestinal, 38.1 percent; pulmonary, 32.6 percent; cardiac, 30.9 percent; central nervous system, 25.4 percent; and two or more organ system anomalies, 69.6 percent. Mortality was 16.6 percent; two deaths were related to airway obstruction problems. There were no deaths in isolated Robin sequence (p = 0.002). Mortality was statistically associated with cardiac anomalies (p < 0.001), central nervous system anomalies (p = 0.001), and two or more organ system abnormalities (p = 0.001). Variables associated with an increased rate of emergency room visits were cardiac anomalies (p = 0.04) and two or more organ system abnormalities (p = 0.04). The presence of two or more organ system abnormalities (p = 0.04) was associated with an increased hospital admission rate. CONCLUSIONS: Mortality and negative quality-of-life measures in Robin sequence are not directly related to respiratory obstruction. Isolated Robin sequence confers no increased risk of mortality. There is a high incidence of cardiac and central nervous system anomalies, which are significantly associated with mortality. Cardiac and cranial imaging should be performed during the initial evaluation of infants with Robin sequence. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

BACKGROUND: The primary aim is to evaluate clinical, radiographic, and histologic parameters of novel implants with "three roots" design that were inserted into fresh multirooted extraction sockets. A secondary aim is to compare this new implant to standard root-form dental implants. METHODS: Immediate implantation of novel or standard design 6 x 6-mm implants was performed bilaterally into multirooted sockets in mandibles of mini-pigs. Twelve weeks later, clinical, radiographic, stability, histomorphometric, and microcomputed tomography (micro-CT) analyses were performed. RESULTS: Survival rates were significantly higher in the test implants compared with control (92.8% versus 33.3%, respectively; P <0.001). Bone loss was greater in the control compared with the test by sounding (mean 3.42 +/- 0.68 versus 1.96 +/- 0.34 mm) and radiography (mean 3.35 +/- 0.62 versus 2.27 +/- 0.33 mm). Histologic and micro-CT analyses demonstrated bone fill in the inner part of the test implants. Moreover, bone-to-implant contact was higher in the test implants (55.50% +/- 3.68% versus 42.47% +/- 9.89%). Contrary to the clinical, radiographic, and histomorphometric results, resonance frequency analysis measurements were greater in the control group (77.74 +/- 3.21 implant stability quotient [ISQ]) compared with the test group (31.09 +/- 0.28 ISQ), P = 0.008. CONCLUSIONS: The novel design implants resulted in significantly greater survival rate in multirooted extraction sites. Further studies will be required to validate these findings.