Faculty Bibliography

This study evaluated the influence of different light-curing modes on the volumetric polymerization shrinkage and degree of conversion of a composite resin at different locations using micro-computed tomography and Fourier transform infrared spectroscopy (FTIR). Specimens were divided into 4 groups based on the light-curing mode used (Bluephase 20i): 1 -High (1,200 mW/cm2); 2 -Low (650 mW/cm2); 3 -Soft-start (650-1,200 mW/cm2); and 4 -Turbo (2,000 mW/cm2). Degree of conversion was calculated by the measurement of the peak absorbance height of the uncured and cured materials at the specific wavenumbers, and was performed by FTIR 48 h after curing resin samples. Degree of conversion was analyzed using two-way ANOVA. No significant differences were observed independent of the region of the restoration investigated (p>0.05). Different curing modes did not influence volumetric shrinkage neither degree of conversion of class I composite resin restorations.

This study presents a systematic review of randomized controlled trials (RCTs) in cleft and craniofacial surgery. All studies reporting on RCTs in cleft and craniofacial surgery were identified on PubMed using the search terms "cleft," "velopharyngeal insufficiency," "velopharyngeal dysfunction," "nasoalveolar molding," "gingivoperiosteoplasty," "Pierre Robin sequence," "craniofacial," "craniosynostosis," "craniofacial microsomia," "hemifacial microsomia," "hypertelorism," "Le Fort," "monobloc," "distraction osteogenesis," "Treacher Collins," and "Goldenhar." Studies were excluded if they were not randomized, did not focus primarily on topics related to cleft or craniofacial surgery, included repeat publications of data, or were unavailable in English. Studies were evaluated on demographic and bibliometric data, study size, specific area of focus, and findings reported. Four hundred forty-seven unique studies were identified. One hundred eighty-three papers met inclusion criteria (115 cleft lip and palate, 65 craniofacial, and 3 spanning both disciplines). Sixty-six (36%) were dedicated to topics related to surgical techniques. There were no studies comparing current cleft lip or soft palate repair techniques and no studies on cleft rhinoplasty. The most frequently reported surgical topic was cleft palate. There were several studies on orthognathic techniques which compared distraction osteogenesis to traditional advancement. Most craniofacial operations, such as cranial vault remodeling and frontofacial advancement/distraction, were not represented. Several standard operations in cleft and craniofacial surgery are not supported by Level I evidence from randomized controlled trials. Our community should consider methods by which more RCTs can be performed, or redefine the acceptable standards of evidence to guide our clinical decisions.

PURPOSE: To evaluate the influence of implant diameter in the reliability and failure mode of extra-short dental implants. MATERIALS AND METHODS: Sixty-three extra-short implants (5mm-length) were allocated into three groups according to platform diameter: O4.0-mm, O5.0-mm, and O6.0-mm (21 per group). Identical abutments were torqued to the implants and standardized crowns cemented. Three samples of each group were subjected to single-load to failure (SLF) to allow the design of the step-stress profiles, and the remaining 18 were subjected to step-stress accelerated life-testing (SSALT) in water. The use level probability Weibull curves, and the reliability (probability of survival) for a mission of 100,000 cycles at 100MPa, 200MPa, and 300MPa were calculated. Failed samples were characterized in scanning electron microscopy for fractographic inspection. RESULTS: No significant difference was observed for reliability regarding implant diameter for all loading missions. At 100MPa load, all groups showed reliability higher than 99%. A significant decreased reliability was observed for all groups when 200 and 300MPa missions were simulated, regardless of implant diameter. At 300MPa load, the reliability was 0%, 0%, and 5.24%, for O4.0mm, O5.0mm, and O6.0mm, respectively. The mean beta (beta) values were lower than 0.55 indicating that failures were most likely influenced by materials strength, rather than damage accumulation. The O6.0mm implant showed significantly higher characteristic stress (eta = 1,100.91MPa) than O4.0mm (1,030.25MPa) and O5.0mm implant (eta = 1,012.97MPa). Weibull modulus for O6.0-mm implant was m = 7.41, m = 14.65 for O4.0mm, and m = 11.64 for O5.0mm. The chief failure mode was abutment fracture in all groups. CONCLUSIONS: The implant diameter did not influence the reliability and failure mode of 5mm extra-short implants.

INTRODUCTION: Innervated muscle transfer can improve functional outcomes after extensive limb-sparing sarcoma resections. We report our experience using composite thigh flaps for functional reconstruction of large oncologic extremity defects. PATIENTS AND METHODS: Between 2011 and 2014, four limb-sparing oncologic resections (3 lower extremities, 1 upper extremity) underwent immediate functional reconstruction with composite thigh free flaps in three males and one female. The age of the patients ranged from 36 to 73 years. There were 3 soft-tissue sarcomas and one giant cell tumor, all required resection of entire muscle compartments. Flap components included fasciocutaneous tissue with sensory nerve, plicated iliotibial band (ITB), and variable amounts of motorized vastus lateralis (VL). RESULTS: All flaps survived without complications. All patients showed VL motor innervation by six months. Follow-up ranged from 20 to 36 months. Motor strength ranged from 2 to 5 out of 5, active range of motion was 25-92% of normal, and Musculoskeletal Tumor Society (MSTS) Scores were between 22 and 29 out of 30. CONCLUSIONS: Limb-sparing techniques for upper and lower extremity sarcomas continue to evolve. Our experience has validated the composite thigh free flap as an excellent option for one-stage functional reconstruction of large limb defects.

BACKGROUND: The septocutaneous tensor fasciae latae (sc-TFL) or lateral thigh perforator (LTP) flap was previously introduced by our group as an alternative flap for autologous breast reconstruction when the abdomen is not suitable as a donor site. The aim of this study was to analyze our experience with the LTP flap and to present the surgical refinements that were introduced. METHODS: A prospective study was conducted of all LTP flap breast reconstructions performed since September 2012. Patient demographics, operative details, complications and flap re-explorations were recorded. Preoperative imaging with MRA was performed in all patients. Surgical refinements that were introduced during this study included limitation of the flap width and the use of quilting sutures at the donor site. RESULTS: A total of 138 LTP flap breast reconstructions were performed in 86 consecutive patients. Median operation times were 277 minutes (range 196-561) for unilateral and 451 minutes (range 335-710) for bilateral procedures. Median flap weight was 348 grams (range 175-814). Two total flap losses (1.4%) were recorded and eleven flaps (8.0%) required re-exploration, which resulted in viable flaps. The incidence of donor-site complications reduced significantly after the surgical refinements were introduced. Wound problems decreased from 40.0% to 6.3%, seroma from 25.0% to 9.5%, and infection from 27.5% to 9.5%, respectively. CONCLUSIONS: The LTP flap is an excellent option for autologous breast reconstruction with minimal recipient-site complications. The surgical refinements resulted in a significant reduction of donor-site complications. Therefore, the LTP flap is currently our second choice after the DIEP flap.

OBJECTIVES/HYPOTHESIS: Although the primary goal of medialization laryngoplasty is to improve glottic closure, implant placement is also likely to alter the biomechanical properties of the vocal fold (VF). We sought to employ novel, nanoscale technology to quantify these properties following medialization based on the hypothesis that different medialization materials will likely yield differential biomechanical effects. STUDY DESIGN: Ex vivo. METHODS: Nine pig larynges were divided into three groups: control, Silastic (Dow Corning, Midland, Michigan, U.S.A.) block medialization, or Gore-Tex (W.L. Gore & Associates, Newark, Delaware) medialization. Laryngoplasty was performed on excised, intact larynges. The larynges were then bisected in the sagittal plane and each subjected to dynamic nanomechanical analysis (nano-DMA) at nine locations using a 250-mum flat-tip punch and frequency sweep-load profile across the free edge of the VF and inferiorly along the conus elasticus. RESULTS: Silastic block and Gore-Tex implant introduced increased storage and loss moduli. Overall, storage moduli mean (maximum) increased from 38 kilopascals (kPa) (119) to 72 kPa (422) and 129 kPa (978) in control, Gore-Tex, and Silastic implants, respectively. Similarly, loss moduli increased from 13 kPa (43) to 22 kPa (201) and 31 kPa (165), respectively. Moduli values varied widely by location in the Silastic block and Gore-Tex groups. At the free VF edge, mean (maximum) storage moduli were lowest in the Gore-Tex group, 20 kPa (44); compared to control, 34.5 kPa (86); and Silastic, 157.9 kPa (978), with similar loss and complex moduli trends. CONCLUSION: Medialization laryngoplasty altered VF structure biomechanical properties; Silastic and Gore-Tex implants differentially impact these properties. LEVEL OF EVIDENCE: NA. Laryngoscope, 2017.

Background: Obesity and type 2 diabetes have not only been linked to fatty liver, but also to fatty kidney and chronic kidney disease. Since non-invasive tools are lacking to study fatty kidney in clinical studies, we explored agreement between proton magnetic resonance spectroscopy ( 1 H-MRS) and enzymatic assessment of renal triglyceride content (without and with dietary intervention). We further studied the correlation between fatty kidney and fatty liver. Methods: Triglyceride content in the renal cortex was measured by 1 H-MRS on a 7-Tesla scanner in 27 pigs, among which 15 minipigs had been randomized to a 7-month control diet, cafeteria diet (CAF) or CAF with low-dose streptozocin (CAF-S) to induce insulin-independent diabetes. Renal biopsies were taken from corresponding MRS-voxel locations. Additionally, liver biopsies were taken and triglyceride content in all biopsies was measured by enzymatic assay. Results: Renal triglyceride content measured by 1 H-MRS and enzymatic assay correlated positively ( r = 0.86, P < 0.0001). Compared with control diet-fed minipigs, renal triglyceride content was higher in CAF-S-fed minipigs (137 +/- 51 nmol/mg protein, mean +/- standard error of the mean, P < 0.05), but not in CAF-fed minipigs (60 +/- 10 nmol/mg protein) compared with controls (40 +/- 6 nmol/mg protein). Triglyceride contents in liver and kidney biopsies were strongly correlated ( r = 0.97, P < 0.001). Conclusions: Non-invasive measurement of renal triglyceride content by 1 H-MRS closely predicts triglyceride content as measured enzymatically in biopsies, and fatty kidney appears to develop parallel to fatty liver. 1 H-MRS may be a valuable tool to explore the role of fatty kidney in obesity and type 2 diabetic nephropathy in humans in vivo .

PURPOSE: This work evaluated the nanomechanical properties of bone surrounding submerged and immediately loaded implants after 3 years in vivo. It was hypothesized that the nanomechanical properties of bone would markedly increase in immediately and functionally loaded implants compared with submerged implants. MATERIALS AND METHODS: The second, third, and fourth right premolars and the first molar of 10 adult Doberman dogs were extracted. After 6 months, 4 implants were placed in 1 side of the mandible. The mesial implant received a cover screw and remained unloaded. The remaining 3 implants received fixed prostheses within 48 hours after surgery that remained in occlusal function for 3 years. After sacrifice, the bone was prepared for histologic and nanoindentation analysis. Nanoindentation was carried out under wet conditions on bone areas within the plateaus. Indentations (n = 30 per histologic section) were performed with a maximum load of 300 muN (loading rate, 60 muN per second) followed by a holding and unloading time of 10 and 2 seconds, respectively. Elastic modulus (E) and hardness (H) were computed in giga-pascals. The amount of bone-to-implant contact (BIC) also was evaluated. RESULTS: The E and H values for cortical bone regions were higher than those for trabecular bone regardless of load condition, but this difference was not statistically significant (P > .05). The E and H values were higher for loaded implants than for submerged implants (P < .05) for cortical and trabecular bone. For the same load condition, the E and H values for cortical and trabecular bone were not statistically different (P > .05). The loaded and submerged implants presented BIC values (mean +/- standard deviation) of 57.4 +/- 12.1% and 62 +/- 7.5%, respectively (P > .05). CONCLUSION: The E and H values of bone surrounding dental implants, measured by nanoindentation, were higher for immediately loaded than for submerged implants.