Faculty Bibliography

Purpose: To simulate coefficient of thermal expansion (CTE)-generated stress fields in monolithic metal and ceramic crowns, and CTE mismatch stresses between metal, alumina, or zirconia cores and veneer layered crowns when cooled from high temperature processing. Materials and Methods: A 3D computer-aided design model of a mandibular first molar crown was generated. Tooth preparation comprised reduction of proximal walls by 1.5 mm and of occlusal surfaces by 2.0 mm. Crown systems were monolithic (all-porcelain, alumina, metal, or zirconia) or subdivided into a core (metallic, zirconia, or alumina) and a porcelain veneer layer. The model was thermally loaded from 900 degrees C to 25 degrees C. A finite element mesh of three nodes per edge and a first/last node interval ratio of 1 was used, resulting in approximately 60,000 elements for both solids. Regions and values of maximum principal stress at the core and veneer layers were determined through 3D graphs and software output. Results: The metal-porcelain and zirconia-porcelain systems showed compressive fields within the veneer cusp bulk, whereas alumina-porcelain presented tensile fields. At the core/veneer interface, compressive fields were observed for the metal-porcelain system, slightly tensile for the zirconia-porcelain, and higher tensile stress magnitudes for the alumina-porcelain. Increasingly compressive stresses were observed for the metal, alumina, zirconia, and all-porcelain monolithic systems. Conclusions: Variations in residual thermal stress levels were observed between bilayered and single-material systems due to the interaction between crown configuration and material properties.

Purpose: To investigate the reliability of titanium abutments veneered with indirect composites for implant-supported crowns and the possibility to trace back the fracture origin by qualitative fractographic analysis. Materials and Methods: Large base (LB) (6.4-mm diameter base, with a 4-mm high cone in the center for composite retention), small base (SB-4) (5.2-mm base, 4-mm high cone), and small base with cone shortened to 2 mm (SB-2) Ti abutments were used. Each abutment received incremental layers of indirect resin composite until completing the anatomy of a maxillary molar crown. Step-stress accelerated-life fatigue testing (n = 18 each) was performed in water. Weibull curves with use stress of 200 N for 50,000 and 100,000 cycles were calculated. Probability Weibull plots examined the differences between groups. Specimens were inspected in light-polarized and scanning electron microscopes for fractographic analysis. Results: Use level probability Weibull plots showed Beta values of 0.27 for LB, 0.32 for SB-4, and 0.26 for SB-2, indicating that failures were not influenced by fatigue and damage accumulation. The data replotted as Weibull distribution showed no significant difference in the characteristic strengths between LB (794 N) and SB-4 abutments (836 N), which were both significantly higher than SB-2 (601 N). Failure mode was cohesive within the composite for all groups. Fractographic markings showed that failures initiated at the indentation area and propagated toward the margins of cohesively failed composite. Conclusions: Reliability was not influenced by abutment design. Qualitative fractographic analysis of the failed indirect composite was feasible.

ABSTRACT: Microporous scaffolds designed to improve bony repair have had limited success; therefore, we sought to evaluate whether time-released porous scaffolds with or without recombinant bone morphogenetic protein 2 (rhBMP-2) could enhance stem cell osteoinduction. Custom-made 15/85 hydroxyapatite/beta-tricalcium phosphate scaffolds were left empty (E) or filled with rhBMP-2 (E+), calcium sulfate (CS), or CS and rhBMP-2 (CS+). All scaffolds were placed in media and weighed daily. Conditioned supernatant was analyzed for rhBMP-2 and then used to feed human adipose-derived mesenchymal stem cells (ASCs). Adipose-derived mesenchymal stem cell ALP activity, OSTERIX expression, and bone nodule formation were determined. E scaffolds retained 97% (SD, 2%) of the initial weight, whereas CS scaffolds had a near-linear 30% (SD, 3%) decrease over 60 days. E+ scaffolds released 155 (SD, 5) ng of rhBMP-2 (77%) by day 2. In contrast, CS+ scaffolds released only 30 (SD, 2) ng (10%) by day 2, and the remaining rhBMP-2 was released over 20 days. Conditioned media from E+ scaffolds stimulated the highest ALP activity and OSTERIX expression in ACSs on day 2. However, after day 6, media from CS+ scaffolds stimulated the highest ALP activity and OSTERIX expression in ASCs. Adipose-derived mesenchymal stem cells exposed to day 8 CS+-conditioned media produced significantly more bone nodules (10.1 [SD, 1.7] nodules per high-power field) than all other scaffolds. Interestingly, day 8 conditioned media from CS scaffolds simulated significantly more bone nodules than either E or E+ scaffold (P < 0.05 for both). Time-released hydroxyapatite/beta-tricalcium phosphate porosity provides sustained growth factor release, enhances ASC osteoinduction, and may result in better in vivo bone formation.

The purposes of this study were to determine the occurrence rate for preoperative breast pain; describe the characteristics of this pain; evaluate for differences in demographic and clinical characteristics; and evaluate for variations in pro- and anti-inflammatory cytokine genes between women who did and did not report pain. Patients (n = 398) were recruited prior to surgery and completed self-report questionnaires on a number of pain characteristics. Genotyping was done using a custom genotyping array. Women (28.2%) who reported breast pain were significantly younger (P < .001); more likely to be nonwhite (P = .032); reported significantly lower Karnofsky Performance Status scores (P = .008); were less likely to be postmenopausal (P = .012); and had undergone significantly more biopsies (P = .006). Carriers of the minor allele for a single nucleotide polymorphism in interleukin (IL)1-receptor 1 (IL1R1) (rs2110726) were less likely to report breast pain prior to surgery (P = .007). Carriers of the minor allele for a single nucleotide polymorphism in IL13 (rs1295686) were more likely to report breast pain prior to surgery (P = .019). Findings suggest that breast pain occurs in over a quarter of women who are about to undergo breast cancer surgery. Based on phenotypic and genotypic characteristics found, inflammatory mechanisms contribute to preoperative breast pain. PERSPECTIVE: In women with breast cancer, preoperative pain may be associated with increases in inflammatory responses associated with an increased number of biopsies. In addition, differences in cytokine genes may contribute to this preoperative breast pain.

INTRODUCTION: A multidisciplinary conference was convened in March 2010 with the charge to develop parameters of care for patients with craniosynostosis. The 52 participants represented 16 medical specialties and 16 professional societies. Herein, we present the dental, orthodontic, and surgical care recommendations for those with craniosynostosis, with special emphasis on craniosynostosis syndromes. METHODS: Plenary and small-group iterative discussions were held to draft specialty-specific parameters of care. All participants reviewed and discussed each specialty-specific document. Special care was taken to ensure cross-discipline interactions, recognizing the importance of interdisciplinary team care. RESULTS: A unified document was produced delineating longitudinal care parameters from prenatal assessment and consultation to adulthood in all the represented specialty areas. The dental and orthodontic care parameters from infancy to adulthood are explained in terms of stages of development and coordinated with interdisciplinary assessments and interventions. CONCLUSIONS: The consensus document provides a detailed description of physical, functional, and cognitive development in persons with craniosynostosis and recommends staged team observations and interventions. The expectation is that the document will help to ensure state-of-the-art care for patients with craniosynostosis and provide a generally acceptable framework for collaborative studies.

BACKGROUND: : Acellular dermal matrix is commonly used in implant-based breast reconstruction to allow for quicker tissue expansion with better coverage and definition of the lower pole of the breast. This study was performed to analyze complications associated with its use in immediate two-stage, implant-based breast reconstruction and to subsequently develop guidelines for its use. METHODS: : A retrospective analysis of 628 consecutive immediate two-stage tissue expander breast reconstructions at a single institution over a 3-year period was conducted. The reconstructions were divided into two groups: reconstruction with acellular dermal matrix and reconstruction without it. Demographic information, patient characteristics, surface area of acellular dermal matrix, and complications were analyzed and compared. RESULTS: : A total of 407 patients underwent 628 immediate two-stage, implant-based breast reconstructions; 442 reconstructions (70.3 percent) used acellular dermal matrix and 186 (29.6 percent) did not. The groups had similar patient characteristics; however, major complications were significantly increased in the acellular dermal matrix group (15.3 versus 5.4 percent; p = 0.001). These complications included infection requiring intravenous antibiotics (8.6 versus 2.7 percent; p = 0.001), flap necrosis requiring excision (6.7 versus 2.7 percent; p = 0.015), and explantation of the tissue expander (7.7 versus 2.7 percent; p = 0.004). CONCLUSIONS: : Use of acellular dermal matrix in immediate two-stage, implant-based breast cancer reconstruction is associated with a significant increase in major complications. Therefore, it should only be used in specific patients and in minimal amounts. Indications for its use include single-stage permanent implant reconstruction and inadequate local muscle coverage of the tissue expander. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, III.

Aplasia cutis congenita, a rare congenital disorder involving defects of some or all of the layers of the cranium, is associated with potential life-threatening complications. Although treatment involves both nonsurgical and surgical techniques, the importance of perioperative management cannot be overstressed. A multidisciplinary team, including personnel from nursing, neonatology, pediatrics, radiology, neurosurgery, and plastic surgery services, diagnosed aplasia cutis congenita and planned local wound care, surgical correction, and prevention of potentially life-threatening complications in a 1-day-old boy with a 6x5-cm full-thickness scalp defect.

The biomechanical effects of a non-thermal plasma (NTP) treatment, suitable for use in a dental office, on the surface character and integration of a textured dental implant surface in a beagle dog model were evaluated. The experiment compared a control treatment, which presented an alumina-blasted/acid-etched (AB/AE) surface, to two experimental treatments, in which the same AB/AE surface also received NTP treatment for a period of 20 or 60 s per implant quadrant (PLASMA 20' and PLASMA 60' groups, respectively). The surface of each specimen was characterized by electron microscopy and optical interferometry, and surface energy and surface chemistry were determined prior to and after plasma treatment. Two implants of each type were then placed at six bilateral locations in 6 dogs, and allowed to heal for 2 or 4 weeks. Following sacrifice, removal torque was evaluated as a function of animal, implant surface and time in vivo in a mixed model ANOVA. Compared to the CONTROL group, PLASMA 20' and 60' groups presented substantially higher surface energy levels, lower amounts of adsorbed C species and significantly higher torque levels (p=.001). Result indicated that the NTP treatment increased the surface energy and the biomechanical fixation of textured-surface dental implants at early times in vivo.

LEARNING OBJECTIVES:: After reviewing this article, the participant should be able to: 1. Evaluate patient's ears for needed adjustments to size, shape, prominence, and symmetry. 2. Identify common ear deformities and describe methods to repair them. 3. Avoid or manage common complications associated with otoplasty and ear reconstruction. SUMMARY:: The essentials of otoplasty will be described/illustrated for the following conditions: Prominent ears, underdeveloped helical rims (shell ear), macrotia, Stahl's ear, constricted ear, cryptotia, and question mark ear.

BACKGROUND:: Despite increasing specialization of craniofacial surgery, certain craniofacial techniques are widely applicable. The authors identified five such craniofacial techniques and queried American Society of Plastic Surgeons members and plastic surgery program directors regarding their comfort level with the procedures and their opinion on resident training for these selected procedures. METHODS:: First, a select group of senior craniofacial surgeons discussed and agreed on the top five procedures. Second, active American Society of Plastic Surgeons were surveyed regarding their opinion on training and their comfort level with each procedure. Third, plastic surgery residency program directors were studied to see which of the top five procedures are taught as part of the plastic surgery residency curriculum. RESULTS:: The top five widely applicable craniofacial procedures are technically described and include the following: (1) cranial or iliac bone graft for nasal reconstruction, (2) perialar rim bone graft, (3) lateral canthopexy, (4) osseous genioplasty, and (5) bone graft harvest for orbital floor defects. For practicing plastic surgeons, comfort level in all procedures increased with advancing years in practice (except those with <5 years). A majority of plastic surgeons (>75 percent), especially those with craniofacial fellowship training, felt competent in all procedures except osseous genioplasty (53 percent). Plastic surgery program directors agreed that all top five procedures should be mastered by graduation. CONCLUSIONS:: Although program directors felt that all five selected craniofacial procedures should be taught and mastered during residency training, plastic surgeons without craniofacial fellowship training were less comfortable with the techniques. Residency training goals should include competence in core craniofacial techniques.