Faculty Bibliography

PURPOSE: To evaluate the effect of diamondlike carbon (DLC) coating on abutments and/or abutment screws on the reliability, characteristic strength, and Weibull modulus of implant-supported single crowns. MATERIALS AND METHODS: Seventy-two external hexagon implants (Emfills Implant 4 mm diameter, 10 mm length, Emfills) were divided into four groups (n = 18 each), according to the presence or not of a DLC coating in the abutment and/or abutment screw, as follows: abutment without coating, screw without coating (AwcSwc); abutment without coating with coated screw (AwcSC); abutment coated with noncoated screw (ACSwc), and coated abutment with coated screw (ACSC). Abutments and screws were evaluated with scanning electron microscopy. The specimens were subjected to step-stress accelerated life testing in water. Use-level probability Weibull curves and reliability for a mission of 100,000 cycles at 150 N (90% two-sided confidence intervals) were calculated. Polarized light and scanning electron microscopes were used for fractographic analysis. RESULTS: For a mission of 100,000 cycles at 150 N, reliability was 0.45 (0.20 to 0.67), 0.12 (0.00 to 0.47), 0.56 (0.17 to 0.82), and 0.44 (0.07 to 0.77) for AwcSwc, AwcSC, ACSwc, and ACSC, respectively. The probability Weibull calculation showed a Weibull modulus (m) of m = 5.50, m = 11.64, m = 16.96, and m = 15.08 and the characteristic strengths (eta, which indicates the load at which 63.2% of the specimens of each group fail) of eta = 202.67 N, eng = 206.64 N, eng = 192.54 N, and eng = 203.59 N for AwcSwc, AwcSC, ACSwc, and ACSC, respectively. Abutment screw fracture was the chief failure outcome in all groups. CONCLUSION: Characteristic strength values were not different among groups; neither was reliability. However, an increase in Weibull modulus (indicating low variability of the results) was observed with DLC coating of abutment or screw or both.

PURPOSE: To investigate the effect of core dental implant materials supporting single crowns on the probability of survival and failure modes. MATERIALS AND METHODS: Thirty-six standard external-hex titanium implants (4.0 mm in diameter) were selected to restore single crowns and divided into two groups according to core material: commercially pure grade 2 titanium (G2) and grade 5 titanium-aluminum-vanadium alloy (Ti-6Al-4V) (G5). Abutments were screwed to the implants, and standardized maxillary central incisor metal crowns were cemented and subjected to step-stress accelerated life testing in water. Use-level probability Weibull curves and reliability for missions of 100,000 cycles at 150 N and 200 N (with 90% two-sided confidence intervals [CIs]) were calculated. Polarized light and scanning electron microscopes were used to determine the failure modes. RESULTS: Use-level probability Weibull calculations showed beta values of 0.59 (CI, 0.31 to 1.11) and 1.22 (CI 0.81 to 1.84) for G2 and G5, respectively, and significantly higher characteristic strength and Weibull modulus for G5. The calculated reliability (90% CIs) for a mission of 100,000 cycles at 150 N showed that cumulative damage would lead to survival of 45% of implant-supported crowns of G2 and 98% of G5. At 200 N the probability of survival decreased to 0.03% for G2 and 21% for G5. Abutment screw fracture was the failure mode for all groups. CONCLUSION: Reliability, characteristic strength, and Weibull modulus were significantly higher for Ti-6Al-4V dental implants than for commercially pure (grade 2) titanium implants. Failure modes were similar for both groups.

BACKGROUND: The abdominal donor site has consistently demonstrated excellent aesthetic outcomes when used for autologous breast reconstruction. However, a consistent point of dissatisfaction is the location and appearance of the abdominal donor-site scar, which can be a frequent cause of distress for the patient. The authors consider the appearance of the donor-site to be as important to the overall reconstructive effort as that of the breast, and believe it worthwhile to achieve an aesthetically pleasing result. Thus, the authors present here their technique for aesthetic revision of the abdominal donor site after autologous breast reconstruction. METHODS: This is a series of 51 patients who underwent autologous tissue breast reconstruction with deep inferior epigastric perforator flaps. All patients subsequently underwent abdominal donor-site revision during the second stage of their reconstruction, including excision and lowering of the abdominal scar, and liposuction of the abdomen and mons pubis to achieve optimum contouring. RESULTS: The donor-site scars were lowered an average of 5.93 cm (range, 5 to 7 cm). The average procedural time was 27 minutes. No wound dehiscence, seromas, hematomas, or infections were reported postoperatively. CONCLUSIONS: With this report, the authors put forth a new obtainable standard for autologous tissue breast reconstruction donor-site aesthetics, and propose a conceptual shift that includes the trunk aesthetic unit as an integral part of the overall reconstructive outcome. The authors' results here demonstrate that this is a safe, successful, and reproducible procedural adjunct to the second stage of breast reconstruction.

BACKGROUND: Currently, there is a lack of clear guidelines regarding evaluation and management of giant juvenile fibroadenomas. The purpose of this study was to conduct a systematic review of giant juvenile fibroadenomas and to evaluate the most common diagnostic and therapeutic modalities. METHODS: A systematic literature search of PubMed and MEDLINE databases was conducted in February 2014 to identify articles related to giant juvenile fibroadenomas. Pooled outcomes are reported. RESULTS: Fifty-two articles (153 patients) met inclusion criteria. Mean age was 16.7 years old, with a mean lesion size of 11.2 cm. Most patients (86%) presented with a single breast mass. Imaging modalities included ultrasound in 72.5% and mammography in 26.1% of cases. Tissue diagnosis was obtained using a core needle biopsy in 18.3% of cases, fine-needle aspiration (FNA) in 25.5%, and excisional biopsy in 11.1% of patients. Surgical treatment was implemented in 98.7% of patients (mean time to treatment of 9.5 months, range, 3 days to 7 years). Surgical intervention included excision in all cases, of which four were mastectomies. Breast reconstruction was completed in 17.6% of cases. There were no postoperative complications. CONCLUSIONS: Diagnosis and treatment of giant juvenile fibroadenoma is heterogeneous. There is a paucity of data to support observation and non-operative treatment. The most common diagnostic modalities include core needle or excisional biopsy. The mainstay of treatment is complete excision with an emphasis on preserving the developing breast parenchyma and nipple areolar complex. Breast reconstruction is uncommon, but may be necessary in certain cases.

Biphasic calcium phosphate (BCP) bioceramics have been successfully applied in a broad variety of presentation forms and with different ratios of hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP). BCPs have been loaded with stem cells from different origins for bone tissue engineering purposes, but evidence of stem cell behavior on different compositions (various HA/beta-TCP ratios) and physical features of BCPs is limited. We compared the adhesion, proliferation, viability and osteogenic potential of human mesenchymal stem cells (MSCs) on granular BCPs with equal HA/beta-TCP ratio of diverse particle sizes and on porous blocks which had different chemical compositions. In addition, the osteogenic differentiation of MSCs was compared to adipose-derived (ADSC) and dental pulp (DPSC) stem cells, as well as to pre-osteoblasts on a particulate BCP. MSCs growing on granular BCPs demonstrated increased number as compared to MSCs growing on blocks. Cells proliferated to a greater extent on small granular BCPs, while large granular BCPs and blocks promoted cell differentiation. Surprisingly, the expression of genes involved in osteogenesis was upregulated in MSCs on bioceramics in basal medium which indicates that BCPs may have osteoinductive potential. This was confirmed with the upregulation of osteochondrogenic markers, at different time points, when stem cells from various tissues were grown on the BCP. This study demonstrates that BCPs, depending on their physical features and chemical composition, modulate stem cell behavior, and that stem cells from different origins are inherently distinct in their gene expression profile and can be triggered toward osteochondrogenic fate by BCPs.

This article aims to demonstrate an individualized approach to an elderly patient requiring scalp reconstruction, to describe the methodology in flap selection, lessons learned, and report outcomes. A retrospective review of a single surgeon's experience of scalp reconstruction (E. D. R.) using free tissue transfer from 2005 to 2011, in patients older than 70 years, was completed. A total of eight patients met the inclusion criteria, five males and three females, with a mean age of 80.4 years (range, 73-92). Free tissue transfer achieved 100% soft tissue coverage. Six of the eight patients required cranioplasty. The mean size calvarial defect was 92 cm(2) (range, 35-285 cm(2)). The mean flap size was 117.6 cm(2) (range, 42-285 cm(2)). Free flaps included three ulnar, three anterolateral thigh, one latissimus dorsi, and one thoracodorsal perforator flap. The mean follow-up time was 18.4 months (range, 3-46 months). Donor site morbidity was minimal. Mortality was 0%. Immediate flap failure was 0%. Other complications occurred in six of the eight patients. Mean revisionary procedures were 1.25 procedures per patient. It was concluded that chronological age does not increase mortality or catastrophic flap complications; however, morbidity is increased in the elderly and revisionary surgery is likely.

BACKGROUND: Given the great variability in perioperative management of craniosynostosis, a large-scale national survey of current practice patterns was conducted. METHODS: Using scaphocephaly as a test diagnosis, 115 craniofacial surgeons at all levels of career experience across the United States were invited to participate in an anonymous survey. RESULTS: Fifty-three surgeons (46%) completed the survey. All respondents complete repair before 1 year of age with a majority operating between 4 and 8 months. Surgeons with greater than 10 years of experience were significantly more likely to perform open repair at extremes of age (<4 months and 8-12 months) (P = 0.03) and reported shorter operative times (P = 0.01) compared with their less experienced colleagues. More than two-thirds of surgeons (68.8%) obtain preoperative imaging for every case; 83% of these prefer computed tomography scans. More than one-fourth of respondents (28%) routinely prescribe an extended course (>24 hours) of antibiotics. Overall transfusion rates remain high, with nearly 2 (65.2%) in 3 transfusing in 76% to 100% of operations. The overwhelming majority of respondents (93.6%) routinely send patients to an intensive care unit postoperatively. CONCLUSIONS: We present the largest US survey of craniosynostosis surgical practice patterns to date. General consensus exists regarding safety and emergency preparedness standards. In addition, we identified several patterns that deviate from published evidence-based guidelines. Specifically, these practices relate to the routine use of high-dose radiation imaging, long-term antibiotics, blood transfusions, and intensive postoperative surveillance. For the first time, stratifying by surgeon experience revealed significant differences in clinical practice.

PURPOSE: Image-guided surgical navigation, or computed tomography (CT)-guided surgery, is a technology used by many specialties to reduce complications and improve surgical outcomes. Its use has become widespread in neurosurgical intracranial and otolaryngological skull base procedures. The authors hypothesize that CT image-guided surgical navigation has a wide scope of utility in complex craniomaxillofacial procedures. With time and experience, its use will further advance the safety and efficacy of craniomaxillofacial surgery. METHODS: A multicenter retrospective study at the University of California-Los Angeles, New York University, University of Pittsburgh, and the University of Kansas Medical Center was conducted. All craniomaxillofacial procedures using CT image-guided surgical navigation were reviewed. RESULTS: Twenty subjects were identified who underwent a total of 26 CT-guided navigation procedures (6 cases were bilateral). Subunits reconstructed included: the upper face (n = 5), middle face (n = 7), and lower face (n = 6). Two additional patients used CT navigation to reconstruct multiple facial subunits. In all 20 subjects, the image-guided system correctly identified the surgical anatomy to less than 2 mm. There were no perioperative complications. Long-term follow-up demonstrated no revisionary procedures were required to date. CONCLUSIONS: Computed tomography-guided navigation is a safe and effective tool with multiple applications in craniomaxillofacial surgery. Indications for its use in complex craniomaxillofacial procedures continue to broaden. Further experience with this technology will continue to expand its clinical utility in craniomaxillofacial surgery.

Bilateral craniofacial microsomia causes obstructive sleep apnea (OSA). We hypothesize that unilateral craniofacial microsomia (UCFM) is an underappreciated cause of OSA. The records of all pediatric UCFM patients from 1990 to 2010 were reviewed; only complete records were included in the study. UCFM patients with OSA (apnea hypopnea index >1/hr) were compared to UCFM patients without OSA. Univariate and multivariate Fisher and chi tests were performed. Of the 62 UCFM patients, 7 (11.3%) had OSA. All OSA patients had Pruzansky IIB or III mandibles. OSA patients presented with snoring (71.4%), failure to thrive (FTT) (57.1%), and chronic respiratory infections (42.8%). Snoring (P < 0.001), Goldenhar syndrome (P = 0.001), and FTT (P = 0.004) were significantly associated with OSA, but race, obesity, clefts, respiratory anomalies, adenotonsillar hypertrophy, and laterality were not. The prevalence of OSA in UCFM patients is up to 10 times greater than in the general population. Snoring, Goldenhar syndrome, and FTT are significantly associated with the presence of OSA.