Faculty Bibliography

Among surface modifications commercially available for dental implants, the incorporation of bioceramic coatings is one of the most popular. However, concerns regarding the effectiveness of the bond between the metallic Surface and the coating have led to the development of thin-film Ca- and P- based bioceramic coatings. The purpose of this study was to evaluate the early bone response to a thin ion bean deposited (Test) bioceramic implant surface compared to an alumina-blasted/acid-etched (Control) surface in a canine model. Results showed that although no difference in bone-to-implant (BIC) could be noted between the two different surfaces, more organized bone architecture was present around the Test implants in 4 weeks. Based on this observation, the incorporation of a thin- film bioceramic coating positively influenced bone healing around dental implants at early times.

BACKGROUND: Patients seeking elective aesthetic surgery often use herbal medications and/or antidepressants. As the popularity of these medications grows, the plastic surgeon must become familiar with these drugs and their potentially harmful effects during the perioperative period. METHODS: The authors performed a PubMed search to identify commonly used herbs and antidepressants and their effects on patients during elective cosmetic surgery. RESULTS: Case series, studies, and reviews for 29 of the most common herbs and antidepressant medications were obtained from this search. On the basis of the existing data, the authors established recommendations for the management of these medications before elective cosmetic surgery. CONCLUSIONS: Most commonly used herbs and antidepressant medications have potentially deleterious effects on the patient during surgery, ranging from increased risk of bleeding to fatal interactions. The plastic surgeon must be familiar with these drugs to manage these patients appropriately

PURPOSE: Mechanical analyses of idealized crown-cement-tooth systems through finite element analysis (FEA) has provided valuable insight concerning design parameters and materials that favor lower stress patterns. However, little information regarding variation of basic preparation guidelines in stress distribution has been available. The primary objective of this study was to evaluate maximum principal stresses on a molar crown veneer plus core system natural tooth configuration preparation with variations in the ratio of proximal axial length (PAL) to buccal axial length (BAL) as well as loading condition and position. MATERIALS AND METHODS: Three-dimensional models comprising a crown veneer (porcelain), crown core (zirconia), cement layer, and tooth preparation (4.2 mm BAL with PAL reductions of 0.8 mm, 1.0 mm, and 1.2 mm) yielding BAL:PAL ratios of 1.23, 1.31, and 1.4 were designed by computer software (Pro/Engineering). The models were imported into an FEA software (Pro/Mechanica), with all degrees of freedom constrained at the root surface of the tooth preparation. Each tooth preparation crown configuration was evaluated under a vertical (axial) 200 N load, and under a combined vertical 200 N and horizontal (buccally) 100 N load applied at different positions from the central fossa to the cusp tip. Maximum principal stress (MPS) was determined for the crown core for each crown BAL:PAL ratio, loading condition, and position. RESULTS: Under both vertical and combined loading conditions, the highest MPSs were located at the occlusal region and in the occlusogingival region of the ceramic core. MPS values increased in the proximal region as the BAL:PAL ratio increased. Combined loading resulted in a general increase in MPS compared to vertical loading. CONCLUSION: Increasing the BAL:PAL ratio (reducing the proximal axial length of the preparation) acted as a stress concentrator at regions near the crown margins, suggesting this area may be vulnerable to damage from fit adjustment as well as during function. Such increases in stress concentration should be considered in clinical scenarios, especially when inherent flaws are present in the material, since extensive high-magnitude tensile stress fields have been noted under all loading conditions

The objective of this study was to physico/chemically characterize and determine the corrosion resistance of a Calcium-Phosphate (Ca-P) based bioceramic thin coating processed by a sputtering process on titanium alloy (Ti-6Al-4V). The samples utilized in this study were uncoated and coated disks of 10 mm diameter by 3 mm thickness. The coating was characterized by SEM, XPS + ion beam milling (IBM), thin-film mode XRD, and atomic force microscope (AFM) (n = 3). Coated and uncoated Ti-6Al-4V disk surfaces were tested in Phosphate Buffered Saline (PBS) at 25 degrees C through an area of 0.79 cm(2). A three-electrode cell set-up was used with a saturated calomel electrode (SCE) and a platinum wire as reference and counter electrodes. After 3, 17, and 25 days of immersion, electrochemical impedance spectroscopy (EIS) experiments were performed (n = 3). The EIS tests were carried out in potentiostatic mode at the open circuit potential (OCP). The frequency range considered was from 100 kHz to 10 mHz, using 10 mV root mean square as the amplitude of the perturbation signal. A potentiodynamic polarization scan using a frequency response analyzer potentiostat, was acquired following 3 days of immersion in PBS. The potentiodynamic polarization scans (n = 3) were carried out with a scan rate of 1 mV/s ranging from -0.8V(SCE) to 3.0V(SCE). Results: The physico/chemical characterization showed an amorphous Ca- and P-based coating of ~400-700 nm thickness with Ca-P nanometer size particles embedded in a Ca-P matrix. The Bode phase angle diagrams showed highly capacitive results at low and medium frequencies for both surfaces tested. The polarization curves showed low current densities at the corrosion potential (E (corr)), in the order of 10(-8)A/cm(2), typical of passive materials with protective surface films. Coated sample current densities were comparable to the uncoated samples. Conclusion: Coated and uncoated samples were stable in the test solution with a protective film maintained throughout the 25 day immersion test period

Peripheral nerve regeneration research has unfolded a wealth of basic science knowledge in the last century. Today, that knowledge has become the fundamental groundwork for evolving clinical applications to treat peripheral nerve defects. This article discusses two clinical applications that have been investigated thoroughly in the laboratory setting for decades and recently tested in the clinical setting: nerve allotransplantation to graft nerve defects, and brief electrical stimulation to promote nerve regeneration. It also discusses the generation of Thy-1-XFP transgenic mice, which express fluorescent proteins in the nervous system and provide new avenues for investigating peripheral nerve regeneration

A 29-year-old woman with Freeman-Sheldon syndrome had a history of recurrent frontal sinus infections for which she underwent a 1-stage frontal sinus obliteration and cranioplasty using a free fibula osteocutaneous flap. This case is unique in that a free fibula flap had never been used to obliterate the frontal sinus in a patient with Freeman-Sheldon syndrome, nor had it been harvested from a limb with a clubfoot.

BACKGROUND: This study was designed to evaluate the efficacy of direct corneal neurotization using contralateral supraorbital and supratrochlear nerves in patients with unilateral facial palsy and corneal anesthesia. A novel surgical procedure in which these donor nerve branches are inserted at the contralateral anesthetic corneal limbus for sensory neurotization is described. METHODS: The charts of six patients were reviewed thoroughly to evaluate changes in corneal sensibility following surgery for direct corneal neurotization. Visual acuity, blink reflex, donor deficit, synesthesia, long-term corneal health, and several psychosocial measures and overall patient satisfaction with the procedure are reported. RESULTS: Six patients with an average denervation time of 7.00 +/- 8.56 years before surgery were followed for an average period of 16.3 +/- 2.42 years. All six eyes showed improvement of corneal sensibility, visual acuity, and corneal health and remained free of ulcers or other signs of advancing neurotropic keratopathy. Average corneal sensibility improved from 2.00 +/- 4.47 mm before surgery to 278.00 +/- 226.00 mm following corneal neurotization (p < 0.016). CONCLUSIONS: Direct neurotization of the cornea using the contralateral supraorbital and supratrochlear branches of the ophthalmic division of the trigeminal nerve appears to be an effective method of restoring the corneal sensibility in patients with unilateral facial palsy and anesthetic cornea. This technique preserves ocular anatomy and cosmesis and restores function by improving corneal health and visual acuity

BACKGROUND: The significance of the oral vestibule is often underappreciated in composite craniomaxillofacial reconstruction, and its deficiency results in considerable incompetence. Results of traditional vestibuloplasty techniques are unpredictable when the recipient bed is compromised in the setting of trauma or irradiation. The authors present an alternative approach for restoring the intractable oral vestibule with free tissue transfer. METHODS: An institutional review board-approved retrospective review of patients who underwent oral vestibular reconstruction was conducted at R Adams Cowley Shock Trauma Center and Johns Hopkins Hospital from 2002 to 2007. RESULTS: Thirteen patients were identified: six defects resulted from tumor extirpation, six resulted from traumatic injury, and one resulted from infection. There were eight men and five women, with a mean age of 46 years. Thirteen free tissue transfers of the oral vestibule were conducted: six ulnar forearm and seven anterolateral thigh perforator flaps. The average follow-up was 17 months. There were no flap failures and only one complication noted, which did not result in negative sequelae. The functional results were good, with all patients experiencing increased labial excursion and subjective improvement in the handling of food bolus and saliva. CONCLUSIONS: Preservation of oral vestibular height, width, and volume is essential for aesthetic appearance and functional competence. Free tissue transfer provides an innovative alternative in the management of the intractable and obliterated oral vestibule. It can be performed successfully, providing excellent results predictably.