Faculty Bibliography

Previous research has documented that oral health is inextricably linked with overall health and is an important component of successful aging. Additionally, peer social interactions are known to improve older adults' general well-being by increasing social opportunities and knowledge of local resources. This study examines the relationship between peer density of participants aged 50 and older in the ElderSmile program and self-reported oral health in northern Manhattan. Results from logistic regression models found that higher peer kernel density estimation values are associated with better self-reported oral health. This reinforces the need for place-based health interventions, and provides new evidence of the importance of peer communities for older adults.

BACKGROUND:: The vascular anatomy of the supraclavicular artery island (SAI) flap has been investigated using both cadaveric anatomic dissections and angiographic studies. Accurate preoperative evaluation and localization of its vascular pedicle confirms its location, course, anatomic variation, and improves flap success. The objective of this report is to demonstrate the utility of multislice computed tomography (CT) angiography for confirming the presence of the vascular pedicle of the SAI flap when planning head and neck reconstruction. METHODS:: Patients were studied using 64-multislice CT angiography to localize the supraclavicular artery, including its origin and destination. Axial images, multiplanar reconstructions, and 3D volume-rendered images were analyzed on a Philips workstation. Radiologic image findings and clinical experience will be described. RESULTS:: SAI CT angiography was successfully performed in 15 patients (30 shoulders) ranging from ages 22 to 81 years. Accurate identification of the main vascular pedicle was achieved in 14/15 patients. Location, course, pedicle length, and anatomic variations were reported for 23 of 30 arteries. Mean vessel diameter was found to be 1.49 mm (range, 0.8-2.0 mm) on the right and 1.51 mm (range, 1.0-2.1 mm) on the left. The mean length of the artery was 38.3 mm on the right (range, 26.6-59.6 mm) and 38.4 mm on the left (range, 24.3-67.0 mm). In all patients, the supraclavicular artery originated off the transverse cervical artery-a branch of the thyrocervical trunk. Positioning of the patient's upper extremities at the side was helpful in the identification of the supraclavicular artery and its distribution. Contrast injection site should be contralateral to the side needed for the flap if sidedness is of importance, secondary to contrast bolus artifact. CONCLUSIONS:: Preoperative evaluation of the SAI flap with multislice computed tomography angiography is feasible in patients. A radiologic study protocol has been developed which improves ability to detect this vessel. This technique provides a noninvasive approach to the identification of the vascular anatomy and is easily standardized/reproducible. The identification of the vascular pedicle and its anatomy can be a benefit to the surgical team during preoperative design of the SAI flap; however, clinical experience confirming these radiologic findings will be needed to optimize surgical outcome.

ABSTRACT: This manuscript is a compilation of clinical lessons learned from 30 years of treating hemangiomas. We review relevant clinical anatomy, the role of lasers and medications, timing of surgery, and operative judgment, as it pertains to the treatment of hemangiomas.

OBJECTIVES: The aim of this study was to assess the effect of abutment's diameter shifting on reliability and stress distribution within the implant-abutment connection for internal and external hexagon implants. The postulated hypothesis was that platform-switched implants would result in increased stress concentration within the implant-abutment connection, leading to the systems' lower reliability. METHODS: Eighty-four implants were divided in four groups (n=21): REG-EH and SWT-EH (regular and switched-platform implants with external connection, respectively); REG-IH and SWT-IH (regular and switched-platform implants with internal connection, respectively). The corresponding abutments were screwed to the implants and standardized maxillary central incisor metal crowns were cemented and subjected to step-stress accelerated life testing. Use-level probability Weibull curves and reliability were calculated. Four finite element models reproducing the characteristics of specimens used in laboratory testing were created. The models were full constrained on the bottom and lateral surface of the cylinder of acrylic resin and one 30 degrees off-axis load (300N) was applied on the lingual side of the crown (close to the incisal edge) in order to evaluate the stress distribution (s(vM)) within the implant-abutment complex. RESULTS: The Beta values for groups SWT-EH (1.31), REG-EH (1.55), SWT-IH (1.83) and REG-IH (1.82) indicated that fatigue accelerated the failure of all groups. The higher levels of sigma(vM) within the implant-abutment connection observed for platform-switched implants (groups SWT-EH and SWT-IH) were in agreement with the lower reliability observed for the external hex implants, but not for the internal hex implants. The reliability 90% confidence intervals (50,000 cycles at 300N) were 0.53(0.33-0.70), 0.93(0.80-0.97), 0.99(0.93-0.99) and 0.99(0.99-1.00), for the SWT-EH, REG-EH, SWT-IH, and REH-IH, respectively. SIGNIFICANCE: The postulated hypothesis was partially accepted. The higher levels of stress observed within implant-abutment connection when reducing abutment diameter (cross-sectional area) resulted in lower reliability for external hex implants, but not for internal hex implants.

Cancer patients often suffer from pain and most will be prescribed mu-opioids. mu-opioids are not satisfactory in treating cancer pain and are associated with multiple debilitating side effects. Recent studies show that mu and delta opioid receptors are separately expressed on IB4 (-) and IB4 (+) neurons, which control thermal and mechanical pain, respectively. In this study we investigated IB4 (+) and IB4 (-) neurons in mechanical and thermal hypersensitivity in an orthotopic mouse oral cancer model. We used a delta opioid receptor agonist and a P2X(3) antagonist to target IB4 (+) neurons and to demonstrate that this subset plays a key role in cancer-induced mechanical allodynia, but not in thermal hyperalgesia. Moreover, selective removal of IB4 (+) neurons using IB4-saporin impacts cancer-induced mechanical but not thermal hypersensitivity. Our results demonstrate that peripherally administered pharmacological agents targeting IB4 (+) neurons, such as a selective delta-opioid receptor agonist or P2X(3) antagonist, might be useful in treating oral cancer pain. PERSPECTIVE: To clarify the mechanisms of oral cancer pain, we examined the differential role of IB4 (+) and IB4 (-) neurons. Characterization of these 2 subsets of putative nociceptors is important for further development of effective clinical cancer pain relief.

Purpose: The purpose of this study was to test the hypothesis that all-ceramic crown core-veneer system reliability is improved by modifying the core design and as a result is comparable in reliability to metal-ceramic retainers (MCR). Finite element analysis (FEA) was performed to verify maximum principal stress distribution in the systems. Materials and Methods: A first lower molar full crown preparation was modeled by reducing the height of proximal walls by 1.5 mm and occlusal surface by 2.0 mm. The CAD-based preparation was replicated and positioned in a dental articulator for specimen fabrication. Conventional (0.5 mm uniform thickness) and modified (2.5 mm height, 1 mm thickness at the lingual extending to proximals) zirconia (Y-TZP) core designs were produced with 1.5 mm veneer porcelain. MCR controls were fabricated following conventional design. All crowns were resin cemented to 30-day aged composite dies, aged 14 days in water and either single-loaded to failure or step-stress fatigue tested. The loads were positioned either on the mesiobuccal or mesiolingual cusp (n = 21 for each ceramic system and cusp). Probability Weibull and use level probability curves were calculated. Crack evolution was followed, and postmortem specimens were analyzed and compared to clinical failures. Results: Compared to conventional and MCRs, increased levels of stress were observed in the core region for the modified Y-TZP core design. The reliability was higher in the Y-TZP-lingual-modified group at 100,000 cycles and 200 N, but not significantly different from the MCR-mesiolingual group. The MCR-distobuccal group showed the highest reliability. Fracture modes for Y-TZP groups were veneer chipping not exposing the core for the conventional design groups, and exposing the veneer-core interface for the modified group. MCR fractures were mostly chipping combined with metal coping exposure. Conclusions: FEA showed higher levels of stress for both Y-TZP core designs and veneer layers compared to MCR. Core design modification resulted in fatigue reliability response of Y-TZP comparable to MCR at 100,000 cycles and 200 N. Fracture modes observed matched with clinical scenarios.