Faculty Bibliography

The clinically beneficial effect of low frequency pulsed electromagnetic fields (ELF-PEMF) on bone healing has been described, but the exact mechanism of action remains unclear. A recent study suggests that there is a direct autocrine mitogenic effect of ELF-PEMF on angiogenesis. The hypothesis of this study is that ELF-PEMF also has an indirect effect on angiogenesis by manipulation of vascular endothelial growth factor (VEGF)-A-based paracrine intercellular communication with neighboring osteoblasts. Conditioned media experiments measured fetal rat calvarial cell (FRC) and human umbilical vein endothelial cell (HUVEC) proliferation using tritiated thymidine uptake. We demonstrate that ELF-PEMF (15 Hz, 1.8 mT, for 8 h) has an indirect effect on the proliferation rate of both endothelial cells and osteoblasts in vitro by altering paracrine mediators. Conditioned media from osteoblast cells stimulated with ELF-PEMF increased endothelial proliferation 54-fold, whereas media from endothelial cells stimulated with ELF-PEMF did not affect osteoblast proliferation. We examined the role of the pro-angiogenic mediator VEGF-A in the mitogenic effect of ELF-PEMF-stimulated osteoblast media on endothelial cells. The production of VEGF-A by FRC as measured by ELISA was not changed by exposure to PEMF, and blocking experiments demonstrated that the ELF-PEMF-induced osteoblast-derived endothelial mitogen observed in these studies was not VEGF-A, but some other soluble angiogenic mediator

Societal changes, including the aging of the US population and the lack of routine dental service coverage under Medicare, have left many seniors unable to afford any dental care whatsoever, let alone the most advanced treatments.(1) In 2004, the Columbia University College of Dental Medicine and its partners instituted the ElderSmile program in the largely impoverished communities of Harlem and Washington Heights/Inwood in New York City. The long-term goal of this program is to improve access to and delivery of oral health care for seniors; the short-term goal is to establish and operate a network of prevention centers surrounding a limited number of treatment centers. Preliminary results indicate substantial unmet dental needs in this largely Hispanic and Black elderly population.

This study evaluated the effect of core-design modification on the characteristic strength and failure modes of glass-infiltrated alumina (In-Ceram) (ICA) compared with porcelain fused to metal (PFM). Premolar crowns of a standard design (PFMs and ICAs) or with a modified framework design (PFMm and ICAm) were fabricated, cemented on dies, and loaded until failure. The crowns were loaded at 0.5 mm min(-1) using a 6.25 mm tungsten-carbide ball at the central fossa. Fracture load values were recorded and fracture analysis of representative samples were evaluated using scanning electron microscopy. Probability Weibull curves with two-sided 90% confidence limits were calculated for each group and a contour plot of the characteristic strength was obtained. Design modification showed an increase in the characteristic strength of the PFMm and ICAm groups, with PFM groups showing higher characteristic strength than ICA groups. The PFMm group showed the highest characteristic strength among all groups. Fracture modes of PFMs and of PFMm frequently reached the core interface at the lingual cusp, whereas ICA exhibited bulk fracture through the alumina core. Core-design modification significantly improved the characteristic strength for PFM and for ICA. The PFM groups demonstrated higher characteristic strength than both ICA groups combined

BACKGROUND: The tear trough and the lid/cheek junction become more visible with age. These landmarks are adjacent, forming in some patients a continuous indentation or groove below the infraorbital rim. Numerous, often conflicting procedures have been described to improve the appearance of the region. The purpose of this study was to evaluate the anatomy underlying the tear trough and the lid/cheek junction and to evaluate the procedures designed to correct them. METHODS: Twelve fresh cadaver lower lid and midface dissections were performed (six heads). The orbital regions were dissected in layers, and medical photography was performed. RESULTS: In the subcutaneous plane, the tear trough and lid/cheek junction overlie the junction of the palpebral and orbital portions of the orbicularis oculi muscle and the cephalic border of the malar fat pad. In the submuscular plane, these landmarks differ. Along the tear trough, the orbicularis muscle is attached directly to the bone. Along the lid/cheek junction, the attachment is ligamentous by means of the orbicularis retaining ligament. CONCLUSIONS: The tear trough and lid/cheek junction are primarily explained by superficial (subcutaneous) anatomical features. Atrophy of skin and fat is the most likely explanation for age-related visibility of these landmarks. 'Descent' of this region with age is unlikely (the structures are fixed to bone). Bulging orbital fat accentuates these landmarks. Interventions must extend significantly below the infraorbital rim. Fat or synthetic filler may be best placed in the intraorbicularis plane (tear trough) and in the suborbicularis plane (lid/cheek junction)

Of all the methods for repair of the unilateral cleft lip, none has gained as much popularity as the rotation-advancement. Millard's original principle of 50 years ago continues to guide surgeons in closure of the cleft lip. Unlike earlier procedures, the brilliance of the rotation-advancement is that it permits individual manipulation and modifications while maintaining Millard's original surgical and anatomical goals. Millard and many other surgeons have made modifications to adjust the procedure to each specific patient, to address some of its faults, and to gain new advantages. In this article, the authors review the techniques of Drs. Ralph Millard, Steve Byrd, Court Cutting, John Mulliken, and Samuel Stal. The variations from Millard's original technique are highlighted, including a discussion of the benefits of each modification

Here we present a case of successful non-operative management of an iatrogenic recto-urethral fistula in a 13-year-old boy. The fistula was created when urethroscopic repair of a urethral stricture was attempted. Due to the anatomy of the lesion and previous urinary diversion, it was deemed possible to spare this patient diverting colostomy or surgical repair of the fistula. The result was successful closure of the fistula, which was confirmed on retrograde urethrogram. While we do not support the routine use of non-operative management for recto-urethral fistulas we have demonstrated that there are circumstances where it can be safely applied

Patients who have developmental disabilities and epilepsy can be safely treated in a general dental practice. A thorough medical history should be taken and updated at every visit. A good oral examination to uncover any dental problems and possible side effects from antiepileptic drugs is necessary. Stability of the seizure disorder must be taken into account when planning dental treatment. Specific considerations for epileptic patients include the treatment of oral soft tissue side effects of medications and damage to the hard and soft tissue of the orofacial region secondary to seizure trauma. Most patients who have epilepsy can and should receive functionally and esthetically adequate dental care

This article presents details of processing, characterization and in vitro as well as in vivo evaluations of powder metallurgy processed Ti-13Nb-13Zr samples with different levels of porosity. Sintered samples were characterized for density, crystalline phases (XRD), and microstructure (SEM and EDX). Samples sintered at 1000 degrees C showed the highest porosity level ( approximately 30%), featuring open and interconnected pores ranging from 50 to 100 mum in diameter but incomplete densification. In contrast, samples sintered at 1300 and 1500 degrees C demonstrated high densification with 10% porosity level distributed in a homogeneous microstructure. The different sintering conditions used in this study demonstrated a coherent trend that is increase in temperature lead to higher sample densification, even though densification represents a drawback for bone ingrowth. Cytotoxicity tests did not reveal any toxic effects of the starting and processed materials on surviving cell percentage. After an 8-week healing period in rabbit tibias, the implants were retrieved, processed for nondecalcified histological evaluation, and then assessed by backscattered electron images (BSEI-SEM) and EDX. Bone growth into the microstructure was observed only in samples sintered at 1000 degrees C. Overall, a close relation between newly formed bone and all processed samples was observed.

Reconstructive algorithms for composite craniofacial defects have focused on soft tissue flaps with or without bone grafts. However, volumetric loss over time limits long-term preservation of facial contour. Application of craniofacial skeletal buttress principles to high-energy trauma or oncologic defects with composite vascularized bone flaps restores the soft tissue as well as the buttresses and ultimately preserves facial contour. We conducted a retrospective review of 34 patients with craniofacial defects treated by a single surgeon with composite bone flaps at R Adams Cowley Shock Trauma Center and Johns Hopkins Hospital from 2001 to 2007. Data collected included age, sex, mechanism of injury, type of defect, type of reconstructive procedures, and outcome. Thirty-four patients with composite tissue loss, primarily males (n = 24) with an average age of 37.4 years, underwent reconstruction with vascularized bone flaps (28 fibula flaps and 6 iliac crest flaps). There were 4 cranial defects, 8 periorbital defects, 18 maxillary defects, and 4 maxillary and periorbital defects. Flap survival rate was 94.1% with an average follow-up time of 20.5 months. Restoration of facial height, width, and projection is achieved through replacement of skeletal buttresses and is essential for facial harmony. Since 2001, our unit has undergone a paradigm shift with regard to treatment of composite oncologic and traumatic defects, advocating vascularized bone flaps to achieve predictable long-term outcomes.