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

INTRODUCTION: Large-volume soft-tissue defects often leave exposed neurovascular and vital structures not amenable to immediate flap coverage. We describe the use of AlloDerm, an acellular dermis allograft, in providing temporary coverage of these structures in multistage reconstruction of the extremity. METHODS: A prospective study of 25 patients was performed using AlloDerm for temporary coverage of exposed vital structures secondary to trauma and oncologic ablation. A direct examination of neurovascular structures and the wound bed after allograft removal was performed as a monitor of outcome. RESULTS: All allografts successfully covered the neurovascular structures at the time of removal with complete viability of neurovascular structures. Granulation tissue was appreciated in the wound bed with no clinical evidence of infection. The allograft was easily removed without damage to underlying structures. CONCLUSION: AlloDerm offers a safe and reliable alternative to cover critical neurovascular structures temporarily, before the definitive reconstruction of soft-tissue defects

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.

The endogenous peptide endothelin-1 (ET-1), originally identified as a potent vasoconstrictor, plays a role in a number of painful conditions. In this review article we discuss the mechanisms that are essential for local sensitization by subcutaneously administered ET-1, and report evidence of ET-1's ability to sensitize distant regions of the body, through the central nervous system and, likely, coupling through the spinal cord. In addition, we will review the latest information on the role of ET-1 in cancerous and non-cancerous conditions. Cancer pain has indeed been shown to be attenuated by antagonists of endothelin receptors, and ET-1 is known to be secreted by cancer cells of many different histologic types. Furthermore, a growing body of evidence links increased expression and secretion of ET-1 to the occurrence of non-cancer related pain syndromes, such as inflammatory and neuropathic pain syndromes.

OBJECTIVES: To define the role of crossing vessels in the pathophysiology of ureteropelvic junction (UPJ) obstruction, we analyzed the relationship between the presence of crossing vessels and UPJ pathologic findings in patients undergoing laparoscopic pyeloplasty. The significance of crossing renal vessels in patients with UPJ obstruction is unclear. METHODS: We performed a retrospective analysis of 155 consecutive patients undergoing laparoscopic pyeloplasty. Pathologic specimens from the UPJ were evaluated in 95 patients. The presence or absence of crossing vessels was documented intraoperatively. The histopathologic findings allowed for categorization into 5 groups: group 1, normal ureteral tissue; group 2, chronic inflammation; group 3, smooth muscle hypertrophy, group 4, fibrosis; and group 5, smooth muscle atrophy. The pathologic findings between patients with and without crossing vessels were compared. RESULTS: Overall, crossing vessels were identified in 98 patients (63.2%). Of the 95 cases with specimens retrieved for histologic analysis, 65 had crossing vessels and 30 did not. The most common UPJ histologic finding in patients with crossing vessels was no intrinsic abnormality (43%). In contrast, this was seen in only 10% of patients without a crossing vessel. In the group without crossing vessels, chronic inflammation (40%) was the predominant histologic findings. Patients with a crossing vessel were less likely to have intrinsic histologic pathologic findings (P < .0003). CONCLUSIONS: Patients with crossing vessels and UPJ obstruction had no histologic abnormalities identified in 43% of cases. This finding implicates crossing vessels in the pathogenesis of select cases of UPJ obstruction and direct mechanical compression as the etiology of obstruction in these individuals

BACKGROUND: Patients presenting with traumatic craniomaxillofacial fractures often have occult concomitant injuries. This study was designed to determine whether facial fracture patterns are associated with a particular constellation of concomitant head and neck injuries. METHODS: A retrospective review of 4786 consecutive patients diagnosed with maxillofacial fractures at a dedicated urban trauma center from 1998 to 2005 was conducted; maxillofacial fractures and cervical spine injuries were grouped by dividing the craniomaxillofacial skeleton and cervical spine into thirds. Univariate and multivariate logistic regression analyses were used to identify associations between facial fractures and other traumatic injuries. RESULTS: Among all patients with facial fractures, 461 (9.7 percent) also had cervical spine injuries and 2175 (45.5 percent) had associated head injuries. Fractures of the upper face were associated with increased likelihood of mid lower cervical spine injuries, severe intracranial injuries, and increased mortality rates. Unilateral mandible injuries were associated with an increased likelihood of having upper cervical spine injuries, whereas unilateral midface injuries were associated with basilar skull fractures and several intracranial injuries. Finally, bilateral midface injuries were associated with basilar skull fracture and death. CONCLUSIONS: Craniomaxillofacial fractures are commonly associated with head and cervical spine injuries that involve predictable patterns of force dispersion from the maxillofacial skeleton and transmission to the cranial vault and cervical spine. These results suggest that concomitant injuries should be investigated closely with distinct types of facial fractures.

BACKGROUND: Vascularized nerve grafts were introduced in 1976. Subsequent studies have suggested the superiority of vascularized nerve grafts. In this study, the authors present 23 years' experience with vascularized ulnar nerve graft. The factors influencing outcomes and a comparison with conventional nerve grafts are presented. METHODS: Between 1981 and 2003, 151 reconstructions with ulnar nerve were performed in 67 patients for brachial plexus injuries. Patients were divided into four groups: those with vascularized ulnar nerve graft from ipsilateral donors, pedicled or free, and those with vascularized ulnar nerve graft from contralateral donors to median nerve or to single motor targets (e.g., axillary, musculocutaneous, triceps) (n = 25, 21, 13, and 8, respectively). RESULTS: Patients with long denervation times yielded inferior results compared with those operated on early. Pedicle and free ipsilateral ulnar nerve grafts yielded comparable results for biceps muscle neurotization. Neurotization of biceps with a vascularized ulnar nerve graft from the contralateral root was not as effective as neurotization from ipsilateral donors. There was a difference in muscle grading when the target was the median nerve versus single motor targets such as axillary, musculocutaneous, or triceps, but there were no differences between preoperative and postoperative muscle grading of median innervated muscles. CONCLUSIONS: Vascularized ulnar nerve grafting is the appropriate solution for brachial plexus injuries with C8 and T1 root avulsion, with outcomes that are superior to those achieved with conventional nerve grafts. Although few changes have been made over time, the use of ulnar nerve grafts for neurotization of multiple motor targets of the median nerve from contralateral donors is under consideration

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)

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