Impact of Communication Between Physicians and Dentists on the Incidence of Jaw Osteonecrosis Caused by Bone Anti-Resorptives

Dental management of osteoporosis patients on anti-resorptive therapy can be challenging for both the dentist and physician because of the risk of osteonecrosis of the jaw (ONJ). This editorial reflects on the paper written by Tagushi et al that expressed a relative lack of communication between health care providers when treating osteoporosis patients. Osteoporosis-related bone fractures can be debilitating and occasionally lethal, but management with anti-resorptives is vital while cognizant of the complication of ONJ that can also negatively impact patient’s quality of life

Analysis of the effects of frequent strikes on academic performance of students in universities in Nigeria: Edo State as a focal point

The history of Academic Staff Union of Universities (ASUU)’s strike can be traced back to 1978, the period of the beginning of the decline in the oil boom, when the country faced the consequences of the failure by its rulers to use the oil wealth to generate production and a social welfare system. Military dictatorship had eroded deeply the basic freedoms in the society. Academic freedom and university autonomy were casualties of military dictatorship. The funding of education, and so of universities, became poorer. The factors required a changed orientation of the union of academics. However, questionnaires were administered to seek the opinions of the students in University of Benin (UNIBEN) and in Benson Idahosa University (BIU), Edo States and one thousand and fifty four staff and students were randomly selected. Nine hundred and seventy one respondents validly returned their questionnaire. From the analyzed data, it was observed that frequent strikes had adverse effects on the academic performance of students. Based on the findings of the study, recommendations were made that adequate measures should be put in place by government and the Academic Staff Union of Universities (ASUU) etc to check incessant strike in the educational system; and conclusively that government owned Universities should emulated private school owners by avoiding strikes and intensify efforts to convince ASUU on the evils of strikes to see that students would have enough time to study so that they can be able to face challenges in the Labour Market. This paper painstakingly appraised several of these issues and concluded that all stakeholders in the education sector and federal polity should  thread softly, be objective, rational, altruistic and magnanimous in order not to make the existence of true federalism (social, political, educational and economic cohesive existence of the people, peace and tranquillity) a fleeting illusion and a mirage.Keywords: ASUU, strikes, Academic performance, economic downturn, NationalUniversities Commissio

Chemical and Radiation Associated Jaw Lesions

Osteonecrosis of the jaw, at one time considered to be infrequent has now become a major public health concern not only in the United States, but throughout the world. The wide-spread use of radiotherapy for head and neck cancer as well as bone antiresorptives and antiangiogenic agents have increased the incidence of osteonecrosis. While the exact pathophysiological process of osteonecrosis is yet to be clearly defined, there has been a much higher incidence of medication-related osteonecrosis of the jaw relative to the other types of osteonecrosis. The traditional osteoradionecrosis still occurs despite better treatment planning and shielding to minimize collateral damage to bone. There are other related necrotic lesions secondary to usage of recreation drugs and the use of steroids. This chapter will give comprehensive information about these different types of bone necrosis; provide the readers with radiographic diagnostic criteria and updates on current theories on pathophysiology of osteonecrosis

Incidental Finding of an Extensive Oropharyngeal Mass in Magnetic Resonance Imaging of a Patient With Temporomandibular Disorder: A Case Report

In this report, we describe the incidental finding of an oropharyngeal mass in a patient who presented with a chief complaint of temporomandibular pain. The patient was initially evaluated by an otorhinolaryngologist for complaints of headaches, earache, and sinus congestion. Due to worsening headaches and trismus, he was further referred for the management of temporomandibular disorder. The clinical evaluation was uneventful except for limited mouth opening (trismus). An advanced radiological evaluation using magnetic resonance imaging revealed a mass in the nasopharyngeal/oropharyngeal region. The mass occupied the masticatory space and extended superioinferiorly from the skull base to the mandible. A diagnostic biopsy of the lesion revealed a long-standing human papilloma virus (HPV-16)-positive squamous cell carcinoma of the oropharynx. This case illustrates the need for the timely radiological evaluation of seemingly innocuous orofacial pain

Dental Perspectives in Fibrous Dysplasia and McCune-Albright Syndrome

McCune-Albright syndrome (MAS) is a rare multisystem disorder characterized by the triad of polyostotic fibrous dysplasia (PFD), endocrine disorders and café-au-lait skin pigmentation. Ninety percent of MAS patients have FD lesions in the craniofacial area, resulting in significant orofacial deformity, dental disorders, bone pain and compromised oral health. Maxillo-mandibular FD is also associated with dental developmental disorders, malocclusion, and high caries index. There is limited data on the outcomes of dental treatments in maxillo-mandibular FD/MAS patients, because clinicians and researchers have limited access to patients, and there are concerns that dental surgery may activate quiescent jaw FD lesions to grow aggressively. This report highlights current perspectives on dental management issues associated with maxillo-mandibular FD within the context of MAS

Human Bone Marrow Stromal Cells Display Variable Anatomic Site-Dependent Response and Recovery From Irradiation

Objectives Orofacial bone is commonly affected by osteoradionecrosis (ORN) during head and neck cancer radiotherapy possibly due to interactions of several factors including radiation damage to resident bone marrow stromal cells (BMSCs). Irradiation causes DNA damage, triggers p53-dependent signalling resulting in either cell-cycle arrest or apoptosis. In same individuals, disproportionately higher rapid growth of orofacial BMSCs relative to those of axial/appendicular bones suggests their response to radiation is skeletally site-specific. We hypothesised that survival and osteogenic recovery capacity of irradiated human BMSCs is site-dependent based on anatomic skeletal site of origin. Methods Early passage BMSCs from maxilla, mandible and iliac crest of four normal volunteers were exposed to 2.5 to 10 Gy gamma radiation to evaluate clonogenic survival, effects on cell cycle, DNA damage, p53-related response and in vivo osteogenic regenerative capacity. Results Orofacial bone marrow stromal cells (OF-MSCs) survived higher radiation doses and recovered quicker than iliac crest (IC-MSCs) based on clonogenic survival, proliferation and accumulation in G0G1 phase. Post-irradiation p53 level was relatively unchanged but expression of p21, a downstream effector was moderately increased in OF-MSCs. Re-establishment of in vivo bone regeneration was delayed more in irradiated IC-MSCs relative to OF-MSCs. Conclusions Effect of irradiation on human BMSCs was skeletal site-specific with OF-MSCs displaying higher radio-resistance and quicker recovery than IC-MSCs

Dynamic Hydrostatic Pressure Promotes Differentiation of Human Dental Pulp Stem Cells

The masticatory apparatus absorbs high occlusal forces, but uncontrolled parafunctional or orthodontic forces damage periodontal ligament (PDL), cause pulpal calcification, pulp necrosis and tooth loss. Morphology and functional differentiation of connective tissue cells can be controlled by mechanical stimuli but effects of uncontrolled forces on intra-pulpal homeostasis and ability of dental pulp stem cells (DPSCs) to withstand direct external forces are unclear. Using dynamic hydrostatic pressure (HSP), we tested the hypothesis that direct HSP disrupts DPSC survival and odontogenic differentiation. DPSCs from four teenage patients were subjected to HSP followed by assessment of cell adhesion, survival and recovery capacity based on odontogenic differentiation, mineralization and responsiveness to bone morphogenetic protein-2 (BMP-2). HSP down-regulated DPSC adhesion and survival but promoted differentiation by increasing mineralization, in vivo hard tissue regeneration and BMP-2 responsiveness despite reduced cell numbers. HSP-treated DPSCs displayed enhanced odontogenic differentiation, an indication of favorable recovery from HSP-induced cellular stress

Canine Mesenchymal Stem Cell Bone Regenerative Capacity is Regulated by Site-Specific Multi-Lineage Differentiation

Objectives Mesenchymal stem cells (MSCs) are promising therapies in dentistry due to their multipotent properties. Selecting donor MSCs is crucial because beagle dogs (canines) commonly used in pre-clinical studies have shown variable outcomes and it is unclear whether canine MSCs (cMSCs) are skeletal site-specific. This study tested whether jaw and long bone cMSCs have disparate in vitro and in vivo multilineage differentiation capabilities. Study Design Primary cMSCs were isolated from mandible (M-cMSCs) and femur (F-cMSCs) of four healthy Beagle dogs. Femur served as non-oral control. Clonogenic and proliferative abilities were assessed. In vitroosteogenic, chondrogenic, adipogenic and neural multilineage differentiation were correlated with in vivobone regeneration and potential for clinical applications. Results M-cMSCs displayed two-fold increase in clonogenic and proliferative capacities relative to F-cMSCs (p =0.006). M-cMSCs in vitro osteogenesis based on alkaline phosphatase (p =0.04), bone sialoprotein (p =0.05), and osteocalcin (p =0.03), as well as adipogenesis (p =0.007), and chondrogenesis (p =0.009) were relatively higher and correlated with enhanced M-cMSC bone regenerative capacity. Neural expression markers, nestin and βIII-tubulin were not significantly different. Conclusions The enhanced differentiation and bone regenerative capacity of mandible MSCs may make them favorable donor graft materials for site-specific jaw bone regeneration

Anatomic Site Variability in Rat Skeletal Uptake and Desorption Of Fluorescently Labeled Bisphosphonate

Objectives Bisphosphonates commonly used to treat osteoporosis, Paget’s disease, multiple myeloma, hypercalcemia of malignancy and osteolytic lesions of cancer metastasis have been associated with bisphosphonate-associated jaw osteonecrosis (BJON). The underlying pathogenesis of BJON is unclear, but disproportionate bisphosphonate concentration in the jaw has been proposed as one potential etiological factor. This study tested the hypothesis that skeletal biodistribution of intravenous bisphosphonate is anatomic site-dependent in a rat model system. Materials and Methods Fluorescently labeled pamidronate was injected intravenously in athymic rats of equal weights followed by in vivo whole body fluorimetry, ex vivo optical imaging of oral, axial and appendicular bones and ethylenediaminetetraacetic acid bone decalcification to assess hydroxyapatite-bound bisphosphonate. Results Bisphosphonate uptake and bisphosphonate released per unit calcium were similar in oral and appendicular bones but lower than those in axial bones. Hydroxyapatite-bound bisphosphonate liberated by sequential acid decalcification was highest in oral relative to axial and appendicular bones (p \u3c 0.05). Conclusions This study demonstrates regional differences in uptake and release of bisphosphonate from oral, axial and appendicular bones of immune deficient rats

Age and Skeletal Sites Affect BMP-2 Responsiveness of Human Bone Marrow Stromal Cells

Bone marrow stromal cells (BMSCs) contain osteoprogenitors responsive to stimulation by osteogenic growth factors like bone morphogenetic proteins (BMPs). When used as grafts, BMSCs can be harvested from different skeletal sites such as axial, appendicular and orofacial bones, but the lower therapeutic efficacy of BMPs on BMSCs-responsiveness in humans compared to animal models may be partly due to effects of skeletal site and age of donor. We previously reported superior differentiation capacity and osteogenic properties of orofacial BMSCs relative to iliac crest BMSCs in same individuals. This study tested the hypothesis that recombinant human BMP-2 (rhBMP-2) stimulates human BMSCs differently based on age and skeletal site of harvest. Adult maxilla, mandible and iliac crest BMSCs from same individuals and pediatric iliac crest BMSCs were comparatively assessed for BMP-2 responsiveness under serum-containing and serum-free insulin-supplemented culture conditions. Adult orofacial BMSCs were more BMP-2-responsive than iliac crest BMSCs based on higher gene transcripts of alkaline phosphatase, osteopontin and osteogenic transcription factors MSX-2 and Osterix in serum-free insulin-containing medium. Pediatric iliac crest BMSCs were more responsive to rhBMP-2 than adult iliac crest BMSCs based on higher expression of alkaline phosphatase and osteopontin in serum-containing medium. Unlike orofacial BMSCs, MSX-2 and Osterix transcripts were similarly expressed by adult and pediatric iliac crest BMSCs in response to rhBMP-2. These data demonstrate that age and skeletal site-specific differences exist in BMSC osteogenic responsiveness to BMP-2 stimulation and suggest that MSX-2 and Osterix may be potential regulatory transcription factors in BMP-mediated osteogenesis of adult orofacial cells