RANK/RANKL/OPG signaling pathways in necrotic jaw bone from bisphosphonate-treated subjects.

Osteonecrosis of the jaw (ONJ) is a chronic complication affecting long-term bisphosphonate-treated subjects, recognized by non-healing exposed bone in the maxillofacial region. The pathophysiological mechanism underlying ONJ has not been fully elucidated. The aim of the present study was to investigate the role of RANK/RANKL/OPG signaling pathway and, in parallel, to evaluate angiogenic and matrix mineralization processes in jaw bone necrotic samples obtained from bisphosphonate-treated subjects with established ONJ. Necrotic bone samples and native bone samples were processed for Light and Field Emission in Lens Scanning Electron Microscope (FEISEM) analyses, for Real-Time RT-PCR to evaluate the gene expression of TNFRSF11A (RANK), TNFSF11 (RANKL), and TNFSF11B (OPG) and for immunohistochemical analyses of VEGF and BSP expression. Morphological analyses performed by Light microscope and FEISEM show empty osteocytic lacunae and alteration of lamellar organization with degradation of the mineralized bone matrix in necrotic bone samples. A significant increase in TNFRSF11A, TNFSF11, TRAF6 and NFAT2 gene expression, and a reduction of TNFSF11B gene transcription level compared is also showed in necrotic bone compared to control samples. No significant difference of VEGF expression is evidenced, while lower BSP expression in necrotic bone compared to healthy samples is found. Even if the pathogenesis of bisphosphonate-associated ONJ remains unknown, a link between oral pathogens and its development seems to exist. We suppose lipopolysaccharide produced by bacteria colonizing and infecting necrotic bone and the surrounding viable area could trigger RANK/RANKL/OPG signaling pathway and, in this context, osteoclasts activation could be considered as a protective strategy carried out by the host bone tissue to delimitate the necrotic area and to counteract infection.

Long term effects of the palatal plate therapy for the orofacial regulation in children with Down syndrome.

The objective of this study was to evaluate long term effects of orofacial regulation therapy with modified Castillo-Morales palatal plate on 68 Down children that attended our Unit from 1992 to 2001. Corrections obtained with palatal plate therapy were evaluated according to the following parameters: spontaneous lingual protrusion based on three level scale, position "open mouth", labial hypotonia and sialorrhea. The results showed distinct improvement in nearly all of the parameters compared to initial conditions.

[Primary Ewing's sarcoma of the mandible. A clinico-pathological and immunohistochemical case study]. / Il sarcoma di Ewing primitivo della mandibola. Studio clinico patologico ed immunoistochimico di un caso.

A rare case of Ewing's sarcoma, originating in the mandible, is reported. The symptomatologic and radiological aspects is often aspecific. For this reason the diagnostic-therapeutic routine is presented and the difficulty of clinical diagnosis is accentuated. In these cases it may be appropriate to make use of immunohistochemical analysis such as the research of markers like the NSE (Neuro-Specific Enolase). This will be useful to reach an accurate preoperative diagnosis and in order to adopt a correct therapeutic protocol.

[Dental pathology in malformation syndromes: the methodology and intervention timing]. / Patologia odontostomatologica nelle sindromi malformative: metodologia e timing di intervento.

Due to the complexity and potential vulnerability of the cranio-facial area (skull, face, nose, oral cavity), specific alterations of this region are associated to genetic and acquired malformations in a high percentage of cases (75%). Often, the specificity and extent of the pathological symptoms occurring in the cranio-facial area are the dominant aspects of the malformation syndrome according to which it is classified. When multiple development anomalies in a newborn suggest the existence of a syndrome, the patient should be placed in the care of a pediatrician, who, together with a team of specialists, will follow the child and face the various problems related to the syndrome at the right time. The frequent marked involvement of the craniofacial area in malformation syndromes suggests the opportunity of a specialist methodology to standardize odontostomatological therapy.