Tommaso Lombardi

Bisphosphonate-associated osteonecrosis of the jaw: A key role of inflammation?

Osteonecrosis of the jaw (ONJ) can be associated with nitrogen-containing bisphosphonates (NBPs) therapy. Various mechanisms of NBP-associated ONJ have been proposed and there is currently no consensus of the underlying pathogenesis. The detailed medical and dental histories of 30 ONJ patients treated with NBPs for malignant diseases (24) or osteoporosis (6) were analyzed. The necrotic bone was resected and analyzed histologically after demineralization. In 10 patients the perinecrotic bone was also resected and processed without demineralization. Alveolar bone samples from 5 healthy patients were used as controls. In 14 ONJ patients, serial technetium-99m-methylene diphosphonate scintigraphic scans were also available and confronted to the other data. Strong radionuclide uptake was detected in some patients several months before clinical diagnosis of ONJ. The medullary spaces of the necrotic bone were filled with bacterial aggregates. In the perinecrotic bone, the bacteria-free bone marrow characteristically showed an inflammatory reaction. The number of medullary inflammatory cells taken as an index of inflammation allowed us to discriminate two inflammation grades in the ONJ samples. Low-grade inflammation, characterized by marrow fibrosis and low inflammatory cells infiltration, increased numbers of TRAP(+) mono- and multineacleated cells was seen in patients with bone exposure<2 cm(2). High-grade inflammation, associated with larger lesions, showed amounts of tartrate-resistant acid phosphatase(+)/calcitonin receptor(-) mono- and multinucleated cells, osteocyte apoptosis, hypervascularization and high inflammatory cell infiltration. The clinical extent of ONJ was statistically linked to the numbers of inflammatory cell. Taken together these data suggest that bone necrosis precedes clinical onset and is an inflammation-associated process. We hypothesize that from an initial focus, bone damage spreads centrifugally, both deeper into the jaw and towards the mucosa before the oral bone exposure and the clinical diagnosis of ONJ.

Solitary Bone Cyst of the Jaws: A Review of the Etiopathogenic Hypotheses

Solitary bone cysts (SBCs) of the jaws are often polymorphic, show scalloped borders when located between the teeth roots, are devoid of an epithelial lining, and are usually empty or contain blood or a straw-colored fluid. The numerous synonyms referring to these lesions reflect their uncertain nature (eg, traumatic bone cyst, simple bone cyst). SBC, also found in other skeletal locations, is often suspected after epidemiologic and radiologic test results and confirmed at surgery. Histology usually shows fibrous connective tissue or only bone. The various etiologic elements responsible for SBC include tumor degeneration, trauma, or abnormalities during bone growth. The pathogenesis of the SBC is unknown, but it is widely accepted that it could be the result of a vascular dysfunction leading to a local posthemorrhagic ischemia, inducing an osseous aseptic necrosis. This article reviews likely but still-debated etiopathogenic hypotheses of lesions of the jaws and other, more frequent bony locations, such as the humeral and femoral metaphysis.

Occurrence of a Pyogenic Granuloma in Relation to a Dental Implant

Pyogenic granuloma is an inflammatory vascular hyperplasia often occurring in the oral cavity. It appears in response to various stimuli such as low-grade local irritation, trauma, or female steroid hormones. A 32-year-old man sought care for a tender and bleeding lesion of the left posterior maxillary gingiva. The intraoral examination showed an exophytic ulcerated nodule measuring 1.0 cm, related to a dental implant placed in the upper left second premolar position. Radiographic examination showed an oversized healing cap. A provisional diagnosis of reactive inflammatory hyperplasia was made, and the lesion was excised and submitted for histologic examination. On microscopy, the surgical specimen showed an ulcerated nodule consisting of a delicate connective tissue stroma containing numerous blood vessels with plump endothelial cells, intermingled with abundant polymorphonuclear lymphocytes. A diagnosis of pyogenic granuloma associated with a dental implant was made. In this case it was the result of an inappropriate choice of a healing cap, thus allowing an accumulation of dental plaque and sustained chronic inflammation of the peri-implant tissue. A conservative excision and replacement of the healing cap were sufficient for definitive treatment.

Congenital intracranial frontotemporal dermoid cyst presenting as a cutaneous fistula

Intracranial extension and a cutaneous sinus tract are rarely seen with craniofacial dermoid cysts, with few cases reported in the literature.

Rehabilitation of the edentulous posterior maxilla after sinus floor elevation using deproteinized bovine bone: a 9-year clinical study.

Objectives:To evaluate the long-term survival rate of rough-surfaced implants placed in maxillary sinuses augmented with deproteinized bovine bone (Bio-Oss; Geistlich Pharma AG, Wolhusen, Switzerland). Materials and Methods:Thirteen maxillary sinuses were augmented in 10 patients with Bio-Oss. After an average healing period of 13.8 months, 24 implants were placed. In 4 cases, biopsies were performed and submitted to histological analysis. Clinical and radiographic evaluation was performed 9 years after implant placement and minimum 8 years after functional loading. Results:At the 9-year control, all the 24 implants were still functional. Thus, the implant survival rate was 100%. Conclusions:Bio-Oss is an acceptable substitute to the autogenous bone, and it can be used as a unique material for sinus floor elevation. Rough-surfaced implants placed in 100% Bio-Oss grafts showed a high survival rate (100%) on the long term. Larger clinical trials are necessary to confirm our results.

COX-2 expression in oral lichen planus.

Oral lichen planus (OLP) is a chronic inflammatory disease of unknown cause, which possesses the potential for malignant transformation. Cyclooxygenases (COX) 1 and 2 are two enzymes known to convert arachidonic acid into prostaglandins. Recent studies have shown an overexpression of COX-2 in oral squamous cell carcinoma and its precursor lesions. The present study investigated the expression of the COX-2 protein in OLP by Western blot analysis. Thirty patients with different degrees of histologically confirmed disease activity participated in the study: 9 patients had a recent onset of active OLP, 12 patients had atrophic OLP with moderate or low activity, and 9 patients presented with atrophic OLP with complete loss of activity. The results showed a high expression of COX-2 in all OLP patients in comparison with the control group. The differences in COX-2 expression in the various stages of OLP were not statistically significant. In conclusion, our results suggest that COX-2 is present during the various clinical forms of OLP. The resulting sustained overexpression of COX-2 in the late stage of the disease could play a role in the malignant transformation of some OLP.

Comparative immunohistochemical analysis between jaw myxoma and mesenchymal cells of tooth germ.

The histogenesis of jaw myxoma is still debated. According to some authors it arises from the primitive mesenchymal components of developing teeth. In this study, we have studied the expression of S-100 protein and vimentin in dental follicle, dental papilla and periodontal ligament cells using monoclonal and polyclonal antibodies. Myxoma of the jaw expresses vimentin and S-100 protein. On the contrary, as compared to jaw myxoma, the normal developmental structures were immunonegative for S-100 protein but stained for vimentin. These results could indicate a difference in the derivation other than tooth mesenchyma.

Infiltrating intramuscular lipoma of the temporal muscle. A case report with molecular cytogenetic analysis

Intramuscular lipomas are uncommon benign mesenchymal tumors which infiltrate skeletal muscle and are exceedingly rare in the head and neck region. Because of the infiltrating nature of the lesion and a high propensity for recurrence, they are sometimes difficult to distinguish from well-differentiated liposarcomas (WDLS). We report, the first case of an infiltrating lipoma of the temporal muscle in a 62-year-old white man who presented with a slow growing mass in the left temporal region. The histopathological examination showed diffuse infiltration of the striated muscle fibers by mature adipocytes. There were no lipoblasts or cells with atypical nuclei as described in WDLS. We performed interphase fluorescence in situ hybridization (FISH) analyses using painting probes for chromosome 12 and a specific probe for the MDM2 gene and comparative genomic hybridization. The results did not identify MDM2 or 12q amplification and therefore confirmed the benign nature of the lesion.

Ultrasonography: A Noninvasive Tool to Diagnose a Caliber-Persistent Labial Artery, an Enlarged Artery of the Lip

Currently, practitioners use clinical and histopathologic examination to diagnose a caliber‐persistent labial artery (CPLA). We illustrate the use of ultrasonography as a noninvasive diagnostic tool to visualize this enlarged artery of the lip.

Intraoral venous malformation presenting with multiple phleboliths

Venous malformations are the most common of all vascular anomalies. Phleboliths are described as characteristic of such malformations; furthermore, when they are encountered in the major salivary glands, they must be differentiated from salivary calculi. We report a case of an intraoral venous malformation in the left retromolar area with multiple phleboliths.