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Biomedical subjects

A Piattelli

Publications and source records attributed to A Piattelli.

At least 73 records · Page 4Linked to original sources
PubMed2000

Liposarcoma involving the periodontal tissues. A case report.

Liposarcomas constitute 15 to 20% of all soft tissue tumors. They are extremely rare in the head and neck and in the oral cavity. A 30-year-old patient was seen for a soft, painless mass in the right palate. Through panoramic radiography it was possible to observe a radiolucent area with sharp margins in the right upper quadrant. The lesion, after an incisional biopsy, was diagnosed as a "myxoid liposarcoma." The patient underwent a wide excision of the lesion with bone laminectomy and he is well at a 4-year follow-up. The differential diagnosis included salivary gland tumors and palatal abscess.

Abscess↗
PubMed2000

Periosteal osteosarcoma of the jaws: report of 2 cases.

Osteosarcoma (OS) occurs most often in the long bones. OS of the jaws has clinical and biologic aspects different from those of the long bones. They tend to occur at an older mean age, pain and swelling are more typical, and prognosis is more favorable. Nearly all OS shows a very prominent central intramedullary bone component. Only rarely are juxtacortical (peripheral) OS located in the jaws. There are 2 main types of juxtacortical OS, periosteal and parosteal. We present 2 cases of OS of the jaws where the clinical, radiologic, and histologic findings pointed to a diagnosis of periosteal OS. Both patients presented, in fact, with lesions located superficially on the bone surface with no marrow involvement. Both tumors were characterized by the presence of a moderately differentiated chondroblastic tumor with foci of osteoid and bone formation. Periosteal OS should be differentiated microscopically from periosteal chondrosarcoma, intramedullary OS with periosteal extension, high-grade surface OS, and parosteal OS. The clinical differential diagnosis was done, in these cases, for epulis, gingival tumors, peripheral odontogenic fibroma, peripheral ossifying fibroma, pyogenic granuloma, peripheral giant cell granuloma, and mesenchymal malignant tumors.

Adolescent↗
PubMed2000

Hepatocellular carcinoma metastatic to the oral mucosa: report of a case with multiple gingival localizations.

BACKGROUND: Metastases to the oral mucosa are rare, representing less than 1% of the tumors at this site. Most of these metastatic neoplasms originate in the lungs, kidneys, and liver. METHODS: The clinicopathologic features of an occult hepatocellular carcinoma, metastatic to the oral mucosa, are reported. The patient, a 70-year-old male, complained of 3 distinct polypoid, reddish lesions of the antero-inferior alveolar crest and both the right and left postero-superior attached gingiva, without bone involvement. The lesions were excised, with the clinical diagnosis of multiple vascular tumors, formalin-fixed, paraffin-embedded, cut and stained with hematoxylin and eosin. Consecutive sections were immunostained for alpha-1-antichymotrypsin, CEA, cytokeratins, EMA, hepatocyte antigen, PSA, S-100 protein, and thyroglobulin, using the alkaline phosphatase/anti-alkaline phosphatase technique. RESULTS: The morphologic features of the lesions were consistent with the diagnosis of carcinoma with trabecular and glandular patterns and bile secretion; furthermore, immunohistochemical reactivity for alpha-1-antichymotrypsin, cytokeratins, CEA, EMA, and hepatocyte antigen was demonstrated and the hepatic origin of the tumor was postulated. Ultrasonography demonstrated a liver mass, which was biopsied and treated by chemoembolization. While no further complications occurred in the oral mucosa, the patient died 8 months after the diagnosis for widespread diffusion of the tumor to the lungs and brain. CONCLUSIONS: This case emphasizes the need to include metastatic tumors in the differential diagnosis of atypical neoplasms of the oral mucosa and to evaluate the opportunity of surgical treatment in order to preserve the functions of the mouth, even if the prognosis of the primary tumors remains unfavorable.

Aged↗
PubMed2000

Peripheral ameloblastoma: a report of 2 cases.

Peripheral ameloblastoma (PA) is a rare odontogenic tumor most common in elderly patients. They are usually solitary; red or pink granular, nodular, or papillary lesions; up to 1.5 cm in diameter; and either not resorb bone or produce a shallow erosion. Peripheral ameloblastoma should be included in the differential diagnosis of soft tissue lumps on the gingiva or edentulous alveolus.

Ameloblastoma↗
PubMed2000

Peripheral clear cell calcifying epithelial odontogenic tumor. Report of a case.

Calcifying epithelial odontogenic tumor (CEOT) is an uncommon, locally aggressive odontogenic tumor representing less than 1% of all odontogenic tumors. Clear cells have been described in CEOT, ameloblastomas, calcifying odontogenic cysts, lateral periodontal, and gingival cysts. It is not yet clear if the clear cell variants of the odontogenic tumors have a different biologic behavior, even if it seems that these tumors are more aggressive with an higher recurrence rate. The authors present a case of a peripheral clear cell CEOT (CCCEOT). It is a rare lesion with only 9 cases reported in the literature. The lesion was removed by excision and no recurrence was found after a 4-year follow-up.

Adult↗
PubMed1999

A microscopical evaluation of 24 retrieved failed hollow implants.

Twenty-four hollow ITI implants (four screws, and 20 cylinders) were retrieved because of failure, and evaluated in our laboratory, in a eight-year period (1989-1996), to see if a common cause could be observed in this implant design. No selection of these implants was carried out, and they represented the total number of implants of this type received in the above-mentioned time frame. The implants had been inserted by several different clinicians and were received from four universities and a private practice. The implants had been removed for mobility, pain, and presence of a vertical bone loss. About two-thirds of the implants were unstable in the jaw at the time of retrieval. Twenty implants had been used as single implants restoration and four in bridge reconstructions. Most of our specimens showed that the inflammatory process had reached the hollow portion of the implants. The following microscopical features were present in almost all our specimens: calculus and plaque on the coronal portion of the implant surface, presence of proliferating epithelium and of bone sequestra, and presence of bone apically to the inflammatory process. Perhaps, when the inflammatory process reaches the implant hollow portion, the infection runs a more rapid course due to the scarce vascularity of the bone inside this part.

Dental Implants↗
PubMed1999

bcl-2 expression and apoptotic bodies in 13-cis-retinoic acid (isotretinoin)-topically treated oral leukoplakia: a pilot study.

In a double-blind study 10 patients with oral leukoplakia were treated daily (three topical applications) with 0.1% isotretinoin gel or a placebo for 4 months. Nine patients completed the treatment, while one patient was lost to follow-up. Subsequently, the patients who had received the placebo used the active medication for an additional 4 months. All patients treated with the active medication showed a significant improvement of the oral lesions while, in the patients receiving only the placebo, the size of the lesions remained the same. Also the group of patients who received the active medication after the placebo showed an improvement in the size and clinical appearance of the lesions. A complete response was defined as the complete disappearance of the lesion as assessed by visual inspection, while a partial response was defined as a 50% or more reduction in the size of the lesions. In total we had a complete response and eight partial responses. No side-effects from the use of the gel were ever observed. The percentage of bcl-2-positive cells was evaluated in the basal layer from a minimum of 1000 cells in each case and the bcl-2 immunostaining was scored using three groups: - (< or = 10% cells); + (< or = 50% cells); +2 (> or = 50% cells). The presence of apoptotic bodies was evaluated in a random fashion in the parabasal layer in 20 HPF. Immunohistochemical analysis for bcl-2 protein showed that before treatment a weak positivity of the basal layers, with a focal positivity of some parabasal cells, was present: five out of nine specimens were positive. Only a few apoptotic bodies were observed. After treatment in almost all specimens it was possible to observe a complete bcl-2 negativity with a positivity in only one specimen out of nine. An increase in apoptotic bodies was observed. Statistical analysis showed that the difference between the bcl-2 positivity in the two groups was not statistically significant (P = 0.134) while, on the contrary, the difference in the count of the apoptotic bodies between the same two groups was statistically significant (P = 0.0193). In conclusion, the data obtained from this pilot study show that good results can be obtained with the topical use of 13-cis-retinoic acid.

Administration, Topical↗
PubMed1999

Guided bone regeneration using demineralized laminar bone sheets versus GTAM membranes in the treatment of implant-associated defects. A clinical and histological study.

This study was designed to compare the regenerative potential at dehisced implant sites of the resorbable demineralized laminar bone sheets and non resorbable GTAM membranes. Twenty-six standard screw-type fixtures showing buccal dehiscences in 7 patients were treated using the GBR principles and received either laminar bone sheets (experimental) or GTAM (control) membranes. Twelve experimental and 10 control sites were available for evaluation at second stage surgery carried out 8 months following implant placement. Height and maximum width of the dehiscence defects were measured at the time of implant insertion and at second-stage procedure. Mean percentage of defect fill was 75.17% in the experimental dehiscences versus 86.70% in the control defects. A statistically significant difference in the percentage of defect fill could not be evidenced between the two treatment modalities. Complete fill was observed in 25% of the experimental versus 70% of the control sites. A significant difference was found in the median Density Index with the GTAM group showing a consistency similar to bone in a larger number of sites. Histologically, material with the same staining features of bone was evidenced inside the GTAM membranes in 3 cases while newly-formed bone was present in all instances under the control GTAM barriers. In the laminar bone-treated sites, the membrane maintained its integrity in almost all cases. Newly formed bone was found underlying the membrane in cases with a Density Index of 5 with no evidence of bony tissue adhering to the laminar sheets.

Absorbable Implants↗
PubMed1999

Electrically charged GTAM membranes stimulate osteogenesis in rabbit calvarial defects.

Bone neogenesis was studied in membrane-protected defects in a rabbit calvaria defect model using neutral, negatively, and positively charged titanium-reinforced GTAM membranes. Two standardized circular 8 mm wide and 1 mm deep defects were created in the calvaria of 36 rabbits leaving the inner cortex intact. The defects were subsequently covered with dome-shaped Ti-reinforced GTAM membranes stabilized with a titanium screw allowing the edges of the membranes to be closely approximated to the bone surface. The animals were divided into 6 groups of 6 rabbits each and were sacrificed at 5 days (Group 1), 10 days (Group 2), 3 weeks (Group 3), 5 weeks (Group 4), 10 weeks (Group 5), and 20 weeks (Group 6). The distribution of the 72 membranes according to charge yielded 4 positively charged, 4 negatively charged and 4 neutral domes in each group. Histomorphometric analysis showed a more rapid and increased bone neogenesis with the negatively charged domes. A mean total area of 27.95% of newly-formed bone was observed in the negatively charged membrane sites at 10 days while negligible bone formation occurred with the neutral and positively charged domes at the same evaluation interval. Over time, negatively charged membranes supported more new-bone formation than neutral membranes while positively charged membranes showed the least new bone. This work demonstrates that negative electrical stimulation accelerates and maintains bone neogenesis. These results also suggest the potential applications of negatively charged GTAM membranes in clinical settings.

Animals↗
PubMed1999

Gingival metastasis from a prostate adenocarcinoma: report of a case.

Prostate cancer is the cause of 10% of cancer-related deaths in males in the United States. Metastases are found late in the course of the disease. Metastatic tumors of the oral cavity are rare, representing about 1% of oral tumors and affect jaws much more frequently than soft tissues. Metastatic prostate cancer tends to involve the bones of the axial skeleton. In a recent review, 22 cases of metastases to the jawbones from prostate cancer were found in 390 cases. On the other hand, only 1 case of a metastasis to the oral soft tissues was reported. The authors describe the second case of oral soft tissue metastasis from a prostate cancer. The metastatic lesion was located in the gingiva. Clinicians should be aware of oral soft tissue metastases since they can be the first sign of a not yet diagnosed malignant tumor and they can be very easily confused with several different benign lesions.

Adenocarcinoma↗
PubMed1999

Myoepithelioma of the gingiva. Report of a case.

Myoepithelioma is a rare form of salivary gland tumor composed entirely of myoepithelial cells. It represents about 1 to 1.5% of all salivary gland tumors and is most frequently located in the parotid. The authors present a case of myoepithelioma of the gingiva. The tumor presented a focal strong positivity for cytokeratins, a diffuse positivity for S-100 protein, and a rare focal positivity for actin. No duct formation was observed. Myoepithelioma must be differentiated from several benign and malignant epithelial and mesenchymal tumors.

Female↗
PubMed1998

Early tissue reactions to polylactic acid resorbable membranes: a histological and histochemical study in rabbit.

The aim of this study, in rabbit tibia, was an evaluation of the early reactions of the tissues to the insertion of polylactic membranes, used in connection with titanium implants. The specimens were retrieved after 1-4 weeks, and a histological analysis was performed. It was possible to see that, in the early implantation phases, no degradation of the macrostructure of the membrane was present. On the outer portion of the membrane many multinucleated giant cells (MGC) were present and membrane fragments were present inside the cytoplasm of these cells. These cells could explain the inflammatory processes reported, in some reports, with the use of materials made by polylactic and polyglycolic acid. We did not observe detrimental effects in the bone tissue around the membrane, and the membrane appeared to have a mechanical stability for the time necessary for bone regeneration.

Animals↗
PubMed1998

Benign cementoblastoma associated with an unerupted third molar.

Benign cementoblastoma is a rare lesion representing less than 1% of all odontogenic tumours. It usually affects young people and is located in the posterior jaw. In almost all cases the tumour tends to be associated with an erupted permanent tooth, most often the first molar: only rarely has an association with an impacted or deciduous tooth been reported. The authors present a case of a cementoblastoma involving an impacted third molar.

Adult↗
PubMed1998

Differentiation of odontogenic keratocysts from other odontogenic cysts by the expression of bcl-2 immunoreactivity.

Odontogenic keratocysts (OKC) present an aggressive course with a marked tendency to recurrence. The epithelium of OKC is thought to have an intrinsic growth potential and has been shown to present a higher rate of proliferation as compared to other types of cyst. bcl-2 has a role in the extension of cell survival. The objective of the present study was to evaluate the bcl-2 protein expression in different odontogenic cysts. A total of 19 dentigerous cysts (DC), 20 radicular cysts (RC) and 14 OKC were used in the present study. DC and RC showed an almost complete negativity for bcl-2. OKC, on the other hand, presented in all cases a strong positivity in the cells of the basal layer, with, in most cases, more than 50% of the cells positive. This bcl-2 positivity of the basal layer of OKC could point to an abnormal control of the cell cycle. The bcl-2 protein overexpression could then produce an increase in the survival of the epithelial cells, and this increased lifespan could, in turn, lead to the peculiar aggressive growth pattern of OKC. Moreover the bcl-2 staining can be useful to differentiate OKC from other types of odontogenic cysts.

Cell Transformation, Neoplastic↗
PubMed1998

Expression of proliferating cell nuclear antigen in ameloblastomas and odontogenic cysts.

The identification of the proliferative activity in tumours may be useful to predict the biological behaviour of different lesions. Proliferating cell nuclear antigen (PCNA) has been used for the evaluation of the proliferative ability of many lesions. In this study 22 ameloblastomas (4 follicular, 5 plexiform, 4 acanthomatous, 5 unicystic, 4 recurrent), 12 odontogenic keratocysts (OKC), 8 dentigerous cysts (DC), and 12 radicular cysts (RC) were analysed. PCNA+ cells were present in all cyst types but the OKC contained the highest number of PCNA+ cells. In OKC the location of PCNA+ cells was mainly suprabasal. In ameloblastoma PCNA+ cells were located mainly in the peripheral portion of the tumour islands. Statistical analysis showed that ameloblastoma had higher PCNA+ cell counts than OKC (P < 0.0001); OKC had higher values than DC and RC (P < 0.0001). Recurrent ameloblastoma presented higher PCNA+ cell counts than other types of ameloblastoma, while unicystic ameloblastoma showed lower values than acanthomatous, plexiform and follicular ameloblastomas (in this latter case the difference was not statistically significant). These data could help to explain the different biological behaviour of these lesions.

Ameloblastoma↗
PubMed1998

Paraneoplastic pemphigus: a report of two cases.

Paraneoplastic pemphigus (PNP) seems to be a separate autoimmune mucocutaneous disease. Forty-five cases have been reported. Almost all cases of PNP are associated with a tumour, mostly with haematologic malignancies. Pemphigus-like autoantibodies are detected by direct and by indirect immunofluorescence studies. These autoantibodies appear to be directed against a novel set of autoantigens. Two cases are presented with clinical, histologic, immunofluorescence and immunoprecipitation findings characteristic of PNP.

Female↗