Double-application of platelet-rich plasma on bone healing in rabbits.

OBJECTIVE: Platelet-rich plasma (PRP) is considered to enhance bone formation especially at early stages of wound healing, depending on the limited and short life-span of platelets and growth factors. The aim of this study was to evaluate efficacy of double-application of PRP (DA-PRP) on bone healing in a rabbit calvarial defect model. STUDY DESIGN: Twenty-eight rabbits, each had two surgically prepared calvarial bone defects (10mm diameter), were included in this study and randomly divided into six groups. Defects (n=56) were treated with single-application of PRP (SA-PRP)(n=10), SA-PRP and beta-tricalciumphosphate (SA-PRP+TCP)(n=10), DA-PRP (n=8), DA-PRP and beta-tricalciumphosphate (DA-PRP+TCP)(n=8), beta-tricalciumphosphate (TCP)(n=10) or left empty (Control)(n=10). Animals were sacrificed at 30 days postoperatively. RESULTS: The new bone (NB%) and defect fill (DF%) percentages were calculated from histological slides by image-analyzer software and statistically analysed. All test groups showed higher NB% than control, but differences among all groups were insignificant. The TCP treated groups had significantly higher DF% than groups treated without TCP, however the DF% differences between control, SA-PRP and DA-PRP or TCP, SA-PRP+TCP or DA-PRP+TCP were insignificant. CONCLUSION: Although new bone formation was histomorphologically remarkable at double-application PRP groups, statistical analyses of the histomorphometric data revealed no significant difference.

Histopathologic study of rat connective tissue responses to maxillofacial silicone elastomers.

The aim of this histopathologic study was to assess and compare the subcutaneous connective tissue reaction to three different maxillofacial silicone elastomers (Cosmesil, Multisil, Episil). The test materials were directly inserted subcutaneously into the dorsal subcutaneous tissue of Wistar albino rats. Histopathological examinations were done at 7, 30, and 90 days after the implantation procedure. The presence of inflammation, presence of inflammatory giant cells, and the thickness of fibrous connective tissue adjacent to each inserted sample were recorded. Data was evaluated by analysis of variance, Wilcoxon signed ranks test and Kruskal Wallis test. Cosmesil, Multisil and Episil silicone elastomers at 7 days elicited a severe inflammatory reaction. However, these reactions decreased by the 30 and 90 days. All silicone elastomers elicited a moderate inflammatory reaction at 30 and 90 days. There were no significant differences in tissue reaction between the materials at 7, 30, and 90 days (P > 0.05). All the maxillofacial silicone elastomers evaluated can not be assigned a favorable biocompatibility level based on this study's histologic findings.

Childhood craniofacial Burkitt's lymphoma presenting as maxillary swelling: report of a case and review of literature.

Burkitt's lymphoma (BL) is an undifferentiated malignant lymphoma comprising of uniformly primitive lymphoreticular cells. The tumor was seen originally in patients in Africa. African type BL usually occurs in the jaws of young children. In American cases, abdominal involvement predominates. Strong evidence implicats Epstein-Barr virus in the development of BL. BL is found most commonly in childhood, with a peak incidence in African cases at 5 to 8 years old and in American cases at 10 to 12 years old. The disease shows a preference for males in a 2:1 to 4:1 ratio. BL is the most rapidly growing neoplasm requiring immediate diagnosis and treatment; however, it is extremely sensitive to chemotherapy. In this report, a case of BL that was initially misdiagnosed as an acute dental abscess is presented and the role of the dentist in the diagnosis and treatment of these patients is emphasized.

An unusual presentation of ossifying fibromyxoid tumor of the mandible: a case report.

A 13-year-old boy who complained rapid swelling on the left side of mandible is presented. Histopathological examination revealed ossifying fibromyxoid tumor (OFMT). OFMT is a rare soft-tissue neoplasm that occurs usually in the subcutaneous tissue of the extremties. Head and neck involvement is relatively rare. In this case, we present the diagnosis, surgical treatment and long-term follow-up of an OFMT due to its unusual site of occurrence. The precise clinical behavior of atypical and malignant types of OFMTs is still unclear. Thus, histopathology report is important, leading surgeon to decide how often and how long to follow-up patient with OFMT.

Dentin dysplasia type I: report of atypical cases in the permanent and mixed dentitions.

Dentin dysplasia type I is a rare hereditary disturbance of dentin formation characterized clinically by nearly normal appearing crowns and severe hypermobility of teeth. Radiographic analysis shows obliteration of all pulp chambers, short, blunted, and malformed roots, and periapical radiolucencies of noncarious teeth. This paper presents 2 cases demonstrating both classic and atypical features of type I dentin dysplasia in the mixed and permanent dentitions. The clinical, radiographic, and histopathologic\findings of this condition and treatment are described.

A review of paediatric oral biopsies in Turkey.

OBJECTIVES: To determine the site and prevalence of oral lesions and the age and gender of a paediatric population in Turkey. DESIGN: A review of the archives of pathology departments. SETTINGS: Six pathology departments in Ankara, Turkey. METHODS: This study presents the findings of 472 oral biopsies from patients, up to 15 years of age, received over an eight-year period. The cases represent 5.5 per cent of the total number of reports examined (8,532). The data were revised and compiled for diagnosis site, age and sex. The patients were divided into three age groups according to dentition periods: primary dentition 0-5 years (Group 1), mixed dentition 6-12 years (Group 2), and permanent dentition 13-15 years (Group 3). The lesions were categorised into five major groups as: 1) reactive and inflammatory lesions 2) neoplastic lesions 3) cystic lesions 4) non-neoplastic lesions 5) dermatologic lesions. RESULTS: Inflammatory and reactive lesions formed the largest group of diagnoses (49 per cent) followed by neoplasms (36 per cent) and cystic lesions (12 per cent). Approximately 60 per cent of the biopsies were from the second group patients with an almost equal distribution among sexes. The predominant site of the biopsies was gingiva (28 per cent) followed by lips (19.2 per cent). CONCLUSION: The majority (49 per cent) of the lesions were in the category of reactive and inflammatory lesions with most occurring in the second age group (6-12 years) that represents mixed dentition. The results of the study suggest that the difficulties in maintaining oral hygiene or the presence of trauma may be the primary factor in mucosal lesions occurring in the mixed dentition period.

The expression of p53, p16 proteins and prevalence of apoptosis in oral squamous cell carcinoma. Correlation with mode of invasion grading system.

OBJECTIVE: Inactivation of p53 and p16 tumor suppressor genes, and apoptosis which is crucial in carcinogenesis have commonly been studied in oral squamous cell carcinoma (OSCC). However, their prognostic value has not yet been clearly established. METHODS: This study was conducted in the Department of Oral Pathology, Faculty of Dentistry, Gazi University, Ankara, Turkey during the period 2002 to 2003 on formalin-fixed paraffin embedded tissue specimens of 12 lip and 18 intraoral primary squamous cell carcinoma cases. The expression of p53 and p16 proteins were studied by immunohistochemistry, and the apoptosis by TdT-mediated dUTP-biotin nick end-labeling (TUNEL) methods. The possible prognostic value of p53, p16 expression and apoptotic index (AI) value in OSCC were examined on the basis of their correlation with mode of invasion (MI) grading system. RESULTS: Seven lip (58%) and 9 intraoral cancer (50%) cases showed p53 positivity; where 5 lip (42%) and 15 intraoral cancer (83%) cases showed loss of p16 protein. P53 positive cases increased parallel to MI grade where the AI value decreased. There was not any correlation either between p16 expression and MI grade or AI value. The mean AI value was found as 1,884. Apoptotic index values were higher in invasive site of tumors, and it was statistically significant in MI grade 2 OSCC cases. Apoptotic index value of both central and invasive sites were lowest in MI grade 4 cases. CONCLUSION: The present findings revealed that p53 mutations alone, may play a role in pathogenesis of lip cancers but not in intra OSCC. P16 may have a greater role in the development of intra OSCC. P53 positivity and low AI value may be a predictor of poor prognosis in OSCC.

The treatment of lymphangioma in the buccal mucosa by radiofrequency ablation: a case report.

Lymphangioma is a benign, hamartomatous tumor of the lymphatic system. It is usually found in the head and neck region and is widely regarded as a developmental lesion rather than a true neoplasia. Most lymphangiomas are present at birth (60%), and by the age of 2 years 80% to 90% are present. In the head and neck area, the most common location is the submandibular region, followed by the parotid gland. When lymphangioma occurs in the mouth, the anterior two thirds of the tongue is the most commonly affected region. Various methods have been tried for treatment of lymphangioma including surgery, radiation, laser therapy, and sclerotherapy. Recently, a new and more conservative surgical approach to this lesion using radiofrequency ablation has been described. In this report, a case of lymphangioma in the right buccal mucosa of the mental foramen area that has been treated by radiofrequency ablation is presented.

Effectiveness of scaling and root planing versus modified Widman flap on nitric oxide synthase and arginase activity in patients with chronic periodontitis.

BACKGROUND: Nitric oxide (NO) is synthesized from the conversion of L-arginine to L-citrulline by NO synthase (NOS). Arginase, which is an arginine-depleting enzyme, can compete with NOS for the common substrate L-arginine and thus inhibit NO production. OBJECTIVES: In the present study, we aimed to examine the correlation between the arginase and NOS activity in patients with chronic periodontitis and to compare the effects of scaling and root planing and modified Widman flap procedures on enzyme activity. MATERIAL AND METHODS: The study included 13 patients diagnosed with chronic periodontitis. Using a split-mouth design, the defects showing>or=7 mm of attachment loss were treated either with scaling and root planing or with modified Widman flap. Gingival biopsies from both sites were obtained at baseline and 2 months after periodontal treatment. Immunohistochemical staining was performed for evaluating NOS expression and specific arginase activity was determined spectrophotometrically. RESULTS: Although inflamed periodontal tissues demonstrated a strong inducible NOS (iNOS) expression at baseline, immunostaining decreased after periodontal treatment. iNOS expression intensity and the number of inflammatory cells showing iNOS expression were found to be higher in the scaling and root planing group compared to the modified Widman flap group. The specific activity of arginase was measured as 0.18+/-0.07 IU/mg protein in the modified Widman flap group and 0.25+/-0.11 IU/mg protein in the scaling and root planing group at baseline. After periodontal therapy, the enzyme level was increased to 0.68+/-0.14 IU/mg protein in the modified Widman flap and to 1.10+/-0.23 IU/mg protein in the scaling and root planing group. CONCLUSION: This study was the first report of evaluating the involvement of the arginine-NO pathway in chronic periodontitis and this might be considered to be of value in understanding the periodontal disease mechanisms.