Spontaneous Condyle-Like Development after Total Resection of Mandible Giant Osteochondroma: Case Report and a Follow-Up for Five Years.

Osteochondroma manifests as a benign tumor that occurs as an abnormal bony development. This tumor is commonly asymptomatic and presents an exophytic outgrowth on bone surfaces, near synovial joints, a condition that invariably induces evident facial deformities. Treatment for this type of tumor usually involves a surgical approach promoting a total or partial resection of the affected anatomical area associated to prosthetic reconstruction of the bone area extracted. We present a case report about a giant mandibular condyle osteochondroma in a 37-year-old female patient. Her treatment involved a total condylectomy without immediate condylar reconstruction, which would be performed in a posterior surgical approach. During the patient's follow-up (every 6 months of post operation), a spontaneous and rudimentary condyle-like formation was observed. Because the stomatognathic function and facial harmony were satisfactory, we observed the condyle-like development for 5 years of follow-up. Also, because both the aesthetic aspect and functional evolution of the maxillary bone were considered satisfactory, no complementary reconstruction surgical treatment was required for the giant osteochondroma of the mandibular condyle.

Leukocyte-platelet-rich plasma (L-PRP) induces an abnormal histophenotype in craniofacial bone repair associated with changes in the immunopositivity of the hematopoietic clusters of differentiation, osteoproteins, and TGF-ß1.

BACKGROUND: Leukocyte-platelet-rich plasma (L-PRP) is considered an important source of growth factors, especially Transforming growth factor ß 1 (TGF-ß1), which modulates the proliferation and regulation of mesenchymal cells, and also exerts an influence on the hematopoiesis, osteogenesis, and adipogenesis in bone microenvironment. Thus, the aim of this study was to evaluate the effect of L-PRP on the calvarial bone repair and compare its results on the presence of TGF-ß1, CD34, CD45, bone morphogenetic protein 2 (BMP2), BMPR1B, and Runx2 proteins detected by immunohistochemistry. MATERIAL AND METHODS: Four bone defects were created on the calvaria of 23 rabbits. The defects were treated with autograft, L-PRP alone, and L-PRP mixed with autograft. The animals were euthanized at 2, 4, and 6 weeks post-surgery. RESULTS: Unlike autograft and sham groups, the defects treated with L-PRP demonstrated significant positivity to TGF-ß1, while the BMP2 was scarce. These results coincided with the lower bone matrix deposited and larger medullary area, which were composed of fibrosis, when treated with only L-PRP, or intense adiposity on defects filled with L-PRP mixed with autograft. The fibrosis that occurred was associated with a minor percentage of osteoproteins, intense presence of CD34(+) CD45(-) cells, and significant expression of TGF-ß1 in all time periods analyzed. The adiposity occurred from the major presence of osteoprogenitor BMPR1B (+) Runx2(+) cells simultaneously to BMP2(-) TGF-ß1(+) and CD34(+) CD45(+/-) expressions predominantly on the earlier period. CONCLUSION: From this study, it can be concluded that the L-PRP used alone or mixed to autograft hindered the osteoneogenesis due to suppression of immunoexpression of BMP2, while the immunopositivity of TGF-ß1 was intense. When used alone, the L-PRP induced a fibrotic condition associated with TGF-ß1 presence and lack of osteoproteins, but when L-PRP was mixed to autograft, it induced the presence of the osteolineage cells (BMPR1B (+) Runx2(+) ), but also inhibited the terminal osteoblastic maturation associated with the lack of BMP2 and the presence of TGF-ß1(+) , a fact that contributed to cellular transdifferentiation into fat cells.

Leukocyte-platelet-rich plasma (L-PRP) impairs the osteoconductive capacity of the autograft associated to changes in the immunolocalization of TGF-ß1 and its co-expression with Wnt10b and CD34 cells.

BACKGROUND: This study evaluated the osteoconductive effect of an autograft, in the presence or absence of the L-PRP, using histomorphometric analysis of the bone formed, and we compared the results in the presence of TGF-ß1, Wnt10b and CD34 detected by immunohistochemistry. MATERIALS AND METHODS: Two bone defects were produced in the calvaria of 20 rabbits. The defects were treated with autograft and autograft combined with L-PRP. The animals were euthanized at 15 and 40 days post-surgery. Data were analyzed by Student-Newman-Keuls (p ≤ 0.05) test for histomorphometric and immunohistochemical interpretation. RESULTS: The results revealed that the presence of bone matrix was significantly less in the defects treated with L-PRP. These results coincided with changes of the immunolocalization of the TGF-ß1. In the L-PRP-free groups the TGF-ß1 was restricted to bone matrix while the CD34 was scarce and the Wnt10b occurred in peritrabecular cells. In contrast, in defects that received L-PRP the presence of TGF-ß1 occurred in cells, which occupied whole area of defect. These TGF-ß1+ cells also were co-expressed to Wnt10b and CD34. CONCLUSION: These results suggest that L-PRP induces a cross-reaction between TGF-ß1 and Wnt10b, which stimulates the self-renewal and maintenance of CD34+ stem cells immunophenotype, impairing the osteoconductivity properties of the autograft.

Giant mandibular condyle osteoma.

Osteomas are benign tumors composed of mature compact or cancellous bone. They represent an uncommon lesion that occurs mainly in craniofacial complex bones. In jaws, they can appear on the bone surface as a polypoid or sessile mass, characterizing a peripheral osteoma (PO), or can be a lesion in the medullar space, then it is called central osteoma. In view of the scarcely reported cases about POs, this article presents a case of PO of the maxillofacial area that was surgically resected using hemicoronal approach.

Platelet-rich plasma (PRP) impairs the craniofacial bone repair associated with its elevated TGF-ß levels and modulates the co-expression between collagen III and α-smooth muscle actin.

Transforming growth factor-ß (TGF-ß) is considered the main inducer of both the α-smooth muscle actin (α-SMA) phenotype and collagen synthesis and deposition and plays a significant role in the tissue repair and the development of fibrosis. Since the PRP constitutes an important source of TGF-ß and its efficacy on the craniofacial bone repair remains controversy, the aim of this study was to evaluate the effect of PRP in the presence of levels of TGF-ß on PRP samples, as well as in the presence of collagen III and α-SMA+ cells, while comparing these results by means of a histomorphometric analysis of the bone matrix and fibrous deposition on the bone repair. Four bone defects of 16 mm(2) were created on the calvarium of 21 rabbits. The surgical defects were treated with either particulate autograft, particulate autograft mixed with PRP and PRP alone. Animals were euthanized at 15, 30, and 45 days postoperative. Histomorphometric and immunohistochemical analyses were performed to assess repair time, as well as the expression of collagen III, and α-SMA. The histomorphometric results demonstrated intensive deposition of fibrous tissue while hinder bone deposition occurred in PRP groups. These results coincided with higher values of the TGF-ß on the PRP sample, also larger occurrence of diffuse collagen III deposition and higher presence of α-SMA+ cells spread among the fibrous tissue. Thus, the higher levels of TGF-ß associated with the both expression of collagen III and α-SMA on defect treated with PRP suggest that its biomaterial induce an effect that can be considered similarly to a fibroproliferative disorder.

Platelet-rich plasma diminishes calvarial bone repair associated with alterations in collagen matrix composition and elevated CD34+ cell prevalence.

The interaction between platelets and both type I and III collagens plays an important role in modulating platelet adhesion and aggregation, also contributing to the chemotaxis of CD34+ cells. The interaction with type III collagen can maintain high levels of collagen and alter the biology of bone repair when the PRP is used. The aim of this study was to evaluate the effect of platelet-rich plasma (PRP) and autograft on the presence of type III and type I collagens, the ratio between them, as well as the presence of CD34+ progenitor cells, while comparing these results by means of a histomorphometric analysis of the bone tissue. Four bone defects (8.0mm in diameter and 2.0mm in depth) were produced on the calvarium of 23 rabbits. The surgical defects were treated with either autogenous bone grafts, autogenous bone grafts with PRP and PRP alone. Animals were euthanized at 2, 4 or 6 weeks post-surgery. Histological, histomorphometric and immunohistochemical analyses were performed to assess repair time, as well as the expression of type I and III collagens, and number of progenitor CD34+ cells. Data were analyzed using the ANOVA and Student-Newman-Keuls test (alpha=5%). An enlarged granulation and medullary tissue areas in the PRP groups were observed. The use of PRP in this study hindered bone deposition, also enhanced type III to type I collagen ratio and the chemotaxis of CD34+ progenitor cells, similarly to a thrombogenic effect.

Histologic and histomorphometric analysis of posterior region of the human temporomandibular disc.

OBJECTIVE: The aim of this study was to analyze histologic and histomorphometric features of the articular disc in groups with and without disc displacement. STUDY DESIGN: A sample of 39 temporomandibular joints TMJs (31 case specimens, 8 control specimens) from 28 patients (mean age 31.2 years) were recruited for this study. The patients were considered to be affected and treated surgically with disc repositioning when presenting painful clinical signs of disc displacement after unsuccessful nonsurgical treatment for at least 6 months. Of the control patients, 4 presented condyle fracture which required opening to be reduced for treatment, and 4 displayed active condyle hyperplasia. The posterior region of the disc was removed and sent for histologic and histomorphometric analysis. Histologic (hematoxylin-eosin) and histomorphometric (picro-Sirius red) analyses were performed. Statistically significant differences between the analyzed groups were accessed through the chi-squared test (P