Distraction Osteogenesis Using Bone Matrix Osteotensors in Ectodermal Dysplasia: A Case Report.

INTRODUCTION: Ectodermal dysplasia patients require complex oral rehabilitation. Bone matrix Osteotensors activate the patient's own stem cells to promote new bone formation through an autogenous growth factor cascade generated by a targeted flapless bone distraction before implant and/or bone graft therapy. MATERIALS AND METHODS: The maxillary and mandibular bone were activated 21 (for type I bone) to 45 days (for type IV bone) before implant and/or bone substitute installation. Purpose-designed Osteotensors initiated massive recruitment of stem cells in the intended bone recipient site, thereby triggering neoangiogenesis and osteogenesis. After new bone formation, root-form implants and Diskimplants were installed. Functional loading was obtained at 48 hours using highly rigid, screw-secured fixed upper and lower full-arch prostheses. RESULTS: At 3 years, all implants appeared clinically and radiologically osseointegrated with an excellent functional and esthetic outcome. CONCLUSION: Flapless distraction osteogenesis using bone matrix Osteotensors several weeks before surgery improved the initial quality and volume of the recipient bone bed. This minimally invasive approach allows future successful immediate implant-supported complete maxillomandibular fixed rehabilitation without preliminary grafting procedures in patients with an unfavorable initial bone anatomy.

The role of radiation therapy in pediatric mucoepidermoid carcinomas of the salivary glands.

OBJECTIVE: To investigate the role of radiation therapy in rare salivary gland pediatric mucoepidermoid carcinoma (MEC). STUDY DESIGN: A French multicenter retrospective study (level of evidence 4) of children/adolescents treated for MEC between 1980 and 2010 was conducted. RESULTS: Median age of the 38 patients was 14 years. Parotid subsite, low-grade, and early primary stage tumors were encountered in 81%, 82%, and 68% of cases, respectively. All except 1 patient were treated by tumoral surgical excision, and 53% by neck dissection (80% of high grades). Postoperative radiation therapy and chemotherapy were performed in 29% and 11% of cases. With a median 62-month follow-up, overall survival and local control rates were 95% and 84%, respectively. There was 1 nodal relapse. Lower grade and early stage tumors had better survival. Postoperative radiation therapy and chemotherapy were associated with similar local rates. Patients with or without prior cancer had similar outcomes. CONCLUSIONS: Pediatric salivary gland MEC carries a good prognosis. Low-intermediate grade, early-stage tumors should be treated with surgery alone. Neck dissection should be performed in high-grade tumors. Radiation therapy should be proposed for high grade and/or advanced primary stage MEC. For high-grade tumors without massive neck involvement, irradiation volumes may be limited to the primary area, given the risk of long-term side effects of radiation therapy in children. Pediatric MEC as second cancers retain a similar prognosis. Long-term follow-up is needed to assess late side effects and second cancers.

Compliance with fluoride custom trays in irradiated head and neck cancer patients.

PURPOSE: The purpose of this study is to assess compliance with fluoride gel custom trays in irradiated head and neck cancer patients. METHODS AND MATERIALS: One hundred fifty-five consecutive patients on remission following radiation therapy of head and neck cancers were assessed retrospectively for dental care practices prior to radiation and prospectively for long-term compliance with custom trays from November 2009 to January 2010. A five-item questionnaire was filled in by patients in the waiting room, and a 15-item questionnaire by the physician in charge during the corresponding follow-up visit. RESULTS: Ten percent of patients were edentulous at inclusion. Among dentate patients, 17% had total extractions. With a mean follow-up of 24 months, 19% of patients used custom trays for over a year. Primary stage, age, and tobacco consumption were correlated with compliance with custom trays. More than half of dentate patients developed carious lesions, and 8% had stage 1-3 osteoradionecrosis of the whole population of edentulous and dentate patients. CONCLUSION: Compliance with custom trays was poor in this series. Specific postirradiation dental care follow-up visits and education have demonstrated their utility in the era of 2D irradiation. We currently advocate an 18-month compliance with custom trays in IMRT patients on the basis of the Parsport trial, after which we assess the quality of salivary recovery before recommending prolonged use or interruption. Data with innovative irradiation techniques are however required.

Fixed rehabilitation of severely atrophic jaws using immediately loaded basal disk implants after in situ bone activation.

Rehabilitation of severely atrophic jaws is facilitated when basal disk implants are used after activation of the future bony implant bed with a purpose-designed instrument (Osteotensor) 45 to 90 days before implant surgery. Fabrication of a highly rigid, screw-secured fixed prosthesis that acts as an external orthopedic fixator permits immediate functional loading. This protocol also represents a second chance for patients who have experienced complete implant loss and/or bone graft failure.

[Juvenile ossifying fibroma: a misgiving tumor of the jaws]. / Une tumeur maxillaire à ne pas méconnaître : le fibrome ossifiant de type juvenile.

Juvenile ossifying fibroma is a rare benign tumour of childhood. It is hardly distinguishable from others fibro-osseous lesions because of their overlapping microscopic features. Juvenile variant of ossifying fibroma may be mistaken for malignancy, particularly osteosarcoma. Radiology is central to their diagnosis because of the very limited nature of the tumour. Microscopically, the lack of cytologic atypia or abnormal mitosis, and the presence of bone maturation or cementum deposits are consistent with an ossifying fibroma. This entity should be kept in mind regarding any bone lesion jaws in children.

Immediate functional loading of an implant-supported fixed prosthesis at the time of ablative surgery and mandibular reconstruction for squamous cell carcinoma.

The authors describe a case of squamous cell carcinoma of the oral cavity managed by ablative surgery, mandibular reconstruction with a fibula free flap, and implant placement during the same session. Immediate functional implant loading, respecting the principles of basal implantology, was performed 48 hours later using a highly rigid, screw-secured fixed prosthesis that served as an external fixator for the implants and grafted bone. Implant loading before external beam radiotherapy improves flap stability, bone consolidation, and quality of life. Functional and esthetic outcomes were evaluated 2 years after radiotherapy was completed.

Primary clear cell meningioma of the orbit mimicking a metastatic carcinoma: usefulness of immunohistochemistry and cytogenetic analysis.

Clear cell meningiomas (CCM) are rare tumors of the nervous system that usually occur in young patients and display high recurrence rates and potentially aggressive behavior. In this report, we describe a primary CCM of the orbit in an 84-year-old man with a previous history of a clear cell carcinoma of the kidney. Histologically, the tumor demonstrated a sheet-like proliferation of clear polygonal cells. Differential diagnosis includes metastasis of clear cell carcinomas. Immunohistochemistry, by showing that tumor cells expressed vimentin, epithelial membrane antigen, and progesterone antigens, and cytogenetic analysis, by identifying a monosomy 22, confirmed the diagnosis of CCM.

[An oral infection not to be underestimated: actinomycosis. A study of 4 cases with extensive bone necrosis]. / Une infection buccale à ne pas sous-estimer: l'actinomycose. Etude de 4 observations avec nécrose osseuse extensive.

We report 4 cases of osteitis with extensive necrosis of the maxillofacial bone due to actinomycosis. Histological study showed soft tissue necrosis with bone involvement, suppuration and granulomatous inflammation. At contact with bone destruction, numerous Gram and PAS positive bacteria with branched filaments, inconsistently associated with granules, were noted. Cultures were negative. Ultrastructural study showed in two cases, some elongated bacteria, variable in size, less to one micron in diameter, associated with ossein destruction. Actinomycetes usually represented in the normal oral flora, may become pathogenic in debilited host. Histologic study is necessary for the diagnosis allowing to confirm the tissue invasion by the bacteria.

L-PRP/L-PRF in esthetic plastic surgery, regenerative medicine of the skin and chronic wounds.

The use of platelet concentrates for topical use is of particular interest for the promotion of skin wound healing. Fibrin-based surgical adjuvants are indeed widely used in plastic surgery since many years in order to improve scar healing and wound closure. However, the addition of platelets and their associated growth factors opened a new range of possibilities, particularly for the treatment of chronic skin ulcers and other applications of regenerative medicine on the covering tissues. In the 4 families of platelet concentrates available, 2 families were particularly used and tested in this clinical field: L-PRP (Leukocyte- and Platelet-rich Plasma) and L-PRF (Leukocyte- and Platelet-Rich Fibrin). These 2 families have in common the presence of significant concentrations of leukocytes, and these cells are important in the local cleaning and immune regulation of the wound healing process. The main difference between them is the fibrin architecture, and this parameter considerably influences the healing potential and the therapeutical protocol associated to each platelet concentrate technology. In this article, we describe the historical evolutions of these techniques from the fibrin glues to the current L-PRP and L-PRF, and discuss the important functions of the platelet growth factors, the leukocyte content and the fibrin architecture in order to optimize the numerous potential applications of these products in regenerative medicine of the skin. Many outstanding perspectives are appearing in this field and require further research.

Osteosarcomas of the mandible: are they different from other tumor sites?

BACKGROUND: Osteosarcomas of the mandible (MOS) affect 1/10 million persons/year, mostly the young adult. Due to lack of specific data, the treatment of MOS is extrapolated from that of extragnathic OS but varies widely between institutions. MATERIALS AND METHODS: We aimed at providing a focused description of MOS histologies and grades through the English literature, at determining the evidence-based role of chemotherapy, of adjuvant radiation therapy and the potential of reconstructive surgery tailored through modern pre-operative multi-modal imaging. RESULTS: The estimated proportion of high grade MOS was 58%. However, low-grade MOS may be underestimated as they are mostly reported as case reports. The intermediate grade was hardly found in the literature. Estimated weighted-mean proportions of chondroblastic and osteoblastic MOS were 37% and 46%, respectively. Multimodal imaging modalities including MRI has a great potential for accurate pre-operative assessment of tumor extensions into bone and soft tissues. Surgery is the mainstay of treatment and margins the most important factor. The role of neoadjuvant chemotherapy in treating occult systemic metastases and in increasing the probability of clear margins is controversial, as well as the histology-dependent response to chemotherapy. The role of adjuvant radiotherapy (mostly proposed for positive margins) and/or adjuvant chemotherapy is still controversial. Crude survival is around 77% and local control around 67%. Local failure is the main cause of death in MOS compared to extragnathic sites.

Dentalmaps: automatic dental delineation for radiotherapy planning in head-and-neck cancer.

PURPOSE: To propose an automatic atlas-based segmentation framework of the dental structures, called Dentalmaps, and to assess its accuracy and relevance to guide dental care in the context of intensity-modulated radiotherapy. METHODS AND MATERIALS: A multi-atlas-based segmentation, less sensitive to artifacts than previously published head-and-neck segmentation methods, was used. The manual segmentations of a 21-patient database were first deformed onto the query using nonlinear registrations with the training images and then fused to estimate the consensus segmentation of the query. RESULTS: The framework was evaluated with a leave-one-out protocol. The maximum doses estimated using manual contours were considered as ground truth and compared with the maximum doses estimated using automatic contours. The dose estimation error was within 2-Gy accuracy in 75% of cases (with a median of 0.9 Gy), whereas it was within 2-Gy accuracy in 30% of cases only with the visual estimation method without any contour, which is the routine practice procedure. CONCLUSIONS: Dose estimates using this framework were more accurate than visual estimates without dental contour. Dentalmaps represents a useful documentation and communication tool between radiation oncologists and dentists in routine practice. Prospective multicenter assessment is underway on patients extrinsic to the database.

Determination of Young's modulus of mandibular bone using inverse analysis.

Development of a numerical model applicable to clinical practice, and in particular oral implantology, requires knowledge of the mechanical properties of mandibular bone. The wide range of mechanical parameters found in the literature prompted us to develop an inverse analysis method that takes into account the exact geometry of each specimen tested, regardless of its shape. The Young's modulus of 3000MPa we determined for mandibular bone using this approach is lower than the values reported in the literature. This difference can be explained by numerous experimental factors, related in particular to the bone specimens used. However, the main reason is that, unlike most previously published papers on the subject, the heterogeneity of bone led us to select a specimen size at the upper end of the scale, close to clinical reality.

In vitro effects of Choukroun's PRF (platelet-rich fibrin) on human gingival fibroblasts, dermal prekeratinocytes, preadipocytes, and maxillofacial osteoblasts in primary cultures.

OBJECTIVES: The objective of this study was to analyze the effects of Choukroun's PRF (platelet-rich fibrin), a leucocyte and platelet concentrate clinically usable as fibrin membrane or clot, on human primary cultures of gingival fibroblasts, dermal prekeratinocytes, preadipocytes, and maxillofacial osteoblasts. STUDY DESIGN: For the proliferation study, these cells were cultivated with or without a PRF membrane originating from the same donor as for the cells. For osteoblasts and fibroblasts, dose-dependent effect was assessed (using 2 membranes). Cell counts and cytotoxicity tests were performed at 3, 7, 14, and 21 days, and even 28 days for osteoblasts. More osteoblast cultures were prepared in differentiation conditions according to 3 modalities (without PRF, with PRF, with PRF the first day and differentiation medium applied only after the first week of culture). Osteoblast differentiation was analyzed using Von Kossa staining and alkaline phosphatase, DNA and total cell proteins dosage. RESULTS: PRF induced a significant and continuous stimulation of proliferation in all cell types. It was dose dependent during all the experiment with osteoblasts, but only on day 14 with fibroblasts. Moreover, PRF induced a strong differentiation in the osteoblasts, whatever the culture conditions. The analysis of osteoblast cultures in differentiation conditions with PRF, using light and scanning electron microscopy, revealed a starting mineralization process in the PRF membrane itself after 14 days. Moreover, PRF leucocytes seemed to proliferate and interact with osteoblasts. CONCLUSIONS: Cultures with PRF are always cocultures with leucocytes. These "chaperone leucocytes" could be the source of differential geographic regulation within the culture and explain the double contradictory effect proliferation/differentiation observed on osteoblasts.