Craniofacial fibrous dysplasia with cystic degeneration - A diagnostic challenge.

Benign fibro-osseous lesions with cystic degenerations have been scarcely reported in craniofacial bones and its unusual characteristics pose a diagnostic challenge. Here, we report a case of craniofacial fibrous dysplasia presenting a large cystic degeneration. A 55-year-old woman had a history of pain, slight asymmetry on the zygomatic region and ocular pressure. Computed tomography revealed on the right side, multiple craniofacial bones showing a ground glass aspect, associated with an extensive hypodense, unilocular, well circumscribed lesion in the maxilla, and smaller lesions in the sphenoid bone. After a surgical procedure performed in another service, there was a complete improvement in symptoms, and after 1 year, the patient remains stable, with no changes. In the literature review, thirty-three reported cases of the same association in the craniofacial region were found. The main symptoms were sudden increase in the lesion and pain, and the indication of intervention in cystic lesions was only indicated in symptomatic cases or functional deficit. The knowledge of the possibility of the association of benign fibro-osseous lesions and cystic degenerations in craniofacial bones is essential to perform a correct diagnosis and treatment for these patients, consequently avoiding unnecessary procedures. Key words:Craniofacial fibrous dysplasia, Fibrous dysplasia, Benign fibro-osseous lesions, Cystic degeneration.

Osteoradionecrosis treatment in head and neck cancer patients: An overview of systematic reviews.

AIMS: Evaluate the existing evidence of osteoradionecrosis (ORN) treatment in adults with head and neck cancer, the methodological quality and the evidence grade within systematic reviews (SRs). METHODS: An extensive systematic literature search of SRs that addressed ORN in head and neck cancer patients was conducted with screening of eligible studies, data extraction, methodological (AMSTAR 2) and evidence quality assessment (GRADE) of the SRs by independent and calibrated authors. RESULTS: A total of six SRs were enrolled. Based primarily on studies from the 1990s, there is critically low- or moderate-quality evidence that hyperbaric oxygen therapy (HBO) improves ORN healing. From 2005 onward, evidence has been discovered in relation to treatment with pentoxifylline and tocopherol (PENTO). The SRs indicate that the management of ORN with PENTO appears to be promising. The greatest rates of healing are seen in mild and moderate stages of ORN. However, the quality of evidence regarding PENTO, surgery and other treatments remains critically low. CONCLUSION: There is no standardized protocol to treat ORN. PENTO appears to be the most promising conservative treatment; however, the current level of evidence regarding PENTO is still critically low. More robust clinical studies are needed to establish the best treatment for ORN.

Secondary primary tumor mimicking osteoradionecrosis.

Nasopharyngeal carcinoma (NPC) is a malignant tumor rarely found in the head and neck, representing about 1% of all malignancies. The main treatment for NPC is radiation therapy, which is often given in combination with chemotherapy. However, such treatment may lead to long-term complications, including second primary tumors (SPTs) and osteoradionecrosis (ORN). Both complications have similar radiological characteristics, which can lead to erroneous diagnoses. This paper describes a case of a second primary tumor in a patient after 20 years of radiotherapy in the area where a previous extraction was performed, mimicking an osteoradionecrosis process.

Pro-angiogenic potential of a functionalized hydrogel scaffold as a secretome delivery platform: An innovative strategy for cell homing-based dental pulp tissue engineering.

Angiogenesis is a key process that provides a suitable environment for successful tissue engineering and is even more crucial in regenerative endodontic procedures, since the root canal anatomy limits the development of a vascular network supply. Thus, sustainable and accelerated vascularization of tissue-engineered dental pulp constructs remains a major challenge in cell homing approaches. This study aimed to functionalize a chitosan hydrogel scaffold (CS) as a platform loaded with secretomes of stem cells from human exfoliated deciduous teeth (SHEDs) and evaluate its bioactive function and pro-angiogenic properties. Initially, the CS was loaded with SHED secretomes (CS-S), and the release kinetics of several trophic factors were assessed. Proliferation and chemotaxis assays were performed to analyze the effect of functionalized scaffold on stem cells from apical papilla (SCAPs) and the angiogenic potential was analyzed through the Matrigel tube formation assay with co-cultured of human umbilical vein endothelial cells and SCAPs. SHEDs and SCAPs expressed typical levels of mesenchymal stem cell surface markers. CS-S was able to release the trophic factors in a sustained manner, but each factor has its own release kinetics. The CS-S group showed a significantly higher proliferation rate, accelerated the chemotaxis, and higher capacity to form vascular-like structures. CS-S provided a sustained and controlled release of trophic factors, which, in turn, improved proliferation, chemotaxis and all angiogenesis parameters in the co-culture. Thus, the functionalization of chitosan scaffolds loaded with secretomes is a promising platform for cell homing-based tissue engineering.

Secondary primary tumor mimicking osteoradionecrosis

ABSTRACT Nasopharyngeal carcinoma (NPC) is a malignant tumor rarely found in the head and neck, representing about 1% of all malignancies. The main treatment for NPC is radiation therapy, which is often given in combination with chemotherapy. However, such treatment may lead to long‐term complications, including second primary tumors (SPTs) and osteoradionecrosis (ORN). Both complications have similar radiological characteristics, which can lead to erroneous diagnoses. This paper describes a case of a second primary tumor in a patient after 20 years of radiotherapy in the area where a previous extraction was performed, mimicking an osteoradionecrosis process.

Dental tissue-derived stem cell sheet biotechnology for periodontal tissue regeneration: A systematic review.

OBJECTIVE: This study aimed to conduct a systematic review of the use of a cell sheet formed by mesenchymal stem cells derived from dental tissues (ddMSCs) for periodontal tissue regeneration in animal models in comparison with any other type of regenerative treatment. DESIGN: PubMed and Scopus databases were searched for relevant studies up to December 2020. The review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. RESULTS: Of the 1542 potentially relevant articles initially identified, 33 fulfilled the eligibility criteria and were considered for this review. Even with a wide variety of selected study methods, the periodontal tissue was always regenerated; this indicates the potential for the use of these cell sheets in the future of periodontics. However, this regeneration process is not always complete. CONCLUSION: Despite the implantation, ddMSCs sheets have a great potential to be used in the regeneration of periodontal tissue. More in vivo studies should be conducted using standardized techniques for cell sheet implantation to obtain more robust evidence of the relevance of using this modality of cell therapy for periodontal tissue regeneration.

Physical and Biological Properties of a Chitosan Hydrogel Scaffold Associated to Photobiomodulation Therapy for Dental Pulp Regeneration: An In Vitro and In Vivo Study.

BACKGROUND: The regeneration of dental pulp, especially in cases of pulp death of immature teeth, is the goal of the regenerative endodontic procedures (REPs) that are based on tissue engineering principles, consisting of stem cells, growth factors, and scaffolds. Photobiomodulation therapy (PBMT) showed to improve dental pulp regeneration through cell homing approaches in preclinical studies and has been proposed as the fourth element of tissue engineering. However, when a blood clot was used as a scaffold in one of these previous studies, only 30% of success was achieved. The authors pointed out the instability of the blood clot as the regeneration shortcoming. Then, to circumvent this problem, a new scaffold was developed to be applied with the blood clot. The hypothesis of the present study was that an experimental injectable chitosan hydrogel would facilitate the three-dimensional spatial organization of endogenous stem cells in dental pulp regeneration with no interference on the positive influence of PBMT. METHODS: For the in vitro analysis, stem cells from the apical papilla (SCAPs) were characterized by flow cytometry and applied in the chitosan scaffold for evaluating adhesion, migration, and proliferation. For the in vivo analysis, the chitosan scaffold was applied in a rodent orthotopic dental pulp regeneration model under the influence of PBMT (660 nm; power output of 20 mW, beam area of 0.028 cm2, and energy density of 5 J/cm2). RESULTS: The scaffold tested in this study allowed significantly higher viability, proliferation, and migration of SCAPs in vitro when PBMT was applied, especially with the energy density of 5 J/cm2. These results were in consonance to those of the in vivo data, where pulp-like tissue formation was observed inside the root canal. CONCLUSION: Chitosan hydrogel when applied with a blood clot and PBMT could in the future improve previous results of dental pulp regeneration through cell homing approaches.

Angiogenic properties of dental pulp stem cells conditioned medium on endothelial cells in vitro and in rodent orthotopic dental pulp regeneration.

OBJECTIVES: To evaluate the effect of SHED-CM on the proliferation, differentiation, migration ability, cell death, gene expression and production of VEGF of HUVEC in vitro and in a rodent orthotopic dental pulp regeneration. METHODS: Three culture media [M199, DMEM/Ham's F12 and DMEM/Ham's F12 conditioned by SHEDs] were used as experimental groups. SHED-CM was prepared maintaining confluent cells in culture without serum for 3 days. The proliferation and cell death marker of HUVECs were assessed using flow cytometry. The capacity of formation of vascular-like structures was analyzed in cells grown over Matrigel® in hypoxic condition. HUVECs migration was followed using the scratch test. VEGF-A expression in HUVECs was assessed using real time RT-qPCR; and VEGF synthesis with ELISA test. SHED-CM was also applied in rodent ortotopic model of dental pulp regeneration in rats. The formed tissue was submitted to histological and immunohistochemical analyses. RESULTS: SHED-CM promoted significantly lower expression of 7AAD in HUVECs; whereas the expression of the Ki67 was similar in all groups. The vascular-like structures were observed in all groups. Migration of SHED-CM group was faster than DMEM/Ham's F12. SHED-CM induced similar expression of VEGF-A than M199, and higher than DMEM/Ham's F12. SHED-CM induced significantly higher VEGF synthesis than other media. SHED-CM induced formation of a vascularized connective tissue inside the root canal. CONCLUSION: The study showed that SHEDs release angiogenic and cytoprotective factors, which are of great importance for tissue engineering. CLINICAL SIGNIFICANCE: SHED-CM could be an option to the use of stem cells in tissue engineering.