Gummy Smile: Mercado-Rosso Classification System and Dynamic Restructuring with Hyaluronic Acid.

BACKGROUND: Gummy smile (GS) is a nonpathological condition causing esthetic disharmony in which an excessive amount of gingival tissue is exposed when smiling. Nowadays, there is not unanimous agreement regarding both classification and management of GS. This study aimed to present an organized and comprehensive clinical classification of the GS, as well as to discuss a therapeutic approach, with hyaluronic acid dermal fillers. METHODS: This study is presenting the clinical experience of the authors regarding GS. RESULTS: The Mercado-Rosso GS classification has into account aesthetic aspects, etiopathogenetic criteria, and functional aspects of the smile. According to Mercado-Rosso GS-classification-system, GS is divided into 3-types: Type 1, characterized by a lack of support and/or a lack of projection of the upper maxilla; Type 2, due to an imbalance between the strength (excess) and the resistance (defect) of the levator muscles; and Type 3, defined by an excessive strength of the zygomatic muscles, which causes a wide smile and an excessive visualization of the molar teeth. CONCLUSIONS: The Mercado-Rosso GS classification system is a tool that facilitates the diagnostic and therapeutic approach to the gummy smile. RD Dynamic Restructuring® constitutes a comprehensive therapeutic approach that makes reference to both the effect of the HA filler on the muscle movement and the balance between the muscle strength and the resistance of the soft tissue to be folded in different facial structures). LEVEL OF EVIDENCE: Level V.

Allogeneic Bone Marrow Mesenchymal Stem Cell Transplantation in Tooth Extractions Sites Ameliorates the Incidence of Osteonecrotic Jaw-Like Lesions in Zoledronic Acid-Treated Rats.

Medication-related osteonecrosis of the jaw (MRONJ) is defined as the exposed necrotic bone involving the maxillofacial structures in bisphosphonate treated patients, and the pathophysiology of this disease remains unclear. The aim of this study was to assess the effects of the allogeneic transplantation of bone marrow-derived mesenchymal stem cells (BM-MSCs) in a model of Wistar mice with induced MRONJ disease. BM-MSCs from five male Wistar rats were characterized and cultured on ß-tricalcium phosphate (ß-TCP) granules. Thirty female Wistar rats were injected intraperitoneally with zoledronic acid and afterwards upper jaw molars were extracted. The animals were randomized to receive: Group 1: 1 × 106 BM-MSCs/ß-TCP construct in the alveolar socket; and Group 2: Saline solution/ß-TCP construct. A clinical and histological analysis was performed. Nested polymerase chain reaction (PCR) was assessed to verify the presence of transplanted male rat cells in the female recipient jaws. Clinical and histological findings evidenced that none of the animals in Group 1 exhibited uncovered sockets or bone exposure associated to MRONJ, whereas we detected 33% of MRONJ cases in Group 2. In addition, male rat cells were detected in the maxillae site four weeks after transplantation in the BM-MSCs-group. Allogeneic BM-MSCs in extractions sites ameliorates MRONJ incidence in zoledronic acid-treated rats compared to non-MSC treatments.

Preclinical Studies of the Biosafety and Efficacy of Human Bone Marrow Mesenchymal Stem Cells Pre-Seeded into ß-TCP Scaffolds after Transplantation.

Background: Cell-Based Therapies (CBT) constitute a valid procedure for increasing the quantity and quality of bone in areas with an inadequate bone volume. However, safety and efficacy should be investigated prior to clinical application. The objective of this study was to evaluate the biodistribution, safety and osteogenic capacity of bone marrow-derived human mesenchymal stem cells (hBMMSCs) pre-seeded into ß-tricalcium phosphate (TCP) and implanted into NOD/SCID mice at subcutaneous and intramuscular sites. Methods: hBMMSCs were isolated, characterized and then cultured in vitro on a porous ß-TCP scaffold. Cell viability and attachment were analyzed and then hBMMSCs seeded constructs were surgically placed at subcutaneous and intramuscular dorsal sites into NOD/SCID mice. Acute and subchronic toxicity, cell biodistribution and efficacy were investigated. Results: There were no deaths or adverse events in treated mice during the 48-hour observation period, and no toxic response was observed in mice. In the 12-week subchronic toxicity study, no mortalities, abnormal behavioral symptoms or clinical signs were observed in the saline control mice or the hBMMSCs/ß-TCP groups. Finally, our results showed the bone-forming capacity of hBMMSCs/ß-TCP since immunohistochemical expression of human osteocalcin was detected from week 7. Conclusions: These results show that transplantation of hBMMSCs/ß-TCP in NOD/SCID mice are safe and effective, and might be applied to human bone diseases in future clinical trials.

Cell therapy in bisphosphonate-related osteonecrosis of the jaw.

OBJECTIVE: Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a clinical condition found in patients who have received intravenous or oral bisphosphonate therapy for various diseases related to bone. This report describes a novel treatment of BRONJ using autologous bone marrow stem cells, platelet-rich plasma, beta tricalcium phosphate, and demineralized bone matrix. STUDY DESIGN: We report a 71-year-old woman with history of multiple myeloma treated with intravenous zoledronic acid during 4 years. After a tooth extraction, the patient presented with a painful BRONJ lesion with no healing wound and cortical bone exposure. The patient was surgically managed with a standardized protocol of autologous stem cell therapy combining bone marrow harvest, cell concentration procedures, and intraoral surgery. RESULTS: CT scan performed 6 months later showed improvement of bone and concentric ossification. Cellular therapy might be considered a new strategy to heal BRONJ lesions.