Regeneration of a Compromized Masticatory Unit in a Large Mandibular Defect Caused by a Huge Solitary Bone Cyst: A Case Report and Review of the Regenerative Literature

Taurine ameliorates radiation-induced oxidative stress in bone marrow mesenchymal stromal cells and promotes osteogenesis

Osteoradionecrosis of the jaw (ORNJ) is a severe complication following head and neck radiotherapy that significantly impacts the quality of life of patients. Currently, there is a lack of comprehensive understanding of the microenvironmental factors involved in ORNJ. In this study, we reveal the activation of taurine metabolism in irradiated mandibular stromal cells using scRNA-Seq and demonstrate a decrease in taurine levels in irradiated bone marrow mesenchymal stromal cells (BMSCs) through metabolomics. Compared with unirradiated BMSCs, taurine uptake in irradiated BMSCs increases. Taurine concentrations in the peripheral blood and jaws of irradiated mice are significantly lower than those in unirradiated mice (P = 0.0064 and 0.0249 respectively). Supplementation with taurine promotes osteogenic differentiation, reduces oxidative stress, and decreases DNA damage in irradiated BMSCs. Oral administration of taurine significantly improves the survival rate of irradiated mice and enhances osteogenesis in irradiated jaws. Our study highlights the role of taurine in the recovery from radiation-induced jaw injury, and suggests its potential as a non-invasive therapeutic option for combating ORNJ.

A case report of a huge unicystic ameloblastoma in the mandible with significant reduction through marsupialization

INTRODUCTION

Marsupialization is a dependable choice for mandibular unicystic ameloblastoma (UA) management. However, investigations regarding its speed of shrinkage (SS) and reduction rate (RR) are lacking. This case report highlights the treatment of a huge mandibular UA with high SS and RR using marsupialization before secondary surgery.

PRESENTATION OF CASE

A 45-year-old male patient presented with severe swelling of the right side of the mandible, resulting in prominent facial asymmetry. Panoramic radiograph revealed a unilocular, radiolucent lesion extending from the mandibular midline to the right ramus. Computed tomography (CT) revealed a large radiolucent lesion that expanded in the buccolingual direction. Incisional biopsy showed that the lesion was UA. After 1.5 years of marsupialization, an SS of 0.183 % per day was reached, leading to an impressive RR of 98.7 %. Treatment was followed by enucleation and peripheral osteotomy. No recurrence was observed at 1 year post-surgery.

DISCUSSION

The treatment of mandibular UA remains controversial, ranging from conservative approaches to aggressive interventions. In the current case, marsupialization was highly effective in reducing the volume of the lesion, thereby facilitating a minimally invasive secondary surgery to preserve function. The intact periosteum, which has the potential to differentiate into various cell types, may be associated with the regeneration of new bone after marsupialization.

CONCLUSION

Marsupialization remains a successful strategy for managing mandibular UA. Even the huge lesions causing facial deformity can be treated with marsupialization combined with secondary surgery, avoiding the aesthetic and functional disruptions associated with radical treatment.

Which devices can be used to decompress odontogenic cystic lesions in the oral cavity? A systematic review

Odontogenic cysts are bony lesions in the jaws that can reach large sizes. Decompression, a technique that helps in their surgical treatment, aims to reduce their size. We aimed to conduct a systematic review of the main types of device used for the decompression of odontogenic cysts and to analyse the indications, types, advantages, and disadvantages of the devices used. We searched PubMed, Science Direct, LILACS, EMBASE, and Web of Science until February 2023, with no time restriction. We considered studies with a minimum of 10 patients published only in English, those that reported cases and case series, randomised clinical trials of the decompression of odontogenic cysts, and the types of devices used during the decompression period. All reported odontogenic cysts had to have been confirmed by biopsy in their respective publications. We found 713 articles in the selected databases. After removing duplicates, 499 remained. After reading the titles and abstracts, we excluded 461 articles so 38 remained. Nine studies were selected for the review, totalling 244 patients. A total of 206 lesions were identified and confirmed by anatomopathological examination: 123 keratocysts, 40 dentigerous cysts, 34 radicular cysts, one cyst of epithelial origin but without specification, and eight unicystic ameloblastomas. Although we did not find out which device is best for the decompression of odontogenic cysts, our findings show that those that are most effective should be as comfortable as possible and should remain in place. They should have stability in the oral cavity and be easy for the patient to clean.

Immune microenvironment: novel perspectives on bone regeneration disorder in osteoradionecrosis of the jaws

Osteoradionecrosis of the jaws (ORNJ) is a severe complication that occurs after radiotherapy of head and neck malignancies. Clinically, conservative treatments and surgeries for ORNJ exhibited certain therapeutic effects, whereas the regenerative disorder of the post-radiation jaw remains a pending problem to be solved. In recent years, the recognition of the role of the immune microenvironment has led to a shift from an osteoblasts (OBs) or bone marrow mesenchymal stromal cells (BMSCs)-centered view of bone regeneration to the concept of a complicated microecosystem that supports bone regeneration. Current advances in osteoimmunology have uncovered novel targets within the immune microenvironment to help improve various regeneration therapies, notably therapies potentiating the interaction between BMSCs and immune cells. However, these researches lack a thorough understanding of the immune microenvironment and the interaction network of immune cells in the course of bone regeneration, especially for the post-operative defect of ORNJ. This review summarized the composition of the immune microenvironment during bone regeneration, how the immune microenvironment interacts with the skeletal system, and discussed existing and potential strategies aimed at targeting cellular and molecular immune microenvironment components.

Placement of a customised load-bearing titanium plate for prevention of iatrogenic mandibular fracture in surgical removal of odontogenic keratocyst recurrence

A 72-year-old woman with a history of removal of a right hemimandibular keratocyst 10 years ago was referred to our attention for a large swelling of the right cheek. The orthopantomography and the CT scan showed a huge osteolytic area of the right mandibular ramus and angle. The patient's refusal to resection and reconstruction with a free flap pushed us towards a conservative treatment. The high probability of a iatrogenic mandibular fracture during and after surgery required the design of a customised titanium plate to be preliminary placed through cervical incision along the posterior border of the mandible. The patient successfully underwent the surgical positioning of the customised plate and subsequent removal of the keratocyst. She was discharged fit and well 5 days after surgery. She did not experience any infections, pathological fractures or relapse in the 6-month follow-up.