Current cell-based bone tissue regeneration strategies cannot cover large bone defects. K-carrageenan is a highly hydrophilic and biocompatible seaweed-derived sulfated polysaccharide, that has been proposed as a promising candidate for tissue engineering applications. Whether κ-carrageenan can be used to enhance bone regeneration is still unclear. In this study, we aimed to investigate whether κ-carrageenan has osteogenic potential by testing its effect on pre-osteoblast proliferation and osteogenic differentiation in vitro. Treatment with κ-carrageenan (0.5 and 2 mg/mL) increased both MC3T3-E1 pre-osteoblast adhesion and spreading at 1 h. K-carrageenan (0.125–2 mg/mL) dose-dependently increased pre-osteoblast proliferation and metabolic activity, with a maximum effect at 2 mg/mL at day three. K-carrageenan (0.5 and 2 mg/mL) increased osteogenic differentiation, as shown by enhanced alkaline phosphatase activity (1.8-fold increase at 2 mg/mL) at day four, and matrix mineralization (6.2-fold increase at 2 mg/mL) at day 21. K-carrageenan enhanced osteogenic gene expression (Opn, Dmp1, and Mepe) at day 14 and 21. In conclusion, κ-carrageenan promoted MC3T3-E1 pre-osteoblast adhesion and spreading, metabolic activity, proliferation, and osteogenic differentiation, suggesting that κ-carrageenan is a potential osteogenic inductive factor for clinical application to enhance bone regeneration.

Purpose of Review: Bone regeneration plays an important role in contemporary clinical treatment. Bone tissue engineering should result in successful bone regeneration to restore congenital or acquired bone defects in the human skeleton. Osteocytes are thought to have a governing role in bone remodeling by regulating osteoclast and osteoblast activity, and thus bone loss and formation. In this review, we address the so far largely unknown role osteocytes may play in bone tissue regeneration. Recent Findings: Osteocytes release biochemical signaling molecules involved in bone remodeling such as prostaglandins, nitric oxide, Wnts, and insulin-like growth factor-1 (IGF-1). Treatment of mesenchymal stem cells in bone tissue engineering with prostaglandins (e.g., PGE₂, PGI₂, PGF_2α), nitric oxide, IGF-1, or Wnts (e.g., Wnt3a) improves osteogenesis. Summary: This review provides an overview of the functions of osteocytes in bone tissue, their interaction with other bone cells, and their role in bone remodeling. We postulate that osteocytes may have a pivotal role in bone regeneration as well, and consequently that the bone regeneration process may be improved effectively and rapidly if osteocytes are optimally used and stimulated.

There has been an increasing trend in oral squamous cell carcinoma (OSCC) in patients under 45 years of age. The aim of this study was to evaluate the burden of OSCC in the Netherlands between 1989 and 2018 among young adults (age 20-34 years) when compared to adults (age 35-44 years), and to describe the burden in older groups as well, utilizing cancer registry data to characterize incidence patterns by age, sex, and risk factors. A total of 18,963 cases of OSCC were reported. The overall incidence rate, as measured by annual percentage change (APC), increased significantly from 1989 to 2010 by 1.3% per year (95% confidence interval (CI) 0.9-1.7%) but decreased thereafter by -0.9% (95% CI -2.5% to 0.7%). Annual incidence increased significantly by 2.4% (95% CI 1.1-3.8%) for patients aged 20-34 years, while it decreased for those aged 35-44 years by -0.9% (95% CI -1.7% to 0.0%). In patients older than 60 years, incidence rates increased overall (60-74 years: APC 1.8%, 95% CI 1.5-2.1%; ≥75 years: APC 1.5%, 95% CI 1.2-1.9%). Overall, 66.5% of patients were smokers and 65.3% were alcohol consumers. The marked differences in incidence within the young age subgroups warrants further investigation to elucidate any likely disparity in biological process and clinical outcomes in these populations.

Objectives. Ameloblastoma is a slow-growing epithelial odontogenic neoplasm of the jaws with a high recurrence rate. The main treatment strategies for this lesion are radical or conservative surgical approaches. The aim of the present study was to analyze clinical presentations, histological types, and treatment strategies of recurrent ameloblastoma and to define its disease-free survival (DFS) rate. Materials and Methods. Twenty-four cases of recurrent ameloblastomas, treated between January 2009 and July 2021, were enrolled in this study. Medical files from each patient, including gender, age, size of the lesion, localization, patient complaints, clinical manifestation, radiographic appearance, histological type, surgical management, and treatment results were reviewed and analyzed retrospectively. Result. Out of 69 operated primary ameloblastomas, the rate of recurrence was 35. Out of 24 recurrent cases, 21 developed after conservative treatment and 3 after radical treatment. In most cases, recurrences were found in the mandible (n=20). A unilocular pattern was predominant in radiographic examination (44). Estimated 3-year DFS was 84.5±4.8, and the 5-year and 10-year DFS were 73.0±6.3 and 43.9±8.343.9±8.3, respectively. Conclusion. Results obtained in the present retrospective study proved the necessity of long-term follow-up after both conservative and radical treatment approaches. The DFS median in our study was 8 years (95 CI 6 years10 years). For recurrent cases, radical resection with histologically free margins after exact MRI determination of the ameloblastoma border within the soft tissues should be considered as the method of choice to avoid secondary recurrence.