Organoid in dentistry: Models for oral biology and disease.

Cell lines and animal models have long been used as essential tools in studies targeting the oral cavity, offering valuable insights into various oral diseases. Each of these research models provides its advantages, such as ease of manipulation in cell lines and the ability to replicate whole-organ interactions in animal models. However, conventional models often have limited native phenotypic features, which do not fully capture the complexity of the human oral cavity. In response to these limitations, organoid technologies have recently been developed and emerged as a promising alternative. Organoids, which are widely applied to mimic the complexity of oral tissues, such as tongue (including taste buds), tooth germs, teeth, salivary glands, periodontal ligament, bone, and oral squamous cell carcinoma, offer a more proper model for studying oral biology and disease. Key signaling pathways, including Wnt/β-catenin, transforming growth factor beta (TGF-β) (bone morphogenetic protein (BMP), and fibroblast growth factor (FGF), have been demonstrated to play important roles in expansion and differentiation of oral organoids. These advancements have opened new avenues for understanding the development and pathology of oral cavity. Therefore, we summarize current novel oral organoid culture strategies and their application, providing a deeper understanding of the biology of the oral cavity and the pathophysiology of oral diseases.