Over the years, the oral and maxillofacial injuries, mainly caries, pulpitis, bone defects, and oral cancer, often involve a variety of organs and tissues, resulting in structural defects, dysfunction, and adverse effects on facial appearance, not only affecting people's chewing, swallowing and other physiological functions, but also to people's physical and mental health burden. As a type of carbon-based nanomaterial, carbon dots (CDs) have been widely used in the diagnosis and treatment of oral and maxillofacial diseases due to its excellent optical properties, good biocompatibility and low toxicity. In addition, surface functionalization or passivation of CDs can change the physical properties of CDs, such as water solubility and chemiluminescence, and broaden the biomedical potential of CDs. In this review, the latest research progress of CDs and its modified CDs in hard tissue regeneration, tumor treatment, antibacterial activity, dentin pulp complex regeneration, teeth whitening, wound healing, drug release, fluorescence tracer and bioimaging were reviewed. In addition, we also discussed the problems of the CDs and the future direction of development.