[Discussion and evaluation of several issues concerning the classification of impacted third molars].

The classification of impacted third molars is important in clinical diagnosis and surgical selection. At present, the common clinical impacted third molar classification is different in the maxillary and mandibular classification criteria. Through the review and analysis of various classification methods of impacted third molar, this paper proposes a more comprehensive and unified classification proposal for the classification of impacted third molar, in order to form a widely accepted application classification method.

[Deciphering the fate of granulation tissue in the human inflammatory alveolar microenvironment using single-cell RNA sequencing].

Objective: To investigate the cellular composition and heterogeneity of granulation tissue in human alveolar sockets and construct single-cell transcriptomic maps to elucidate the potential outcomes of natural resolution in the inflammatory microenvironment. Methods: Granulation tissues from 12 alveolar sockets undergoing tooth extraction due to periodontitis and scheduled for delayed site preservation or autologous tooth transplantation were collected in the Department of Oral and Maxillofacial Surgery, School of stomatology Fourth Military Medical University from September 2022 to August 2023. This study used HE staining and single-cell RNA sequencing (scRNA-seq) to observe the cellular composition and morphological changes of different types of granulation tissues. This approach enabled us to identify cellular sequence variations in the inflammatory dental alveolar granulation tissue within specific microenvironments, construct single-cell atlases for different types of human dental alveolar granulation tissues, and explore the spatiotemporal patterns of cell type distribution and key gene changes during the resolution process of inflammatory granulation tissue. Results: HE staining revealed extensive infiltration of inflammatory cells in the dental alveolar inflammatory granulation tissue. After allowing the inflammatory granulation tissue to naturally resolve for three weeks, its histological morphology was essentially consistent with that of reparative granulation tissue. ScRNA-seq captured a total of 20 448 cells from granulation tissues, and the gene expression quantification analysis revealed total gene counts of 33 835 for inflammatory granulation tissue, 36 058 for naturally resolved granulation tissue, and 34 719 for reparative granulation tissue. At the single-cell level, granulation tissue was annotated into ten cell subgroups, including vascular endothelial cells, mesenchymal stem cells, and fibroblasts. Differences were observed in the proportion of cell compositions between inflammatory and naturally resolved granulation tissues. Pseudo-temporal analysis illustrated two main outcomes in tissue resolution and healing, involving immune responses and angiogenesis. Among these, genes associated with inflammation regulation and immune response, such as Igbp5, Zfp36, and Hspa1b, as well as genes involved in extracellular matrix secretion and the formation of vessels and fibers such as Timp3, Postn, and Rgs5, showed significant differences in expression between the two types of granulation tissues. Conclusions: Inflammatory granulation tissue exhibits heterogeneity in cell composition, gene expression, and biological functions compared to naturally resolved granulation tissue. When the inflammatory granulation tissue in the alveolar socket is left undisturbed to undergo natural resolution, it displays a cellular composition similar to that of reparative granulation tissue at both the histological and single-cell levels. Moreover, it modulates the inflammatory response and the healing process through immune reactions and tissue remodeling.

[Strolling through the glorious years of Alveolar Surgery, bravely stepping onto the path of practice and innovation].

This article summarizes and organizes relevant publications in journals, along with a review of medical history, systematically summarizing the development process of dental alveolar surgery in China. The initial establishment phase (1935-1952) marked the starting point of Chinese Alveolar Surgery. Despite the impact of wars, it laid the foundation for subsequent research and practice. During the early development phase (1953-1966), the "Chinese Journal of Stomatology" was founded, which promoted the development of Alveolar Surgery. Research focused on tooth extraction methods and complications. Tooth Transplantation and Preprosthetic Surgery gradually began to take off. The stagnant phase (1967-1977) occurred due to the interruption of international exchanges, leading to an almost complete halt in the development of Alveolar Surgery. Entering the rapid catch-up phase (1978-1985), Alveolar Surgery scholars in China began striving to overcome the stagnation of the previous decade. While some progress was made, no significant innovative achievements emerged. In the scientific development phase (1986-2010), clinical research, basic experiments, and paper writing in modern Chinese Alveolar Surgery began to adhere to scientific standards with the rise of experimental medicine. The exploration and innovation stage (2011-2023) is the current development phase, during which Chinese Aveolar Surgery has reached its peak, making substantial progress in technology, clinical practices, and basic research, gradually reaching or even surpassing international advanced levels. Looking back at the development history in China, we can find the wisdom and hard work of the older generation of Alveolar Surgery scholars. However, contemporary challenges and issues, such as standardizing technology, promoting clinical practices, and talent cultivation, need to be addressed by present-day Alveolar Surgery professionals as they forge ahead.