Anterior diastema is a common esthetic defect in China. The general treatment for a patient with diastemata, including orthodontics and direct and indirect restorations, is a multidisciplinary clinical procedure covering the orthodontics, operative dentistry, general dentistry, and prosthodontics department. Given the diversity of departments and the complex etiology of this defect, decision-making regarding the closing methods and time selection is undefined and unintegrated, which makes the long-term stability of closure unpredictable. This article proposed an etiology-based decision tree with actual measurement of diastemata width for diastemata closure. The decisional steps include classifying the etiological factors based on patients' medical history and clinical manifestation to evaluate the stability of diastemata. After maintaining the stability of diastemata, contemporary and multidisciplinary treatment plans were selected in accordance with the measured width of diastemata and patients' cosmetic psychology, economics, and available time. These decision trees focus on the challenges of collaboration among dental departments, propose an objective and efficient ways for connections, and promote efficient and effective diastemata closure.

Objective This study aimed to investigate the temporal and spatial changes in the expression of periostin during periodontal inflammation in mice. Methods A periodontitis model was constructed using silk thread ligation. Mice were randomly divided into five groups including control group, 4-day ligation group, 7-day ligation group, 14-day ligation group, and self-healing group (thread removal for 14 days after 14-day ligation). Micro-CT and histological staining were performed to characterize the dynamic changes in the mouse periodontal tissue in each group. RNAscope and immunohistochemical staining were used to analyze the pattern of changes in periostin at various stages of periodontitis. The cell experiment was divided into three groups: control group, lipopolysaccharide (LPS) stimulation group (treated with LPS for 12 h), and LPS stimulation removal group (treated with LPS for 3 h followed by incubation with medium for 9 h). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of periostin, transforming growth factor-β1 (TGF-β1), and matrix metalloproteinase 2 (MMP2). Results Significant alveolar bone resorption was observed 7 days after ligation. With increasing duration of ligation, the damage to the mouse periodontal tissue was aggravated, which manifested as increased osteoclasts, widening of the periodontal membrane space, and decreased alveolar bone height. Some degree of periodontal tissue repair was observed in the self-healing group. Periostin expression decreased at 4 and 7 days compared with the control group and increased at 14 days compared with 4 and 7 days. A significant recovery was found in the self-healing group. The qRT-PCR results showed that the expression of periostin and TGF-β1 in the LPS stimulation group decreased compared with that in the control group but significantly recovered in the LPS removal group. Conclusion Periostin expression in the PDL of mice showed a downward and upward trend with inflammation progression. The significant recovery of periostin expression after removing inflammatory stimuli may be related to TGF-β1, which is crucial to maintain the integrity of the PDL.