Periodontal bone defects, primarily caused by periodontitis, are highly prevalent in clinical settings and manifest as bone fenestration, dehiscence, or attachment loss, presenting a significant challenge to oral health. In regenerative medicine, harnessing developmental principles for tissue repair offers promising therapeutic potential. Of particular interest is the condensation of progenitor cells, an essential event in organogenesis that has inspired clinically effective cell aggregation approaches in dental regeneration. However, the precise cellular coordination mechanisms during condensation and regeneration remain elusive. Here, taking the tooth as a model organ, we employed single-cell RNA sequencing to dissect the cellular composition and heterogeneity of human dental follicle and dental papilla, revealing a distinct Platelet-derived growth factor receptor alpha (PDGFRA) mesenchymal stem/stromal cell (MSC) population with remarkable odontogenic potential. Interestingly, a reciprocal paracrine interaction between PDGFRA⁺ dental follicle stem cells (DFSCs) and CD31⁺ Endomucin⁺ endothelial cells (ECs) was mediated by Vascular endothelial growth factor A (VEGFA) and Platelet-derived growth factor subunit BB (PDGFBB). This crosstalk not only maintains the functionality of PDGFRA⁺ DFSCs but also drives specialized angiogenesis. In vivo periodontal bone regeneration experiments further reveal that communication between PDGFRA⁺ DFSC aggregates and recipient ECs is essential for effective angiogenic-osteogenic coupling and rapid tissue repair. Collectively, our results unravel the importance of MSC-EC crosstalk mediated by the VEGFA and PDGFBB-PDGFRA reciprocal signaling in orchestrating angiogenesis and osteogenesis. These findings not only establish a framework for deciphering and promoting periodontal bone regeneration in potential clinical applications but also offer insights for future therapeutic strategies in dental or broader regenerative medicine.
Receptor, Platelet-Derived Growth Factor alpha/metabolism* ; Humans ; Neovascularization, Physiologic/physiology* ; Dental Sac/cytology* ; Single-Cell Analysis ; Transcriptome ; Mesenchymal Stem Cells/metabolism* ; Bone Regeneration ; Animals ; Dental Papilla/cytology* ; Periodontium/physiology* ; Stem Cells/metabolism* ; Regeneration ; Angiogenesis

Objective:To explore the clinical effect on reconstruction of the soft tissue defects after resection of mucous cysts of distal interphalangeal joint (DIP) with transfer of the flap of dorsal branch of proper palmar digital artery.Methods:From September 2021 to September 2023, 8 patients (8 digits) with mucous cysts on DIP were treated in the Department of Hand and Microsurgery, the Affiliated Hospital of Binzhou Medical University. All 8 cases were females, aged 55-65 years old, with an average age of 60 years old. The cyst was located in the thumb in 1 case, in the index finger in 3 cases, in the middle finger in 3 cases, and in the ring finger in 1 case. After extensive resection of the mucous cysts, the size of soft tissue defects was at 0.8 cm×0.6 cm-1.7 cm×0.9 cm. Pedicled with the dorsal branch of proper palmar digital artery, the flaps adjacent to the defects were designed to cover the wounds. The size of the flaps was 1.2 cm×1.0 cm-2.0 cm×1.2 cm. Donor sites of the flap were covered by the full thickness skin grafts of medial upper arm. The postoperative follow-up was conducted by the combination of outpatient revisits and telephone reviews to observe the survival of the flap, and the functional recovery was evaluated according to the Evaluation Standard of Upper Limb Functional of Hand Surgery of Chinese Medical Association.Results:All flaps survived well after surgery. Postoperative follow-up ranged from 4 to 12 months, with a mean of 10 months. At the final follow-up, there was no recurrence of mucous cyst and all symptoms disappeared. All flaps healed well, with good appearance, soft texture and without obvious difference in colour from the surrounding skin. All skin grafts healed in one stage. The range of motion of the affected DIP was 0°-70°, and the TPD was at 7-8 mm, both caused no impact on daily life. The outcomes were excellent according to the evaluation criteria set by the Evaluation Standard of Upper Limb Functional of Hand Surgery of Chinese Medical Association.Conclusion:The flap pedicled with dorsal branch of proper palmar digital artery has obvious advantages with less damage and simple operation in the treatment of a mucous cyst of DIP. It is an ideal surgical procedure.