Introduction: Dental pulp stem cell (DPSC)-mediated dental pulp regeneration is considered a promising method for the treatment of deep caries with pulpitis. However, mesenchymal stem cell (MSC) senescence is an adverse factor from the perspective of cell-based therapies. In this study, we investigated the characteristics and expression profiles of DPSCs from young and old donors. Methods: DPSCs from young and old donors were cultured in differentiation medium, and their differentiation potentials were assessed. Long noncoding RNA (LncRNA) microarray assays and a bioinformatic analysis were performed to investigate differences in LncRNA and mRNA expression profiles between DPSCs from young and old donors. Results: We found that DPSCs from young donors exhibited more powerful proliferation ability and greater osteogenic and adipogenic differentiation potentials than DPSCs from old donors. In DPSCs from young donors, numerous LncRNAs were significantly up- (n = 389) or down-regulated (n = 172) compared to DPSCs from old donors. Furthermore, 304 mRNAs were differentially expressed, including 247 up-regulated genes and 57 down-regulated genes in DPSCs from young donors. The bioinformatic analysis identified that several pathways may be associated with DPSC characteristics, such as those involved in the cell cycle and RNA transport, and revealed nuclear transcription factor Y subunit β, general transcription factor IIB, and nuclear receptor subfamily 3 group C member 1 as core regulatory factors and FR249114, FR299091, and ENST00000450004 as core LncRNAs. Conclusions: Our results indicated that senescence impaired the proliferation and differentiation potentials of DPSCs and that donor age is an important factor that affects their use for tooth regeneration. We also provide insight into the mechanisms responsible for senescence in DPSCs.

OBJECTIVE: To evaluate the changes of maxillary expansion and upper airway structure after microimplant assisted rapid palatal expansion (MARPE) using cone-beam computed tomography (CBCT). METHODS: This retrospective study included 19 subjects (15 females and 4 males) aged 15-29 years old (mean, 19.95 ± 4.39 years) with maxillary transverse deficiency treated with MARPE. CBCT was performed at the initial diagnosis and 3 months after MARPE treatment. Measurements were taken to evaluate the amount of total expansion, skeletal expansion, and dental expansion at the maxillary first premolar (P1), second premolar (P2), first molar (M1), second molar (M2) regions and upper airway changes. RESULTS: After MARPE treatment, the maxillary skeletal base expansion, skeletal expansion, alveolar expansion and dental expansion were achieved at the P1, P2, M1, M2 region. The nasopharyngeal volume significantly increased 8.48% after MARPE treatment compared with that before the treatment (P < 0.05). The change of nasal lateral width (NLW) was also significantly different before and after MARPE (P < 0.05). However, there were no statistically significant change in the oropharyngeal, palatopharyngeal, glossopharyngeal and airway total volume (all P > 0.05). CONCLUSIONS: MARPE can produce more transverse bone expansion, relieve maxillary transverse deficiency and improve upper airway ventilation.