ABSTRACT
Objective@#Preservation of the periodontal ligament (PDL) is vital to the success of tooth autotransplantation (TAT). Increased PDL volumes and facilitated tooth extraction have been observed upon orthodontic preloading. However, it is unclear whether any changes occur in the expressions of bone biomolecules in the increased PDL volumes. This study aimed to determine the expressions of runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), receptor activator of nuclear factor kappa-B ligand (RANKL), and osteoprotegerin (OPG) in PDL upon preloading. @*Methods@#Seventy-two premolars from 18 patients were randomly assigned to experimental groups that received a leveling force for 1, 2, or 4 weeks or to a control unloaded group. Following extraction, PDL volumes from 32 premolars of eight patients (21.0 ± 3.8 years) were evaluated using toluidine blue staining. The expressions of the biomolecules in the PDL from 40 premolars of ten patients (21.4 ± 4.0 years) were analyzed via immunoblotting. @*Results@#The median percentage of stained PDL was significantly higher at 2 and 4 weeks after preloading than in the unloaded condition (p < 0.05). The median RUNX2 and ALP expression levels were significantly higher at 2 and 4 weeks after preloading than in the unloaded condition (p < 0.05), whereas the median RANKL/OPG ratios were significantly higher at 1 and 4 weeks after preloading (p < 0.05). @*Conclusions@#Orthodontic preloading for 4 weeks enhances PDL volumes as well as the expressions of RUNX2, ALP and the RANKL/OPG ratio in the PDL, suggesting this loading period is suitable for successful TAT.
ABSTRACT
Zingiber cassumunar Roxb. was previously shown to possess potent anti-inflammatory activity. We investigated the effect of its ethanol extract on hyaluronan (HA), an extracellular matrix compound with proinflammatory activity synthesis in human oral fibroblasts. Cultured fi broblasts were treated at various times with different concentrations of the extract (0.1-50 μg/mL) with or without retinoic acid (RA; 10 μM), or left untreated as a control. Culture medium was analyzed for HA quantities by the ELISA-based assay. Total RNA was harvested and RT-PCR analyses were performed to determine mRNA expression of hyaluronan synthase (HAS) -1, -2, and –3. Z. cassumunar extract, at 25 and 50 μg/mL, with or without 10 μM of RA, significantly decreased HA levels (p \< 0.05). Consistent with decreased HA levels, mRNA expression of HAS-2, but not HAS-1 or HAS-3, was selectively down-regulated by the extract. Collectively, these data indicate that the ethanol extract of Z. cassumunar inhibits HA synthesis in human oral fibroblasts, which may be involved in chronic inflammatory disorders, particularly in the oral cavity.