Genotyping analysis of the Pax9 Gene in patients with maxillary canine impaction.

Background: Paired-box gene 9 ( PAX9) mutation is potentially associated with impaction in some patient populations. Here, we analyzed the relationship between PAX9 polymorphism and the occurrence of maxillary canine impaction. Methods: Patients with and without maxillary canine impaction were selected based on specific inclusion criteria, and samples of genomic DNA were obtained from a buccal mucosa swab. DNA was amplified by polymerase chain reaction and sequenced for further bioinformatics analysis to identify single nucleotide polymorphism (SNP) genotypes. Genotype and allele counting was performed in both case and control groups prior to conducting statistical analysis. Results: Four SNPs were identified in patients with maxillary canine impaction, with relative confidence determined based on chromatogram-peak assessment. All SNPs were located in exon 3 of PAX9 and in the region sequenced by the primer pair -197Fex3 and +28Rex3. Three of the SNPs (rs375436662, rs12881240, and rs4904210) were reported previously and are annotated in NCBI (dbSNP version 150), whereas another SNP mapped to chromosome 14 has not been reported. Patients with a CC genotype at SNP 3 [odds ratio (OR): 2.61 vs. TT; 1.28 vs. CT] and a CC genotype at SNP 4 [OR: 0.71 vs. GG; 0.79 vs. CG] were more likely to have maxillary canine impaction. Conclusions: These results demonstrated that the presence of SNPs 3 and 4 is associated with increased likelihood of suffering from maxillary canine impaction.

Mechanical evaluation of effect of grape seed proanthocyanidins extract on debilitated mandibles in rats.

Grape seed proanthocyanidins extract (GSPE), whose principal ingredient is proanthocyanidins, shows many activities such as cholesterol lowering effects, antioxidant effects, anti-tumor effects, cardioprotective effects, and protection against ultraviolet rays. However, reports of the effects of GSPE on bone are rare. We performed a mechanical analysis of the effect of GSPE on the interior structure of rat mandibular bone in the growth period, using three-dimensional peripheral quantitative computed tomography (pQCT). A low-calcium/high-calcium diet with supplementary GSPE was compared to a low-calcium/high-calcium diet in rats with debilitated mandibular bones. The group who received added GSPE showed a significant increase in cortical bone density, cross-sectional area, and trabecular bone mineral content (p<0.05). A significant increase was also seen in the results of a non-invasive stress strain index (SSI) (p<0.01) in the added GSPE. Our findings suggest that GSPE can increase bone quality and bone strength of rat mandibles in the growth period.

Grape seed proanthocyanidins extract promotes bone formation in rat's mandibular condyle.

We studied the effect of dietary supplementation with grape seed proanthocyanidins extract (GSPE) 3 mg added in 100 g high-calcium diet with a calcium content of 1697 mg 100 g(-1) on mandibular condyle bone debility, which was induced by a low-calcium diet. Forty Wistar male rats, 5 week old, were randomly divided into control (Co), low-calcium diet (LC), low-calcium/high-calcium diet (LCH), and low-calcium/high-calcium with supplementary GSPE diet (LCHG) groups for 6 wk. Bone formation of the mandibular condyle was measured using peripheral quantitative computed tomography (pQCT). Significant differences were not seen among the four groups for body weight, measured weekly. The LCHG group scored significantly higher in cortical bone density, total bone cross-sectional area, cortical bone cross-sectional area, cortical bone mineral content, total bone density, total bone mineral content, and in the stress-strain index to the reference axis x when compared with the LCH group. We concluded that a high-calcium diet combined with GSPE supplementation is more effective in reversing mandibular condyle bone debility in rats than is a low-calcium diet, standard diet, or high-calcium diet alone.