Transforming Growth Factor Beta Receptor 2 (TGFBR2) Promoter Region Polymorphisms May Be Involved in Mandibular Retrognathism.

Skeletal malocclusions are common phenotypes in humans and have a strong influence on genetic factors. Transforming growth factor beta (TGFß) controls numerous functions of the human body, including cell proliferation, differentiation, and migration. Thus, this study is aimed at evaluating whether genetic polymorphisms in TGFB1 and its receptor TGFBR2 are associated with mandibular retrognathism in German children and adolescents. Children and teenagers older than 8 years in the mixed or permanent dentition were included in this study. Patients with syndromes and facial trauma and patients with congenital alterations were excluded. Digital cephalometric tracings were performed using the anatomical landmarks point A, point B, sella (S), and nasion (N). Patients that have a retrognathic mandible (SNB < 78°) were selected as case group, and the patients with an orthognathic mandible (SNB = 78°- 82°) were selected as the control group. Genomic deoxyribonucleic acid (DNA) from saliva was used to evaluate four genetic polymorphisms in TGFB1 (rs1800469 and rs4803455) and TGBR2 (rs3087465 and rs764522) using real-time PCR. Chi-square or Fisher exact tests were used to compare gender, genotype, and allele distribution among groups. Genotype distribution was calculated in an additive and recessive model. Haplotype analysis was also performed. The established alpha of this study was 5%. A total of 146 patients (age ranging from 8 to 18 years) were included in this epidemiological genetic study. The genetic polymorphism rs3087465 in TGFBR2 was associated with mandibular retrognathism. Carrying the AA genotype in the rs3087465 polymorphism decreased the chance of having mandibular retrognathism (odds ratio = 0.25, confidence interval 95% = 0.06 to 0.94, p = 0.045). None of the haplotypes was associated with mandibular retrognathism (p > 0.05). In conclusion, we found that the genetic polymorphism rs3087465 in the promoter region of the TGFBR2 was associated with mandibular retrognathism in Germans.

Association of third molar agenesis and microdontia with genetic polymorphisms in vitamin-D-related genes.

The present study aimed to evaluate if functional genetic polymorphisms in vitamin-D-related genes are associated with third molar agenesis and third molar microdontia in German orthodontic patients. Pre-orthodontic and follow-up treatment records were evaluated for phenotype definition. Saliva samples were collected for DNA extraction. Eight potential functional genetic polymorphisms in VDR [rs731236 (TaqI), rs7975232 (ApaI), rs2228570 (FokI), and rs1544410 (BsmI)], CYP27B1 (rs4646536), CYP24A1 (rs927650), GC (rs4588), and SEC23A (rs8018720) were evaluated using real-time PCR. Comparison among the groups were performed (third molar anomaly vs. control; third molar agenesis vs. control; and third molar microdontia vs. control) with an alpha of 5%. A total of 164 patients were analyzed. Forty-nine (29.9%) patients had at least one third molar anomaly. In the haplotype analysis, genetic polymorphisms in VDR and CYP27B1 were associated with third molar anomalies (p < 0.05). The G allele in rs8018720 (SEC23A) was more frequent in microdontia cases. In the genotype distribution analysis, rs8018720 in SEC23A was associated with third molar microdontia in the co-dominant (p = 0.034; Prevalence Ratio [PR]=5.91, 95% Confidence Interval [CI]= 1.14-30.66) and in the recessive (p = 0.038; PR=5.29; 95% CI= 1.09-25.65) models. In conclusion, vitamin D-related genes could be involved in third molar anomalies.