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Objectives: To evaluate the association of three single-nucleotide polymorphisms (SNPs) of growth hormone receptor (GHR) gene with mandibular prognathism (MP) and relationships between mandibular morphology and GHR gene SNPs in the Korean population., Materials and Methods: A total of 325 subjects were divided into two groups based on sagittal maxillomandibular relationship by the lateral cephalography: the MP and control groups. From the SNPs in the GHR gene, three SNPs (rs6180, rs6182 and rs6184) were selected. SNP genotyping was performed using direct sequencing. The craniofacial measurements of lateral cephalography were analysed., Results: We found a lack of association between GHR and MP. However, in the analysis according to the values of cephalometric measurements, rs6180 was significantly associated with ANB, SNB, effective mandibular length and SNMP in females. Additionally, rs6182 and rs6184 were significantly associated with ramal height in males., Conclusion: Growth hormone receptor SNPs may affect not only the sagittal development of mandible but also the vertical development of ramal height, and GHR SNPs may gender-differently influence mandibular morphology. This finding supports that the GHR might be susceptible on mandibular morphogenesis in the Korean population., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: To investigate SNPs in bone- and cartilage-related genes and their interaction in the aetiology of sagittal and vertical skeletal malocclusions., Settings and Sample Population: This study included 143 patients and classified as follows: skeletal class I (n = 77), class II (n = 47) and class III (n = 19); maxillary retrusion (n = 39), protrusion (n = 52) and well-positioned maxilla (n = 52); mandibular retrognathism (n = 50), prognathism (n = 50) and well-positioned mandible (n = 43); normofacial (n = 72), dolichofacial (n = 55) and brachyfacial (n = 16)., Materials and Methods: Steiner's ANB, SNA, SNB angles and Ricketts' NBa-PtGn angle were measured to determine the skeletal malocclusion and the vertical pattern. Nine SNPs in BMP2, BMP4, SMAD6, RUNX2, WNT3A and WNT11 were genotyped. Chi-squared test was used to compare genotypes among the groups. Multifactor dimensionality reduction (MDR) and binary logistic regression analysis, both using gender and age as co-variables, were also used. We performed Bonferroni correction for multiple testing., Results: Significant associations at P < .05 were observed for SNPs rs1005464 (P = .042) and rs235768 (P = .021) in BMP2 with mandibular retrognathism and for rs59983488 (RUNX2) with maxillary protrusion (P = .04) as well as for rs708111 (WNT3A) with skeletal class III (P = .02; dominant model), rs1533767 (WNT11) with a brachyfacial skeletal pattern (P = .01, OR = 0.10; dominant model) and for rs3934908 (SMAD6) with prognathism (P = .02; recessive model). After the Bonferroni correction, none of the SNPs remained associated. The MDR predicted some interaction for skeletal class II, dolichofacial and brachyfacial phenotypes., Conclusion: Our results suggest that SNPs in BMP2, BMP4, SMAD6, RUNX2, WNT3A and WNT11 could be involved in the aetiology of sagittal and vertical malocclusions., (© 2020 The Authors. Orthodontics & Craniofacial Research published by John Wiley & Sons Ltd.)

Malocclusions affect individuals worldwide, resulting in compromised function and esthetics. Understanding the etiological factors contributing to the variation in dentofacial morphology associated with malocclusions is the key to develop novel treatment approaches. Advances in dentofacial phenotyping, which is the comprehensive characterization of hard and soft tissue variation in the craniofacial complex, together with the acquisition of large-scale genomic data have started to unravel genetic mechanisms underlying facial variation. Knowledge on the genetics of human malocclusion is limited even though results attained thus far are encouraging, with promising opportunities for future research. This review summarizes the most common dentofacial variations associated with malocclusions and reviews the current knowledge of the roles of genes in the development of malocclusions. Lastly, this review will describe ways to advance malocclusion research, following examples from the expanding fields of phenomics and genomic medicine, which aim to better patient outcomes., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

To present current views that are pertinent to the investigation of the genetic etiology of Class III malocclusion. Class III malocclusion is thought to be a polygenic disorder that results from an interaction between susceptibility genes and environmental factors. However, research on family pedigrees has indicated that Class III malocclusion might also be a monogenic dominant phenotype. Recent studies have reported that genes that encode specific growth factors or other signaling molecules are involved in condylar growth under mechanical strain. These genes, which include Indian hedgehog homolog (IHH), parathyroid-hormone like hormone (PTHLH), insulin-like growth factor-1 (IGF-1), and vascular endothelial growth factor (VEGF), and variations in their levels of expression play an important role in the etiology of Class III malocclusion. In addition, genome-wide scans have revealed chromosomal loci that are associated with Class III malocclusion. It is likely that chromosomal loci 1p36, 12q23, and 12q13 harbor genes that confer susceptibility to Class III malocclusion. In a case-control association study, we identified erythrocyte membrane protein band 4.1 (EPB41) to be a new positional candidate gene that might be involved in susceptibility to mandibular prognathism. Most of the earlier studies on the genetic etiology of Class III malocclusion have focused on the patterns of inheritance of this phenotype. Recent investigations have focused on understanding the genetic variables that affect Class III malocclusion and might provide new approaches to uncovering the genetic etiology of this phenotype.