• Jaijam Suwanwela D.D.S. Ph.D.
• Virunpat Nitipong D.D.S.
• Naruborn Ongprakobkul D.D.S.

Objective To identify single nucleotide polymorphisms (SNPs) that associated with different
occlusal relationship in a group of Thai population.

Materials and Methods One hundred and sixty unrelated Thai subjects†who participated†in Ramathibodi
GWAS study for thyrotoxic hypokalemic periodic paralysis (TTPP) (Jongjaroenprasert, 2012) were
selected. The subjects that were 20 years old and above with at least a pair of untilted permanent first
molars or canines were selected from these subjects. Seventeen subjects met these criteria in our study.†
Angleûs/canine classification of subjects were observed† both intraorally and from diagnostic models.
Eight hundred and sixty four† human active SNPs from 28 related genes were selected from previous
craniofacial studies. PERL software with Fisher exact test was used to identify the SNPs that correlated
with subjectsû occlusal relationship.†

Results There were 17 SNPs† from 6 genes including IGF1, HSPG2, MATN1, TGFB2, VEGF and
EVC† that significantly correlated with Angleûs/canine class I occlusal relationship and† 27 SNPs from†
5 genes including IGF1, HSPG2, MATN1, TGFB1 and LTBP2 that significantly correlated with
Angleûs/canine class III occlusal relationship†(P value < 0.05). These findings show that there are
specific SNPs in the marker genes that correlated with Angleûs/canine class l and class III occlusal
relationship.

Conclusion There are significant correlations between SNPs and occlusal relationship in a Thai
population subgroup. This finding leads to a†further understanding in genetic †basis of occlusal
relationship.

(CU Dent J. 2015;38:185-196)