216 Dental Journal (Majalah Kedokteran Gigi) 2021 December; 54(4): 216–220 Original article INTRODUCTION Class II skeletal malocclusion is often encountered in orthodontics and is one of the main reasons for patients to seek treatment. Previous studies have shown that the occurrence of class II malocclusion is quite high among populations around the world. 1 A study in Denmark found a 25% occurrence of class II skeletal malocclusion in their population. 2 In Asia, a study with people of Mongoloid ethnicity that showed 33.1% of this population had class II malocclusion 3 and another study in India showed 30.1% class II malocclusion in the population. 1 A study in Singapore with people of Chinese ethnicity showed a 23.1% occurrence of class II malocclusion 4 and 70% occurrence was found in Iran. 5 Rosenblum 6 found out that in 103 class II skeletal malocclusion cases, 56.3% had maxillary prognathism and only 27% showed mandibular retrognathism. The differentiation of the osteoblast from its progenitor requires the activity of specific transcription factors which are expressed during development. Runt-related transcription factor-2 (Runx2) is a member Runt family of transcription factors that is essential for skeletal development. 7-9 Runx2 is essential for osteoblast differentiation in endochondral and intramembranous ossification. 10 The Runx gene consists of Runx1, Runx2 and Runx3. Runx2 plays an important role in osteogenesis, cartilage formation, cell migration, vascular bone invasion and tooth formation. 8,11,12 Runx2 is essential Dental Journal (Majalah Kedokteran Gigi) p-ISSN: 1978-3728; e-ISSN: 2442-9740. Accredited No. 32a/E/KPT/2017. Open access under CC-BY-SA license. Available at https://e-journal.unair.ac.id/MKG/index DOI: 10.20473/j.djmkg.v54.i4.p216–220 Runx2 rs59983488 polymorphism in class II malocclusion in the Indonesian subpopulation Fadli Jazaldi 1 , Benny M. Soegiharto 1 , Astrid Dinda Hutabarat 2 , Noertami Soedarsono 3 and Elza Ibrahim Auerkari 3 1 Department of Orthodontics, 2 Orthodontic Postgraduate Program, 3 Department of Oral Biology, Faculty of Dentistry, University of Indonesia, Jakarta, Indonesia ABSTRACT Background: Class II malocclusion is one of the main orthodontic issues for patients in seeking treatment. The prevalence of class II malocclusion varies in different populations. Variation in skeletal profile is mainly controlled internally by a regulatory gene. Runt-related transcription factor-2 (Runx2) plays a role in osteoblast differentiation and is highly expressed during development. Purpose: This study aimed to evaluate the relation of regulatory gene variation in the Runx2 promoter with class II malocclusion. Methods: DNA samples were acquired from 95 orthodontic patients in Jakarta, Indonesia, who were divided into two groups: class I skeletal malocclusion (control group) and class II malocclusion. A single nucleotide polymorphism was investigated using the polymerase chain reaction and restriction fragment length polymorphism techniques. The distribution of alleles was assessed using the Hardy-Weinberg test. The relationship between polymorphism and skeletal variation was assessed with the Chi-Square test and logistic regression. Results: The frequency distributions of genotypes and alleles were tested for Hardy-Weinberg equilibrium and found to be slightly deviated. There was an equal distribution of G and T alleles throughout class II and class I skeletal malocclusions and the Chi-Square test showed that this relationship was not significant (p=0.5). Conclusion: Runx2 rs59983488 polymorphism was found in the Indonesian subpopulation; however, an association between Runx2 rs59983488 polymorphism and class II skeletal malocclusion was not found. Keywords: class II; G330T; Indonesia; polymorphism; Runx2; rs59983488 Correspondence: Fadli Jazaldi, Department of Orthodontics, Faculty of Dentistry, University of Indonesia. Jl. Salemba Raya No.4, Jakarta Pusat, Jakarta 10430, Indonesia. Email: fadli.jazaldi@ui.ac.id