Differences in the heritability of craniofacial skeletal and dental characteristics between twin pairs with skeletal Class I and II malocclusions
10.4041/kjod.2021.51.6.407
- Author:
Heon-Mook PARK
1
;
Pil-Jong KIM
;
Joohon SUNG
;
Yun-Mi SONG
;
Hong-Gee KIM
;
Young Ho KIM
;
Seung-Hak BAEK
Author Information
1. Department of Orthodontics, School of Dentistry, Seoul National University, Seoul, Korea
- Publication Type:Original Article
- From:The Korean Journal of Orthodontics
2021;51(6):407-418
- CountryRepublic of Korea
- Language:English
-
Abstract:
Objective:To investigate differences in the heritability of skeletodental characteristics between twin pairs with skeletal Class I and Class II malocclusions.
Methods:Forty Korean adult twin pairs were divided into Class I (C-I) group (0° ≤ angle between point A, nasion, and point B [ANB]) ≤ 4°; mean age, 40.7 years) and Class II (C-II) group (ANB > 4°; mean age, 43.0 years). Each group comprised 14 monozygotic and 6 dizygotic twin pairs. Thirty-three cephalometric variables were measured using lateral cephalograms and were categorized as the anteroposterior, vertical, dental, mandible, and cranial base characteristics. The ACE model was used to calculate heritability (A > 0.7, high heritability). Thereafter, principal component analysis (PCA) was performed.
Results:Twin pairs in C-I group exhibited high heritability values in the facial anteroposterior characteristics, inclination of the maxillary and mandibular incisors, mandibular body length, and cranial base angles. Twin pairs in C-II group showed high heritability values in vertical facial height, ramus height, effective mandibular length, and cranial base length. PCA extracted eight components with 88.3% in the C-I group and seven components with 91.0% cumulative explanation in the C-II group.
Conclusions:Differences in the heritability of skeletodental characteristics between twin pairs with skeletal Class I and II malocclusions might provide valuable information for growth prediction and treatment planning.
