Heritability of cephalometric variables of airway morphology in twins with completed active growth

Monika Šidlauskienė; Mantas Šidlauskas; Antanas Šidlauskas; Simonas Juzėnas; Kristina Lopatienė

doi:10.1186/s12903-023-02919-x

Heritability of cephalometric variables of airway morphology in twins with completed active growth

BMC Oral Health. 2023 Apr 27;23(1):244. doi: 10.1186/s12903-023-02919-x.

Authors

Monika Šidlauskienė^{1

2}, Mantas Šidlauskas³, Antanas Šidlauskas³, Simonas Juzėnas⁴, Kristina Lopatienė³

Affiliations

¹ Department of Orthodontics, Faculty of Medicine, Lithuanian University of Health Sciences, Eivenių 2, Kaunas, LT-50161, Lithuania. monika.sidlauskiene@lsmu.lt.
² Clinic of Orthodontics, Medical Academy, Lithuanian University of Health Sciences, J. Lukšos-Daumanto str. 6, Kaunas, LT-50106, Lithuania. monika.sidlauskiene@lsmu.lt.
³ Department of Orthodontics, Faculty of Medicine, Lithuanian University of Health Sciences, Eivenių 2, Kaunas, LT-50161, Lithuania.
⁴ Institute of Digestive Research, Faculty of Medicine, Lithuanian University of Health Sciences, Eivenių 2, Kaunas, LT-50161, Lithuania.

Abstract

Background: The interplay between genetic and environmental impacts on dental and facial morphology has been widely analyzed, but little is known about their relative contributions to airway morphology. The aim of this study was to evaluate the genetic and environmental influences on the cephalometric variables of airway morphology in a group of postpubertal twins with completed craniofacial growth.

Materials and methods: The materials comprised lateral head cephalograms of 94 pairs of twins (50 monozygotic, 44 dizygotic) with completed craniofacial growth. Zygosity was determined using 15 specific DNA markers. The computerized cephalometric analysis included 22 craniofacial, hyoideal, pharyngeal structural linear and angular variables. Genetic analysis and heritability estimation were performed using maximum likelihood genetic structural equation modeling (GSEM). Principal component analysis (PCA) was used to assess the correlations between cephalometric measurement variables.

Results: Upper airway dimensions showed moderate to high genetic determination (SPPW-SPP and U-MPW: a² = 0.64 and 0.5, respectively). Lower airway parameters showed only common and specific environmental determination (PPW-TPP a² = 0.24, e² = 0.38; LPW-V c² = 0.2, e² = 0.63; PCV-AH c² = 0.47, e² = 0.28). The relationship between the maxilla and the hyoid bone (for variables PNS-AH, ANS-AH d² = 0.9, 0.92, respectively) showed very strong additive genetic determination. The size of the soft palate was affected by additive and dominant genes. Its length (SPL) was strongly influenced by dominant genes, while its width (SPW) showed a moderate additive genetic influence. Owing to correlations in the behavior of variables, the data could be expressed in 5 principal components that jointly explained 36.8% of the total variance.

Conclusions: The dimensions of the upper airway are strongly determined by genes, while the parameters of the lower airway depend mainly on environmental factors.

Trial registration: The protocol has been approved by the Kaunas Regional Ethical Committee (No. BE - 2-41., May 13, 2020).

Keywords: Cephalometrics; Genetics; Orthodontics; Twin study; Upper airway.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cephalometry / methods
Face* / anatomy & histology
Humans
Maxilla* / anatomy & histology
Pharynx / diagnostic imaging