The use of parental data to evaluate soft tissues in an Anatolian Turkish population according to Holdaway soft tissue norms

Introduction: The relative influence of genetic and environmental factors in the etiology of malocclusion has long been a matter for discussion. The aim of this study was to compare the soft tissue structures of parents and their prepubertal, pubertal, and postpubertal offspring according to the Holdaway soft tissue norms to determine the similarity among them. Differences related to age and sex between the parents and offspring were also evaluated. Methods: Lateral cephalometric radiographs were used to determine the similarities in soft tissue structures in 120 families, which were divided into prepubertal (n = 40), pubertal (n = 40), and postpubertal (n = 40) groups according to the children's skeletal ages. A total of 12 variables (2 angular and 10 linear) were measured according to Holdaway's soft tissue analysis. Pairs were formed between family members (mother to son, mother to daughter, father to son, father to daughter, midparent (mean of the father's and mother's values) to son, and midparent to daughter) in each group. Descriptive statistics and multiple linear regression analysis were performed. Results: Statistically significant correlations between parents and their offspring were found. The parental data showed that a mother's genetic influence on her child's soft tissues was greater than the father's. Moreover, it was found that daughters had greater genetic influences from their parents than did sons. As age increased, the similarity was greater. Soft tissue facial angle (β: 0.671), soft tissue chin thickness (β: 0.549), and basic upper lip thickness (β: 0.537) were the most similar variables between parents and their offspring. Conclusions: A few selected cephalometric measurements of the parents might furnish important data to the clinician in predicting a child's facial growth characteristics and aging process.