Materials and methods
This single-center, cross-sectional study was conducted at XXX University, School of Medicine, Department of Plastic, Reconstructive and Aesthetic Surgery Department between September 2017 and June 2018. A total of 546 male adolescents aged 15 to 17 years without any known history of major facial trauma and sport injuries were included in the study. Those with a history of major nasal trauma, nasal surgery, congenital and/or acquired cranio-facial and hand anomalies were excluded. The participants were randomly selected from six high schools of XXX municipality of XXX province. All participants were informed about the nature of the study and a written informed consent was obtained from parents and/or legal guardians of the participants. The study protocol was approved by the institutional Ethics Committee (No: 09.2016.275; Date: 01/04/2016). The study was conducted in accordance with the principles of the Declaration of Helsinki.
All examinations were performed by a single plastic surgeon through inspection. The midline was determined using the midpoint of the nasion and nasal spine. Accordingly, each participant was examined for the presence or absence of nasal bone pyramidal deviation, caudal septal deviation, side of the deviation, and nostril asymmetry. The data were recorded in the Microsoft Excel table.
The dominant hand was recorded on the personal profile of the participant for the preferred hand mostly used for activities such as writing, using forks and knives, throwing objects, grabbing door handles, and waving.
According to the XXX District Governorship data, there were a total of 34,612 high school students with the overall district population of 712,000 individuals at the time of this study, representing 5% of the population (14). Using the simple random sampling, minimum 203 participants were required with d=0.03 and p=0.05.
Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS) for Windows version 23.0 (IBM Corp., Armonk, NY, USA). Descriptive data were expressed in mean ± standard deviation (SD), median (min-max) or number and frequency, where applicable. The normality was checked using the Shapiro-Wilk test. As the normality was not achieved, non-parametric Mann-Whitney U test was used for pairwise comparisons. The Kruskal-Wallis H test was used for multiple comparisons. A p value of <0.05 was considered statistically significant.