## 4 Discussion  
This study aimed at analysing the relationship between septal deviation and facial asymmetry. Therefore, it used a unique approach, by looking at the three-dimensional morphology of the face, its decomposition into asymmetric and symmetric morphological components, and its relationship to age, sex, and degree of septal deviation from an ontogenetic perspective. The methodologies used combined traditional [40] and novel [38] approaches to the study of asymmetry, thus guaranteeing a comprehensive analysis. In the introduction, our null hypothesis stated:  
**H0. **_The degree of nasal septum deviation is not linked to the development of a more asymmetric face._  
To test this hypothesis, first, a distribution plot was produced, investigating the magnitude of septal deviation in the male and female sample, to observe for any potential differences in septal deviation linked to sexual dimorphism. The plot suggests no difference between males and females in the degree of septal deviation, although males show overall higher values of septal deviation. This result was confirmed by the Kolmogorov-Smirnov test, which showed no significant difference in the distributions of the two sexes. This result confirms and is supported by studies looking at septal deviation in male and female children [48] and adults [49], which found no significant difference in frequency of nasal septum deviation between the two sexes. Moreover, the distribution plot suggests a prevalence of septal deviation along the left side of the face for both males and females (higher distribution values), but significantly more pronounced values of right septal deviations. Similar studies have found more frequent left deviations [50]; however, the majority of \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Overall Facial** & **Degrees of Freedom** & **R2** & **F** & **Z (Effect Sizes)** & \(p\)**-Value** & **Interpretation** \\ \hline
**Reflection** & 1 & 0.004 & 0.37 & \(-\)2.73 & \(\sim\)1.00 &
\begin{tabular}{c} Effect of directional asymmetry \\ \end{tabular} \\ \hline
**Septal deviation** & 1 & 0.009 & 0.89 & \(-\)0.12 & 0.52 &
\begin{tabular}{c} Effect of septal deviation \\ \end{tabular} \\ \hline
**Age** & 1 & 0.13 & 13.25 & 5.60 & **0.001 *** & Effect of ontogeny \\ \hline
**Sex** & 1 & 0.16 & 1.65 & 1.61 & 0.056 &
\begin{tabular}{c} Effect of sexual dimorphism \\ \end{tabular} \\ \hline
**Individual × Ref.** & 2 & 0.03 & 1.51 & 1.66 & 0.055 &
\begin{tabular}{c} Effect of fluctuating asymmetry \\ \end{tabular} \\ \hline
**Refl. × Septal dev.** & 1 & 0.001 & 0.16 & \(-\)5.49 & \(\sim\)1.00 &
\begin{tabular}{c} Combined effect of nasal deviation and directional asymmetry \\ \end{tabular} \\ \hline Residuals & 84 & 0.80 & & & & \\ \hline \hline \multicolumn{1}{l}{Type III Sum of Squares. Sample size: 92 specimens (original and mirrored).} & & & & \\ \hline \end{tabular}
\end{table} 
Table 7: Results of the Multivariate Procrustes ANOVA between the dependent variable of overall facial shape and the independent variables of reflection, septal deviation, age, sex, and the joint effect of individual × reflection and reflection x septal deviation. Asterisks indicate significance: * \(p\)-value \(\leq\) 0.05; ** \(p\)-value \(\leq\) 0.01; *** \(p\)-value \(\leq\) 0.001.  
studies focus on septal corrections [51] or the impact of septum on sinusitis [52; 53; 54] and do not investigate the impact of septal deviation side on facial architecture from a morphological and/or an ontogenetic perspective; therefore, further studies are needed to investigate causes and consequences of this left frequency. To explore the relation between septal deviation and ontogeny, a scatter plot showing the relation between magnitude of left/right septal deviation and age was performed.