Nasal Septal Deviation and Nasofacial Skeletal Form: A Cross-Sectional CBCT Study of a 7-18 Year-Old Cohort

Abstract

Objective: The objective of this study was to examine the relationship between nasal septal deviation and the shape of the nasofacial skeleton during ontogeny. Materials and Methods: Nasal septal size was retrospectively measured on existing cone-beam computed tomograms (CBCT) in 66 mixed-sex orthodontic patients of European ancestry aged 7-18 years. First, the septum was manually segmented using CBCT reconstructions and the volume of the structure calculated. Next, a midsagittal volume that followed the borders of the septum was constructed as a model for a non-deviated septum. Nasal septal deviation was then calculated for each individual. Nasofacial skeletal form was quantified using a series of coordinate landmarks of the facial skeleton in the nasal region and the cranial base. Using geometric morphometric techniques, size and shape information was distilled from the landmark data. Multivariate regression analyses were used to assess the interactions between the septum and the nasofacial skeleton. Results: There was no significant correlation between nasal septal deviation and age or nasofacial size. Nasofacial shape changes correlated with septal deviation followed a different pattern than allometric shape changes. In individuals with a deviated septum, the sphenoid body was anteriorly positioned, reducing the size of the nasofacial skeleton. This pattern of morphological variation was independent of the stage of development. Conclusion: Normal developmental changes in nasal cavity and cranial base form are not related to an increase in nasal septum deviation. Rather, a nasofacial skeletal configuration with anterior displacement of the sphenoid may place spatial constraints on the growth of the septum, resulting in deviation.