The morphology of the nasal septum in identical twins.

A comparison was made of the nasal septums of 41 pairs of identical twins to assess the impact of genetic and environmental factors on the formation of deformities of the nasal septum. Deformities of the anterior nasal septum (cartilaginous septum) were present in 22% of all the individuals studied, and in the posterior nasal septum (bony septum), some deformity was present in 74% of the persons studied. The distribution of deformities within pairs suggests that anterior deformities might be of external origin (e.g., traumatic), and posterior deformities may be considered to be part of a normal developmental process of the maxillary complex, where both genetic and epigenetic factors may play a role.