Nasal bone takes up 1/3 of the whole nose. It is composed of 1/3 of upper lateral cartilage and 1/3 of the lower lateral cartilage.
If you see this structure closeryou can notice that the lower it gets the softer it is. This is because the nasal bone is the most protruded it is easily breakable so in order to lessen the bone fractures we have to design a softer structure. That is we should maintain the respiratory path(shape of nose)and lessen the fracture of the nasal bones at the same time.
The lower lateral cartilage is softer and since it cannot get the support from the nasal septums it is connected to the upper lateral cartilage by other various soft tissues.
This is the reason why you shouldn't insert the silicone all the way to the tip of the nose and to help you understand the necessity of a nose tip surgery.
The picture where the nasal septum meets with the blue line is called the cartilage.