The nose is made up of a fixed and rigid part that is called nasal pyramid, although it rather has the shape of a tent or roof, and a pliable mobile part which is the nasal tip, the alae and its annexes. The nasal pyramid is formed by two types of structures or tissues; in the most cephalic or upper part the nasal pyramid is formed by the nasal bones and the ascending process of the maxilla, that is, by bone tissue; the most caudal or lower part of the nasal pyramid is formed by the triangular cartilages or also called quadrangular or lateral or upper lateral, that is, by cartilaginous tissue.
Both halves or walls of the nasal pyramid join and fuse horizontally with each other in the center of the nose to form the dorsum, hump or nasal bridge (misnamed by many people as the septum, which is not part of the nasal dorsum), creating what is called pyramid or bony or osseous or hard dorsum (cephalic or upper), formed by synostosis or fusion between bones, and the cartilaginous middle vault or soft pyramid or dorsum (caudal or lower), formed by synchondrosis or fusion between cartilages. In turn, the nasal dorsum is joined and merged by its lower or posterior face with the nasal septum, nasal septum which also, in turn, consists of a cephalic or upper bony part and a caudal or lower cartilaginous part, corresponding the bony septum to the fusion with the cephalic or upper or bony dorsum and the cartilaginous septum to the fusion with the caudal or lower or cartilaginous dorsum, forming a tripod in which the lateral legs are the nasal wall and the central leg the nasal septum.
In many occasions the patient is unable to detect the nasal asymmetry, attributing their dissatisfaction to the lopsidedness of their nasal pyramid for being crooked. The osseous and cartilaginous walls forming the nasal pyramid, as well as the alar or lower lateral cartilages building the nasal tip and alae, might be of different size and shape from one side to the other, leading to a high grade of nasal deviation; nasal asymmetries have very difficult or partial, if any, correction, or they might need very complex and rebuilding surgical strategies, having no connection with really crooked noses.
Some patients call crooked nose what is really nasal asymmetry, or both problems coexist so we would be before a case of nose deviation aggravated by the asymmetry of the nasal structures. It must be borne in mind that when the nose is crooked this causes a severe aggravation of the nasal asymmetries, and vice versa, which may confuse patients and surgeons who are not experienced in rhinoplasty surgery. In other words, the greater the asymmetry of the nose, the more it seems that there is nasal crookedness, but it is not the real grade of deviation; the actual grade of deviation is seen once the nose is in its correct position.
It is very important that the patient receives an exact diagnosis, because under no circumstances should nasal asymmetry be treated by deviation correction techniques for misinterpreting that such lopsidedness is due to crookedness, as it would entail a grotesque and artificial appearance.
In most cases, the patients suffer at the same time from nose deviation along with a greater or lesser degree of nasal asymmetry, so it is a discretional decision treating either or both of the problems.
The structures involved causing nasal pyramid crookedness are the nasal bones, the triangular or quadrangular or upper lateral cartilages, the hard or osseous nasal septum, the soft or cartilaginous nasal septum, the nasal dorsum, etc. Therefore treatment may require varied techniques addressing each problem, like osteotomies (infractures or outfractures of the nasal bones), spacer or spreader grafts, septoplasty, septal strut, etc.