Non-segmental curvature of the nose refers to a nose with an irregular shape. This feature is often the result of asymmetry in bone growth and development. The anatomy of the nose includes several different structures that contribute to this shape. These structures include the nasal bones, which make up the upper third of the nose. These structures are pyramid-shaped, and gradually become thinner towards the Rhinion. They are attached to the frontal bone at the radix, which forms the frontonasal angle. Additionally, they articulate with the ascending process of the maxilla and overlap the upper lateral cartilages.
Traditional methods for treating bony vault and non-segmental cleft nose formation include lateral osteotomies and transverse osteotomies. These techniques aim to narrow the bony vault while conserving cartilage. These methods have several limitations, including potential overresection, asymmetries, and instability. In addition, the lack of visualization of the bony vault complicates the procedure. PEI, on the other hand, enables greater precision and reduces the risk of fracture.
Another important feature of modern plastic surgery is the ability to directly treat contour asymmetries in nose formation. Conventional osteotomies and fine rasping were once used to correct bony asymmetries. However, with the advent of ultrasonic rhinosculpture, surgeons can now direct-repair these problems using a single procedure.
The osseocartilaginous dorsal hump is composed of a thin bony cap that is overlying the cartilaginous vault. The initial phase of the procedure involves the gradual removal of the bone in the hump with a coarse PEI rasp, followed by finer rasps. In some cases, a bone-free nasion is achieved with a deepening of the nasion in the anterior-posterior plane.
The upper third of the nose is made up of nasal bones that are pyramidal in shape and gradually become thinner as they meet the frontal bone of the skull. The nasal bones are attached to the frontal bone at the radix, where they form the frontonasal angle. On the other hand, the lower part of the nose is comprised of cartilage, which makes up the thinnest part of the nose.
Non-segmental curvature noses are not segmental in form, but may have one or more dorsal humps. The changes in the bony skeleton can be camouflaged by the thick overlying soft tissue draped between the higher riding rhinion and glabella. The nasal bones also define the width and dorsal projection. The bony septum is a minor contributor to the dorsum, but deviations in the upper third may also involve the septum.
The reduction of a dorsal hump in a non-segmental curvature is a common surgical procedure to correct the problem. The procedure reshapes the nasal bones into similar widths and enables correction of a twisted dorsum. In a non-segmental curvaceous nose, a cartilaginous hump reduction redefines the dorsal vault dorsum and septal cartilage, although thinner septal cartilage may require grafts to support the septum.
The frontal view of the nose is the most useful when assessing a dorsal hump. The submental and oblique views also provide valuable information. Photographs are also important for preoperative analysis and for medicolegal reasons.
A non-segmental curvature nasal dorsum has various causes and no single surgery can be applied to all cases. Preoperative analysis should focus on the underlying bony and cartilaginous anatomy to identify the correct surgical approach for each case. If the deviation is due to bony deviation, it is different from a collapsed upper lateral cartilage or a dislocated caudal septum. In addition, a nasal dorsum can also be linear but deviated to one side. Therefore, surgical repair should address the underlying framework problem.
Infra tip prominence
An infra-tip prominence can indicate a non-segmental curvature of the nose. This type of deformity often accentuates the transition between the nasal tip and alar lobule. In extreme cases, the nasal tip may appear pinched or rounded.
A retrodisplaced nasal tip-columella complex may be the cause. Mass movement of the adjacent soft tissues is another possibility. These changes can lead to ballooning of the ala and a widening of the columellar base.
Surgical treatment can correct an over-protruding nasal tip. The LLCs must be repositioned three-dimensionally in the midline in order to restore a normal nasal tip. This procedure can improve both aesthetic and functional outcomes and can be performed in a single surgery. In addition to preserving the nasal tip’s natural softness, it also minimizes swelling and avoids external incisions.
Insufficient alar strut grafts can also lead to incomplete stenting of the medial crus and a pinched appearance of the nasal tip. In this case, the deficiency on the right side is more pronounced than the left. The patient also complained of right-sided nasal obstruction and collapse of the inspiratory nasal valve.
The non-segmental curvature of the nose is a complex and variable structure. Its width depends on the degree of lateral and medial crura angulation. The nasal tip is also divided into seven distinct subunits. These can be viewed from the base view. They include the nasal tip itself, nasal width, projection, and nostril shape and symmetry.
The interdomal width of patients before surgery is usually between 10 and 13 mm. However, a small minority (less than 15%) have interdomal widths that are greater than 10 mm. In such cases, the nasal tip would not be narrowed.
The non-segmental curvature of the nose is usually corrected with a septal graft. This can help to improve the nasal tip’s definition. It also can correct an overprojecting nasal tip. The septal grafts must extend far enough medially to correct the original domal angle. If the grafts are insufficient, the nasal tip can become convex and the septum may develop an S-shaped deformity.
The supra-alar fold is an important landmark for nasal tip analysis. It should be soft and easily visible. If the supra-alar folds are deep, this creates an unnaturally deep demarcation between the nasal sidewall and the alar lobule. An overzealous resection of the cephalic margin of the LLC is one of the main causes of over-angulation of the supra-alar fold. Overresection is often required to compensate for excessive nasal tip volume.
In non-segmental curvature, the nasal tip is narrowest at the domal angle, and this is the most important part of the nose for tip shape. The ideal nose is characterized by cephalic margins that diverge in the middle and a curved, non-segmental domal angle. Too wide a domal angle, however, results in a boxy nasal tip.
The domal angle determines the position of the ala and the nasal tip relative to the columella. The nose base should be triangular with an isosceles triangle with a gentle flare. When the nose is shaped with a broad dome, the nostrils are usually angulated between thirty and forty degrees from midline. The caudal septum is also evaluated to determine whether it is straight and oriented to the anterior nasal spine.
The upper third of the nose is made up of bony vaults formed by the frontal process of the maxilla and a pair of nasal bones. The nasal bones articulate with the frontal bone at the radix to form the frontonasal angle. The frontal process of the maxilla is attached to the upper lateral cartilage posteriorly, while the infra and supra-septal cartilages overlap and converge on the nasal bones, forming the keystone area.
The Domal angle is also affected by dynamics of the nasal tip. The conjoined medial and intermediate crura create tension in the M-arch structure, and the lateral crura project the tip anteriorly and inferiorly. In addition, soft tissue contributes to the balancing act between opposing forces. It is also the factor that determines the tip-defining point in space.
Nasal septum is a structure found at the base of the nose. It is formed by two oblong bones that meet at the bridge. The bones are connected by a rigid, fibrous joint, called the nasofrontal suture. These bones also form one of three nasal vaults, which are the thickest part of the nose. The septum is located at the base of each nostril.
Studies of human skulls have linked nasal septum size to various features, such as facial prognathism and nasal projection. However, the relationship between nasal septum size and non-segmental curvatures is less clear. For example, some patients have non-segmental curvature in one ear, while others do not.
A patient may undergo nasal septoplasty, a surgical procedure to straighten the nasal septum. This procedure is typically safe, but there is a small risk of bleeding or infection. In addition, the patient may experience numbness in the nose or around the front teeth.
A normal nasal septum and non-segmental curves are both important for breathing and for facial appearance. This region is important in regulating air flow and protects the nasal tissue from foreign matter. It is covered by respiratory epithelium and mucous cells. The air that enters the nasal cavity is warm and moist and reaches near 100 percent humidity. A neurovascular supply is present in the nasal septum that assists airflow. The superior cervical ganglia controls blood volume, while sympathetic nerves control the opening and closing of the nasal cavity.
A deviated nasal septum is associated with lateral facial asymmetry. This condition can also be associated with asymmetries in the nasal floor. The relative lateral deviation of the posterior nasal floor is illustrated in Fig. 4.