Vertical Dome Division Rhinoplasty

Nasal tip surgery is among the most complex and difficult tasks in rhinoplasty surgery. Vertical dome division (VDD) is one of a variety of techniques that may be used in refining nasal tip appearance. ^[1]  Collectively, vertical dome division (VDD) refers to one of many methods of vertically dividing the lower alar cartilage at or near the dome to modify nasal tip aesthetics. The technique was originally recommended as an alternative in altering tip projection and appearance while minimizing use of implants and the degree of postoperative tip ptosis. Vertical dome division (VDD) targets various nasal deformities, including overprojection or underprojection, suboptimal rotation, disproportionate lobule ratios, and broad or asymmetrical tip. ^[2]  The surgeon must strive to achieve an aesthetically pleasing nasal tip that is in balance with the remainder of the nose without compromising nasal airway function.

Safian originally alluded to the philosophy and technique of vertical dome division (VDD) in the 1930s. ^[3]  In 1957, Goldman popularized vertical dome division (VDD) as a method of refining tip position without the use of columellar grafts. ^[4]  Despite its initial acceptance, the technique was later stigmatized because of the postoperative sequelae associated with it. Once the dynamics of nasal tip surgery were better realized, the technique regained a degree of popularity and acceptance with modified techniques offered by Simons and Adamson. The indications and applications for vertical dome division (VDD) are now much broader; some surgeons continue to embrace its application, although others strictly avoid it. ^[5]

Frequency

Although the exact frequency of vertical dome division (VDD) is unknown, the technique is used quite commonly by a variety of plastic and reconstructive surgeons.

Candidates for vertical dome division (VDD) typically present for rhinoplasty evaluation with a desire to correct an unfavorable nasal tip appearance. The typical patient presenting for vertical dome division (VDD) usually has a poorly defined or malpositioned tip with a combination of abnormal projection/rotation, broad or amorphous lobule, asymmetric tip defining points, and/or boxy, trapezoidal base.

Selection principles

Vertical dome division (VDD) is a philosophical and technical approach to management of the nasal tip. This philosophy is based on the belief that vertical dome division (VDD) is a more conservative maneuver than horizontal excisional techniques traditionally used in tip refinement surgery. Adherents to this principle argue that horizontal excisional techniques rely too heavily on unpredictable and uncontrollable postoperative scarring to produce desired tip results. Proponents of vertical dome division (VDD) believe that vertical incisional and excisional techniques, on the other hand, offer a more definitive and reliable means to achieve desired tip changes.

Goldman originally described this technique in 1957, although he never used the term vertical dome division (VDD). ^[4] In this landmark paper, he attempted to highlight the significance of the medial crura in nasal tip projection. Transecting the domes across the apex, as he described it, was a novel alternative technique intended to help refine and maintain nasal tip appearance without the requirement of grafts or implants. Since this first description, newer insight into nasal tip dynamics has broadened the application and use of vertical dome division (VDD) as an adjunctive tool in rhinoplasty.

In principle, the technique of vertical dome division (VDD) separates the medial and lateral crura into 2 independent units. By transecting the dome, the inherent spring within the arch is released and allows realignment of the newly divided medial and lateral segments to reconstruct the nasal tip.

In general, techniques that preserve the integrity of the alar cartilage anatomy and minimize excision should be considered as first-line methods of modifying the nasal tip. Vertical dome division (VDD) is typically reserved for more complicated cases that require greater changes to effect tip refinement than could be achieved using other techniques. Nearly all variations of vertical dome division (VDD) used today involve some modification of the original Goldman technique. These numerous versions of vertical dome division (VDD) make it a versatile technique that may be applied in patients requiring alterations or corrections in tip projection, tip rotation, infratip lobule abnormality, domal width, and tip asymmetry.

Alteration of tip projection

The underprojected tip

Most cases in which vertical dome division (VDD) is used patients presenting with an underprojected nasal tip. By essentially borrowing from the lateral crus, the length of the medial crura can be augmented to provide an increase in tip projection. The Simons method of vertical dome division (VDD) is a common technique used when mild-to-moderate changes are required. In cases for which more dramatic changes in tip alignment and projection are desired, the classic Goldman procedure is recommended over the modified techniques.

The overprojected tip

Retroactive tip displacement can be accomplished with vertical dome division (VDD) in patients with marked overprojection. In patients with less severe overprojection, more conservative techniques, such as repositioning the medial crural footplates closer to the facial plane, may suffice. By dividing the lower alar cartilage medial to the dome, the medial crus can be overlapped and shortened to drop the anterior projection of the nasal tip complex.

Alteration of tip rotation

The underrotated tip

Vertical dome division (VDD) may also be indicated in patients requiring increased tip rotation. First-line techniques for increasing rotation include simple domal suturing, cephalic trimming of the lateral crura, and cutback of the lateral crural hinge region. Vertical dome division (VDD) can be used to further rotate the nasal tip by dividing the lobule medial to the dome. The lateral crural segments then can be rotated superiorly and repositioned along the caudal septum in a more cephalic orientation relative to the medial segments. This aids in widening the nasolabial angle and, as a result, increases tip rotation. ^[6]

The overrotated tip

Vertical dome division (VDD) can also be used to decrease tip rotation (counter-rotation). After dividing the alar cartilage medial to the dome, the cut edge of the lateral segment can be overlapped on the remaining medial crus, in a similar fashion to vertical dome division (VDD) for the overprojected nose. By realigning the lateral segment in a more caudal orientation, counter-rotation of the tip is achieved in addition to a decrease in tip projection.

Alteration of other abnormalities

Lobule abnormalities

Many patients presenting with an underprojected tip also have a noticeably short or hypoplastic infratip lobule as observed on base view. Vertical dome division (VDD) is a reliable technique to help lengthen this lobule while providing an increase in tip projection.

The relationship between the infratip lobule and the surrounding tip structures (nasal tip lobule, columella, soft tissue triangles) is complex. The infratip lobule is located between the nasal lobule and the columella and is most typically lunate (crescent moon) shaped in appearance. The structure primarily responsible for the prominent infratip lobule length is the overly long intermediate crus.

Other patients present for nasal tip modification with a disproportionately elongated lobule. Many other techniques used to shorten this lobular region reduce the length of the lateral legs of the nasal tripod; however, they do little for the remaining medial tripod leg. Using these techniques in this situation only serves to further shorten the columellar and overall nostril dimensions, leaving a lobule that is even more disproportionately long. Vertical dome division (VDD) medial to the domes, with overlapping of the medial crural segments, aids in shortening the lobule as well as in correcting overprojection in these patients.

Other patients may present with a hanging infratip lobule abnormality as a secondary indication for vertical dome division (VDD). Ideally, the infratip lobule is observed on lateral view as a subtle break in the columellar profile, with slight cephalic angulation. Patients with a hanging infratip lobule, instead, demonstrate a pronounced inferior curvature or droop in this region. This irregularity must be distinguished from a hanging columella, since techniques intended to correct these deformities are different.

Widened dome

Patients with a widened domal arch present with a relatively broad, amorphous nasal tip with a trapezoidal appearance noted on base view. As the width of the arch increases, definition in the lobule region decreases. Vertical dome division (VDD) may be indicated to help correct this abnormality by narrowing the convergence of the apex and arch, thus increasing projection and restoring a more triangular base appearance.

Tip asymmetries

Asymmetries of the nasal tip and lobule are a frequent and challenging problem for the rhinoplasty surgeon. Vertical dome division (VDD) is a particularly useful technique for managing these asymmetries. Each dome is addressed individually and is divided vertically to achieve a more balanced tip with symmetric domal highlights. Redundant or knuckled cartilage may be excised either unilaterally or bilaterally, and tip rotation or narrowing may be addressed as needed for each side.

Successful application of vertical dome division (VDD) requires a fundamental understanding of the anatomic components and dynamics of the nasal tip. The most anterior projecting point of the nasal tip is considered the tip defining point. The nasal tip is characterized by the shape of the lobule, which is formed by the contour of the underlying alar cartilage.

The lobule is defined as the portion of the nasal tip complex that is situated anterior to the nostrils; it extends from the tip defining point to the junction with the columella, as observed on base view. The alar cartilage (lower lateral cartilage) is C-shaped and can be divided into the medial, middle, and lateral crus. The middle (intermediate) crus comprises the domal segment and largely influences the shape of the lobule and, therefore, the form and definition of the nasal tip. The dome is considered the highest arching segment within the nasal vestibule.

Important parameters to consider in vertical dome division (VDD) include tip projection and rotation, lobule size, and nasal length. Projection of the tip refers to the posterior-to-anterior distance that the tip extends from the alar-facial groove. Rotation can be defined in terms of relative tip position along a circular arc, with the radius centered at the nasolabial angle and extending toward the tip defining point.

Nasal length is simply the distance from the nasion to the tip defining point. Several methods of calculating tip projection have been developed. The simplest method, as described by Simons, defines projection as the distance from the subnasale to the tip defining point as seen on a profile view, with an ideal distance equal to the height of the upper lip. Tip rotation can be referenced as a function of the nasolabial angle, with ideal rotation measuring 90-100° in males and 95-105° in females. The lobule size can be assessed in comparison to the columellar length. If the base view demonstrates a columellar-to-lobule ratio of approximately 2:1, the structural support and configuration of the nasal tip is considered adequate. A long nasal length reflects an acute nasolabial angle; a short length reflects an obtuse nasolabial angle.

The anatomy of the nasal tip is often described using the tripod concept to facilitate understanding of the key structural components and to provide a simple explanation of tip dynamics. According to this analogy, the cartilaginous framework of the lower third of the nose is compared to a tripod that is attached to the facial frontal plane. The 2 individual lateral crura represent 2 legs of the tripod, and the conjoined medial crura and caudal septal attachments correspond to the third leg.

By lengthening or shortening any or all legs of the tripod, the changes that will be effected in tip projection and rotation can be predicted. For instance, techniques that augment or lengthen the medial crural segment enhance projection. Shortening the medial crura or disrupting their septal attachments without reduction of lateral crural length decreases projection and rotation of the nasal tip. Shortening the lateral crura and maintaining or lengthening the medial crural segment would be expected to increase rotation.

Essentially, 4 major mechanisms contribute to nasal tip support as follows:

• The overlap (scroll) of the caudal border of the lower lateral cartilage overlapping the cephalic margin of the upper lateral cartilage

• The membranous attachment between the anterior septal angle and the interdomal ligament

• The membranous attachment of the medial crural footplates to the caudal septal margin

• The length, width, orientation, and inherent strength of the lateral crura

In most rhinoplasty procedures, violation of these support mechanisms is avoided or countered using augmentation or reinforcement techniques. By respecting these major mechanisms and by understanding their role in tip projection, potential postoperative complications and tip irregularities can be minimized.

Vertical dome division (VDD) is predominantly contraindicated in patients with relatively thin skin. These patients are particularly prone to developing visible cartilage edges along the nasal tip region. This results from contraction of the thin overlying skin and soft tissue envelope around the new and more prominent medial cartilaginous strut. A thick overlying skin and soft tissue envelope is better able to cushion the appearance of prominent cartilaginous structures, such as those in vertical dome division (VDD).

Avoid classic vertical dome division (VDD) in patients who show evidence of already weakened lateral nasal walls. Dividing the domal region without reapproximation of the cartilage segments disrupts the integrity and continuity of the lower lateral cartilage. The lateral nasal wall is more susceptible to structural collapse than the newly reinforced medial footplates. As a result, lateral wall weakening and collapse are further potentiated.