| THE MOBILE TRIPOD TECHNIQUE
The Key to Nasal Tip Refinement
Alvin I. Glasgold, MD, Mark J. Glasgold, MD, and David B. Rosenberg, MD
Professionally, the senior author (AIG) has dedicated the last 35 years to understanding nasal anatomy and dynamics. Since the beginning of his practice, his goal has been to develop a rhinoplasty approach that produces consistent, predictable, and long-lasting results. Early in the senior author's career, he realized the need for a comprehensive rhinoplasty technique that could address all components of nasal tip dynamics and cosmesis because, in most instances, nasal tip refinement is the most challenging and important aspect of rhinoplasty. The available techniques three decades ago for adjusting tip definition, rotation, and projection were less predictable than today. As appreciation of nasal dynamics improved, the senior author's approach to rhinoplasty evolved. This article summarizes these developments in the senior author's career and specifically describes the mobile tripod concept, his technical answer to rhinoplasty after three decades of surgical maturation.
During the senior author's career, he has transitioned through several rhinoplasty techniques, first as an endonasal surgeon and then as an advocate of external rhinoplasty. He began performing rhinoplasties using the Gold-man tip, which essentially was a vertical dome division. Soon afterwards, Anderson and Reese and Wood-Smith" began to emphasize the importance of maintaining an intact cartilage rim. Therefore, the senior author started to achieve tip refinement using varying degrees of cephalic trim of the lower lateral cartilages performed through a cartilage splitting and delivery technique. These maneuvers were effective in thin-skinned individuals requiring subtle tip improvement but often proved inadequate in the diverse ethnic mix of patients within the senior author's practice.
Additionally, early in the senior author's career it was evident that endonasal techniques used to expose the nasal structure resulted in loss of tip support. Consequently, what seemed to he a simple rhinoplasty often be-came a complex problem of tip restructuring. The endonasal placement of a columellar strut was an important advancement in maintenance of tip support.' This graft could also be used to increase tip rotation and projection. ephalic rotation of the domes, however, in-creased supratip bulk and thus mandated excessive trimming of the lower lateral cartilages. This structural violation contributed to bossa formation, alar retraction, and external valve collapse.
The introduction of the external rhinoplasty approach helped the senior author better understand the dynamic forces acting on the nasal tip.' Altering tip contour requires the ability to change shape, position, projection, and rotation. Anderson's tripod theory formed a foundation for adjusting tip rotation and projection. Geometrically, the nasal tip is a tripod with two lateral limbs formed by the lower lateral cartilages and the medial leg made up of the combined medial crura (Fig. 1).
It was evident that to reduce nasal length or to rotate the tip, the downward force of the lateral crura had to be altered (Fig. 2).
Lateral crura transection or resection of the distal ends of the lateral crura decreased this downward force and allowed the tip to be rotated. Lengthening of the medial limb enhanced rotation and projection, which was achieved using a columellar strut.'
Although the tripod concept addressed nasal rotation and increased projection, it was not the ideal solution for tip narrowing or reducing projection. Although release of the tip support did allow the tip to drop, and dome binding sutures did narrow the tip, these maneuvers were not solutions that gave the senior author the desired level of predict-ability.
It became evident that separating the tripod into its component parts - one medial leg and two lateral limbs - removed the resistance of the intact crural arch and allowed greater mobility and contouring of these components (Fig. 3).
It also became evident that division of the alar cartilages at the angles rather than the domes was anatomically the more natural point of separation. This allowed for better contouring of the individual medial and lateral crura. The mobile tripod concept builds on Anderson's approach by giving much more control over tip rotation, projection, deprojection, and narrowing. Over the last decade, this technique has produced consistent, predict-able, and long-lasting results and has ad-dressed all components of nasal tip correction (Fig. 4).
TECHNIQUES Following the standard external rhinoplasty elevation of the nasal skin and soft tissues, the medial crura are identified and separated in the midline. Bilateral mucoperichondrial flaps are elevated to expose the entire septum, and then septal surgery is performed to correct a deviation or to obtain cartilage for grafts. The mucosal flaps are then closed with a 4.I chromic suture in a quilting manner.
The cartilaginous angle between the medial and lateral crura are then identified and transected bilaterally. The medial crura are thereby completely separated from the lateral crura. This disconnection of the medial and lateral limbs produces a tripod in which each of the components are freely mobile (Fig. 5).
A 6.I Prolene suture is placed approximately 4 mm below the superior edges of the medial crura to reapproximate them and form a single medial limb of the tripod.
The lateral crura are now addressed. The cephalic margins of the lower lateral cartilages are elevated off of the underlying mucosa for approximately one third of the width of these crura. At the same time, the attachments of the upper lateral cartilages are separated from the lower lateral cartilages. The appropriate amount of the medial and cephalic margins of the lower lateral cartilages are resected (Fig. 6).
The amount excised depends on the size of the lower lateral cartilages and the degree of narrowing of the tip necessary. It should be noted that a minimum of 6 mm of lower lateral crura width is retained for adequate structural support.
These maneuvers allow for cephalic rotation and medial positioning of the lower lateral cartilages. If additional rotation is necessary, the lateral-most aspect of the lower lateral cartilages, where they meet the sesamoid cartilages, are resected. Thus, narrowing of the nasal tip, shortening of the nasal length, and rotation are accomplished.
At this point, the relationship of the medial and lateral crura are assessed. The examination includes degree of tip projection, tip width, the shape of the medial crura, and the effect superiorly beyond the columellar lobule junction. The strut and both medial crura are sutured together now with a 6.0 prolene suture to firmly establish the medial limb of the tripod. The skin is returned again to its original position to visualize tip projection in its relationship to the dorsum. Now the degree of tip narrowing and the shape of the tip formed by the new relationship of the medial and lateral crura are assessed.
The relationship between the tip and the dorsum is evaluated, and the appropriate amount of dorsal reduction is performed. Me-dial or lateral osteotomies are accomplished at this time. The skin and soft tissue complex are redraped and the nose evaluated once again. The relationship between the tip and the dorsum are reassessed. Whether or not a supratip break is present or desired is examined. The degree of narrowing of the tip complex and the absence of supratip fullness are checked. At this time, additional trimming of the cephalic portion of the lower lateral cartilages can be accomplished if necessary.
If further tip definition, rotation, or additional projection is required, the use of an ex-tended shield graft can now be considered. This cartilaginous graft is commonly used in noncaucasian or revision noses in which the structure of the tip has been violated, removed, or is so weak that additional tip projection is necessary.
The extended shield graft is ideally fashioned from septal cartilage because of its strength, but auricular cartilage also can be used. The top of the extended shield graft should be rounded and contoured so that it is finer than its body and does not produce projecting points at the tip. To insert this graft, a pocket is created anterior to the complex of the medial crura and columellar strut. The pocket is dissected in a downward fashion, and the extended shield graft is placed into this pocket and then evaluated as to its length and curvature (Fig. 9).
This graft is firm and straight and can add length to the nose. If further rotation is desired, the graft can be horizontally cross-hatched in its superior margin so that it curves cephalically. In all instances, the extended shield graft must extend above the medial and lateral crura so that it forms a new tip configuration (Fig. 10).
If necessary, the extended shield graft can be trimmed to decrease its length. The medial and lateral crura now become a part of the supratip region instead of the tip. The graft is sutured in place with a stitch through the inferior portion of the medial crura. For a more firm fixation, a second suture is placed toward the top one third of the shield graft that passes through the graft into the medial crura and then back again through the graft and then tied (Fig. 11).
At this point, the skin and soft tissue envelope is returned to its natural position. The nose is examined. If it appears that the shield graft extends too far, its superior aspect can he further trimmed. Closure of the original incision is performed carefully. It is crucial that the marginal incision is closed, thereby firmly establishing the position of the lateral crura and its relationship to the medial crura without having to suture the lateral crura to the me-dial crura.
Closure of the marginal incision produces a more natural tip contour than achieved 1w reapproximating the medial and lateral crura. Once closure is accomplished, the width of the nostril should be evaluated. If alar base resection is necessary, it is now performed.
DISCUSSION The nasal tripod concept has helped the senior author understand the dynamic forces that act on the nasal tip. This theory, as taught 1w Anderson, gave the senior author the foundation to develop the mobile tripod approach, a predictable technique for adjusting tip rotation, definition, and projection. This is best per-formed through an external approach that allows the surgeon to be more exact in trimming and positioning the component parts of the tripod.
Before the mobile tripod technique, nasal tip narrowing was accomplished by cephalic trim of the lower lateral cartilages. Aggressive cephalic trim was required in the broad tip and sometimes led to loss of ala support, resulting in bossa and tip asymmetries. The use of a dome-binding suture produced a narrow tip without the need for excessive ala trimming, but the senior author found it inconsistent in creating the degree of tip refinement desired. Angle division, lower lateral cartilage cephalic trimming, and medialization have allowed the senior author to narrow the tip in a precise manner without adding to supra tip bulk (Fig. 12).
In the platyrrhine nose, the improved results using the mobile tripod technique have been dramatic. Tip narrowing has been consistent and predictable (Fig. 13).
Before vertical angle division, tip rotation was achieved by lateral crura transection and resection as espoused in Anderson's% tripod theory. Although useful in understanding tip rotation, it did not fully address the downward force of the lower lateral cartilages. The senior author has achieved consistent and predictable control of tip rotation by the mobile tripod concept, notably angle division, lateral crura repositioning, and medial crura support with a columella strut.- This method has successfully adjusted rotation in revision rhinoplasty and primary cases (Figs. 14 and 15).
It particularly addresses the problem encountered in the mature patient who presents with worsening tip ptosis (Fig. 16).
The mobile tripod approach has proved effective in revision rhinoplasty cases. Angle di-vision, columella strut placement, appropriate medial and caudal trimming of the lateral crura, and extended shield graft insertion have consistently corrected tip asymmetries, poor tip definition, and inappropriate columella ala relationships" (Figs. 17 and 18)
Adjusting nasal tip projection is always a challenge. The mobile tripod, with angle division and trimming the superior edges of the medial crura, allows predictable tip deprojection to be achieved (Fig. 19).
Increased projection can be accomplished with angle division, columella strut placement, and extended shield graft insertion when necessary" ( Fig. 20).
Addressing the proper relationship of the medial and lateral crura is overlooked too frequently in rhinoplasty. Gross disharmony generally presents as the appearance of a columella hang. More subtle distortions, such as columella retraction, also occur frequently, particularly following a rhinoplasty. This can contribute the medial and lateral crura and allows them to an attractive appeareance of the lower one third of the nose. Columella hang is frequently the consequence of excessive curvature of the medial crura. The mobile tripod separates to be repositioned, establishing an appropiate distance of 2 to 4 mm between the alar margin and the most caudal aspect of the columella (Figs. 21 and 22).
The retracted columella is also corrected by this approach with the addition of a wide columella strut that reverses the effect of an over-shortened septum.
The mobile tripod has been particularly useful in the patient population desiring subtle changes in nasal appearance. These patients generally need slight rotation and improvement in tip definition. The mobile tripod has given the senior author the confidence to deal with this patient population (Fig. 23).
The senior author's experience with the mobile tripod has included more than 14(R) external rhinoplasties. This technique has never resulted in a tip collapse and has markedly reduced the number of postoperative problems to a minimum. Over the last 7 years, the senior author has taught the mobile tripod approach to fellows in training and found that they have reproduced it successfully on entering private practice.
His appreciation of nasal tip dynamics has evolved over his career. The mobile tripod approach has given the senior author the ability to address all of the aesthetic problems of the nasal tip, and it has led to better results than obtained before using this method.
REFERENCES
- L Anderson J: A plan of nasal tip surgery. Eye, Ear, Nose and Throat Monthly , 1962
- Anderson I, Johnson C, Adamson P: Open rhinoplasty: An assessment. Otolaryngol Head Neck Surg 90:272 274, 1982
- Anderson JR, Ries WR: Surgery of the nasal base: Setting tip projection and location. In Anderson JR, Ries WR (ens): Rhinoplasty: Emphasizing the External Approach. New York, Thieme, 1966, pp 63-78
- Arden R, Crumley R: Cartilage grafts in open rhinoplasty. Facial Plastic Surgery 9:285-294 1993 Glasgold A: Dynamics of the columella strut. American journal of Cosmetic Surgery 1:41-44, 1984
- Glasgold A: Revision rhinoplasty: Open approach.
- American Journal of Cosmetic Surgery 4:251 255, 1987
- Glasgold A, Glasgold M, Silver F: Cartilage graft in
- nasal surgery. Am J Rhino 3:167 171, 1989
- Glasgold M, Glasgold A: Tip grafts and their effects on tip position and contour. Facial Plastic Surgery Clinics of North America 3:367-379, 1995
- Rees TD, Wood-Smith D: Rhinoplasty: Rees TI, Wood-Smith D (eds): Cosmetic Facial Surgery. Philadelphia, WB Saunders, 1973, pp 268-493
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