Skin thickness differences in the nasal dorsum
Dr. Sam Rizk, a USA rhinoplasty surgeon and a NY rhinoplasty surgeon and specialist, explains the importance of the differences in skin thickness on the nose and how it affects how we reduce or augment the dorsum. The skin differences in its thickness on the nose affect its stretch ability and its response to reduction of a bump as well. In white patients the dorsum should have sufficient width and height to constitute distinct anatomic structure that separates the eyes. The root of the nose between the eyes has a slight depression that differentiates it from the glabella and from the dorsum, which are both often more projecting. Dr. Sam Rizk sees patients who have had rhinoplasty and have an unnatural nasofrontal angle that is blunted and he is able to correct this with a technique he pioneered to reduce the nasofrontal angle to a more normal level. Since the skin in this area is less responsive to reduction of the bone, it is necessary to address the soft tissue structures directly to significantly impact the nasofrontal angle.
Dr. Sam Rizk, a NYC rhinoplasty surgeon who is double board certified in facial plastic surgery, reduces the procerus muscle bulk in this nasofrontal angle through the use of endoscopic 3d high definition telescopes inserted intranasally. This technique which Dr. Sam Rizk pioneered creates a more natural nasofrontal angle in revision rhinoplasty or secondary rhinoplasty by removing an unnecessary soft tissue muscle which has no function except to create wrinkles as we age. Dr. Sam Rizk reduces this muscle as well in primary rhinoplasty endoscopically to prevent it from rising and creating an unnatural angle. It tends to rise when the bony work is done on the nose and therefore blunts this nasofrontal angle creating an unnatural nose.
Grafting to the dorsum and root of the nose has several points in common, since these are in continuity, but they should be considered as two distinct zones because of differences in their skeletal structures as well as soft tissue thickness. In the root area, the covering tissues are thicker, with a mean of 7-7.5 mm; this thickness diminishes caudally as well as laterally, where the skin tends to be as thin as the eyelid skin. The bony profile in this area is concave; this concavity appears more pronounced when the glabella is projecting or the bony hump is large. The inner canthus constitutes a fixed point that prevents the soft tissue covers to redrape laterally. The soft tissue response to excessive bony removal is only 25% in the nasofrontal angle unless, as Dr. Sam Rizk, a New York rhinoplasty surgeon, discovered, the reduction is performed in the actual soft tissue itself consisting mainly of procerus muscle.
In the middle third of the dorsum, the soft tissue thickness is less important (2-3 mm at the level of the rhinion) where the skin is sometimes stretched over the osteocartilaginous framework. The soft tissue response to a dorsal reduction is about 60%. The osteocartilaginous profile is more or less convex and remains so when the dorsum is straight. These considerations should be kept in mind when cartilage grafts are planned in dorsal augmentations or reductions of the nasal bridge.
Cartilage Grafts to the Nasal Root
The nasofrontal angle represents the transition zone between the frontal area and the nasal pyramid. The extent of the nasofrontal depression should be appreciated in relation to the projections located above and below to create facial harmony with the nose. According to Dr. Sam Rizk, a New York City rhinoplasty or nose job surgeon, the glabella above and the bony hump below need to be appreciated in doing any dorsal reductions or augmentations to maintain facial and nasal harmony. Since the glabella cannot be modified, one should rely on alterations of the root and dorsum, either a reduction or an augmentation. One should consider the root as a part of the dorsum-a projecting structure that creates a clear separation between the eyes-and grafting should also create a smooth transition zone from the root to the dorsum.
The use of cartilage grafts to the root is indicated to provide a better equilibrium when the root is low and the nasal base is large, which would otherwise require a very extensive or even impossible reduction. Grafting to the root is appropriate when there is a substantial nasal hump, which will look less prominent after augmentation of the root and consequently will require less reduction. The material of choice for grafting the root should be a thin, supple piece of cartilage. The resected portions of the lateral crura are particularly suitable, because this supple, thin cartilage adapts itself adequately to the bony root; one need only lightly crush the lateral edges of the cartilages with a hemostat to avoid a visible edge laterally where the skin becomes thinner. The septal cartilage is less malleable and must be bruised and the edges beveled.
A moderate undermining is carried out at the level of the root, followed by a light rasping to remove soft tissue that is still remaining on the periosteum. One or more fragments are inserted using a smooth forceps; these fragments can be superimposed, the deepest fragment saddling the root. When grafting the dorsum is required, NYC Rhinoplasty Surgeon Dr. Sam Rizk recommends in case of thin skin that the graft extend the entire length of the dorsum and sometimes it is useful to deepen a root to accommodate a graft. Also Dr. Sam Rizk covers the implants on the nasal dorsum with a soft tissue cover like temporalis fascia or alloderm to make the graft edges soft and invisible. The deformities secondary to cartilage graft on the root are most often seen laterally and may result from improper modeling and thinning of the graft edges which may reveal itself by a projection catching the light.
Graft Visibility Prevention is one of the key elements of Dr. Sam Rizk's techniques and advancements. In addition to the soft tissue cover he creates, Dr. Rizk, a ny facial plastic surgeon and rhinoplasty specialist, sculpts the grafts with a specialized micro-powered sanding tool instead of the surgical knife, to create rounded soft edges (please see article in Plastic Surgery Practice Magazine featuring Dr. Rizk on this topic in the media section).
Sometimes if a nose has significant disequilibrium or a lack of harmony between its dorsum and tip, augmentation of the low radix and dorsum can be combined with a reduction of tip projection. Tip projection can be reduced by resetting the dome inward or resecting cartilage from the nasal tip.
Cartilage Grafts on the Dorsum
A dorsal graft can provide normal height as well as harmonious continuity with the root by presenting two curved and slightly divergent lines that extend from the supraciliary ridges to the tip defining points and are always separated by at least 5mm of space. The width of root and tip-defining points should therefore be a guide in determining the width for dorsal grafts. Septal cartilage is the material of choice for a graft to the dorsum because of its consistency, flat shape, and ability to be incised and/or crushed and used as multilayered grafts. Sometimes for major dorsal augmentation, alloplastic materials such as medpor are the best option. The advantage of medpor is that it does not absorb as natural material like rib, septum or ear cartilage (of note-all natural material will absorb with time and the degree of absorption varies individually). Dr. Rizk custom sculpts the medpor implant to fit your nose during your procedure, It is not a one size fit all implant.
Recipient site of the graft
The recipient graft bed should be carefully prepared and checked by palpation and if possible, directly visualized to trim any projection or irregularity that would cause instability or displacement of the graft. The recipient site should be regular, sufficiently wide, and flat or slightly convex. Dr. Sam Rizk, a NY rhinoplasty specialist, states that at the level of the bony dorsum, rasping can be done to prepare a flat and regular surface. Dr. Rizk explains that the recipient site is not stable over the cartilaginous dorsum, particularly when the cartilaginous dorsum has been resected and the edges of the upper lateral cartilages lack rigidity to stabilize or support a dorsal graft. Consequently, Dr. Sam Rizk, further explains that stabilization of the grafts partly depends on their extension up to the bony part of the dorsum, that is over a recipient bed that is stable and sufficiently wide.
Several techniques can be used to provide graft stability. The dorsal graft can be placed as an onlay, with its upper half placed over the bony dorsum. Furthermore, Dr. Sam Rizk, a NY rhinoplasty expert, explains, that using 2 spreader grafts under the onlay graft can provide a wider and more stable bed in the cartilaginous portion of the nasal dorsum. The external approach results in a more secure placement and more precise stabilization of these types of grafts.
Dimensions of the cartilage graft
Dr. Sam Rizk, a NYC rhinoplasty specialist and a NY revision rhinoplasty surgeon, emphasizes the importance of precise evaluation of length, width, and volume of a graft to avoid overcorrection or under correction.
Length - It is often better to have a graft that extends from the root of the nose to the supratip region, which corresponds to the length of 2.5-4 cm.
Width -The width of the graft is determined by the width of the root and the tip lobule. The graft also needs to cover an open roof deformity and blend with the lateral nasal walls.
Volume -volume of a graft should be carefully sculpted and beveled at the edges with less edge volume to make graft blend in and create a smooth dorsum. The volume also needs to take into account the aesthetics of a natural profile without saddles or bumps. Volume of a graft will vary to create either a masculine or a feminine profile.
Sculpting the Grafts
First, to tailor the graft, the surgeon must consider the convex contour of the bony cartilaginous dorsum and the variable thickness of the overlying soft tissues. The ends of the graft can be crushed by using smooth-tipped clamp and the edges and surface can be smoothed and beveled with Dr. Sam Rizk's powered sculpting techniques instead of the older technique of sculpting with the blade. Dr. Sam Rizk, a NY rhinoplasty specialist, has pioneered the use of powered sanding instrumentation to smooth out the edges and surfaces of grafts and implants, to achieve superb and natural contours. The older blade sculpting method by its very nature will result in angles and visible edges. The powered diamond sanding tools Dr. Rizk uses result in smooth non-visible edges.
Second, Crushed cartilage has an interesting application in the technique of cartilage grafting. In fact, crushing makes it possible to modify a resistant structure by changing its elasticity and modifying the flat or curved shape of the cartilage to obtain a weakened fragment that can be modeled and that has a greater surface area, less thickness, and a more fragile and malleable consistency. The purpose of using crushed cartilage is that it flattens out the surface of an irregular graft to fashion a thinner and more regular one that can be used as a covering graft. Septal cartilage is used in most cases-it is rigid and has certain cohesion even after crushing. Crushing can be carried out to several degrees-moderate crushing provides a flat septal fragment that is malleable and tile-shaped., or if crushing is more vigorous, cartilage will become more adaptable and perfect for use under very thin skin. Dr. Sam Rizk, a NYC rhinoplasty surgeon, points to the fact that auricular or ear cartilage does not respond as well to crushing and often breaks into separate fragments.
Cartilage grafts can be superimposed in two or three layers, according to Dr. Sam Rizk, depending on how much augmentation is needed. These layers of cartilage can be sutured together as one piece. In normal-thickness skin, it is preferable to assemble and fix the grafts with the narrow graft placed superficially; these two assembled grafts are then tailored and customized to the patient by beveling the edges and the length and width. In thin skin, it is better to place the wider graft superficially. When the harvested cartilage grafts are not of adequate size, the best fragment serves as a cover and the other fragments can be stacked underneath, if necessary, after having been crushed.
Fixation of the graft
Fixation is desirable to prevent displacement or movement of grafts. Dr. Sam Rizk, a New York City rhinoplasty surgeon, points out that when the pocket is narrow and limited then fixation may not be necessary as in when grafts are placed though an endonasal approach. The grafts can be placed in the jaws of a forceps and introduced into this limited pocket. Transcutaneous sutures can also be used to stabilize the graft through the endonasal approach in a certain position and these sutures are then pulled out in a week. The external approach has no real advantage in grafting the area of the nasal root. On the dorsum it allows better assessment of the recipient site and suturing of the inferior end of a graft to the anterior borders of the septum and the upper lateral cartilages.
Harvesting Auricular cartilage
When it is not possible to harvest septal cartilage because of previous septal surgery, the cartilage from the auricular concha is available in a substantial amount, and it can be harvested from both sides. This is a fibroelastic cartilalge, of good quality, which has convex surfaces and many angles. When one needs to fill in a significant depression, the quality of cartilage obtained from the concha is insufficient and other sources of grafts such as rib or implants needs to be used. Conchal or ear cartilage is excellent for a camouflage graft to make nose look straighter, for batten grafts in a mild external nasal valve collapse, and as an onlay tip graft for projection and definition. Conchal cartilage may be harvested through a postauricular incision or an anterior auricular incision at the edge of the concha.
Dr. Sam Rizk, a NYC rhinoplasty specialist, states that the uses of auricular cartilage are best for depressions in the nose and is best used in thick skin. Dr. Sam Rizk, does not like to use the ear cartilage for depressions on the bony dorsum where the skin in thin. Dr. Rizk states auricular cartilage may be best used in the nose for depressions in the cartilaginous dorsum in the supratip region where the skin in thicker. It may also be used as an onlay graft in the tip lobule to achieve projection and definition and in this case the convex portion is towards the skin. It may also be used in the nasal alae or to reconstruct or support the lateral crura of the lower lateral cartilage. If used on the dorsum, the ear cartilage needs to be a staighter piece. If the curved piece of auricular cartilage is used on the nasal dorsum, Dr. Rizk crushes the ear cartilage and scores it to remove the curved cartilage memory. Scoring or crushing cartilage. Crushing can be achieved by using the mallet on the crusher incrementally while checking the suppleness of the graft after each stroke.
Written by Dr. Sam Rizk