Eric W. Cerrati, MD
Assistant Professor, Facial Plastic & Reconstructive Surgery, Division of Otolaryngology–Head & Neck Surgery, University of Utah, Salt Lake City, UT
Regan Thomas, MD
Professor, Facial Plastic & Reconstructive Surgery, Department of Otolaryngology–Head & Neck Surgery, Northwestern University, Chicago, IL
Eric W. Cerrati, MD
30 No. 1900 E. Room 3C120 SOM
Salt Lake City, UT 84132
Phone: (801) 585-3223
Successful tip modification and location control is an integral part of both cosmetic and functional rhinoplasty. With a multitude of variables that can be altered, many consider this part of the operation to be the most complex. Investigation into this area has been the basis for many research topics and publications. When simplified, the goals of these maneuvers are to adjust the lower lateral cartilage to accomplish the desired tip rotation and projection. A powerful technique is explored, in which both variables can be altered in a reproducible and predictable manner.
Anatomy & Preoperative Analysis
Prior to discussing surgical control of the nasal tip, a thorough understanding of the anatomy is critical. The external nasal appearance can be divided into thirds. The upper third consists of paired nasal bones. These bones overlap with the paired upper lateral cartilages, which make up the middle third. Caudally, paired lower lateral cartilages form the tip of the nose. In between extending inferior to the paired nasal framework, the nasal septum is a composite (osseo-cartilaginous) structure that divides the nose into two similar halves.
The lower lateral cartilages can be further sub-classified. Each cartilage can be divided roughly into thirds: lateral crus, intermediate crus, and medial crus. The lateral crus provides shape and support to the ala. It also articulates with the upper lateral cartilage, in an area called the scroll. The intermediate crus contains the dome and is often the narrowest portion of the cartilage. The medial crus extends down the columella providing stability to the nasal base with attachments to the caudal septum. The strength of the lower lateral cartilages along with its attachments to the septum and upper lateral cartilage comprise the major tip support mechanisms. Therefore, cosmetic manipulation can have drastic functional changes and vis versa.
Repositioning of the tip depends mainly on changing the degree of nasal tip projection and/or nasal tip rotation. These maneuvers are accomplished by altering the shape and orientation of the paired lower lateral cartilages. The nasal tip projection refers to the posterior-anterior projection of the tip from the vertical facial plane. Tip rotation is defined as movement of the tip along a circular arc, with its radius maintained from the facial plane. Many quantitative and qualitative methods for measuring nasal tip projection and rotation have been reported. Guidelines along with measurement estimates have been established in order to assist in creating the ideal nasal tip position.
In 1969, Anderson introduced the tripod theory in which the cartilaginous framework of the nasal tip simulates a tripod, with 2 lateral legs formed by the lateral crura on each side and 1 medial leg formed by the conjoined medial crura. Through this simplified model, one can imagine the resulting changes when different structures are manipulated. When the nose is overprojected, it draws abnormal attention and disrupts the normal facial harmony. This is particularly true when tip ptosis is also present. In 1989, Kridel and Konior showed that the nose can be deprojected while also correcting tip ptosis through a single procedure called a lateral crural overlay. It involved shortening the bilateral lower lateral crura resulting in incremental retrodisplacement with increased rotation. The result was predictable and allowed the nasal tip integrity to be maintained, thus eliminating the potential for creating tip asymmetry. Additionally, it’s important to note that the strength and resilience of the lateral crura is increased after the procedure, which lessens the likelihood of developing nasal valve collapse postoperatively. Of note, the same procedure can also be performed on the medial crura, termed a medial crural overlay, to allow controlled deprojection and decreased rotation.
The lateral crural flap is performed through an open rhinoplasty approach. In contrast to the endonasal approach, an open view allows the lateral crura to be fully visualized and evaluated in their natural, undistorted and unobstructed position. Additionally, the major and minor nasal tip support mechanisms remained unaltered.
An inverted-v transcolumellar incision is connected to bilateral marginal incisions allowing the soft tissue envelope to be elevated in the avascular sub-muscular plane, immediately superficial to the perichondrium. This elevation is continued up to the nasal bones, where it transitions to a subperiosteal plane if the bony nasal pyramid is going to be addressed. The rhinoplasty sequence is usually performed in a top-down method with adjustments to be tip occurring after the upper and middle thirds have been addressed.
Prior to performing the lateral crural flap, the lower lateral cartilages are prepared. The nasal base support is re-inforced by suturing the medial crura together with a 5-0 polydioxanone (PDS) suture. If indicated, a columellar strut or tongue-in-groove maneuver can be performed at this time. In patients with wide lateral crura, a cephalic trim can be performed with careful attention to ensure at least a 5mm caudal margin remains. Additionally, intra- and inter-domal sutures are placed with 5-0 PDS sutures.
An incision is planned across the midportion of the lateral crus on each side, at least 1cm from the dome. By placing the incision in this lateral position, the overlapping cartilage is sufficiently camouflaged by the thicker alar skin. Once this location is identified, the vestibular mucosa is elevated from the under surface of the cartilage. Hydrodissection can be performed to help facilitate. This elevation releases tethering forces that could restrict tip rotation and also allows safe transcartilaginous suturing. The cartilage cut extends in a straight line from the cephalic to the caudal crural margins. The free ends are then overlapped with the proximal portion remaining on top. The amount of overlap is determined preoperatively by amount of the desired tip movement. The integrity of the cartilage is then re-established with horizontal mattress sutures of 5-0 PDS.
The soft tissue envelope is then redraped. The transcolumellar and marginal incisions are meticulously closed. The nose is then cleaned, taped and casted in the usual fashion. Lastly, telfa with bacitracin is placed into each nasal cavity to provide pressure to the dissected areas.
Patients are discharged with pain medication and 5 days of prophylactic antibiotics. They are encouraged to limit physical exertion for the first week and keep their head elevated to approximately 45 degrees while supine. The nasal plugs are removed in the office on postoperative day 1. Twice daily application of an antibiotic ointment is recommended along with nasal saline sprays. At 1 week, the nasal splint and tape are removed. Additional tape is often placed for another week to help minimize edema. Gradually over the following month, physical limitations are lifted.
The lateral crural flap is a reasonable technique to increase tip rotation and decrease tip projection. This powerful maneuver is relatively safe with low risks and can be performed in an acceptable amount of operative time. Like all rhinoplasty procedures, patient selection is key to ensuring high patient satisfaction with the desired aesthetic.
- Abdilkarim DA. Lateral crural overlay of the lower lateral cartilages, a technique to enhance nasal tip rotation, and reduce projection in the droopy nasal tip. Med Sci, Vol.22, No. (1), April, 2018.
- Foda HM, Kridel RW. Lateral crural steal and lateral crural overlay: an objective evaluation. Arch Otolaryngol Head Neck Surg. 1999;125:1365-1370.
- Insalaco L, Rashes ER, Rubin SJ, et al. Association of lateral crural overlay technique with strength of the lower lateral cartilages. JAMA Facial Plast Surg. 2017;19(6):510-515.
- Wise JB, Becker SS, Sparano A, et al. Intermediate crural overlay in rhinoplasty. Arch Facial Plast Surg. 2006;8:240-244.