Cosmetic Lip Surgery: Lip Anatomy and Histology




The lips serve many functions: eating, drinking, speaking, mimetic animation, kissing, and serving as a valve for the terminal oral airway. Lips are among the most vascular structures on the face and are supplied by the superior and inferior labial branches of the facial artery as it branches from the external carotid artery. The labial artery lies in the posterior third of the lip at about the incisor level ( Fig. 11.1 ). The depth of this artery is an important landmark to keep in mind, but fortunately, it is deep to most lip-reduction procedures.




Fig. 11.1


The labial artery (arrows) lies in the posterior one-third of the lip and is generally away from the surgical field in most procedures.


The anatomy of the lip is very unique, in that there is a triple transition from hair-bearing skin to vermilion tissue to oral mucosa. The hair-bearing skin terminates at the cutaneous/vermilion junction. The vermilion tissue consists of a very thin keratinized stratified squamous epithelium with extensive interdigitations with the underlying dermis ( Fig. 11.2 ). The vermilion is devoid of hair follicles, sweat glands, and sebaceous glands (although they may be sparsely present). The lack of sebaceous glands causes the vermilion to dry and crack, and hence the lips must remain moistened with saliva. The vermilion derives its color from the rich vascular plexus in the underlying dermis. This area is also highly sensitive, owing to its rich sensory innervation.




Fig. 11.2


The vermilion tissue lacks hair follicles, sweat glands, and sebaceous glands (which may be sparsely present). D, dermis; E, epithelium.


The thin, keratinized stratified squamous epithelium of the exposed vermilion transitions into a thick, non-keratinized stratified squamous epithelium and becomes the intraoral mucosa. Under this thicker epithelium lies a submucosa containing numerous accessory salivary glands, including serous, mucous, and mixed seromucous glands.


The bulk of the lip volume is made up of the circumoral orbicularis oris muscle, which blends laterally into the complex modiolus, a convergence of the perioral mimetic muscles. The orbicularis muscle lies more to the posterior region of the lip and curls over the vermilion surface and ends at the vermilion/cutaneous junction ( Fig. 11.3 ). Fig. 11.4 shows the lip structures in cross-section.




Fig. 11.3


A, Facial skin surrounding the lips contains hair follicles and sweat and sebaceous glands. B, The vermilion portion of the lip consists of thin, keratinized, stratified squamous epithelium. C, Transitions to the thick, non-keratinized, stratified squamous epithelium of the oral mucosa. D, The submucosa of the intraoral mucosa contains numerous minor salivary glands. E, The orbicularis oris muscle is seen underlying these structures and constitutes the bulk of the lip. The vermilion is almost in contact with the orbicularis oris muscle anteriorly.

(Courtesy Oklahoma University School of Dentistry.)



Fig. 11.4


Transverse section through the lower lip. The dermis (D), fat (F), orbicularis oris muscle (OOM), vermilion (V), and oral mucosa (M). Note the orbicularis muscle is situated closer to the oral surface of the lip than the facial surface and also terminates as it curves around the vermilion cutaneous junction.


Surgical Lip Lift


This is also referred to as a subnasal lift, angel wing lift, or bullhorn lift. From time to time, patients come to the cosmetic surgery practice for lip enhancement but anatomically are not great filler candidates. Lengthened upper lips present numerous cosmetic problems. First, the elongated upper lip is unaesthetic; younger patients have short, curvaceous lips with adequate volume. The aging lip becomes elongated, sustains volume loss, and loses its curves ( Fig. 11.5 ). In addition, a long lip can cover the upper teeth and give the patient a “denture” appearance.




Fig. 11.5


(A) The youthful lip is short, curvaceous, and full. (B) The senescent lip is longer, devoid of curvature, and hypovolemic.


The “lip lift” procedure produces several aesthetic improvements. It shortens the elongated senescent lip to a more youthful, shorter lip and rolls the lip back, which shows vermilion border to provide a more voluminous lip posture ( Fig. 11.6 ). It also allows several millimeters of incisor show, which is considered a pleasing attribute. An attractive smile shows several millimeters of incisor edge exposure in repose and more in smile. Patients that do not show any incisal edge appear older or have an unbalanced smile.




Fig. 11.6


The lip lift procedure vertically shortens the lip for a more aesthetic appearance and an increased upper incisor show. It also rolls the lip posteriorly, which creates a rounder plumper lip.


The basis of the subnasal lift is to excise a mustache or bullhorn-shaped piece of skin from the subcolumellar region. When the tissue is excised and the incision closed, the lip is not only shortened (lifted), but the vermilion border is rolled upward and forward. This procedure is only performed on patients with enough vertical lip excess to accommodate reduction without over-shortening. This is important because performing this procedure on a patient with a short lip will expose excessive incisor show and may prevent the patient from being able to put their lips together. The width of the excision is commensurate with the amount of desired lift and can be corrected by 25% to accommodate for relapse. At least 6 mm of skin excision is required for a noticeable result and care is taken to not decrease the lip length to <10–15 mm. This is an arbitrary measurement and many other factors need to be taken into consideration for a balanced appearance. Most cases are performed as a “skin only” excision but some surgeons advocate orbicularis oris excision for severe cases. I have seen numerous cases from other surgeons with dysfunction and appearance problems after muscle excision should be left to surgeons experienced with lip lifting.


Procedure


This procedure can easily be performed with local anesthesia, but intravenous (IV) anesthesia may provide a more relaxed patient given that you are operating literally under the patient’s nose. The success of this procedure largely relies on the accuracy of the marking. In this case, it is not only the measurements of the marking but also the delicate curves and tapers. A curvilineal line under the nose is an invitation for a poor aesthetic outcome. The architecture of the alae, columella, and nares require a delicate, curvaceous, tapered incision of the upper extent and a corresponding reciprocal incision on the bottom portion of the incision. Although I have been performing this procedure for almost two decades, I still view a picture of the proposed incision when marking the patient ( Fig. 11.7 ). The incision is marked just inferior to the nasal sill and extends and tapers out from one ala to the other. The incision should not cross the curvature of the nostril sill into the nasal vestibule. The excision is relative to the amount of lip length and generally 6–10 mm of skin is excised ( Fig. 11.8 ).




Fig. 11.7


Keeping a picture of an ideal angel wing (bullhorn) diagram ensures the proper contours are replicated every time.



Fig. 11.8


(A) A preoperative lip length of almost 22 mm and (B) the proposed excision on this patient was 8 mm, which would leave a net lip length of 14 mm.


The actual incision is made with a No.11 or No.15C scalpel and it is important to incorporate the delicate outlines of the wings ( Fig. 11.9 ). After the incision is made, I prefer a bloodless modality such as a CO 2 laser or radiowave microneedle to dissect the skin off of the subcutaneous tissue ( Fig. 11.10 ). I do not usually remove orbicularis oris muscle unless it is hypertrophic. After the skin is excised the procedure is basically finished except for the suturing. The peaks and troughs of the incision outline will allow the surgeon to precisely line up the incision edges and this is secured with several subcutaneous 5-0 gut sutures ( Fig. 11.11 ). After the subcutaneous suture a running 6-0 nylon suture is used ( Fig. 11.12 ).




Fig. 11.9


The angel wing (bullhorn) outline is made to the level of the subcutaneous tissue with a scalpel blade.



Fig. 11.10


(A) The subcutaneous dissection can be completed with numerous incisional modalities but I prefer hemostatic modalities such as laser or radiowave microneedle. Hemostasis is achieved with small-tipped bipolar forceps.



Fig. 11.11


(A) The excised skin to the subcutaneous level and (B) subcutaneous closure with 5-0 gut suture. This should be a smooth approximation without step-off of the approximated edges to achieve maximum aesthetics.



Fig. 11.12


The final closure and the excised skin specimen.


Figs. 11.13–11.18 show selected before and after images for the angel wing lip lift.




Fig. 11.13


A patient (A) before and (B) 3 months after lip lift. Note the shorter and fuller upper lip.



Fig. 11.14


A patient (A) before and (B) 8 weeks after lip lift showing a shorter and plumper upper lip.



Fig. 11.15


A patient (A) before and (B) after lip lift, the aesthetic improvements in length and pout are obvious.



Fig. 11.16


(A) The long upper lip and small incisor show during half smile before surgery. (B) A shorter lip with increased incisor show.



Fig. 11.17


A three-quarter view of a patient (A) before and (B) after lip lift. A shorter lip with increased pout. This scar is a candidate for CO 2 laser revision.



Fig. 11.18


This denture patient had poor upper incisor exposure and the lip lift greatly improved her smile.

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Sep 8, 2018 | Posted by in Aesthetic plastic surgery | Comments Off on Cosmetic Lip Surgery: Lip Anatomy and Histology
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