Lip Anatomy and Histology
The lips serve many functions, such as 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.
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, 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 as a result of its rich sensory innervation.
The thin, keratinized, stratified squamous epithelium of the exposed vermilion transitions into a thick, nonkeratinized, 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 it 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.
Surgical Lip Lift
From time to time, patients come to the cosmetic surgery practice for lip enhancement but anatomically are not great filler candidates. A lengthened upper lip presents numerous cosmetic problems. First and foremost, the elongated upper lip is unaesthetic; younger patients have short, curvaceous lips with adequate volume. The aging lip becomes elongated, undergoes volume loss, and loses its curvature ( Fig. 11.5 right sided picture). In addition, a long lip can cover the upper teeth and give the patient a “denture” appearance. An attractive smile shows several millimeters of incisor edge exposure in repose and more in smile. Patients who do not show an incisal edge appear older or have an unbalanced smile.
The lip lift procedure (also known as a subnasal lift, angel wing lift , and bullhorn lift ) produces several aesthetic improvements. It shortens the elongated lip to a more youthful, shorter lip and rolls the lip superiorly, which increases the vermilion border similar to fillers and provides a more voluminous lip posture ( Fig. 11.6 ). In many patients, it also allows several millimeters of incisor to show at rest and several millimeters of gingiva to show at full smile, which is considered a pleasing attribute.
The basis of the subnasal lift is to excise a mustache or bullhorn-shaped piece of skin from within the delicate curves of the subcolumellar region. When the tissue is excised and the incision is 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 overshortening. This is important because performing this procedure on a patient with a short lip will expose excessive incisal show and may prevent the patient from being able to put the lips together. The width of the excision is commensurate with the amount of desired lift, and 6–10 mm of skin excision is usually required to aesthetically elevate the lip without overcorrection. Shortening the lip more that 15 mm can create overcorrection, although in selected cases I have reduced an upper lip to 10 mm with positive aesthetics. This estimation of skin excision is an arbitrary measurement, and other factors must be considered 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, so this procedure should be left to surgeons who are experienced with lip lifting.
Different surgeons or articles measure lip length from different anatomic points. In this chapter, total lip length is measured from the columella to the most inferior tip of the vermilion border.
In general, I shy away from surgical predictions and instead have people examine my before-and-after photos, which I believe are graphically representative of the variety of results. One way the surgeon and patient can estimate the result of a lip lift is to draw the surgical outline with the proposed incision distance and manually elevate the lip until the superior and inferior lines touch ( Fig. 11.7 ). This is a “guestimate” but can indicate whether excessive incisal show is present or in general how the result may look.
Contraindications to the surgical lip lift include patients who would exhibit excessive incisal show. This is a common “deal breaker” for many consults that I see. A patient wants a shorter lip but would show excessive incisor tooth structure. An additional contraindication are patients with unrealistic expectations. It is not uncommon for young female patients to see a lip lift procedure on social media and desire to have it performed thinking it will be transformative. Inflated expectations or body dysmorphic tendencies are a definite contraindication. A lip lift is not an easy procedure to reverse, so careful patient selection is critical.
This procedure can be performed with local anesthesia, but intravenous sedation may provide a more relaxed patient when 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 and intricate 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 requires a delicate, curvaceous, tapered incision of the upper extent and a corresponding reciprocal incision on the bottom portion of the incision. Understanding this incision is integral. It is actually simple as it simply follows the curvilineal anatomy of the lateral alae, the columella, and the nasal sill. I have seen patients who were treated with a simple “smile face” curved incision that did not follow the nasal topography, and the incisions are vary apparent. Tracing the superior limb of the incision is relatively straightforward. The more difficult part is to duplicate the curves of the upper incision on the lower incision. In effect, it is a mirror image. I have performed this procedure many times, but I frequently end up drawing the lower incision and wiping it off and redrawing it until it is perfect. Besides the outline of the incision, it must also be consistent with the amount of skin to be removed. Finally, it must taper laterally to a fine point at the lateral alae ( Fig. 11.8 ). The incision should not cross into the nostril. For the novice surgeon, referring to a photo of an ideal angel wing diagram before marking ensures that the proper contours are replicated.
The excision is relative to the amount of lip length, and generally 6–10 mm of skin is excised ( Figs. 11.9 and 11.10 ). After local anesthesia infiltration, the actual incision is made with a #11 or #15C scalpel. Is important to incorporate the delicate outlines of the wings ( Fig. 11.11 ). After the incision is made, I prefer a bloodless modality like CO 2 laser or radiofrequency microneedling to dissect the skin off of the subcutaneous tissue ( Fig. 11.12 ). As stated, I do not usually remove the orbicularis oris muscle unless it is hypertrophic.
After the skin is excised, the inferior edge can be lifted with forceps to approximate the wound while viewing the amount of incisal show. If insufficient tooth structure is visible, more skin can be trimmed (see Fig. 11.12 ). This is a rare event in my experience. If more skin is removed, it must be done with caution as edema, local anesthesia, and general anesthesia can all make a difference in the true lip posture. Generally, a 6- to 8-mm skin excision is sufficient to make a positive cosmetic change.
After the skin is excised and hemostasis obtained, 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 ( Figs. 11.13 and 11.14 ). After the subcutaneous suture, a running 6-0 nylon suture is used ( Fig. 11.15 ).
I tell all patients that I will perform complimentary laser resurfacing of the scar at 4–6 weeks, but most patients do not require this. I have seen several cases of minor wound dehiscence that healed uneventfully. Fig. 11.16 shows a typical incision at 1 week. Figs. 11.17–11.25 show selected before and after images for the surgical lip lift.