Bunny Lines -Some patients will present with complaints of oblique nasal sidewall rhytides, caused by hyperactivity of the transverse portion of the nasalis muscle. These rhytides are commonly referred to as bunny lines, owing to the patient appearance with maximal contraction of the nasalis muscle.
The nasalis muscle is a paired structure, each consisting of an alar and transverse portion. The transverse nasalis muscle originates on the maxilla near the medial canthus and converging in a medial aponeurosis that overlies the nasal dorsum. Contraction results in superomedial elevation of the nasal sidewall skin and production of oblique skin rhytides.
Treatment recommendations: The nasalis muscles can effectively be treated by injection in each muscle belly or a single, central injection. We prefer the 2-injection technique to soften the appearance of bunny lines.
Typical injection sites in nasalis muscle (lateral) and procerus muscle (midline) for nasal lines (bunny lines). May range from 1 to 3 injection points (1 – 2 U of BOTOX or 2 – 4 U of AZZALURE per point).
Injection occur at the wings of the nose. Should be directed upwards. Total amount of units – 4 per side. 2 injections of 2 units each per side. Be mindful of performing this treatment to clients with a round or bulbous nose as this treatment can excaggerate this feature.
Injection occurs at the of the nose. The columella (tip) is lifted up and the needle is inserted deep into the sub nasal part under the tip. 2 units of BOTOX or 4 units of Azzalure in a single injection.
This treatment goal is to reduce the hyperactive muscle responsible for the gummy smile and to reduce the amount of gum exposure. Weakening of these muscles make smile more harmonious and pleasing to the eye. 2 single units of BOTOX are injected into each side of the nostril.
In more severe cases additional injection points can be used to achieve desired results. 1-2 units per injection point. This can be topped up only after 2 weeks later.
The sphincter action of the orbicularis oris muscle is responsible for dynamic vertical rhytides of the upper lip. Vertical perioral rhytides are a common complaint among patients seeking facial rejuvenation. Although some activities, including excessive sun exposure or smoking, can accentuate or hasten the appearance of these lines, they are almost universally found with increasing age. As with other areas of the face, aging in the perioral region is multifactorial; although injections can improve dynamic—and to some extent, static—rhytides, they are rarely, if ever, used in isolation to treat this area of the face. Dermal fillers are most often used to improve the contour of static rhytides and address volume loss in the upper lip. However, judicious use of toxin in the upper lip has been found to improve lip contour, eversion, and fulness.
The orbicularis oris muscle encircles the upper and lower lips, originating from the modiolus complex and inserting into the skin and subcutaneous tissues of the upper lip. Its primary function is as a sphincter to aid in oral competence and speech. It also functions to protrude the upper and lower lips. Because of its disruption in congenital clefts of the upper lip, the anatomic and functional study of this muscle is vast, and a complete discussion is beyond the scope of this article.
Before treatment, patients should be advised that they may have difficulty with activities that require pursed lips, including pronunciation of certain plosives and drinking through a straw. Moreover, in this area, we prefer to err on the side of possible under correction with subsequent touch-ups rather than ove treat and risk excessive paresis of the perioral musculature. To avoid iatrogenic paralysis of the upper lip elevators, injections should be kept medial to a vertical line dropped from the lateral nasal ala to the upper lip vermillion. Small aliquots (1–2 U of Botox Cosmetic each, total dose 4–6 U) are injected between 2 to 4 symmetric sites along the superior vermillion border. The lower lip injections should similarly stay at least 1 cm medial to the oral commissures and should mirror or bisect the upper lip injections.
Intradermal Injections of 0.5 – 1 units of BOTOX per injection point. 0.5cm away from the vermilion border.
Injections take place on the very ridge of the vermilion border.
1 Unit of Botox on the inner side and 0,5 on the outer side. Intradermally.
Treatment of the lower face and neck
As with the mid face, the mainstays of treating aging-related changes in the lower face and neck are restoration of volume and re suspension of descended tissues; however, there are several aesthetic indications for treatment with BTA.
Depressor Anguli Oris
Contraction of the depressor anguli oris (DAO) muscle produces a downturn to the corners of the mouth. Hyperactivity of the DAO contributes to accentuation of the melomental fold, also known as the marionette line and can give the impression of sadness or anger by inverting the corners of the mouth. Patients often present with complaints of an angry look to their face, which they attribute in part to a downturned mouth at rest. Chemodenervation of these muscles can reduce the downward pull and provide a subtle lift to the oral commissures, correcting an inverted smile.
The DAOs are fan-shaped muscles originating with a broad base along the mandibular body, anterior to the masseter, and inserting into the oral commissures at the modiolus complex. At each oral commissure, the fibres of the DAO interdigitate with other muscles of the modiolus complex, the orbicularis oris, and risorius muscles. The DAO functions primarily as a depressor of the modiolus complex.
As mentioned above, the modiolus complex is an anatomically complex structure, with interdigitation of depressors, elevators, and sphincters of the lips. As a result, accurate placement of BTA is essential to avoid complications of asymmetry, phonation, or impaired oral competence. The location of the DAO is most readily identified indirectly, by palpating the anterior border of the masseter muscle. The patient is asked to clench their jaw, which facilitates palpation of the anterior border of the masseter. The DAO muscle belly can be safely injected 1 cm medial from this point, 2 to 3 mm above the inferior border of the mandible Although the muscle belly is cantered medial to this, injection
at this point will target the lateral fibres responsible for pulling the modiolus downward while minimizing the risk of diffusion to surrounding musculature. As an additional reference point, injections should be kept at least 1 cm lateral to the lateral oral commissure. Typical starting doses are as low as 0.5 -2 units of Botox. Injected at the very bottom end of the marionette line.
Cobblestone Chin (Mentalius)
Hyperdynamic activity of the mentalis muscle can create the undesirable appearance of wrinkling or dimpling of the skin overlying the chin, often referred to as a peau d’orange appearance. This is most evident during periods of facial expression. Although a less commonly used indication, these patients can also be treated with botulinum toxin to relax the underlying mentalis muscle.
The mentalis is a paired muscle that serves as the primary evertor of the lower lip and also serves to elevate the skin of the chin. It arises from the incisive fossa on the anterior mandible and inserts into the subcutis of the chin on either side of the lower lip frenulum. The mentalis lies deep to, but interdigitates with the fibers of the orbicularis oris and the depressor labii inferioris.
Injection of the mentalis can be either be accomplished with a single injection in the midline at the origin of both bellies of the mentalis or, more commonly, with an injection into each muscle belly. For the 2-injection method, treatment points are located 2 mm above the inferior border of the mandible and approximately 5 mm to the left or right of midline. In either pattern, injections should be kept deep to avoid inadvertent spread to the overlying orbicularis oris and depressor labii inferioris muscles.
2-3 units of BOTOX per injection point is recommended as a starting dose. Intradermally. Should be placed at least 3 cm away from the vermilion border. Should be placed as close as possible to the medial line to avoid diffusion into the depressor labii inferioris muscle.
Hypertrophy of the masseter can create a square appearance to the lower third of the face and convey an impression of heaviness to the face. Moreover, a hypertrophic masseter can impart a masculine appearance to a female face. Although genetic and habitual components are involved in the pathogenesis, the underlying treatment is similar, regardless of cause. Several reports describe treatment of masseteric hypertrophy, predominantly in Asian populations. Moreover, each of the commercially available forms of injectable botulinum toxin has been independently shown to reduce undesirable hypertrophy.
The masseter is a primary muscle of mastication, with origins on the zygoma and zygomatic process of the maxilla and insertion along the ramus and angle of the mandible. The muscle consists of a superficial and smaller deep head and functions synergistically with—but much stronger than— the medial pterygoid muscles to elevate the mandible. The mandible is overlapped by the risorius muscle, which arises on the parotid fascia and inserts near the angle of the mouth to retract the commissure laterally, as in a false smile or smirk. Superiorly, the masseter is overlapped by the zygomaticus muscle, which functions to elevate the angle of the mouth in true smile.
Treatment of the masseter differs from other areas in that the primary indication for treatment is to induce muscle atrophy rather than limit muscle contractions to alleviate skin wrinkling. Care must be taken to avoid excessive paralysis undesirable hypertrophy that would weaken mastication. Other complications include asymmetry, changes in facial expression, speech disturbances, dysgeusia and transient muscle bulging. When injecting in the mandible, it is important to keep in mind the location of the surrounding musculature, most notably the risorius muscle, but also the zygomaticus muscle. Inadvertent injection to either of these would alter the kinetics of the angle of the mouth, causing facial asymmetry. Further, injecting deep into the substance of the muscle bellies will reduce the incidence of unwanted medication diffusion. The point of maximal muscle hypertrophy is identified and marked as the starting point. Two additional injection points are marked above this, one medial and one lateral to the first. Attention is paid to keep the injections inferior and lateral to limit diffusion to the surrounding risorius and zygomaticus muscles that run medial and superior, respectively. Average starting doses are among the highest of any area in the face, approximately 4-6 Units of Botox per injection point.
For aesthetic (not medical) treatment 3-4 injections are given in a triangular shape into a more superficial layer of the muscle.