Establishing standards for Yonsei point in a White South African population for the treatment of gummy smile

The aim of this study was to clarify the heights and spatial relationships of the facial muscles acting on the nasolabial fold (NLF) by dissection and three-dimensional microcomputed tomography for use in aesthetic treatments. This study used 56 specimens from 34 embalmed adult Korean. A reference line (RF) was set to imitate the NLF after removing the skin, from the superior point of the alar facial crease to the lateral point of the orbicularis oris muscle at the level of the corner of the mouth. The heights and spatial relationships of the facial muscles along the RF could be categorized into five main patterns. The dominant pattern was that the levator labii superioris alaeque nasi muscle (LLSAN), levator labii superioris muscle (LLS), zygomaticus minor muscle (Zmi), and zygomaticus major muscle (Zmj) were on the medial third, medial half, middle third, and lateral third of the RF, respectively. In micro-CT imaging, beneath the skin of the medial half of the NLF, the LLSAN and Zmi fibers inserted into the dermis of the NLF and adjacent to the NLF. Beneath the skin of the middle third of the NLF, the Zmi fibers were found before the muscle inserted into the dermis of the NLF and adjacent to the NLF. Beneath the skin of the lateral third of the NLF, the lateral margin of the orbicularis oris muscle and some Zmj fibers were found at the location of the NLF. The present study utilized dissections and micro-CT to reveal the general pattern and variations of heights and spatial relationships of the facial muscles passing beneath the NLF. These findings will be useful for understanding which muscles affect specific parts of NLFs with various contours, for reducing the NLF in aesthetic treatments, and for reconstructing the NLF in cases of facial paralysis.

BACKGROUND: An acute nasolabial angle and prominent medial nasolabial fold are features of the aging midface.1 The medial nasolabial fold is a difficult area to correct and is not easily addressed by current facelift procedures. As minimally invasive procedures are becoming mainstay in aesthetic surgery2, botulinum toxin has become a preferred method for treating dynamic facial rhytides. We therefore sought to identify relevant nasolabial fold and midfacial musculature anatomy to determine the ideal location of neurotoxin injection for patients with prominent nasolabial folds and midface rhytids. METHODS: Twelve hemifacial cadaveric dissections were performed to expose the midfacial muscles and identify their origin, points of insertion, relationship to surrounding musculature, greatest width, and vector of pull. Particular attention focused on the levator labii superioris alaeque nasi (LLSAN), levator labii superioris (LLS), nasalis, and orbicularis oris. Measurements were obtained based on palpable surface landmarks, including the medial canthus, for future neurotoxin injection. RESULTS: The central portion of the LLSAN was located 8.4 (+/- 0.9) mm inferior and 4.6 (+/- 0.8) mm medial to the medial canthus. Insertion sites included the medial nasolabial fold and alar base. The LLS has a broad insertion into the middle third of the nasolabial fold before extending to meet the obicularis oris at a point 4.5 (+/- 0.4) cm inferior and 5.9 (+/- 0.8) mm lateral to the medial canthus. We also uncovered a tubular muscle, obliquely oriented between the orbital obicularis oculi and the LLSAN, separated by adipose tissue, with its cephalad origin in continuity with the LLSAN and its insertion into the malar fat pad. This so-called “malar levator” was found in all twelve specimens and diverges from the LLSAN 8.7 (+/- 2.1) mm inferior and 2.8 (+/- 0.5) mm lateral to the medial canthus. The effects of this muscle on medial periorbital rhytids and the tear trough deformity were observed in the live patient. CONCLUSION: This cadaveric study further defines the musclular anatomy of the midface and medial nasolabial fold and provides new insights into the use of neuromodulators for midfacial rhytids, tear trough deformity, and the medial nasolabial fold, all of which are challenging areas to correct with current surgical techniques. Neuromodulators may be sufficient to provide a youthful midface and soften the snarl appearance that comes with age, without affecting the upper lip. REFERENCES: 1. Pessa JE: Improving the acute nasolabial angle and medial nasolabial fold by levator alae muscle resection. Ann Plast Surg. 1992; 29:23–30. 2. American Society of Plastic Surgeons. 2015 plastic surgery report. 2000/2014/2015 national cosmetic procedures. Available at: http://www.plasticsurgery.org/Documents/news-resources/statistics/2015-statistics/cosmetic-procedure-trends-2015.pdf. Accessed February 26, 2016.

Botulinum toxin type A (BTX-A) is recent technique for the treatment of gummy smile. The aim of this randomized controlled preliminary clinical trial was to evaluate the effects of BTX-A on excessive gingiva display (EGD) reduction, muscle activity, and patient satisfaction at 2, 8, 12, 16, 21, and 25 weeks. Group 1 (G1) received 4 points of BTX-A application (2 U/point) for relaxation of the levator labii superioris alaeque nasi and levator labii superioris muscles; Group 2 (G2) received 2 points of BTX-A (2 U/point) for relaxation of only the levator labii superioris alaeque nasi muscle. A high dropout of patients from follow-up sessions occurred. Therefore, because of this data limitation, the results were considered a preliminary outcome. At 2 weeks, there was a significant difference between baseline regarding the reduction of EGD in G1 and G2, reduction in muscle activity in G1, and increased satisfaction in G1 and G2. At 2 weeks, there was no difference between the 2 groups. Statistically significant EGD reduction was maintained until 16 weeks in G2 and 25 weeks in G1. After 14 days there was a gradual recovery of muscle activity in both groups until recovery of baseline values by 25 weeks. Patients' satisfaction with treatment lasted 21 weeks in G1 and 16 weeks in G2. Increasing the number of BTX-A injection points resulted in a prolonged effect regarding EGD reduction and patient satisfaction but did not increase the intensity of the outcome. However, due to the high dropout of patients, this is a preliminary conclusion and further studies are necessary to confirm these results.

The human smile is a complex coordinated activity of mimetic muscles predominantly recognizable by a superolateral pull at the commissure and elevation of the upper lip. The aim of this study was to revisit the muscles of facial expression responsible for these motions, evaluate their relational anatomy and orientation, and relate this to optimal positioning of free muscle transfer in smile reanimation. Nineteen hemifaces from fresh cadaveric specimens were dissected. A subsuperficial muscular aponeurotic system skin flap was elevated to expose the zygomaticus major, zygomaticus minor, levator labii superioris, and levator labii superioris alaeque nasi. Muscle location, length, width, angle of pull, and any anatomic variation were noted. All specimens had zygomaticus major, levator labii superioris, and levator labii superioris alaeque nasi muscles present bilaterally. Conversely, the zygomaticus minor was present in only 10 of 19 hemifaces. There was no significant difference in muscle length, width, or line of pull between specimen sides. Of all the assessed muscles, the zygomaticus minor had the most transverse line of pull, at 31.6°; the zygomaticus major was more oblique with a line of pull of 55.5°; and the levator labii superioris and levator labii superioris alaeque nasi were oriented almost vertically with angles of 74.7° and 79.0°, respectively. The mimetic muscle vector is quite vertical in comparison to the angle obtained by traditional dynamic smile reconstruction surgeries. A more vertical vector, especially at the upper lip, should be considered in smile reconstruction.

A perfect smile is dictated by the balance among 3 parameters: the white (teeth), the pink (gum), and the lips: excessive gingival display while smiling has been a cause of esthetic embarrassment for many patients, thus affecting their psychosocial behavior. With respect to different etiologies, treatment of gummy smile must be properly planned: treatment options include facial surgery, oral surgery, or laser. Given the growing demand for less invasive techniques and observed complications secondary to botulinum toxin injection, we present a novel treatment option aimed at correcting gummy smile using hyaluronic acid injection and review the published techniques and the anatomy of the involved facial muscles. The treatment was performed by infiltration in the paranasal area, in the location of the most cranial portion of the nasojugal fold, about 3 mm lateral to the alar cartilage wing, according to a vector perpendicular to the cutaneous plane, to gently compress the lateral fibers of the levator labii superioris alaeque nasi without invading it. A Vycross® technology filler was used for all the treatments. All patients had an immediate improvement, with a maximum duration ranging from 186 to 240 days (mean, 213 days), according to parameters of the Global Aesthetic Improvement Scale (GAIS 4.06). This new, less invasive and safer technique to correct dynamic excessive gingival display was shown to be feasible and safe with a long-lasting result. This treatment could be a novel effective option for experienced injectors to treat aesthetic facial flaws.

The harmony of the smile depends not only on the dentition, but also on the gum tissue, which excessively exposed can negatively affect aesthetics of the smile. Exposure of a small amount of gum during a smile is acceptable however a smile in which the exposure of the gum is more than 2 mm is considered an aesthetic defect called gummy smile. Among the causes of gingival smile listed are: shortened or hyperactive upper lip muscles (levator labii superioris, levator labii superioris alaeque nasi, zygomatic minor muscles), vertical maxillary excess, extrusion of alveolar ridges, altered passive eruption. In the case of hyperactive upper lip muscles, botulinum toxin can be used — this procedure was used in the described cases, and the effects were assessed using the FotoMedicus system and measurements of gingival exposure. In first case Bocouture botulinum toxin was administered on both sides, 4 units bilaterally in the levator labii superioris muscle and 2 units into levator anguli oris muscle. In total, 12 units were given. During the follow‑up the patient reported the start of the effect from the 5th day after the supply with the maximum effect after 12 days. A 6 mm correction of gummy smile was achieved. In the second case 4 units of botulinum toxin were applicated bilaterally into levator labii superioris alaeque nasi muscle. A 3 mm correction of gummy smile was achieved. The aesthetics of the face in a smile definitely improved in both men.

Summary:We report a case, function preservation of the upper lip after tumor resection was possible using residual orbicularis oris muscle and attached levator labii superioris alaeque nasi. Patient was 67-year-old male with squamous cell carcinoma at the vermilion border. The tumor was resected with an 8-mm margin, leaving the oral mucosa as intact as possible. To reconstruct the red lip, we used the oral mucosa as a rotational transposition flap. The white lip was reconstructed with a cheek rotation flap. A levator labii superioris alaque nasi muscle flap, which was attached to the remaining orbicularis oris muscle, was used to increase marginal lip volume. The movement of the reconstructed lip was good. At 9 postoperative months, induration of the red lip was palpable, and we suspected that the blood supply to the levator labii superioris alaque nasi was borderline insufficient. Slight drooping of the reconstructed lip occurred. We dissected this was caused by dissection of mid facial muscles from orbicularis oris muscle to ease downward rotation of the cheek flap and obscure the original nasolabial fold. Although some drooping and induration of the lip occurred, the white and red lip were reconstructed in a single-stage procedure, which resulted in good movement and preserved the function of the orbicularis oris muscle.

The prominent nasolabial fold is a distinct feature of the aging midface. As minimally invasive procedures have become mainstream, chemodenervation is a preferred method for treating dynamic facial rhytids. We therefore sought to identify relevant nasolabial fold and midfacial muscular anatomy to determine the ideal location of neuromodulation to improve the aesthetics of the midface and nasolabial fold without altering the upper lip and smile. Twelve hemifacial cadaveric dissections were performed to identify midface muscle origin, insertion, width, vector of pull, and neighboring structures. Attention was focused on the levator labii superioris alaeque nasi (LLSAN), levator labii superioris (LLS), nasalis, and orbicularis oculi. Measurements were obtained based on surface landmarks including the medial canthus for future neurotoxin injection. The LLSAN inserts into the medial nasolabial fold and alar base, while the LLS inserts into the middle third of the nasolabial fold. The broadest portion of the superior LLSAN was on average 8.4mm inferior and 4.6mm medial to the medial canthus. A separate muscle obliquely oriented between the orbicularis oculi and LLSAN was identified and found to insert into the malar fat pad. This "malar levator" was present in all specimens and has implications on medial periorbital rhytids and the tear trough deformity. This study further defines midfacial and nasolabial fold muscular anatomy and provides new insights into the use of neuromodulators for these areas without affecting upper lip position. The malar levator muscle appears to be a separate midfacial muscle with independent action. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Therapeutic effects of botulinum toxin type A in subjects with gummy smile: A longitudinal sEMG approach

The aim of this study was to clarify the morphology and topography of the deep layer of levator labii superioris alaeque nasi muscle (LLSAN) and the transverse part of the nasalis. Anatomical variations in the topographic relationships were also described to understand the function of the LLSAN and the transverse part of the nasalis. Anatomical dissections were performed on 40 specimens of embalmed Korean adult cadavers. The LLSAN was divided into two layers, which were superficial and deep in the levator labii superioris muscle (LLS), respectively. The superficial layer of LLSAN descended on the LLS, and the deep layer was located deep in the LLS. The deep layer of LLSAN originated from the superficial layer of LLSAN and the frontal process of the maxilla. It inserted between the levator anguli oris and the orbicularis oris muscles. This transverse part of the nasalis received some muscle fibers from the superficial layer of LLSAN in 90% (36/40) of specimens. The transverse part of the nasalis originated from the maxilla and ascended, passing posterior to the superficial layer of LLSAN in 65% (26/40) of specimens. However, it originated as two muscle bellies from the maxilla and the upper half of the alar facial crease, respectively, in 35% (14/40) of specimens. These findings will be crucial data to understand the structure and function of the LLSAN and the transverse part of the nasalis.

The study aimed to visualize the changes in the facial muscles of patients with severe facial palsy who showed no improvement for more than 3months on acute stage. The 102 patients with severe facial palsy over House-Brackmann grade IV or an 80% degenerative ratio on ENoG at the initial examination, who showed no improvement for more than 3months on acute stage were indicated to undergo ultrasonography of the face to evaluate the facial muscles. Muscular degeneration was observed in 537/918 muscles (58.5%). Muscle volume shrinkage was observed in 209/918 muscles (22.8%). Fascial adhesions were observed in 209/918 muscles (22.7%). Among all the muscles assessed for degenerative changes, zygomaticus major/minor was the most affected by degenerative changes (91.2%). Degenerative changes were observed in the levator labii superioris muscle in 84.3% patients. The shrinkage was most frequently observed in the zygomaticus major muscle (61/102 patients [59.8%]), followed by the zygomaticus minor muscle (43.1%). Shrinkage of the levator labii suprioris was observed in 24.5% patients. The zygomaticus major/minor muscle had the highest proportion of fascial adhesions in 61.8% and 66.7% patients respectively. The levator labii suprioris muscle showed the lowest proportion of fascial adhesions, with only 7.8% patients being affected. This study confirmed that the zygomaticus major, zygomaticus minor, and levator labii suprioris muscles, which raise the corner of the mouth, are the first to degenerate in patients with severe facial paralysis. This study demonstrated that ultrasonography is a simple and non-invasive examination for facial paralysis.

Botulinum toxin is a neurotoxin that has been utilized to induce chemo-denervation of muscles. Cutaneous wounds represent a special situation in which the tensile forces applied by these muscles on wound edges might have deleterious effects on the healing process. The aim of this review was to investigate such an effect and to review other mechanisms this toxin might have on the healing process. We also reviewed the role of botulinum toxin in the management of hypertrophic scars and cleft lip repair.

To propose a safe and reproducible injection point for botulinum toxin-A (BTX-A) as a supplementary method for the treatment of gummy smile, as determined by assessment of the morphologic characteristics of three lip elevator muscles. A total of 50 hemi-faces from 25 adult cadavers (male 13, female 12; ages, 47 to 88 years) were used in this study. Topographic relations and the directions of the lip elevator muscles (ie, levator labii superioris [LLS], levator labii superioris alaeque nasi [LLSAN], and zygomaticus minor [ZMi]), were investigated. Possible injection points were examined through the study of predetermined surface landmarks. The insertion of the LLS was covered partially or entirely by the LLSAN and the ZMi, and the three muscles converged on the area lateral to the ala. The mean angle between the facial midline and each muscle vector was 25.8 +/- 4.8 degrees for the LLS, 55.7 +/- 6.4 degrees for the ZMi, and -20.2 +/- 3.2 degrees for the LLSAN; no significant differences were noted between male and female subjects or between left and right sides. The three vectors passed near a triangular region formed by three surface landmarks. The center of this triangle, named the "Yonsei point", was suggested as an appropriate injection point for BTX-A. The clinical effectiveness of the injection point was demonstrated in selected cases with or without orthodontic treatment. Under careful case selection, BTX-A may be an effective treatment alternative for patients with excessive gingival display caused by hyperactive lip elevator muscles.

In this investigation the jaw–mouth–lip (JML) co-ordination is quantified using cross-correlation (CC) between facial electromyography (EMG) while speaking words ‘zero to nine’. The facial EMG data of four prominent facial muscles, namely Zygomaticus Major (ZM) from the mouth region, Levator Labii Superioris (LLS), Orbicularis Oris Inferioris (OOI) from the lip region and Anterior Belly of Diagastric (ABD) from the jaw region are collected and analysed. A total of six muscle pairs, (1) ABD–ZM, (2) ZM–LLS, (3) OOI–ZM, (4) ABD–LLS, (5) ABD–OOI and (6) LLS–OOI, are formed based on their position. Based on correlation study, all these muscle pairs show a significantly different co-ordination level (p < 0.05). The CC of the ABD–LLS muscle pair is observed with maximum co-ordination level among all spoken words (Tukey’s post-hoc, α = 0.05). These investigations based on CC in JML co-ordination could be used in designing various biomedical engineering tools such as speech prosthesis, facial lie detectors, etc.

This study aimed to introduce a novel approach to study the facial mimetic muscles (FMMs) in relation to the nasolabial fold (NLF) and realize the visualization of complex three-dimensional (3D) structures and spatial relationships of the FMMs. Nano-computed tomography (nano-CT) and iodine staining techniques were used to obtain the two-dimensional (2D) radiographs of the FMMs. Materialise Mimics software was then used to reconstruct the 3D model of the FMMs. The zygomaticus major muscle (ZMM) was divided into trunk fibers and branch fibers. The trunk fibers of the ZMM were subdivided into branch fibers layer-by-layer. Adipose tissue in the cheek was not a mass of unorganized fat. It was separated and fixed by branch fibers. Moreover, the trunk fibers of the ZMM were directly connected to the levator anguli oris (LAO), not the skin. On the contrary, the ZMM was connected to the skin by its subdivided branch fibers indirectly. The muscle fibers in the modiolus were organized, rather than disorganized. In other words, the terminal of the trunk fibers of the ZMM was located in the LAO. Moreover, the terminal of the trunk fibers of the LAO was located at the terminal of the trunk fibers of the musculus depressor anguli oris at the corner of the mouth. Furthermore, the levator labii superioris alaeque nasi was not directly connected to the orbicularis oris muscle. It was connected to the combination of the LLS and the rhinaeus. Although nano-CT has many disadvantages, it enabled the 3D anatomical study of the FMMs in relation to the NLF when combined with iodine staining. We imported the 2D images obtained by nano-CT scanning into the Mimics software, successfully reconstructed the FMMs, and finally obtained images of complex 3D structures of the FMMs. The shapes, positions, and 3D spatial relationships of the FMMs were clearly visualized. The novel insights into the 3D anatomy of the FMMs may help understand the formation of the NLF. Finally, the results of this study may help improve the rejuvenation surgery of the NLF soon. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.