Quantitative Mobility Analysis of the Face and its Relevance for Surgical and Non-surgical Aesthetic Facial Procedures.

BACKGROUND: Understanding the degree of facial mobility upon postural changes is of great clinical relevance especially if facial assessment, facial measurements and/or facial markings are done in an upright position, but facial procedures are performed in a supine position. OBJECTIVE: The objective of this study is to investigate regional facial skin displacement and facial volume changes in individuals between upright and supine positions. METHODS: This multi-center study analyzed a total of 175 study participants with a mean age of 35.0 (10.2) years and a mean body mass index of 24.71 (3.5) kg/m2. 3D surface scanning technology with automated registration and alignment was utilized, and multivariate analyses were performed with adjustment for age, gender, body mass index, facial skin sagging and laxity. RESULTS: The medial face displaced less than the lateral face in both cranial (0.88 mm) and in lateral (0.76 mm) directions, and the lower face displaced more than the middle face in both cranial (1.17 mm) and lateral directions (1.37 mm). Additionally, the medial face lost, on average, 3.00cc whereas the lateral face increased by 5.86cc in volume; the middle face increased by 2.95cc, whereas the lower face decreased by 0.98cc in volume. All p < 0.001. CONCLUSION: Practitioners should be mindful that there is a statistically significant change in facial soft tissues between the upright and supine positions and that the magnitude of the change does not necessarily reflect on the aging process alone but is a multi-factorial process which should be individualized for each patient's needs. LEVEL OF EVIDENCE IV: 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 .

Influence of Rheological Properties and Needle Size on Extrusion Forces of Hyaluronic Acid Based Soft Tissue Fillers.

BACKGROUND: To date no precise data are available for extrusion forces related to the G-prime and G-double-prime of fillers in combination with different 27G and 30G needles. Therefore, the objective of this study was to analyze extrusion forces of various product-needle-combinations containing two different 27G and two different 30G needles in combination with fillers of a wide range of elastic moduli starting from 2.0 – 166.0 Pa. MATERIAL AND METHODS: Four different fillers with the following elastic moduli 1.87, 11.65, 61.80, 165.50 Pa were combined with four different needles: 27G ½”, internal diameter: 0.300 μm; 27G ½”, internal diameter: 0.241 μm; 30G ½”, internal diameter: 0.241 μm and 30G ½“, internal diameter: 0.240 μm. Product-needle-combination were subjected to uni-axial mechanical testing and the respective extrusion force was measured. RESULTS: The results of this study revealed that the G-prime and the G-double-prime of a product are statistically significantly related to their extrusion force, with higher G-prime/G-double-prime products requiring higher extrusion forces. The results additionally revealed that whether the size of the needle was described as 27G or 30G by the respective manufacturer statistically significant differences between the measured extrusion forces were detected. CONCLUSION: Injectors need to be aware that not every 27G/30G needle has the same extrusion force even though the external diameter is similar (27G or 30G); this might additionally influence the ability to withdraw blood during a pre-injection aspiration manoeuvre. J Drugs Dermatol. 20(5): doi:10.36849/JDD.5237.

Signal-To-Noise Ratio Calculations to Validate Sensor Positioning for Facial Muscle Assessment Using Noninvasive Facial Electromyography.

The evaluation of neuromodulator treatment outcomes can be performed by noninvasive surface-derived facial electromyography (fEMG) which can detect cumulative muscle fiber activity deep to the skin. The objective of the present study is to identify the most reliable facial locations where the motor unit action potentials (MUAPs) of various facial muscles can be quantified during fEMG measurements. The study population consisted of five males and seven females (31.0 [12.9] years, body mass index of 22.15 [1.6] kg/m2). Facial muscle activity was assessed in several facial regions in each patient for their respective muscle activity utilizing noninvasive surface-derived fEMG. Variables of interest were the average root mean square of three performed muscle contractions (= signal) (µV), mean root mean square between those contraction with the face in a relaxed facial expression (= baseline noise) (µV), and the signal to noise ratio (SNR). A total of 1,709 processed fEMG signals revealed one specific reliable location in each investigated region based on each muscle's anatomy, on the highest value of the SNR, on the lowest value for the baseline noise, and on the practicability to position the sensor while performing a facial expression. The results of this exploratory study may help guiding future researchers and practitioners in designing study protocols and measuring individual facial MUAP when utilizing fEMG. The locations presented herein were selected based on the measured parameters (SNR, signal, baseline noise) and on the practicability and reproducibility of sensor placement.

The Influence of Different Light Angles During Standardized Patient Photographic Assessment on the Aesthetic Perception of the Face.

BACKGROUND: 2D baseline and follow-up clinical images are potentially subject to inconsistency due to alteration of imaging parameters. However, no study to date has attempted to quantify the magnitude by which such images can be influenced. OBJECTIVE: The objective of the present study is to identify the magnitude by which images can be influenced by changing the imaging light angle. METHODS: This study is based on the evaluation of 2D frontal images of the face and included a total of 51 subjects of which n = 14 were males and n = 37 were females. Faces were photographed at 0°, 30°, and 60° light angle under identical and standardized conditions. Images were randomized and rated by 27 blinded raters for age, facial attractiveness, body mass index (BMI), temporal hollowing, lower cheek fullness, nasolabial sulcus severity, and jawline contour. RESULTS: Facial attractiveness decreased, facial unattractiveness increased and the evaluated BMI (based on facial assessment) increased statistically significantly at 60°. The assessment of regional facial scores, i.e., temporal hollowing, lower cheek fullness, and jawline contour, showed no statistically meaningful changes both at 30° and at 60° light angle. CONCLUSION: The results indicate that there might be an observed blind range in light angle (0°-30°) which does not influence facial assessment. Increasing the light angle past the threshold value to 60° might result in a statistically significant impact on facial perception which should be accounted for when documenting and/or presenting facial 2D images. LEVEL OF EVIDENCE V: 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 .

The Change of Plane of the Supratrochlear and Supraorbital Arteries in the Forehead-An Ultrasound-Based Investigation.

BACKGROUND: Injecting soft tissue fillers into the deep plane of the forehead carries the risk of injection-related visual compromise due to the specific course of the arterial vasculature. OBJECTIVES: The aim of this study was to investigate the 2- and 3-dimensional location of the change of plane of the deep branch of the supratrochlear and supraorbital artery, respectively. METHODS: A total of 50 patients (11 males and 39 females; mean age, 49.76 [13.8] years, mean body mass index, 22.53 [2.6] kg/m2) were investigated with ultrasound imaging. The total thickness and the distance of the arteries from the skin and bone surface were measured with an 18-MHz broadband compact linear array transducer. RESULTS: The deep branch of the supraorbital artery changed plane from deep to superficial to the frontalis muscle at a mean distance of 13 mm (range, 7.0-19.0 mm) in males and at 14 mm (range, 4.0-24.0 mm) in females and for the deep branch of the supratrochlear artery at a mean distance of 14 mm in males and females (range, 10.0-19.0 in males, 4.0-27.0 in females) when measured from the superior orbital rim. CONCLUSIONS: Based on the ultrasound findings in this study, it seems that the supraperiosteal plane of the upper and lower forehead could be targeted during soft tissue filler injections because the deep branches of both the supraorbital and supratrochlear arteries do not travel within this plane. The superficial plane of the lower forehead, however, should be avoided due to the unpredictability and inconsistent presence of the central and paracentral arteries.

Intraarterial Degradation of Calcium Hydroxylapatite Using Sodium Thiosulfate - An In Vitro and Cadaveric Study.

BACKGROUND: The most severe complications following soft tissue filler injections result from the intraarterial administration of the filler product. Although hyaluronic acid-based filler can be trans-arterially dissolved with hyaluronidase, no information is available on calcium hydroxylapatite (CaHA)-based fillers. OBJECTIVE: The authors sought to test whether CaHA-based fillers can be trans-arterially dissolved by sodium thiosulfate (STS) when evaluated in cadaveric and in vitro models. METHODS: Human cadaveric facial arterial segments were each filled with 0.2 cc of commercially available CaHA product and submerged for 24 hours in 4 different STS-containing solutions: 10 cc STS (300 mg/cc) (pure, 1:1 dilution, 1:2 dilution), 0.9% saline and 10 cc STS (300 mg/cc), and 300 IU (bovine) hyaluronidase in a 1:1 ratio. RESULTS: Intraarterial CaHA was detected in human facial artery segments after 24 hours independent of the STS concentration employed. Submerging the arterial segments in STS (300 mg/cc) and 300 IU (bovine) hyaluronidase (1:1 ratio) also did not dissolve the intraarterial CaHA product. Gray scale analyses did show, however, that increasing concentrations of STS resulted in increased disintegration of CaHA in an in vitro experimental setting. CONCLUSIONS: The results of this study indicate that STS is limited in its potential to dissolve intraarterial CaHA of cadaveric human facial arteries, despite the fact that it appears effective when in direct contact with the CaHA. Adverse events caused by intraarterial administration of CaHA-based fillers still lack a suitable antidote.

The Influence of the Insertion Angle on Middle and Lower Face Tissue-Mechanics When Treating the Nasolabial Folds with Facial Suspension Threads-An Experimental Split-Face Cadaveric Study.

A novel treatment approach to address the nasolabial fold is the insertion facial suspension threads. However, there is a paucity of data available to guide insertion techniques and material selection. Three female and two male cephalic specimens of Caucasian ethnicity (73.6 ± 6.5 years; 21.41 ± 2.2 kg/m2) were included into this experimental split-face study. One facial side was treated with polycaprolactone (PCL) thread: 180 mm, bidirectional, 18G 100 mm cannula, 20 degrees trajectory, preauricular approach whereas the contralateral side was treated with polydioxanone (PDO) thread: 100 mm, bidirectional, 19G, 60 mm cannula, 50 degrees trajectory, infraorbital approach. Three-dimensional imaging outcome measures included vertical and horizontal skin displacement and volume changes at the nasolabial sulcus, at the labiomandibular sulcus, and along the jawline. Comparing PCL 180 mm 20 degrees to PDO 100 mm 50 degrees: vertical lifting effect 1.42 ± 2.63 mm versus 1.24 ± 1.88 mm (p = 0.906); horizontal lifting effect 3.42 ± 1.44 mm versus -2.02 ± 1.84 mm (p = 0.001); nasolabial volume change -0.80 ± 0.65 mL versus -0.52 ± 0.17 mL (p = 0.367); labiomandibular volume change -0.45 ± 0.42 mL versus -0.16 ± 0.16 mL (p = 0.191); jawline volume change 0.02 ± 0.43 mL versus -0.01 ± 0.21 mL (p = 0.892). The study provides objective evidence for the short-term effectiveness of facial suspension threads in treating the nasolabial folds. The results point toward a better aesthetic outcome when utilizing long facial suspension threads that can effect full-face changes as compared with short facial suspension threads.

Reevaluation of the Layered Anatomy of the Forehead: Introducing the Subfrontalis Fascia and the Retrofrontalis Fat Compartments.

BACKGROUND: Novel imaging methods have provided new insights into the layered anatomy of the forehead. This study seeks to critically reevaluate the layered anatomy of the forehead by using ultrasound imaging and cadaveric dissection to provide an accurate anatomical description that can be used to guide safer surgical and minimally invasive frontal procedures. METHODS: This study used ultrasound imaging in a sample of 20 volunteers (12 female and eight male volunteers; aged 35.25 ± 4.2 years; body mass index, 24.28 ± 3.5 kg/m2) and cadaveric dissections of 16 body donors (12 female and four male body donors; aged 72.76 ± 9.5 years) to reevaluate the layered anatomy of the forehead. Layer-by-layer dissections and ultrasound-based measurements of the frontal structures guided conclusions. RESULTS: The following layered arrangement was identified: layer 1, skin; layer 2, superficial fatty layer; layer 3, suprafrontalis fascia; layer 4, orbicularis oculi and frontalis muscle (same plane); layer 5, a homogenous layer of fat [preseptal fat (in the upper eyelid), retro-orbicularis fat (deep to the orbicularis oculi muscle), and retro-frontalis fat (deep to the frontalis muscle); layer 6, subfrontalis fascia; layer 7, preperiosteal fat within the prefrontal space in the lower forehead and deep compartments in the upper forehead; and layer 8, periosteum. CONCLUSIONS: The results of this study add to the current understanding of the layered arrangement of the forehead. The combination of ultrasound imaging and cadaveric dissections provided evidence for a continuous fatty layer deep to the frontalis muscle.

Revisit, Reform, and Redesign: A Novel Dissection Approach for Demonstrating Anatomy of the Orbit for Continuing Professional Development Education.

Advanced postgraduate medical education for health-care professionals is constantly evolving. Understanding facial anatomy and especially its vascular system is crucial when performing soft tissue filler injections to avoid adverse events including tissue loss or irreversible blindness. Standard anatomical resources often fall short of elucidating clinically relevant concepts in more highly specialized areas of interest. A novel dissection approach for demonstrating the anatomy of the lateral orbit was presented at scientific meetings to participants from dermatology, plastic surgery, and general practice. Results from the post-course online survey (n = 52) were analyzed. The results of the survey reveal a high educational impact and a high clinical relevance of the novel dissection approach. In addition, the majority of respondents (97.7%; n = 51) felt that the exposed anatomical structure of the orbit and face improved their ability to safely perform cosmetic procedures on the face. More experienced respondents who had previously attended at least five cadaveric dissections were more likely to strongly agree that reviewing anatomy through this novel dissection approach increased their confidence in avoiding periorbital vascular danger zones. As minimally invasive outpatient procedures continue to evolve, practicing physicians and mid-level providers often face the challenge of having to reconcile preexisting anatomical knowledge with new clinical practice. Skills required to navigate high impact anatomy include visualization of structures that form the navigational landscape and avoidance of key danger zones. The novel dissection approach to the lateral orbit reflects the increasing focus on revisiting, reforming, and redesigning anatomy for continuing professional development activities.

Respecting upper facial anatomy for treating the glabella with neuromodulators to avoid medial brow ptosis-A refined 3-point injection technique.

BACKGROUND: Current injection algorithms for treating the glabella rely on a five- or seven-point injection technique with possible medial eyebrow ptosis and lateral eyebrow elevation as undesirable outcomes. OBJECTIVE: The objective of this study was to investigate the efficacy and safety profile of a refined 3-point injection technique targeting horizontal and vertical glabellar lines. METHODS: A total of n=105 patients (27 males and 78 females) with a mean age of 40.90 ± 9.2 years were investigated. The injection technique relied on targeting the muscular origin of the procerus and the corrugator supercilii muscles exclusively. The time of effect onset and the injection-related outcome 120 days after the treatment was evaluated using the 5-point glabellar line severity scale. RESULTS: The onset of the neuromodulator effect was on average 3.5 ± 1.5 days. There was no statistically significant difference in the amplitude of movement before or 14 days after the treatment with 2.99 ± 4.4 mm vs. 3.39 ± 3.6 mm (p = 0.149) for the medial head of the eyebrow and with 3.18 ± 4.7 mm vs. 3.33 ± 4.3 mm (p = 0.510) for the lateral head of the eyebrow, respectively. CONCLUSION: Incorporating anatomic concepts into clinical practice for glabellar frown line neuromodulator treatments with the investigated 3-point injection technique resulted in the absence of adverse events like eyebrow ptosis, upper eyelid ptosis, medial eyebrow ptosis, and lateral frontalis hyperactivity. This technique demonstrated efficacy throughout the 4-month study period.

Anatomy behind the Paramedian Platysmal Band: A Combined Cadaveric and Computed Tomographic Study.

BACKGROUND: The muscular hypothesis explanation of the pathophysiology behind paramedian platysmal bands does not seem to provide a sufficient explanation for the clinical presentation of these platysmal bands in aged individuals with cervical soft-tissue laxity. The purpose of this study was to investigate the fascial relationships of the anterior neck to enhance appropriate surgical treatment. METHODS: Retrospective analysis of computed tomographic scans of 50 Caucasian individuals (mean age, 55.84 ± 17.5 years) and anatomical dissections of 20 Caucasian and 10 Asian body donors (mean age, 75.88 ± 10.6 years) were conducted. Fascial adhesions were classified according to platysma fusion types, and platysma mobility was tested during dissection procedures. RESULTS: Fusion between the left and right platysma muscles occurred in 64 percent in the suprahyoid region and in 20 percent at the thyroid cartilage, and in 16 percent, the platysma attached to the mandible without fusion. In the absence of muscular fibers, a fascial adhesion zone with limited mobility was observed where the superficial cervical fascia fused with the investing layer of the deep cervical fascia. CONCLUSIONS: Muscular contraction of the platysma results in elevation of the most medial platysma muscle fibers, which are not attached in the fascial adhesion zone. The presence of a fatty layer deep to the platysma enables platysmal movement and anterior and inferior gliding of the skin and platysma when cervical soft-tissue laxity exists. Surgical treatments should include transection of the fascial adhesion; this could potentially prevent the recurrence of paramedian platysmal bands.

To click or not to click - The importance of understanding the layers of the forehead when injecting neuromodulators - A clinical, prospective, interventional, split-face study.

BACKGROUND: Differences in the effectiveness of neuromodulator treatments for horizontal forehead lines dependent on depth of product administration have been described. However, knowledge in respect to the fascial anatomy of the forehead still remains elusive. AIMS: To relate the fascial anatomy of the forehead to the effectiveness of neuromodulator treatments by conducting a clinical, prospective, interventional split-face study in which injections for the treatment of horizontal forehead lines are performed differently between facial sides. METHODS: This study included a total of n = 14 patients with a mean age of 35.71 (7.8) years and mean body mass index of 21.9 (3.0) kg/m2 . One side of the forehead was injected superficially by positioning the product in the superficial fatty layer, whereas the contralateral side was injected deep targeting the supraperiosteal plane (random selection). The treatment outcome was rated by the physician and by two independent observers according to a forehead line severity scale (0-4) at 14 and at 30 days. RESULTS: All three observers agreed in their ratings (ICC: 0.942) that the deep injection technique resulted in a superior outcome: D14 (superficial vs deep) 0.17 (0.4) vs 0.14 (0.4; P = .583) at rest and 1.26 (0.6) vs 0.43 (0.5; P < .001) for frontalis contraction; D30 0.17 (0.4) vs 0.14 (0.3) at rest (P = .583) and 1.21 (0.6) vs 0.43 (0.5; P < .001) for frontalis contraction. CONCLUSION: The results of this study underscore how detailed anatomic knowledge can enhance results of aesthetic interventions, in this case horizontal forehead line treatment with neuromodulators.

Soft tissue distribution pattern of facial soft tissue fillers with different viscoelastic properties.

BACKGROUND: Soft tissue filler product distribution and tissue integration have been shown to depend on myriad factors including the injector type, injector size, and injection angle. AIM: This study aims to investigate the magnitude of product spread across fascial soft tissue layers in relation to product viscoelastic properties. PATIENTS/METHODS: A total of 168 injection procedures were conducted in two female Caucasian body donors with a mean age of 80 years (range: 79-81) and a mean body mass index of 23.6 kg/m2 (range: 21.0-26.6). The injection procedures were performed in the forehead, scalp, zygomatic arch, mandible, clavicle, and sternum. The injected materials included Belotero® Soft, Belotero® Balance, Belotero® Intense, Belotero® Volume, Radiesse® , and Radiesse® Plus. Layer-by-layer dissections were performed to investigate the vertical distribution of the injected product. RESULTS: The mean product spread was for Belotero® Soft 4.54 ± 0.91; Belotero® Balance 3.85 ± 1.19; Belotero® Intense 3.04 ± 1.34; Belotero® Volume 2.58 ± 1.27; Radiesse® 1.31 ± 0.47; and Radiesse® Plus 1.27 ± 0.45 with P < .001. Bivariate correlations between product spread and storage modulus (G') revealed an inverse relationship of moderate strength with rp  = -0.651 and P < .001. CONCLUSION: The results of the present study revealed that products that were more fluid and less viscous distributed into more superficial fascial layers than products that were less fluid and more viscous (P < .001). This relationship held true irrespective of injected location.

Full-face effects of temporal volumizing and temporal lifting techniques.

BACKGROUND: Most injection techniques utilizing hyaluronic acid-based soft tissue fillers have predictable outcomes at the location injected. However, the temporal region has been identified to have aesthetic effects beyond the temple. AIMS: To identify and quantify the panfacial aesthetic effects of three different temporal injection techniques. PATIENTS/METHODS: The medical records of nine female and five male Caucasian patients with a mean age of 50.9 ± 11.9 years were retrospectively reviewed for the effects of these techniques: supraperiosteal, interfascial, and subdermal. Panfacial effects were evaluated by the semiquantitative assessment of aesthetic scores for the temple volume, the temporal crest visibility, the lateral orbital rim visibility, the position of the eyebrows, the severity of lateral canthal lines, the midfacial volume, and the contour of the jawline. RESULTS: The supraperiosteal injection technique had the greatest influence on improving the temporal volume (25.0%), the temporal crest (33.3%), and the lateral orbital rim visibility (31.0%) scales but had no effects in other facial regions. The interfascial injection technique revealed good effects on improving temporal hollowing (23.3%) but had an even greater effect on the crow's feet (26.8%) and on the position of the eyebrow (33.3%). The subdermal injection technique had its greatest effects in the lower face by improving the contour of the jawline (26.8%) followed by the improvement of the lower cheek fullness scale (14.3%). CONCLUSION: Future injection algorithms could utilize all three injection techniques together as one multi-layer injection approach with a tailored proportion of each technique based on the aesthetic needs of the patient.