Facial Anatomy Research Articles

Best Practices for the Use of High-Frequency Ultrasound to Guide Aesthetic Filler Injections—Part 2: Middle Third of the Face, Nose, and Tear Troughs

The midface is a key area in facial aesthetics, highly susceptible to age-related changes such as fat pad absorption, bone resorption, and loss of skin elasticity. These changes lead to the formation of prominent folds, such as the nasolabial fold. In addition, critical vascular structures and non-vascular components, such as the facial artery, angular artery, and parotid gland, make this region prone to complications during filler injections. High-frequency ultrasound (HFUS) offers real-time, radiation-free visualization of facial anatomy, enabling injectors to accurately target the desired treatment planes and avoid critical structures. This article is the second in a series of articles on ultrasound-guided facial injections and focuses on the midface. It provides a detailed overview of the sonographic anatomy of key areas, including the nose, tear trough, nasolabial fold, zygomatic, and preauricular regions. Step-by-step techniques for ultrasound-guided filler injections are described, emphasizing the importance of scanning both before and during injections to ensure safe filler placement. By using ultrasound in this area, injectors can possibly minimize risks such as vascular occlusion and other complications, such as the Tyndall effect and intra-parotid injection. With ongoing advancements, ultrasound-guided injections are expected to become more refined, enhancing both aesthetic outcomes and patient safety.

The Dangers of Oversimplifying Facial Anatomy in Aesthetic Education

The Dangers of Oversimplifying Facial Anatomy in Aesthetic Education

Secondary Reconstruction of Panfacial Fractures With Virtual Reality Surgical Planning Using Both Pre and Postreconstruction Scans.

Late secondary reconstruction is sometimes required in patients with suboptimal primary panfacial fracture repair. At this stage, it can be difficult to discern original facial architecture due to malunion and bony remodeling. By utilizing the original postinjury CT scan to complete fracture reduction in the virtual reality (VR) planning environment, the surgeon may attempt to recreate an "ideal" facial bony anatomy for patients. This technique was completed in 2 patients presenting with facial deformity secondary to malunited panfacial fracture. Each had a cone-beam CT (CBCT) scan taken at presentation and the initial postinjury CT scans were obtained. Fracture reductions were completed in VR to recreate the preinjury anatomy. The resulting model was overlaid with current anatomy to create surgical aids. The first patient, a 23-year-old man, presented with malunion of all bones of the midface. Cutting guides were designed for the Lefort 1 segment, left zygomaticomaxillary complex (ZMC), and naso-orbito-ethmoid (NOE) osteotomies. The second patient, a 30-year-old woman, had bilateral ZMC and subcondylar fractures, midface retrusion, and malunion of parasymphyseal fracture. A 2-stage procedure was planned, including an initial Lefort I and bilateral sagittal split osteotomy with midline wedge excision. To address malar projection, a second surgery was planned using custom MEDPOR midface implants for the NOE and zygomatic regions. Both patients were discharged home, and all surgical goals and esthetic objectives were achieved.

Enhanced Understanding of Facial Nerve Anatomy and Arborization in the Indian Population: Implications for Surgical Procedures.

The anatomy and arborization patterns of the extraparotid facial nerve show considerable variation among different populations, impacting surgical approaches in plastic, head and neck, and ENT surgeries. This study focuses on the Indian population to provide a detailed understanding of these variations, specifically highlighting the Davis type IV arborization pattern's prevalence and its clinical relevance. We conducted a comprehensive dissection of 16 formalin-preserved Indian cadaveric hemifaces. The study meticulously mapped the facial nerve trunk (FNT), its furcation points, and branches. Key anatomical landmarks for locating these nerve structures were identified, including the tip of the mastoid process, the angle of the mandible, and a novel line between the lateral palpebral fissure and otobasion superioris. The most common arborization pattern observed was Davis type IV (31.3%). The study provided precise measurements for locating the FNT and its branches, using identifiable landmarks. These findings facilitate more accurate surgical planning, crucial for procedures involving nerve repair or grafting. This research offers vital insights into the facial nerve anatomy specific to the Indian population, with significant implications for surgical precision and patient outcomes. By establishing reliable anatomical landmarks and elucidating the predominant arborization pattern, the study enhances the understanding of facial nerve behavior during surgical interventions, particularly in the context of facial paralysis treatment and reconstructive surgeries. Due to the small sample size, however, this study only acts as a pilot for further research.

Anatomical Considerations for Thread Lifting Procedure.

Thread lifting is a minimally invasive procedure that enhances facial aesthetics by repositioning sagging tissues with absorbable threads. It requires a comprehensive understanding of facial anatomy for safe and effective results. This study aims to highlight the critical anatomical considerations in thread lifting, including the navigation of facial vascular structures, the protection of facial nerves, manipulation of fat compartments, and engagement of retaining ligaments. These factors are essential for minimizing complications and achieving optimal outcomes. A review was conducted focusing on the anatomical elements critical to thread lifting. The study analyzed clinical outcomes related to vascular structures, nerve pathways, fat compartments, and ligaments in patients undergoing the procedure. The review revealed that careful navigation of facial blood vessels is crucial to avoid complications such as bleeding and bruising. Knowledge of facial nerve pathways is essential to prevent nerve damage, which could result in facial weakness or paralysis. Proper manipulation of facial fat compartments helps address aging-related changes, and engaging retaining ligaments is vital for a sustainable lift without tissue distortion. Thread lifting demands not only technical skill but also a deep understanding of facial anatomy to ensure patient safety and desired aesthetic results. Expertise in these anatomical considerations is essential for minimizing complications and preserving the natural function of facial structures.

Virtual Reality Surgical Planning of a Complex Two-Jaw Defect

Head and neck reconstruction poses challenges requiring stable coverage and optimal appearance and functionality. In complex cases, and beyond the right choice of flap, Virtual Reality (VR) surgical software and preoperative planning, are needed to optimize outcomes. Our patient is a 16-year-old with a history of rhabdomyosarcoma necessitating maxillary-mandibular defect reconstruction. VR-based preoperative planning facilitated the intervention by creating 3D-VR models of facial anatomy and fibula, simulating resection margins, and creating surgical guides for intraoperative use. Our 2-team surgeons opted for a single-staged reconstruction using a vascularized fibula free flap. This case demonstrates successful single-flap reconstruction of a maxillary-mandibular defect, addressing challenges of recipient vessel scarcity, fibrotic scarring, and poor tissue quality. It also underscores the efficacy of a 2-team approach and VR-based preoperative planning in achieving successful outcomes in complex maxillary-mandibular reconstruction. The use of a single fibula flap minimized possible complications and operative time, and the 2-team approach helped by combining the expertise and training of craniofacial and microsurgical trained surgeons. Acknowledging limitations in imaging quality and real-time adaptability, we advocate for continued exploration of VR technologies in enhancing surgical precision in challenging cases.

Botulinum toxin-related blepharoptosis in emergency department admissions

The use of Botulinum Toxin Type A (BoNT-A) has become prevalent not only for therapeutic purposes but also for cosmetic applications. Among healthcare professionals, there has been an increase in BoNT-A administration within familial or friend circles. This rise has corresponded with a notable increase in cases of unilateral blepharoptosis presenting in emergency department admissions. This trend may be attributed to insufficient knowledge and experience regarding the proper dosing of BoNT-A, inadequate understanding of facial anatomy, or anatomical variations of the supraorbital foramen or neurovascular pedicle. While BoNT-A administration for reducing facial wrinkles may appear straightforward for a healthcare professional, a thorough understanding of anatomy and the causes and treatment of blepharoptosis is essential.

Landmark-in-facial-component: Towards occlusion-robust facial landmark localization

Despite great efforts in recent years to research robust facial landmark localization methods, occlusion remains a challenge. To tackle this challenge, we propose a model called the Landmark-in-Facial-Component Network (LFCNet). Unlike mainstream models that focus on boundary information, LFCNet utilizes the strong structural constraints inherent in facial anatomy to address occlusion. Specifically, two key modules are designed, a component localization module and an offset localization module. After grouping landmarks based on facial components, the component localization module accomplishes coarse localization of facial components. Offset localization module performs fine localization of landmarks based on the coarse localization results, which can also be seen as delineating the shape of facial components. These two modules form a coarse-to-fine localization pipeline and can also enable LFCNet to better learn the shape constraint of human faces, thereby enhancing LFCNet's robustness to occlusion. LFCNet achieves 4.82% normalized mean error on occlusion subset of WFLW dataset and 6.33% normalized mean error on Masked 300W dataset. The results demonstrate that LFCNet achieves excellent performance in comparison to state-of-the-art methods, especially on occlusion datasets.

Understanding clinical meaningfulness when targeting the depressor anguli oris muscle (DAO) with neuromodulators: a clinical prospective interventional study.

Neuromodulator injections in the US increased by 24% from 2021 to 2022. This rise is attributed to new products and growing acceptance of minimally invasive aesthetic treatments. Recent studies emphasize the importance of facial anatomy for precision and, consequently, a higher efficacy of neuromodulator treatments. This study aims to evaluate the clinical efficacy of a novel previously proposed injection technique targeting the depressor anguli oris (DAO) muscle to improve oral commissure position. This clinical, prospective study included 34 volunteers from the Shinobu Clinic, São Paulo, Brazil. Patients received 3 units of onabotulinumtoxinA per side, injected mid-distance between the oral commissure and jawline, following the labiomandibular sulcus (LMS). Standardized photographs and assessments using the Oral Commissure Severity Scale (OCSS) and Global Aesthetic Improvement Scale (GAIS) were conducted before and 30days post-treatment. Statistical analyses included t-tests, Wilcoxon Signed Rank test, and generalized linear models. The average increase in commissural height was 5.22% (p < 0.001). OCSS ratings improved significantly from baseline (clinician: 1.21 to 0.72, p < 0.001; patient: 0.93 to 0.69, p < 0.001). However, GAIS scores indicated no significant change (patient: 0.32, observer: 0.38; p = 0.491). The proposed injection technique improves perioral aesthetics objectively and subjectively. However, the lack of significant change in GAIS scores suggests that perceived improvements may not be clinically meaningful to patients. Future studies should focus on patient-centered evaluation methods to better assess aesthetic outcomes.

The role of oculoplastic surgeons in minimally invasive cosmetic injectables.

In recent years, the field of aesthetic medicine has witnessed a paradigm shift with an increasing demand for minimally invasive cosmetic procedures, including cosmetic injectables. This review aims to delineate the distinctive role played by oculoplastic surgeons in the administration of cosmetic injectables, comparing their expertise to that of nonphysician practitioners. Complications arising from cosmetic injections are discussed, including skin discoloration, inflammation, necrosis, vision loss, retinal pathology, and central nervous system adverse effects. Injector expertise, patient factors, type of filler, location of injection, and management strategies are reviewed. Findings highlight diverse practitioner involvement, common adverse effects like skin necrosis and vision loss, with hyaluronic acid fillers being prominent. Areas at the highest risk for ocular complication include the glabella and nose with potential management involving dissolving fillers and reducing pressure. Emphasis is placed on expert injector selection and patient awareness. The administration of cosmetic injectables requires a profound understanding of facial anatomy, vasculature, and potential complications. In contrast to nonphysician practitioners, oculoplastic and aesthetic surgeons bring a level of anatomical precision and clinical acumen that is essential for navigating the complexities of cosmetic injectables. Emphasis on training and collaboration among practitioners will be essential in advancing the field while prioritizing patient safety and satisfaction.

3D 4K Exo-Endoscopic Temporal Bone Dissection: A Novel Approach for Sharing the Anatomy.

Temporal bone dissection is overwide recognized as an ideal training method for otologic surgeons. The knowledge of temporal bone anatomy and especially of the course of infratemporal facial nerve is pivotal in practice. The 3D exoscope is an innovative and promising tool, that was recently introduced in ear surgery. A high-definition 3D exoscope (3D VITOM®) mounted on the VERSACRANETM holding system (Karl Storz) was used to perform two temporal bone dissection, with the aim to study the anatomy of infratemporal facial nerve. The 3D endoscope (TIPCAM®1 S 3D ORL, Karl Storz) was used in combination to provide a close-up high-quality view and to provide a different angle of view on fine anatomical relationships. The high-definition 3D exoscope allowed to conduct the dissection with high quality visualization and to share the same surgical field with trainees. Moreover, it showed a high interchangeability with the 3D endoscope. 3D 4K Exo-endoscopic temporal bone dissection seems to have benefits in terms of educational purpose, especially concerning anatomy understanding. The superiority in teaching value of this tool should be further investigated in cohort studies.

The integration of facial aesthetics and aesthetic dentistry

The aesthetics industry is still unregulated in the UK, and with the surge in people seeking facial aesthetic procedures, there has been a concomitant increase in the incidence of complications associated with these procedures. Dentists are especially well positioned to undertake facial aesthetic treatments providing that they have the appropriate training. Dentists generally have a strong foundational understanding of facial anatomy, in particular skeletal jaw structure, musculature, nerve and main vascular supply. In particular, dentists are exceptionally insightful around the peri-oral region and the smile. CPD/Clinical Relevance: There are many parallels and transferable skills between dentistry and facial aesthetics and dentists are well positioned to undertake facial aesthetic treatments after appropriate training.

Sonoanatomy of injecting botulinum neurotoxin into the facial muscles.

Ultrasonography (US) has become an essential tool for guiding botulinum neurotoxin (BoNT) injections in facial muscles, enhancing precision and safety. This narrative review explores the role of US in BoNT administration, particularly in complex anatomical regions, highlighting its impact on treatment customization, real-time visualization, and complication reduction. A comprehensive literature search was conducted using PubMed, MEDLINE, Embase, and Cochrane Library for articles published from January 2018 to December 2023. Search terms included "Botulinum neurotoxin," "facial anatomy," "ultrasonography guided injection," and "facial muscle sonoanatomy." Studies focusing on US-guided BoNT injections in facial muscles were included. Data extraction and synthesis were performed independently by two reviewers, focusing on study design, ultrasonography techniques, outcomes, and conclusions. The review found that US guidance significantly enhances the precision of BoNT injections by providing real-time visualization of facial muscles and blood vessels, thereby reducing the risk of adverse events. US enables tailored injection strategies, ensuring symmetrical facial expressions and minimizing over-treatment. The technique also offers immediate feedback, allowing for on-the-spot adjustments to improve treatment efficacy and safety. However, the review identified limitations, including potential selection bias and variability in US techniques across different studies. US guidance for BoNT injections into facial muscles offers substantial benefits in terms of precision, safety, and treatment customization. Despite the identified limitations, the integration of US into clinical practice is poised to enhance patient outcomes in aesthetic and therapeutic procedures. Further research is needed to standardize US techniques and broaden the inclusivity of studies to validate these findings comprehensively.

Review of the Adverse Effects Associated with Dermal Filler Treatments: Part I Nodules, Granuloma, and Migration.

The increase in the use of filler treatments within minimally invasive cosmetic surgery has correspondingly escalated the variety and frequency of associated side effects. Initially, unregulated procedures led to primary side effects such as infections, foreign body reactions, and granuloma formation. However, severe vascular complications like skin and tissue necrosis and blindness have emerged as recognized risks. Side effects from filler treatments can range from mild to life-threatening, including edema, pain, tenderness, numbness, bleeding, bruising, hematoma, redness, erythema, pigmentation, allergic reactions, itching, pruritus, the Tyndall effect, asymmetry, irregularity, migration, skin and soft tissue infections, nodules, granulomas, and vascular compromise. These side effects are categorized into early and delayed types. Many complications, particularly those related to vascular abnormalities, are frequently linked to procedural issues, emphasizing the importance of understanding filler properties, injection techniques, and facial anatomy. Preventing side effects is ideal, but early detection and treatment are crucial. Recognizing potential side effects based on their timing and understanding appropriate preemptive treatment methods is essential. This discussion addresses non-vascular side effects, highlighting their onset, symptoms, and management strategies. The comprehensive understanding and careful management of these side effects are vital for minimizing complications and ensuring patient safety in filler treatments.

New anatomical findings in the mandibular body region: Two parts that make up bucco-mandibular space.

Soft tissue spaces not only enable gliding by contraction of the facial muscles, but they also cause drooping of the superficial fat due to gravity in the upright position. This study was performed to clarify the structures around the bucco-mandibular space (BMS) and to apply this anatomical knowledge to clinical practice. Four sides of the face were dissected using a conventional gross anatomical dissection technique, and 10 sides (5 horizontal and 5 frontal sections) of the removed semi-facial soft tissue were dissected using the stretched tissue dissection (STD) method. Histological examination of the mandible was performed on two sides to confirm the findings of conventional gross anatomical dissection and STD. In all cases, both gross dissection and STD revealed that the BMS was composed of two parts. The superficial part was filled with adipose tissue containing nerves and vessels, including the marginal mandibular branch of the facial nerve, facial artery, facial vein, and mental nerve. We named this part the adipo-neuromandibular part. By contrast, the deep part was separated from the adipo-neurovascular part by facial deep fascia and composed of loose connective tissue. We named this deep part the loose connective tissue part. The STD method enabled us to obtain detailed anatomical findings of the mandibular region and elucidate two parts of the BMS in which the neurovasculature is distributed. We believe that these findings provide new insights into facial anatomy by resolving existing anatomical uncertainties and will contribute to safer surgical treatment in the facial region.

Neuromodulators in Men.

Botulinum toxin treatment is gaining popularity among men for cosmetic purposes driven by workplace competition and a desire for confidence and youthfulness. Because of the unique features of male facial anatomy, careful consideration is necessary during assessment and treatment execution. The peer-reviewed literature on male facial anatomy in relation to neuromodulator treatment was analyzed with a particular emphasis on studies involving male subjects and the use of botulinum toxin type A. Anatomic differences in muscle mass and contraction patterns between men and women help guide treatment. Men appear to require higher doses for effective treatment of facial wrinkles and, in the case of glabellar lines, often require double the standard dose for women. Treatment of the frontalis muscle in men, responsible for forehead creases, requires precise dosage and placement to avoid brow ptosis. The lateral canthal wrinkles are often the first area that men seek consultation for. Although FDA approval for lower face regions is lacking, off-label use can still be considered. Successful botulinum toxin treatment in men necessitates understanding facial anatomy, customized treatment plans, and appropriate dosing. Further research is warranted to refine protocols and enhance outcomes for male patients.

The importance of individualized and multiple landmarks for the identification of facial nerve trunk: a narrative review

The identification of the facial nerve trunk(FNT) is an important step in surgical procedures involving the parotid gland and adjacent structures to minimize the risk of inadvertent nerve damage which leads to facial muscle paralysis. Despite the availability of various anatomic landmarks such as the tragal pointer, posterior belly of digastric muscle, tympanomastoid suture, digastric branch of facial nerve and styloid process, no single landmark is perfect, with variations observed between individuals. Therefore, a comprehensive knowledge of facial nerve anatomy is essential for FNT identification. In this review, we tried to introduce clinically meaningful methods for the localization of facial nerve trunk. The preference of landmark could be changed by the major of the surgeon or the location of the tumor of the patients. Understanding the characteristics and drawbacks of the landmarks and choosing multiple landmarks that were convenient for surgeon would be necessary.

Exploring CT pixel and voxel size effect on anatomic modeling in mandibular reconstruction

BackgroundComputer-aided modeling and design (CAM/CAD) of patient anatomy from computed tomography (CT) imaging and 3D printing technology enable the creation of tangible, patient-specific anatomic models that can be used for surgical guidance. These models have been associated with better patient outcomes; however, a lack of CT imaging guidelines risks the capture of unsuitable imaging for patient-specific modeling. This study aims to investigate how CT image pixel size (X-Y) and slice thickness (Z) impact the accuracy of mandibular models.MethodsSix cadaver heads were CT scanned at varying slice thicknesses and pixel sizes and turned into CAD models of the mandible for each scan. The cadaveric mandibles were then dissected and surface scanned, producing a CAD model of the true anatomy to be used as the gold standard for digital comparison. The root mean square (RMS) value of these comparisons, and the percentage of points that deviated from the true cadaveric anatomy by over 2.00 mm were used to evaluate accuracy. Two-way ANOVA and Tukey-Kramer post-hoc tests were used to determine significant differences in accuracy.ResultsTwo-way ANOVA demonstrated significant difference in RMS for slice thickness but not pixel size while post-hoc testing showed a significant difference in pixel size only between pixels of 0.32 mm and 1.32 mm. For slice thickness, post-hoc testing revealed significantly smaller RMS values for scans with slice thicknesses of 0.67 mm, 1.25 mm, and 3.00 mm compared to those with a slice thickness of 5.00 mm. No significant differences were found between 0.67 mm, 1.25 mm, and 3.00 mm slice thicknesses. Results for the percentage of points deviating from cadaveric anatomy greater than 2.00 mm agreed with those for RMS except when comparing pixel sizes of 0.75 mm and 0.818 mm against 1.32 mm in post-hoc testing, which showed a significant difference as well.ConclusionThis study suggests that slice thickness has a more significant impact on 3D model accuracy than pixel size, providing objective validation for guidelines favoring rigorous standards for slice thickness while recommending isotropic voxels. Additionally, our results indicate that CT scans up to 3.00 mm in slice thickness may provide an adequate 3D model for facial bony anatomy, such as the mandible, depending on the clinical indication.

From masks to muscles: Mapping facial structure of Nycticebus.

Facial musculature in mammals underlies mastication and nonverbal communicative facial displays. Our understanding of primate facial expression comes primarily from haplorrhines (monkeys and apes), while our understanding of strepsirrhine (lemurs and lorises) facial expression remains incomplete. We examined the facial muscles of six specimens from three Nycticebus species (Nycticebus coucang, Nycticebus javanicus, and Nycticebus menagensis) using traditional dissection methodology and novel three-dimensional facial scanning to produce a detailed facial muscle map, and compared these results to another nocturnal strepsirrhine genus, the greater bushbaby (Otolemur spp.). We observed 19 muscles with no differences among Nycticebus specimens. A total of 17 muscles were observed in both Nycticebus and Otolemur, with little difference in attachment and function but some difference in directionality of movement. In the oral region, we note the presence of the depressor anguli oris, which has been reported in other primate species but is absent in Otolemur. The remaining muscle is a previously undescribed constrictor nasalis muscle located on the lateral nasal alar region, likely responsible for constriction of the nares. We propose this newly described muscle may relate to vomeronasal organ functioning and the importance of the use of nasal musculature in olfactory communication. We discuss how this combined methodology enabled imaging of small complex muscles. We further discuss how the facial anatomy of Nycticebus spp. relates to their unique physiology and behavioral ecology.

Management of fractures involving the mandibular body, parasymphyseal, and subcondylar regions

Background: The mandibular bone plays a crucial role in various aspects of facial anatomy, including digestion, speech, and facial aesthetics. Given its significance in these functions, surgeons must not only address functional aspects but also consider aesthetic concerns during treatment. Mandibular fractures represent a prevalent form of traumatic injury in the maxillofacial region. Despite the existence of established treatment methods that have been in use for a considerable time, untreated fractures and complications following surgery can still significantly impact the patient's quality of life. Purpose: Understand the principles of managing cases of mandibular corpus, mandibular parasymphysis, subcondyle fractures using a combination of Mini Plate and Reconstruction Plate. Case: A 54-year-old man with mandibular parasymphysis fracture Dekstra, corpus mandibular fracture sinistra, subcondyle fracture sinistra, dentoalveolar fracture regions 32-42 accompanied by avulsions 32, 31, 41, 42, and hypertension was reported. Results: The treatment in this case was Open Reduction and Internal Fixation (ORIF). Fixation of the fracture segments with 2 vertical mini-plates on the parasymphysis of the dextral mandible, 1 mini-plate and reconstruction plate on the corpus and subcondyle fracture sinistra. Conclusion: The use of two plates and screws in the parasymphysis of the mandible, one mini-plate and one reconstruction plate in mandibular corpus and subcondyle fractures, resulted in good occlusion with minimal complications.