Reduction malarplasty is a widely performed facial contouring procedure, particularly in Asian populations, to achieve a slimmer and more oval facial shape. While various surgical techniques exist, there is a lack of standardized guidelines for tailoring the procedure to different zygomatic morphologies. This study aims to establish a strategic classification-based approach to optimize reduction malarplasty outcomes. A total of 3997 patients underwent a reduction malarplasty over a 3-year period. Patients were classified into 3 distinct zygomatic types based on clinical and radiological assessments. The surgical technique was customized for each type, incorporating variations in ostectomy, rotation, setback of the zygomatic body, and medial impaction of the zygomatic arch. The classification-based approach allowed for precise modifications in osteotomy techniques, resulting in improved contouring and patient satisfaction. The beveled osteotomy of the zygomatic arch facilitated enhanced bone healing, reduced palpability, and minimized anterior malar depression. In addition, high L-osteotomy and orbital rim shaving were utilized in cases with a prominent inferolateral orbital rim to optimize outcomes. By categorizing patients into distinct zygomatic types, this study presents a systematic surgical approach that enhances precision and predictability in reduction malarplasty. These findings highlight the importance of individualized surgical planning to achieve optimal aesthetic outcomes and patient satisfaction. Further studies with long-term follow-up are needed to refine these techniques.

ABSTRACTOrientallactaga sibirica (O. sibirica), a member of the family Dipodidae, is widely distributed across Central Asia and plays a significant role in grassland ecosystems. Although substantial ecological data exist for this species in China, research on intraspecific cranial variation is limited, and no comprehensive surveys have been conducted across its distribution range in China. This study aims to address this gap by collecting specimens of O. sibirica from various geographic regions in China, conducting geometric morphometric analyses of their skulls, and examining the influence of current climatic conditions on cranial morphology. Our results show that significant cranial variation in O. sibirica is observed in the nasal, parietal, and maxillary regions near the nasal end, as well as the zygomatic arch and preorbital bridge. These differences cause skulls from northeastern China to cluster distinctly from those from the Qinghai‐Tibet Plateau. Regression analyses indicated that skull size is primarily associated with annual precipitation, whereas skull shape is significantly associated with altitude. Our findings reveal a distinct morphological pattern in the Qinghai–Tibet Plateau population, suggesting a high degree of geographic differentiation that warrants further investigation. Characterizing environment‐associated intraspecific variation provides a baseline for understanding morphological diversity in O. sibirica across China.

Patients with chronic limb-threatening ischemia (CLTI) often have multiple comorbidities and a poor prognosis. This study analyzes the association between the masseter muscle area (MMA), pneumonia, and the overall survival of CLTI patients older than 65years. The subjects of this retrospectively analysis were 54 consecutive patients with CLTI. The MMA was assessed by computed tomography (CT) as the largest cross-sectional area of the masseter muscle, located 2cm below the zygomatic arch, at diagnosis. Pneumonia was defined as radiographic infiltrates with fever or leukocytosis, requiring hospitalization within 1year after diagnosis. The endpoints were pneumonia incidence and survival. Pneumonia developed within 1year in 22 patients (41%). Multivariate analysis revealed significant associations with male gender (OR: 6.24, p = 0.048), history of pneumonia (OR: 5.21, p = 0.048), and low MMA (OR: 4.46, p = 0.045). Survival rates were 72% at 1year, 35% at 5years, and 24% at 10years. Low MMA was the only significant predictor of overall survival (p < 0.001). The MMA was significantly associated with pneumonia and the poor prognosis of CLTI patients over the age of 65years. As an indicator of oral frailty, the MMA may serve as a useful prognostic marker to guide treatment planning and interventions in this high-risk population.

To describe an ultrasound-guided in-plane technique for maxillary nerve block in dogs and its clinical analgesic application. Descriptive anatomical study and retrospective case series. A group of 12 canine cadavers and six client-owned dogs. Cadavers were placed in lateral recumbency, and the ultrasound transducer was positioned transversely across the head, ventral to the zygomatic arch and cranial to the mandible to visualize the pterygopalatine fossa. The fascial plane between the zygomatic gland and medial pterygoid muscle was identified, and a 22 gauge, 50 mm insulated needle was advanced in-plane to inject 0.1 mL of a 1:1 dye-saline per hemimaxilla. Injection success was assessed by staining of the maxillary nerve or its perineural fascia during dissection. Clinical anaesthesia records from six dogs undergoing maxillofacial procedures were reviewed retrospectively. Blocks were performed using the pulsation of the maxillary artery as a sonographic landmark. Block success was defined as absence of nociceptive response to upper lip pinching postoperatively. Staining success is presented as numbers and percentages (n/n, %). In the cadavers, 14/24 injections (58.3%) resulted in maxillary nerve or perineural fascia staining. In the clinical series, median body mass was 26.6 (range: 4.4-34.8 kg). A total of nine blocks were performed in six dogs using 0.5% bupivacaine (0.06-0.2 mL kg-1): bilateral blocks in three dogs and unilateral blocks in three dogs. All dogs (9/9, 100%) demonstrated postoperative sensory blockade; however, two dogs required intraoperative fentanyl. This ultrasound-guided in-plane approach achieved a moderate success rate in cadavers. In vivo, the pulsatile maxillary artery served as a reliable landmark for injection with consistent postoperative sensory blockade. The technique appears feasible and may represent a clinically effective alternative to traditional blind approaches.

Surgical Anatomy of Interfascial Dissection for Safe Exposure of the Zygomatic Arch

Filler procedures in the temporal region are frequently preferred in aesthetic practice; however, the complex vascular anatomy of this area poses significant risks. Misplaced injections into the superficial temporal artery (STA) or the zygomatico-orbital artery (ZOA) can cause blindness, while those into the middle temporal vein (MTV) may lead to pulmonary embolism. Therefore, a detailed and integrated understanding of the anatomical structure of the STA, ZOA, and MTV is essential for safe and effective procedures. This study aims to identify the anatomical course of the STA, ZOA, and MTV to enhance injection safety and minimize the risk of complications. The variations of the STA, ZOA, and MTV were evaluated on computed tomography angiography images of 200 patients, and vertical distances to six points on the zygomatic arch and horizontal distances to four points on the lateral orbital rim were measured. The most dangerous filler injection areas were identified as follows: in females STA-A2 4.2 cm, STA-A4 4.2cm, STA-O2 4.6cm, ZOA-A3 1.3cm, ZOA-O1 0.8cm, ZOA-O1 1.3cm, MTV-A3 2.0-2.4cm, MTV-O3 0.8cm, and MTV-O34.2 cm; in males, STA-A2 4.2cm, STA-A3 4.8cm, STA-O2 4.8cm, STA-O3 4.9cm, ZOA-A2 1.5cm, ZOA-A3 1.7cm, ZOA-O1 1.0cm, ZOA-O1 2.0cm, MTV-A3 2.8cm, MTV-A5 2.1cm, MTV-O1 2.0cm, and MTV-O3 4.1cm. An anatomical map of the STA, ZOA, and MTV was created to define key distances for safe filler injections. 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 .

We propose a minimally invasive surgical approach for open reduction and internal fixation (ORIF) of zygomatic arch fractures. The incision is made within the preauricular hairline. A "double-channel tunnel-like" approach achieves complete exposure of the zygomatic arch without requiring any special instruments or auxiliary incisions. This enables precise reduction and robust fixation of zygomatic arch fractures under full direct visualization. A patient presenting with a left zygomatic arch fracture following a fall underwent closed reduction via Keen technique, which proved unsuccessful. Subsequently, zygomatic arch fracture reduction and fixation were achieved via a preauricular incision. Postoperative computed tomography revealed that the fracture had been satisfactorily reduced and fixed. The postoperative scar was inconspicuous, and no injury to the frontal branch of the facial nerve was observed. This technique significantly streamlines the surgical procedure for zygomatic arch fractures.

Bone hyperplasia after reduction mandibuloplasty can impair the aesthetic outcome of the surgery which may require a revision. The adjacent masseter has been reported to be a decisive factor in postoperative mandibular hyperplasia. Our clinical practice suggested that simultaneous reduction malarplasty with zygomatic arch elevation may reduce masseter accumulation after reduction mandibuloplasty and contribute to less mandibular hyperplasia. Thus, a retrospective study was conducted to clarify our observation. From September 2015 to April 2024, patients who underwent reduction mandibuloplasty with or without simultaneous reduction malarplasty with zygomatic arch elevation were retrospectively reviewed. Computed tomography data were utilized to measure the preoperative, immediate postoperative, and follow-up postoperative mandibular volume. The volume of resected mandibular bone and regenerated mandibular bone was calculated. The measurements of masseter thicknesses, elevation distance of the zygomatic arch, as well as correlations analysis between them were performed. Fifty-two patients receiving reduction mandibuloplasty with simultaneous reduction malarplasty (combined-operation group) and 35 patients receiving reduction mandibuloplasty only (single-operation group) were included. After the operation, the masseter muscle in both groups became significantly thicker. The average masseter thickness increase was 0.89 ± 1.21 mm in the combined-operation group and 2.70 ± 1.10 mm in the single-operation group. Single-operation group had severer masseter thickening and mandibular hyperplasia. Pearson correlation analysis revealed that masseter thickening was positively correlated to mandibular resected volume, and that mandibular hyperplastic volume was positively correlated to masseter thickening with statistical significance. Simultaneous reduction malarplasty with zygomatic arch elevation induced less masseter redundancy and mandibular hyperplasia. In maxillofacial contouring surgeries, if necessary, performing the two procedures simultaneously and applying the bracing technique with zygomatic arch elevation can effectively improve the aesthetic outcomes of reduction mandibuloplasty. 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 .

Recent studies have challenged the traditional two-layer description of the masseter, suggesting a distinct innermost layer. Clarifying the identity of this structure requires integration of macroscopic, histological, and functional perspectives. We examined 22 Korean cadavers using lateral and medial dissection routes. We prepared transverse histological sections (H&E and Masson's trichrome) and performed ultrasonography at standardized anatomical landmarks. Morphometric variables were recorded, and associations with sex and age were analyzed. The innermost layer originated from the medial surface of the zygomatic arch and inserted onto the mandibular notch and posterior coronoid process. Well-defined fascial planes separated this layer from the temporalis and from the traditional deep portion of the masseter, designated here as the middle part. Comparative anatomy linked this layer to the maxillomandibularis in nonhuman primates. Quantitative analyses showed pronounced sexual dimorphism and progressive age-related atrophy. We propose redefining the masseter as a three-layer muscle - superficial, middle (formerly deep), and deep (the newly characterized layer). This framework increases anatomical precision and evolutionary continuity and may provide a more reliable basis for future functional studies and clinical applications.

This study aimed primarily to establish a precise surgical anatomical guide for masseteric-to-facial nerve (MN-FN) anastomosis using reproducible anatomical landmarks. The secondary objective was to identify novel and reliable landmarks to facilitate the localization and dissection of the masseteric nerve (MN) during facial reanimation procedures. A cadaveric study was performed on 22 hemifaces from 11 formalin-fixed cadavers. Standardized preauricular and temporal scalp incisions were used to expose the facial nerve (FN) and identify the MN. Distances from the tragus, zygomatic arch, and relevant bony landmarks to the MN were measured. Angles and depths were recorded bilaterally. Statistical analyses included Wilcoxon signed-rank test (p < 0.05). For the primary objective, the MN was consistently located deep to the zygomatic arch, at a mean distance of 2.6 ± 0.4cm anterior to the tragus and a mean depth of 1.2 ± 0.3cm. The trajectory formed an average angle of 52.1 ± 6.2° with the zygomatic arch. These parameters were symmetrical bilaterally (p > 0.05), confirming their reproducibility. For the secondary objective, we identified a new "subzygomatic triangle" bordered by the zygomatic arch, posterior masseter border, and condylar neck. The MN was reliably found within this triangle in all specimens (12/12, 100%), with significantly reduced depth variability compared to standard techniques (p = 0.018). This study defines reproducible anatomical references and introduces a novel landmark to enhance the safety and precision of MN-FN anastomosis in facial reanimation surgery.

Endoscopic Brow Lifting: A 35-Year Experience and Lessons Learned.

ABSTRACT Background The lateral pterygoid muscle is important for temporomandibular joint function and is closely related to the maxillary artery, which is clinically significant during procedures like botulinum toxin injections and infratemporal fossa surgery. Methods Thirty hemifaces from human cadavers were dissected. The study documented the number of muscle heads, insertion sites, and the course of the maxillary artery in relation to the muscle (superficial, deep, or transitional). Morphometric measurements included the distance between the maxillary artery and surface landmarks. Results A two-headed lateral pterygoid muscle was observed in 93.3% of specimens. The superior head most commonly inserts into both the articular disc and joint capsule (60%). The maxillary artery most frequently follows a superficial course (53.3%). The mean vertical distance to the tragus is 13.5 mm, the transverse distance is 34.1 mm, and the mean depth from the zygomatic arch is 23.3 mm. Conclusions The observed anatomical variability and morphometric data offer clinically practical guidance to minimize the risk of vascular injury during temporomandibular joint procedures.

Race or ancestry estimation plays a crucial role in forensic anthropology for identifying unknown individuals through skeletal analysis. The cranium, as the most diagnostic part of the skeleton, provides essential morphological indicators that vary among racial groups. This literature review aims to summarize current findings on race determination using both metric and non-metric methods of the cranium. Metric analysis relies on quantitative anthropometric measurements such as cephalic and nasal indices, while non-metric analysis focuses on morphological traits including nasal aperture shape, zygomatic arch prominence, palatal form, and the presence of torus palatinus. Various studies indicate that combining both methods yields more reliable results compared to using either alone. Although no single cranial feature can definitively determine race, a combination of multiple cranial and dental traits enhances the accuracy of ancestry estimation. Repeated measurements and observer agreement are necessary to minimize subjective bias and improve forensic reliability. This article review will describe race determination from the cranium in the odontology field.

Abstract This study investigates the osteometric differences between the Sardinian pine marten ( Martes martes latinorum ) and its continental counterpart ( Martes martes martes ), focusing on both cranial and postcranial skeletal elements. According to the island rule, small mammals on islands tend to increase in size. The Sardinian pine marten exhibits an increase in skull size (+12% in both sexes) compared to European subspecies, while its overall body mass shows a smaller increase (+9%). Analysis of the masticatory apparatus suggests hypertrophy of the temporalis and masseter muscles, reflected in a more robust zygomatic arch and a narrower postorbital constriction (−3.5% in males, −2.9% in females), suggesting a dietary shift toward increased meat consumption. The cranial capacity of Sardinian pine martens (22.85 cm 3 in males, 21.48 cm 3 in females) remains relatively large, possibly due to the cognitive demands associated with predation. Limb bones are longer in Sardinian females (+5.8%) but show negligible difference in males (&lt; 1%) compared to the European subspecies. This study provides the first comprehensive osteological analysis of M. m. latinorum , demonstrating that the Sardinian marten population forms a distinct insular cluster, as also confirmed by genetic data. Historical and archeological evidence suggests that the Sardinian pine marten was introduced during the Neolithic (approximately 8,000 years ago). Therefore, the observed skeletal modifications, including the increased size of the skull, occurred in a relatively short evolutionary timescale.

Detailed knowledge of venous valves and valve-like structures is essential in reconstructive surgery, as these structures may contribute to postoperative venous congestion following flap transfer. However, their presence in the superficial temporal veins (STVs), which are frequently utilized in craniofacial reconstruction, remains unclear. The authors performed morphological and morphometrical examinations of venous valves and valve-like structures in the STVs through cadaver dissection.This study involved the longitudinal dissection of 24 STVs from 12 cadavers. The veins were then examined under a stereomicroscope to determine the presence of venous valves or valve-like structures, and their quantity and location were recorded.The STVs contain both venous valves and valve-like structures known as venous cristae. All observed venous valves were bicuspid, whereas venous cristae were characterized by ridge-like protrusions of venous wall into the lumen. A total of 5 venous valves and 69 cristae were identified across 24 STVs. Venous valves were exclusively located in the main trunks of the STVs, whereas venous cristae were classified into five types based on their locations, with venous bifurcations being the most common sites. Most main trunks (22/24)contained either one venous valve or one crista, and the average distances from these structures to the superior margin of the zygomatic arch were 8.42 ± 0.80 and 9.03 ± 0.86 mm, respectively.A comprehensive understanding of the characteristics, quantity, and distribution of venous valves and cristae in the STVs could provide valuable insights for surgeons in preventing postoperative venous congestion.

A clear understanding of the superficial musculoaponeurotic system (SMAS) perfusion during extended SMAS rhytidectomy is helpful for surgical planning and for elucidating the structural characteristics of the SMAS. To determine the vascularity of the SMAS during extended SMAS rhytidectomy, as assessed using indocyanine green angiography (ICGA), and to discuss the clinical relevance of the SMAS perfusion pattern for surgical practice. A total of 20 patients who underwent extended SMAS rhytidectomy were evaluated intraoperatively. The perfusion patterns of the buccal-mandibular area SMAS and the superficial temporal fascia before and immediately after dissection were assessed by means of ICGA. Perfusion of the buccal-mandibular area SMAS originated from a transverse facial artery perforator in the deep layer before dissection, but was absent after dissection. No perfusion was observed after elevation of the buccal-mandibular area SMAS. In contrast, a prominent axial vessel was visible within the superficial temporal fascia. When this fascia was dissected, it was predominantly perfused by the parietal branch of the superficial temporal artery, which was present bilaterally in all patients. The superficial temporal fascia showed a marked peak in blood perfusion after dissection. Perfusion of the buccal-mandibular area SMAS originated from a transverse facial artery perforator in the deep layer and remained poor during extended SMAS rhytidectomy. Because of the poor perfusion of the buccal-mandibular area SMAS after elevation, high-risk patients may benefit from composite facelifts, less extensive skin dissection, or preservation of the transverse facial artery perforator. The superficial temporal fascia can be harvested as an inferior-pedicled flap down to the zygomatic arch, whereas the buccal-mandibular area SMAS cannot be reliably harvested in this manner.

Abstract Open‐mouth jaw locking, characterised by an inability to close the mouth, is uncommon in cats. A 4‐year‐old, entire, female domestic short‐haired cat presented with a wide‐open mouth after suspected high‐rise syndrome. Physical exam revealed right eye blindness and malocclusion with mandibular displacement. Computed tomography scans showed mandibular symphysis separation, ventrolateral displacement of the left mandibular coronoid process relative to the zygomatic arch, multiple fractures, including one involving the right palatine bone, which was in contact with the periocular soft tissues. Magnetic resonance imaging of the brain revealed no parenchymal abnormalities. Manual reduction and fixation of the mandibular symphysis were performed using circummandibular cerclage wires with a ventral twist technique. This report describes open‐mouth jaw locking in cats with associated neurological findings and right eye blindness, highlighting the clinical features, imaging diagnosis and treatment.

Zygomatic fractures are among the most common types of maxillofacial trauma, typically resulting from direct facial trauma such as assaults, motor vehicle accidents, and falls. These fractures predominantly affect adult males, with the most common sites being the zygomatic arch, infraorbital rim, and zygomatico-frontal suture. The diagnosis of zygomatic fractures generally involves both clinical examination and advanced imaging techniques, with multidetector CT (MDCT) being the gold standard for assessing the extent of the fracture and displacement. The Knight and North classification system is widely used to categorize these fractures based on their severity, guiding treatment decisions. This case report describes the management of a 58-year-old male patient who presented with a left zygomatic fracture following an assault. The patient exhibited typical symptoms, including left infraorbital pain, red eye, lacrimation, and periorbital oedema. A preoperative ophthalmic consultation revealed no visual impairment. MDCT confirmed a Group I zygomatic fracture according to the Knight and North classification, with minimal displacement. Under general anesthesia, fracture reduction was achieved via an infraorbital approach using a surgical hook, followed by stabilization with an L-shaped titanium miniplate. The patient experienced an uneventful postoperative recovery, with no signs of complications, malunion, or recurrence during a six-month follow-up period.

A common cause of teeth malocclusion and feeding disorders in guinea pigs is macrodontia and odontogenic abscesses. If the maxillary second or third molar teeth are affected, surgical access to them has so far been achieved through enucleation or orbital evisceration due to their location at the base of the orbit. The study aims to demonstrate a transorbital surgical approach to the apices of the maxillary molar teeth (M2 and M3) in guinea pigs, allowing preservation of the eye. Twenty six apicoectomies of maxillary M2 and M3 were performed. The surgical approach involved a skin incision above the zygomatic arch, followed by soft tissue dissection, incision of the orbital ligament, and gentle dorsolateral displacement of the eyeball. Blunt dissection between the lacrimal and zygomatic glands provided direct access to the affected tooth apices, which were removed using a dental bur. After the procedure, the soft tissues and the eye were repositioned and the skin was sutured. All animals recovered uneventfully. The described method may be applied in cases where it is necessary to perform maxillary second and/or last molar tooth apicoectomy while avoiding damage to the eyeball. Care must be taken to protect the corneal surface of the affected eye.

Introduction: Restoring premorbid form and function is the goal of craniofacial trauma surgery. Comminuted facial fractures are difficult to reconstruct due to bone loss and instability. Traditional fixation with plates and screws often fail due to resorption and secondary deformities. Titanium mesh is used in cranioplasty and orbital reconstruction, but its application in other facial regions is rare. This study presents a series of acute trauma patients treated with customized titanium mesh exoskeletons, molded intraoperatively using virtual planning models (VSP) to restore structure and function. Methods: This retrospective review (2022-2024) identified 23 patients with comminuted facial fractures treated with customized titanium exoskeletons. Craniofacial computed tomography (CT) Digital Imaging and Communications in Medicine data was used for virtual surgical planning (VSP) to achieve fracture reduction references, using mirror imaging of the uninjured contralateral side or a normal cohort image. Intraoperatively, the post-reduction models were used to shape standard titanium mesh to the patient’s craniofacial skeleton to generate a customized titanium exoskeleton that would bridge the area of comminuted fractures. Postoperative CT scans assessed anatomic reduction, and patient charts were reviewed for complications. Results: This technique was employed successfully in all patients with comminuted facial fractures. It was successful in several regions of the facial skeleton, including naso-orbital ethmoid (NOE), zygomaticomaxillary complex (ZMC), zygomatic arch, and mandible. This technique was more efficient and accurate in fracture reduction compared to standard plating methods. Postoperative CT scans demonstrated good anatomic reduction and VSP plan validity. Clinical assessment revealed excellent form and function long-term. One patient had partial intraoral exposure of mesh, which required limited removal. There were no known infectious, bleeding, or secondary deformity complications. Conclusion: This study presents the largest series of comminuted acute craniofacial fracture repairs using a customized titanium exoskeleton, demonstrating its effectiveness in stabilization, anatomical restoration, and secondary contour maintenance.