Zygomatic Arc Research Articles

Neurosurgical Importance on Temporal Branch of the Facial Nerve.

We aimed to determine anatomic features of the temporal branch (TB) of the facial nerve and its relation to various anatomic landmarks on the face in order to prevent damage in the surgical approach after head trauma or in planned neurosurgical interventions. Nine male cadavers preserved with formalin, were bilaterally dissected under a microscope at the laboratory of anatomy department of the university. The anatomical features of the branch and branching pattern of facial nerve and its relationships with adjacent neurovascular structures were evaluated using descriptive statistical data. The mean distance at the lateral canthus level between the far most anterior branch and far most posterior branch of the TB (APD) was 14.93 mm. The mean distance to the tragus of the entrance point of the TB to the orbicularis oculi muscle (ETT) was 74.72 mm. The mean distance between the origin point of the TB to the tragus (TT) was 24.50 mm. The angle between the far most anterior branch and far most posterior branch at the level of the lateral canthus (APA) was minimum 15°, maximum 40° and the mean value of APA was 24.61°. The number of branches originating from the TB (NB) were one to three branches which lay under the zygomatic arch and two to five branches upper the zygomatic arch, respectively. The number of anastomosis between the TB and zygomatic branch (AN) varies between 1 and 4; AN was found to be less intense in 10 sides and very intense in eight sides. The APA and APD value is mentioned for the first time in this study and nerve angle is considered to be as important as temporal branching in directing facial neurosurgical operations. We found that the unsafety zone may be exist for a 40 degree and 1.5 cm long area at the lateral canthus level, especially on the zygomatic arc where branching pattern is greater and 2.5 cm in front of the tragus. The data is significant for neurosurgeons to reach exactly this area without causing postoperative complications such as facial paralysis.

The Skull Shape Analysis of Wistar Albino Rats: A Geometric Morphometric Study

The aim of the study was to evaluate the skull shape of Wistar albino rats using the geometric morphometry method. For this purpose, a total of 52 adult rat skulls, 31 female and 21 male, were evaluated. Skulls were photographed from equal distance in dorsal and ventral directions. 13 and 18 landmarks were marked in dorsal and ventral images, respectively. Percentage variation values of principal components were calculated by performing principal component analysis in the MorphoJ program. Average shape graphs showing the positive and negative boundaries of the first three principal components were obtained. It was defined that scatter plot graphic showing the degree of grouping of male and female rats according to the first and second principal component. The study also examined the allometric effect with regression. Discriminant function analysis was performed to examine gender dimorphism. As a result of the study, it was determined that the most significant shape change was in the zygomatic arc and palate regions according to individuals, while it was also in the neurocranium acording to gender. We believe that the study will contribute to anatomy, biology and archeology studies on the shape of skull.

Navigating Diagnostic Dilemmas in Subacute Subdural Hemorrhage: A Case Report

In this case report a 64-year-old male patient with recent past medical history of head injury complicated by zygomatic arc fracture and mild subarachnoid hemorrhage is studied. He had been presented to the Emergency Department because of progressive neurological symptoms and neurological deficits in the physical examination that could have been indicating subcacute subdural hemorrhage. However, the patient was reluctant to undergo diagnostic imaging due to concerns about radiation exposure. After several explanations, a CT scan was done, which revealed a bilateral subacute subdural hematoma. Neurosurgical management was initiated and intravenous corticosteroid therapy was administered to reduce local edema. The challenge of this case is based on the subtlety of symptoms that might cause patients to delay seeking medical attention. Additionally, patient reluctance to undergo diagnostic tests can complicate management, emphasizing the importance of patient education and therapeutic alliance. Multidisciplinary management involving Neurology and Neurosurgery is crucial for optimal patient care in such cases. This report underscores the significance of effective communication and collaborative decision-making between healthcare providers and patients to ensure timely and appropriate management of complex medical conditions.

Assessing the reliability of zygomatic bone landmarks as guides to reach the inferior orbital fissure in orbitozygomatic osteotomy: anatomical study of 83 human skulls.

To perform an adequate orbitozygomatic craniotomy, it is very important that the bone cut which passes through the body of the zygoma reaches the inferior orbital fissure (IOF). To reach the IOF, two surface landmarks on the body of the zygoma are described: a point located directly superior to the malar eminence and the zygomaticofacial foramen. The article explores the reliability of these landmarks and three other alternative points to reach the IOF. Eighty-three adult skulls were used in this study. The IOF dimensions and the relationship with the malar eminence, the point superior to the malar eminence, the zygomaticofacial foramen, and 3 alternative points (E, C, F) were analyzed. The malar eminence was unacceptable for use as a guide to the IOF. The point superior to the malar eminence was also unacceptable as a guide as only 9.4% and 10.9% were in the projection of the IOF on the right and left, respectively. 59.7% of the total zygomaticofacial foramina fell in the IOF projection. The point F fell in the projection of the IOF in 98.8% and 100.0% on the right and left, respectively. The use of the malar eminence as a guide to reach the IOF is unreliable in one third of cases as it is not easily identified intraoperatively in these cases. The zygomaticofacial foramen cannot be considered a reliable surgical landmark to reach the IOF. The authors recommend using a novel landmark which may be identified as a midpoint between intersections of the anterior and posterior margins of the zygomatic frontal process on a line extending from the inferior margin of the zygomatic arc. This point is reliable in 98.8-100% of cases.

Can Whitnall’s tubercle be localized using palpable landmarks around the orbit?

Objectives: Whitnall’s tubercle (WT) is located deep in the lateral canthus and on the lateral orbital wall and has crucial structures attach to it. We aimed to define the location of WT using the palpable bone landmarks which can be used as reliable landmarks in eyelid and orbital surgery to prevent the damage of stuctures associated with WT. Methods: Forty-four adult skulls (22 right, 22 left) were included to the study. The skulls were divided into two groups according to the apparancy of the WT. The distances from WT to the frontozygomatic suture, the marginal tubercle, the anterior point of the zygomatic arch, and the lateral margin of the orbit were measured. The clock positions of WT according to the marginal tubercle and the anterior point of the zygomatic arc were determined. Results: The distances of the WT to the marginal tubercle, the anterior point of the zygomatic arch, the lateral margin of the orbit, and the frontozygomatic suture were 9.92±1.65 mm, 16.48±1.86 mm, 2.32±0.53 mm and 9.66±1.44 mm, respectively. WT was at 8 and 9 o’clock positions on the left, and at 4, 3, and 2 o’clock positions on the right according to the marginal tubercle. WT was at 10 o’clock position on the left, and 2 and 1 o’clock positions on the right according to the anterior point of the zygomatic arch. Conclusion: The marginal tubercle, the lateral margin of the orbit, and the anterior point of the zygomatic arch can be used as standart bony landmarks in eyelid and orbital surgery to prevent the soft tissue damage relevant to WT. The high kappa values of the interclass and intraclass correlations suggest that these parameters are reliable and repeatable for clinical use. Out of these parameters, the anterior point of the zygomatic arch is more beneficial to locate the WT because of the standard clock positions. The WT is typically located at 10 o’clock position on the left and 2 o’clock position on the right according to the anterior point of the zygomatic arch.

Direct Three-Dimensional Diagnosis of Ex Vivo Facial Fractures.

The aim of the present study is to assess the reliability and accuracy of different 3-dimensional (3D) reconstruction algorithms in detecting undisplaced condylar, zygomatic arc, and orbital rim fractures based on cone-beam computed tomography data set. Twenty sheep heads were used in the present study. Sixty fractured and 60 nonfractured (control) zones were randomly allocated. Three groups consisting of nondisplaced fractures of condyle (CF, n = 20), orbital (OF, n = 20), and zygomatic arc (ZF, n = 20) were created by using a diamond cutting disc. Soft tissues were only dissected and no fractures were generated in the control group (n = 60). The 3D reconstructions were created by using multiplanar reconstruction (MPR), surface rendering (SR), volume rendering (VR), and maximum intensity projection (MIP) algorithms. Final 3D models were examined in Osirix software (Pixmeo SARL, Bernex, Switzerland) by 6 observers. Diagnostic accuracies of each algorithm were statistically compared by receiver operating characteristics (ROC) and area under the ROC curves (AUCs). For the detection of CF, AUC for VR algorithm was found to be statistically larger than that of MIP while AUCs for VR and MIP were larger than those of MPR and SR for OF detection. For the detection of ZF, AUCs for MPR and VR were significantly larger than those of MIP and SR (P < 0.05 for each). Within the limitations of this experimental study, it can be concluded that for maxillofacial surgeons, it is more likely to detect condylar, orbital, and zygomatic fractures by using VR algorithm in 3D reconstruction.

Multilobular Tumor of Bone in a Dog

Background: Multilobular tumor of bone (MTB) is a primary bone neoplasm, uncommon in dogs. This tumor was called of many names for a long time, as: chondroma rodens, multilobular osteochondrosarcoma, multilobular osteoma, multilobular chondroma, calcificating aponeurotic fibroma, although MTB was preferred chosen, because these other name could be correlated with humans’ tumors. This tumor is observed specially in skull bone, although it was reported in zygomatic arc, hard palate, axilla, spine and penis. Mostly happen in big breeds dogs, and middle to old age patients. Clinical signs depending of region and how aggressive the tumor is, usually are related to compression of any structure. The growth of MTB is frequently slow and progressive, locally invasive, occurring relapse after surgical revomal, although the tumor has low to moderate metastatic potential. The aim of this study is to report a case of MTB in a female dog and describe anatomopathological changes.Case: A female dog, mixed breed, 13 year-old, of middleweight was admitted in Pathology Department of College of Agricultural Sciences and Veterinary Medicine (FCAV-Unesp), Campus of Jaboticabal - SP, to be undergone to necropsy. The patient have never shown any epileptic crisis or neurologic signs. In macroscopic examination was found a mass in skull, which invaded the orbit and frontal sinus, but it was not invading brain cavity. The neoplasm had and irregular surface, firm consistent, color was white mixed to red areas, after cut it was granular and rough, and had some point mineralized areas. The lobs of lung had much firm masses, colored gray to white. In cytology it was observed fusiform to polyhedric isolated mesenchymal cells, moderated pleomorphic, basophilic cytoplasm, thin granulated nuclear chromatin, and visible nucleoli that was involved by eosinophilic extracellular matrix. The proposed diagnostic was bone sarcoma. Histopathological assessment showed mesenchymal neoplastic proliferation, and multilobular characteristic, the lobules had different sizes and was well organized, and they were separated by thin conjunctive septs. In the center of lobules, there was an “island” with mineralized or chondroitin bone matrix, in some of these islands there were osteoclast. The cells had moderated pleomorphism and low mitotic activity (three mitotic cells in ten high-power field). At least, it showed big necrosis areas and invasion of near tissue. In lung was observed metastatic areas, which had same histopathologic way of primary neoplasm in skull. That way, the histopathologic exam was similar to Multilobular tumor of bone grade II.Discussion: The MTB is an uncommon neoplasm, which assaults mostly skull bone in large breeds dogs and middle age of eight years old. This case accord to literature about breed size, age and local of tumor. The clinical signs in this dog was related to region what it was growing and near structure compression. Besides that, the patient had lung metastasis, that is the principal metastatic sites according to literature. The Histopathologic exam showed the same characters of MTB, which was considered grade II according to literature. Despite MTB is an uncommon neoplasm in clinic of dogs and cats, the epidemiological knowns as age, breed and localization, anatomopathological changes, and histopathological exam allows to have a diagnosis, showing the importance of including this neoplasm in differential diagnosis of bone tumor in dogs.

Brazilian Consensus Recommendation on the Use of Polymethylmethacrylate Filler in Facial and Corporal Aesthetics.

Considering that aesthetic benefits can be obtained with the use of permanent filling materials, this work focuses on the development of a consensus regarding the facial and corporal use of polymethylmethacrylate (PMMA) filler in Brazil. A questionnaire regarding PMMA treatment, which included items on the main indication, application site, volume of product applied, criteria for selection of the material, complications, contraindications, and individual professional experience, was distributed to the Expert Group members. In addition, the responses were summarized, constituting the starting point for the debate regarding the use of PMMA-based fillers on The First Brazilian PMMA Symposium to create a guideline to be followed in PMMA facial and corporal treatments. This survey involved 87,371 cases. PMMA treatment is recommended for restorative and aesthetic purposes in facial and corporal cases, particularly for facial balance. PMMA 30% filler is recommended in specific facial sites (nose, mentum, mandible angle, zygomatic arc, and malar). PMMA filler is contraindicated in other sites (lips) regardless of concentration. With regard to facial treatment, the juxtaperiostal is the application plane most recommended. For PMMA corporal application, intramuscular is the application plane most indicated, while intradermal and justadermal planes are contraindicated. The submuscular plane application is relative to PMMA filler concentration. The experts also inquired regarding the amount of PMMA recommended in each corporal site (50mL in the calf, 100-150mL in the gluteal region). These recommendations provide a guideline for physicians, supporting them to perform safe and efficacious treatment with PMMA fillers. 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 Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The Relationship of the Temporal Branch of the Facial Nerve to the Fascial Planes of Temporal Region in Human Fetuses.

The aim of this study was to obtain information by assessing the relationship between temporal region fascial structures, fat pads, and temporal branches of facial nerve in human fetuses to use the knowledge on treatment of early childhood period surgeries. This anatomic dissection study was conducted on 40 hemifaces with no visible external abnormalities on their faces. Fascial layers and related fat pads of temporal region were dissected layer by layer beginning from superficial to deep. The relations of temporal branches of facial nerve and temporoparietal fascia and the structures of these fascial layers were evaluated. Temporoparietal fascia showed continuity below zygomatic arc with superficial musculoaponeurotic system. Temporal branches of facial nerve showed a multiple branching. Parotid-masseteric fascia became very thin on the superficial of zygomatic arch and ran with superficial layer of temporal fascia above without attaching to periosteum. Temporal branches of facial nerve entered between multilayered layers of temporoparietal fascia. Temporoparietal fascia became thicker on anterior and middle parts because of the localization of superficial temporal fat pad. Temporal fascia was a 2-layered thick and fibrous tissue enveloping intermediate fat pad. Deep layer connected to periosteum of zygomatic arch and superficial layer continued passing superficial of zygomatic arch and connected to the parotid-masseteric fascia. Deep temporal fat pad was found on the deep to deep layer of temporal fascia and surface of temporal muscle. The findings of this study may contribute to the knowledge of the topographical localization of temporal branches of facial nerve with temporal region fascial structures and fat pads in fetuses.

A New Infracture Technique for Reduction Malarplasty with an L-Shaped Osteotomy Line.

BackgroundReduction malarplasty is one of the most common surgical procedures performed in the Asian population for aesthetic purposes. Although multiple methods have been developed for reduction malarplasty, including a variety of infracture techniques, most of the current procedures have limitations. In the current study we created a new infracture method to circumvent these shortcomings.Material/MethodsBetween January 2004 and October 2013, we applied this novel infracture technique in 700 patients. The highest area of the zygomatic body was marked pre-operatively and ground intra-operatively through an intraoral incision. An L-shaped incomplete osteotomy of the zygomatic body was performed with a reciprocating saw, and then a complete perpendicular osteotomy (1 cm anterior to the articular tubercle of the zygomatic arch) was made through a pre-auricular incision. Light pressure on the posterior part of the arch produced a greenstick fracture of the anterior osteotomy site, resulting in posterior-inward repositioning of the malar complex. Internal fixation was not required.ResultsSatisfactory aesthetic results and good post-operative stability were achieved. Three months post-operatively, the bone around the zygomatic arc osteotomy line was remodeled. The bone posterior to the articular tubercle of the zygomatic arch was partially absorbed, leading to a depression of the root of the arc and a natural transition on both sides of the osteotomy line, making the midface more slender. Instead, the anterior bone presented with new bones, making the malar complex more stable.ConclusionsThis new method has multiple advantages, including simple manipulation, no need for internal fixation, short operative and recovery times, and few complications. X-ray images showing the bony changes demonstrated that the infracture technique is an effective and ideal method for reduction malarplasty.

Mandibular Corpus Horizontal Distraction in an Edentulous Case and Its Effects on the Contralateral Coronoid Processus-Arcus Zygomaticus Relation

Purpose Interaction between the coronoid processus and the arcus-zygomaticus on contralateral hemi-mandible often drops off the radar in case of distraction osteogenesis of the mandibular corpus. We presented a 42 years old male without any teeth applied to hospital for facial asymmetry, short hemi-mandible and chewing problems. Case 2D and 3D computerized tomography and stereo-lithographic models were used for planning, predicting possible movements on the contralateral condyle and anticipate the relation of contralateral coronoid process the with zygomatic arc. Maximum safe amounts of distraction were calculated with cooperation with orthodontics and radiology. The rotation angle on the axis of the contralateral condyle is calculated in order to measure the defect to be corrected to take the maxillary and mandibular midlines to the same plane. Total calculated defect were shortened for preventing any interaction between the coronoid processus and the arcus-zygomaticus on contralateral hemi-mandible. Result Patient was satisfied and started to use new dentures two months after removal of the distraction device. Conclusion In order to achieve successful distraction without any problem regarding to opposite side rotation angles of the condyle, and position changes in the coronoid processus, collaboration and multidisciplinary approach are essential with orthodontics and radiologist in case of unilateral mandibular corpus distraction.

Anatomia aplicada do ramo temporal do nervo facial: estudo do risco potencial de lesão durante a cirurgia do rejuvenescimento facial

INTRODUCAO: O ramo temporal do nervo facial e um dos nervos mais comumente lesados, devido a pouca tela subcutânea que o protege a partir da sua saida da glândula parotida. METODO: Vinte e cinco hemifaces de cadaveres foram dissecadas e analisadas as relacoes entre o ramo temporal e glândula parotida, arco zigomatico, SMAS, arteria temporal superficial e musculo frontal. RESULTADOS: Doze ramos temporais dissecados perderam a protecao da glândula parotida a uma distância de 1,7 cm anterior ao trago. O cruzamento do arco zigomatico por dois ramos temporais foi o mais frequente. A passagem pelo arco zigomatico ocorreu entre 3,2 e 3,9 cm posteriores a borda lateral da orbita. O curso do ramo temporal junto as faces profundas do SMAS e da fascia temporoparietal, e acima da lâmina superficial da fascia temporal profunda foi constante. O ramo frontal da arteria temporal superficial foi superior e sua trajetoria paralela ao ramo temporal em 92% das disseccoes. CONCLUSAO: O ramo temporal do nervo facial segue um plano constante ao longo da face profunda da fascia temporoparietal e esta muito superficial quando cruza o arco zigomatico.

Anatomic Bases of Superficial Temporal Artery and Temporal Branch of Facial Nerve

The superficial temporal artery (STA)-based flaps have been used for different reconstructive purposes. These operations may cause facial nerve injury. The variations of the STA and its relation to temporal branch of the facial nerve (TBFN) were evaluated in this study. Thirteen cadavers with 26 STA and TBFN have been dissected. The bifurcation of STA was found to be 60% above the superior border of the zygomatic arc and 40% below this level. The mean lengths of frontal and temporal branches (FB and TB) of STA were 11.5 and 11.4 cm, respectively. The mean numbers of perforators of FB and TB to deep plane were 1.30 and 1.34, respectively. The mean diameter of STA at the superior border of zygomatic arc was 2.5 mm. The mean diameters of TB and FB at the level of bifurcation were 1.8 mm and 2.0 mm, respectively. The mean number of TBFN at the level of zygomatic arc was 3.70. The mean distance of the first and last branching of TBFN to tragus was found to be 24 mm. The mean number of TBFN at the level of the middle orbita was found to be 2.7. The mean distance of first and last branches of TBFN to the lateral orbital rim was 12 and 24 mm, respectively. The results found in this study may increase the accuracy of flaps based on STA and decrease the risk of facial nerve paralysis during these operations.

THE GROWTH OF CAPTIVE BRED FIELD MICE (APODEMUS AGRARIUS)

The growth of field mice (Apodemus agrarius) was investigated using 266 captive bred individuals aged from 16 to 1,233 days. They attained greater body weight and body length than animals in wild populations though skulls were not bigger. The average body weight in the oldest captive bred mice was lower than in medium-aged animals, i.e., growth curve was an arc-shaped. The average body weight and length, and some of skull characters were subjected to sexual dimorphism - males grew larger. The length of the cranial (upper) and lower diastema, length of nasalia, zygomatic arc length and zygomatic skull width continued to grow throughout the life of an animal, though growth intensity was higher in the young age. Correlations of skull character measurements with body weight were best in young specimens. The height of the mandibula (at, and including, the first molar), the maximum height of the mandibula (excluding the coronoid process), zygomatic skull width and the length of the cranial (upper) diastema were highly correlated with body weight. In general, correlations in captive mice were weaker than in captive voles with the exception of the coronoid height of the mandibula and the length of the mandibular diastema.

Elevatorium for fractures of the nasal bone and zygomatic arch

Unsuitable instruments are often used for the reduction of nasal fractures and fractures of the zygomatic arc. A new instrument for elevation and reduction of these common fractures is presented. The special shape of the elevator, which is adapted to the anatomy of the nasal dome, is helpful in nasal surgery. The bayonet-shaped angle also allows elevation of compressed fragments of the zygomatic arc. This instrument was successfully used in the reduction of 107 bony fractures of the nose and 36 fractures of the zygomatic arc. From the clinical point of view the elevator can be recommended for ENT specialist working in a trauma setting.

A Case of Unilateral Mandibulo-Facial Dysostosis Associated with Complicated Malformation of the Ear

A case of a male child aged 6 years, who had an unilateral, incomplete mandibulo-facial dysostosis associated with rare deformities of the ear, was reported. There was no significant family history concerning the congenital abnormalities. He was born at full term after what appeared to have been an uneventfull pregnancy. It was considered as one of causal factors that the early rupture of the faetal membran had made his birth very difficulf. His mental and bodily development was assured to be normal by the pediatric examination. On the otological and radiographic examination, we found that he had very complicated and various deformities on the left side of the head, face and neck.Significant findings among these deformities are listed as follows.1. A fissure, having been operated several days after his birth, extending laterally from the left angle of the mouth.2. The grossly deformed left auricle, microcia, lop ear and auricular appendixes, displaced to caudo-ventrally at the angle of the lower jaw. There was an opening of soft external auditory meatus, covered with the deformed auricle, directed latero-cranially and ended at the ossal part.3. Although asymmetry of palpebllar fissure was recognized, there were no manifest eye signs relating to this syndrom.4. The atrophia of the left zygomatic arc and branch of the mandibule, as one of representative signs of dysostosis mandibulo-facialis, was marke also in this case.5. Paralysis of the left facial nerve caused by the lesion in the facial canal.6. On the radiographic examination of the left temporal bone, the poorly developed mastoid cells, antrum and tympanic cavity were recognized. Moreover, dislocation of the left pyramis, deformity of labyrinth capsule, and a large notch at the internal porus of the acoustic nerve, were demonstrated.7. About an average of 30db hearing loss of bone conduction of the left ear was revealed by audiometrtic examination. Audiogram of the right ear was almost normal pattern.Based on the radiographic findings of the left pyramis, we assumed the perceptive type hearing loss of the left ear to the conginital damage of the accoustic nerve.A reviw of literatures was done, and the geneses of these congenital abnormalities were discussed.