Zygomatic Bone Research Articles

Extraoral anatomy in CBCT – a literature review. Part 2: Zygomatico-orbital region

This second article about extraoral anatomy as seen in cone beam computed tomography (CBCT) images presents a literature review of the zygomatico-orbital region. The latter bounds the maxillary sinus superiorly and laterally. Since pathologic changes of the maxillary sinus are a frequent indication for three-dimensional radiography, the contiguous orbital cavity and the zygomatic bone may become visible on CBCT scans. The zygomatic bone forms the cheek prominence and has large contact areas with the maxilla through the zygomaticomaxillary suture in the infraorbital region as well as with the sphenoid bone along the lateral orbital wall. Each of the three surfaces of the zygomatic bone displays foramina that transmit neurovascular structures. The orbital cavity is located immediately above the maxillary sinus from which it is separated only by a thin bony plate simultaneously serving as the orbital floor and the roof of the maxillary sinus. Several openings, such as the superior and inferior orbital fissures, the ethmoidal and cranio-orbital foramina, and the optic and infraorbital canals, connect the orbit to the anterior and middle cranial fossae as well as to the infratemporal and pterygopalatine fossae.

Isolated Zygomatic bone fracture: assessment of outcome by two point fixation.

Objectives: The purpose of the present study was to assess the outcome of two-point fixation in isolated zygomatic bone fracture. Study Design: Descriptive study. Setting: Department of Oral & Maxillofacial Surgery, Faculty of Dentistry, LUMHS, Jamshoro/Hyderabad. Period: From 1/3/2018 to 31/8/2018. Material & Methods: Consisted of 46 patients with displaced isolated zygomatic bone fractures. All fractures were treated by reduction with transoral (Keen’s) approach & fixation was done by two point fixation with titanium miniplates. Patient was discharged from the hospital next day & advised follow-up after two weeks. Mean ± St & ard deviation was computed for qualitative variables. Diplopia was described in frequencies. Mouth opening was measured on 7th day or 1 month & measured in 1mm by metallic ruler. T-test was applied to find the P Value. Results: There were 34 male & 12 female patients. 56.5% injuries were caused by road traffic accident. Mean mouth opening at 1st week was 25.23±5.15mm & at 2nd week was 38.75±2.00 mm. At 1st week diplopia was found in 26.1% subjects while at 2nd week, diplopia was found in 10.9% subjects. There was significant difference in mean mouth opening at 1st week with 2nd week. The results also showed significant association of diplopia at 1st week with 2nd week. Conclusion: isolated zygomatic fractures can be reduced & immobilized by two-point fixation with screws & titanium mini bone plates at frontozygomatic & the zygomatic buttress area. Post-operative complications i.e. opening of mouth & diplopia were suggestively decreased afterward 15 days of treatment.

A Comparative Analysis of Outcomes After Reduction of Zygomatic Fractures Using the Carroll-Girard T-bar Screw.

Several approaches are available for managing zygomatic fractures; however, each approach has its complications. Use of the Carroll-Girard T-bar screw (CGTS) can reduce complications because it reduces the number of approaches needed for reduction. This study aimed to analyze the efficiency of the CGTS compared with the 3-point approach. A retrospective study was conducted by reviewing the computed tomography scans of 204 patients who underwent reduction surgery of Knight and North type 3, 4, or 5 zygomatic fractures from March 2009 to August 2017. Facial asymmetry, operative time, and complications were evaluated to compare 2 groups of patients: those who underwent CGTS and those who did not. Bilateral differences in the distance from the reference plane to the malar eminence in 3 dimensions based on computed tomography scans were used to calculate facial asymmetry. Among 204 patients, 91 were treated with CGTS whereas 113 patients underwent a 3-point approach. Bilateral differences in the position of the malar eminence and facial asymmetry were not statistically different in both groups. Operative time was not different in both groups. However, when patients with type 4 fracture were independently compared, the mean operative time was significantly shorter for the CGTS group. Wound dehiscence occurred in 11 patients (9.7%) in the 3-point approach group, compared with none in the CGTS group. None of the patients in the CGTS group complained of postoperative cheek scars over their incision sites. This study revealed that CGTS is a useful and feasible instrument that can reduce the number of approaches for zygomatic bone reduction and help clinicians achieve satisfactory outcomes.

THE IMPACT OF USE DIFFERENT TYPE OF IMAGE INTERPOLATION METHODS ON THE ACCURACY OF THE RECONSTRUCTION OF SKULL ANATOMICAL MODEL

The paper presents comparative studies concerning the use different methods of image resampling on the accuracy of the reconstruction of oral and maxillofacial geometry. The study was conducted on 14 different patients. In order to extract the oral and maxillofacial models from DICOM data, a region-growing algorithm was used. Thresholds were set above 200 HU to select only craniofacial tissue. After an oral and maxillofacial tissue was segmented from DICOM data, a marching cubes algorithm was used for computing isosurfaces. Model with [Formula: see text][Formula: see text]mm voxel was chosen as the gold standard for models of [Formula: see text][Formula: see text]mm structure and improved with image resampling filters. In the study 7 different kernels were used allowing for filtration. The image resampling filters minimize maximum positive deviations, especially in the occipital, mandible and zygomatic bone area, and maximum negative deviations in the area of the maxilla and nasal bone. Lanczos filtering is the best method of interpolation as compared to other used methods, due to significantly increased visibility of the edges of the segmented structures. As a result of applying this method, partial volume effect artifact was minimized. The distributions and statistical parameters of resampled DICOM data prove that on this stage of data editing, it is possible to increase the accuracy of segmentation and reconstruction of the geometry.

Coronoid hyperplasia: A review

Coronoid hyperplasia is one of the rare causes of progressive limitation of mouth opening due to impingement of the enlarged coronoid process of the mandible on the zygomatic bone. A review was performed on all cases reports and case series on coronoid hyperplasia. Gender, age at treatment, age of onset, types of hyperplasia (unilateral/bilateral), associated history, treatment, surgical approach, preoperative mouth opening, intraoperative mouth opening, mouth opening at follow up and follow up period were recorded and analyzed. A total of 82 articles which reported 115 cases were included. Coronoid hyperplasia was commonly reported at mean age of 22.64 years old with male preponderance. Most of the cases were diagnosed and treated between the age of 11–20 years old. This condition commonly involved bilateral coronoid process of mandible. The mean width of preoperative mouth opening was 16.5mm and was improved to a mean mouth opening of 36.3mm intraoperatively. Mean mouth opening was 34.8mm at an average follow up of 19 months. While the etiopathogenesis of coronoid hyperplasia is still not conclusive, treatment with either coronoidectomy or coronoidotomy produced good improvement in mouth opening.

Expert Consensus on Navigation-guided Unilateral Delayed Zygomatic Fracture Reconstruction Techniques.

The zygoma is located in the medial and lateral parts of the face, supporting the midfacial contour. The forward projection of the zygoma and the zygomatic arch often expose them to injury. Fractures of the zygoma can lead to the displacement of the zygoma and the zygomatic arch, causing facial collapse deformity. For delayed zygomatic fractures, the loss of normal anatomical landmarks caused by the malunion of the fracture lines and remodelling of the bony contour makes it difficult to determine the correct positions of the zygomatic bones. In such cases, ideal and steady outcomes with satisfactory midface symmetry have been difficult to obtain using traditional surgical methods. Nowadays, the application of digital surgical software and surgical navigation helps surgeons to perform accurate preoperative simulations to obtain ideal three-dimensional virtual surgical plans and achieve accurate reduction by intraoperative navigation systems, which increase the accuracy and predictability of fracture reduction outcomes. Experts from the Society of Oral and Maxillofacial Surgery, Chinese Stomatological Association have fully discussed and formulated an expert consensus on navigation-guided unilateral delayed zygomatic fracture reconstruction techniques to standardise the clinical operation procedures and promote the application.

Evaluation of Relation between Bizygomatic Width and Mesiodistal Dimension of Maxillary Central Incisor in Saudi Population: An In-vivo Study

Introduction: Selection of the maxillary anterior teeth is one of the most crucial steps in fabricating a removable prosthesis. To overcome this challenge, the relationship between facial measurements and natural teeth could be used as a guide in selecting the Maxillary Central Incisor (MCI) teeth. To improve aesthetics, various efforts have been made to associate the Mesiodistal Dimension (MD) of the MCI with various facial parameters. Aim: To determine the relationship between Bizygomatic Width (BZW) and the MD of the MCI in the Saudi population. Materials and Methods: The cross-sectional study selected two hundred dentulous subjects (100 males and 100 females) using a simple random sampling technique from December 2019 to March 2020. BZW was measured between the two most prominent points on the zygomatic bone, and the MD of the MCI was measured between the interproximal contact points. Both measurements were made with the help of a digital vernier caliper. Descriptive statistics and student’s t-test were used to compare all the measurements between males and females with a level of significance at 5% (0.05) and the power of the study of 95%. Pearson’s correlation coefficient (r) was used to find the interconnection between MD of MCI and BZW by linear correlation analysis. Results: The average values for BZW for males and females were found to be 123.56±3.74 mm and 117.33±3.21 mm, respectively. The average MD values of MCI for males and females were found to be 8.6±0.46 mm and 8.4±0.53 mm, respectively. A statistically significant difference was observed in the mean values of the BZW (p-value<0.001) and MD of MCI (p-value 0.002) when a comparison was done among males and females. The average ratio of MD of MCI to BZW was found to be 0.07±0.004 for males, whereas it was 0.072±0.004 for females and was statistically significant (p-value 0.001). The ratio of MD of MCI to BZW was found to be 1:14 for males and females. Pearson’s correlation coefficient (r) was positive and ranged from 0.067 to 0.007. Conclusion: Males had greater values for BZW and MD of MCI than females. There was an inconsistency when Berry’s biometric ratio was applied and when compared with the actual MD of MCI measurement in the present study. The findings of this study showed that there was a weak positive correlation between the MD of MCI and the BZW.

Treacher Collins syndrome: A case report

Introduction: Treacher Collins syndrome (TCS) is a congenital craniofacial morphogenesis disorder of autosomal dominant inheritance, which symptoms vary greatly ranging from almost unnoticeable to severe. The most common clinical features include hypoplasia of the malar bones and the lower jaw, antimongoloid slanting of palpebral fissures, and ear abnormalities. Imaging, especially computed tomography (CT), enables both a quantitative and qualitative analysis of the malformations, allowing the diagnosis and the planning of surgical interventions. Case Report: We report a case of a fully expressed Treacher Collins syndrome in a 3-month-old male child brought by his mother for dental malocclusion causing difficulties in breastfeeding. The examination revealed hypertelorism with antimongoloid slanting of palpebral fissures, hypoplasia of the malar and zygomatic bones, the mandible, and a microtia with no external auditory canal identified. The CT of the facial area revealed bilateral and symmetrical hypoplasia of the zygomatic bones, the mandible, the maxillary bones, and the temporal bone with agenesis of the bony external auditory canals. Conclusion: Treacher Collins syndrome is a malformative craniofacial congenital disorder that can be well managed if the diagnosis is done early.

Minimal Invasive Computer Assisted Dental Reconstruction of Atrophic Maxilla by Zygomatic Implants Combined with Conventional Implants

Purpose: The aim of the study was to evaluate and apply a minimal invasive approach for reconstruction of atrophic maxilla using computer-guided implant surgery by zygomatic implants combined with conventional implants. Material and methods: 10 patients with severely atrophic edentulous upper arch were included in this study, each patient had 2 conventional implants placed in the anterior maxilla, and 2 zygomatic implants on either sides placed in the zygomatic bone. In all patients a computer guided approach using a computer guided stent was used for drilling the conventional and zygomatic implants. All patients followed a clinical and radiographic follow up Result: Zygomatic Implants success was 90.0% while conventional implants success was 80.0%. The mean ± standard deviation values of coronal deviation were 3.24 ± 1.9 mm for Zygomatic implants and 2.9 ± 2.5 mm for conventional implant. The mean ± standard deviation values of apical deviation for were 4.2 ± 2.5 mm for zygomatic implants and 2.6 ± 2.5 mm for conventional implants. The mean ± standard deviation values of bone implant contact for zygomatic implant were 19.5 ± 5.3 mm, the bone covering the zygomatic implant laterally were 6 ± 2.3 mm, the minimum distance from the orbit were 5.6 ± 3.2 mm. General satisfactions for the treatment was 8.6. Conclusion: The use of zygomatic implants combined with conventional implants using virtual computer guided planning and surgery was useful for reconstruction of atrophic maxilla allowing an accurate, safe, graft less, less invasive surgery and provided a high patient satisfaction.

Fractures caused by car accidents admitted to a tertiary care hospital: A cross-sectional study

Objectives: Car accidents (CAs) are considered as one of the leading causes of mortality worldwide. They cause various ramifications on individuals and society, with fractures being a major one. Because of poor local epidemiological data, economic burden, and the enormity of the outcomes of CA, the aim of this study was to provide vital statistics about the most frequent sites of fractures due to CA. Methods: This is a retrospective cross-sectional study conducted in King Abdulaziz Medical City, Riyadh, Saudi Arabia. It included individuals who were admitted to the hospital with fractures from CA. The study looked for bone fractures related to CA, the length of hospital stay, the age, and the gender of each individual. The data included all patients aged ≥15 years who were admitted to inpatient departments from January 2011 to December 2015. Results: A total of 1396 individuals were included, of which 86% were male. The median age of injured patients was 26 years. The median length of hospital stay was 10 days. The most common fracture found was in the acetabulum (10%). The most common region to be fractured was the skull (n = 376, 27%). Males were more predisposed to fractures in the acetabulum (11%) and the base of the skull (10%). Females were more prone to develop fractures in the pubis (10%) and the malar and maxillary bones (9%). Conclusions: The study showed that the young population has the highest number of fractures after CA, and these fractures are common in the acetabulum and skull.

Morphogenesis of maxillary sinuses in infants, during early and first childhood

The aim: To study the peculiarities of the structure and to see the development of maxillary sinuses in infants, during the early and first childhood periods of human ontogenesis. Materials and methods: The study of the peculiarities of the development and formation of the maxillary sinuses' wall was carried out on 50 species of the upper jaws, turtles and sections of the head of the human corpses during different periods of ontogenesis (in infants, during early and first childhood) with the help of histological examination, preparation, CT scan, radiography and morphometry. Results and conclussions: In infants and during the early and first childhood periods of human ontogenesis in the MS there are changes in both quantitative and qualitative nature. In infants (10 days - 1 year), maxillary sinuse is located more lateral to the basis of the lower nasal concha. In this period, it begins to form its lower wall, which in the form of a narrow strip invaginates into the alveolar process. The growth of the sinus is due to the protrusion of the external wall in the direction of the zygomatic bone. The wall of the maxillary sinuse is covered with mucosa (respiratory mucous membrane), which is lined by pseudostratified columnar ciliated epithelium, which is located on the basement membrane. X-ray examination of maxillary sinuse in infants shows that it is a pear-shaped in the anterior projection. Clearly the following walls of the sinuses are visible: the upper, the lower, one, which is arched-shaped, the front and the median, which in lower part are crossed as arch to each other. Investigation of biological specimens of the maxillofacial area of the early childhood period (1-3 years) showed that maxillary sinuses in all specimens are determined more laterally to the basis of the lower nasal concha. Its vertical dimension is 7.5-8.0 mm, transverse - 5.7-6.0 mm, anterior-posterior - 13.9-14.5 mm. X-ray examination of maxillary sinuse in early childhood in the front projection shows that it has an oval shape. There are the following walls of the sinus: upper, lower, front and middle. The study of biological specimens of the facial area in the period of the first childhood (4-7 years) has been established that the configuration of maxillary sinuse is changing. All walls are determined, but the upper wall is rather short, and the front wall is narrow. The median wall has the most prominent development. On X-rays in the anterior projection, a slight extension of the maxillary sinuse is noted laterally. Therefore, one should thoroughly study the peculiarities of the development and structure of the walls of the maxillary sinuses in order to prevent the development of complications and to achieve the treatment of inflammatory diseases of the MS in an optimal term.

Minimally Invasive Technique for Treatment of Zygomatic Bone Fracture

Minimally Invasive Technique for Treatment of Zygomatic Bone Fracture

The Use of Rotation Flap to Cover a Facial Defect—A Case Study

Background: There are often situations that require the correction of facial defects. Local fasciocutaneous flaps provide a reasonable option for reconstruction of facial defects with good colour and texture match and good success rate. Among the various options of local flaps is the use of a rotation flap. Aim: The aim of this work is to demonstrate the reliability of the rotation flap in the correction of facial defects and its ability to achieve a good aesthetic outcome by applying the knowledge of facial aesthetic units. Case Presentation : This is a case report of a 28-year-old woman who suffered an avulsion injury to the face with loss of facial tissue resulting in exposure of the left zygomatic bone. The defect measured 5 cm × 6 cm. A rotation flap was used to cover the defect after the wound had been previously irrigated and debrided. Her wounds healed well. She suffered no facial nerve injury. The rotation flap resulted in a good colour match with no disruption of facial contour. Conclusion: The Rotation flap provides a reasonable option for reconstruction of facial defects with good colour and texture match.

Epidemiological Analysis of Zygomatic Bone Fractures in North-Western Romanian Population: A 10-Year Retrospective Study.

Midface fractures represent a challenge for medical practitioners due to the severe esthetic and functional consequences. This study aimed to determine the causes and to provide a demographic analysis of zygomatic bone fractures in our geographical area, with a view to implementing the necessary prevention methods, training the medical staff for a certain type of patients and decreasing the required costs. A retrospective statistical epidemiological analysis of 242 patients with zygomatic bone fractures over a 10-year period was performed. The most affected age group was 20-29 years (27.27%). The most affected were men (n=211, 87.19%) from urban areas (n=140, 57.85%), and without education (n=122, 50.41%). The most frequent cause was interpersonal violence (54.04%), followed by falls (17.36%) and road traffic accidents (16.53%). Interpersonal violence as a cause of zygomatic bone fractures is currently reaching epidemic proportions. Taking legal measures to prevent aggression is a public health emergency that would considerably decrease the incidence of these fractures in our population.

Coronoid Hyperplasia (Jacob’s Disease) as a Rare Cause of Restricted Mouth Opening: a Case Report

Introduction: Restricted mouth opening (MO) is associated with the problems in intra/extra-articular components such as trauma to the articular bone component especially at the early ages, chronic displacement of the articular disk, tumors, condylar anomalies, coronoid hyperplasia and hyperactivity of jaw muscles. A pseudo-joint can form between the zygoma and the hyperplastic coronoid process (Jacob’s disease). Pseudo-joint restricts MO, it causes multiple problems for patients, and finally it decreases the quality of their or patients’ lives. Therefore, early diagnosis and treatment are very important. Case Report: Described here is a 28-year-old man that due to trauma in childhood, his coronoid process became hyperplastic. The pseudo-joint formed between coronoid process and zygomatic bone interfere with MO. Discussion: The intraoral approach offers direct access without the risk of facial nerve injury or scars on the face

PATTERN OF CONDYALR FRACTURES AND ITS TREATMENT IN TERTIARY CARE HOSPITAL-A STUDY

Objective: To evaluate the occurrence of mandibular condylar fractures in our area regarding age, gender, etiological factors, type and level, any associated facial fractures and treatment modality adopted in our centre.
 Materials and Methods: Data of 120 patients presented with the features of mandibular condylar fracture at Oral and Maxillofacial Surgery Unit, Bacha Khan Medical College Mardan from September 2016 to October 2019 was recorded. Non probability, convenience sampling technique was used. History, clinical and radiographic examination was performed for diagnosis. Treatment modalities included conservative, closed reduction and open reduction and internal fixation. Data regarding the age, gender, etiology, pattern and level of fracture, associated facial fractures and treatment modalities were evaluated and analyzed.
 Results: Mean age was 21 ± 11.97 years, with an age range of 5-75 years. Age group 11-20 years were most commonly affected (38.4%).The ratio of male and female was 3.80:1. Road Traffic Accidents (38.3%) was the common cause of injury. Unilateral fractures (65%) dominated the bilateral pattern (35%).Condylar head was most common fracture (58.60%). Parasymphysis was most common associated fractures (26.3%) followed by body and zygomatic bone (18.4%). Most of the patients were treated by closed reduction (54.2%).
 Conclusion: Public awareness is required regarding the significance of the condylar injuries. Randomized Controlled Trials are required to compare the outcome of different treatment modalities.

Lifting effect of sequential autologous fat injection (SAFI) in three patients with small and flat malar bones

Lifting effect of sequential autologous fat injection (SAFI) in three patients with small and flat malar bones

Anatomical and topometric features of the zygomatic bone of adult. The practical implementation the clinical problem of maxillofacial surgery on the topic “Zygomatic implants”

Relevance. The method of setting the implant in the zygomatic bone often is conjugated errors and severe complications, as well as the need for anatomical justification, is still not widely used. their application. Purpose. Purpose. Study of the anatomical and topometric features of the zygomatic bone of an adult taking into account the age, sex and loss of natural teeth in the framework of the practical implementation of the clinical problem of maxillofacial surgery on the topic «Zygomatic implants». Materials and methods. The object of the study was the material of the modern craniological collection. For a collection of studying the anatomical and topometric features of the zygomatic bone and assessing the impact of tooth loss on its size, more than 200 skulls of people who died aged 18 to 79 years were studied. Results. In the study the linear dimensions and thickness of the adult zygomatic bones of an adult person have not been identified age-related features, as well as changes in the studied parameters, taking into account the side of the skull and the loss of natural teeth. Conclusion. Regardless of the side of the skull, age, sex and degree of tooth loss, the size of the zygomatic bone of men and women is determined by the size of the skull. Digital bata obtained, taking into account the size of the patients skull (very small, small, small, medium, large and very large) showed that the structure of the zygomatic bone is characterized by the presence of a thick layer of compact substance and a small-cell spongy substance, and the direction of the bone plates of the compact substance of the zygomatic buttress, as a rule, coincides with the direction of chewing stresses.

Analysis of Factors Affecting Quality of Life in Patients Treated for Maxillofacial Fractures.

Maxillofacial fractures (MFF) belong to the major modern medicine and public health concerns. The recovery from MFF is associated with a number of social problems. The patient’s mood may be affected by the change in self-image and lack of satisfaction with life, in many cases leading to a deepening of mental health disorders, resulting in alcoholism, loss of job or conflicts in the area of family life. The aim of this study was to evaluate the quality of life of patients with MFF, with respect to demographic and medical variables. The mean age of the 227 patients was 36 years. The mandible was the most frequent MFF location (52.9%), followed by the zygomatic bone (30.8%) then the maxilla (16.3%). Bone fracture displacement occurred in 79.3% of patients. A comminuted fracture was found in 71% of patients. The quality of life of patients with MFF was significantly better in all analyzed domains 3 months after the end of hospitalization compared to the initial survey carried out shortly after implementation of the treatment. Among the demographic variables, older age had a statistically significant but weak positive association with the improvement of the quality of life of respondents in General health perception domain.

Primary tuberculosis of zygomatic bone: A rare case report

Tubercular osteomyelitis of zygomatic bone is extremely rare. Here we have reported a rarest case of primary tuberculosis (TB) of zygomatic bone in a 20 year male who presented with discharging sinus over right zygomatic region. Anti-tubercular chemotherapy given and patient improved well.