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The maxillary sinus aeration using the computational fluid dynamics (CFD) method based on individual adult patients' computed tomography (CT) scans were analyzed. The analysis was based on CT images of 4 patients: one with normal nose anatomy and three with nasal septal deviation (NSD) and concha bullosa (CB). The CFD simulation was performed using the Reynolds-Average Simulation approach and turbulence closure based on linear eddy viscosity supplemented with the two-equation k- ω SST model. As a result, it was found that the lower part of NSD has the most significant impact on the airflow change within the maxillary sinuses compared to CB and the upper part of NSD. In a healthy nose, the airflow in the sinuses is continuous, while NSD and CB change this flow into pulsatile. Multiple changes in the direction of flow during one respiratory phase were observed. The flow intensity within the maxillary sinus opening is lower on the NSD side. The concept of vorticity measure is introduced to evaluate and compare various patients qualitatively. Typically, the lowest values of such measures are obtained for healthy airways and the highest for pathological changes in the nasal cavity. [ABSTRACT FROM AUTHOR]

Introduction and objective. Craniofacial injury at the workplace may lead to orbital blowout fractures. The aim of the study is the development of own numerical model of the eye orbit, assessment of the damage zones, and comparing them with clinical examinations. In addition, the current legal status of patients after injuries is presented. Materials and method. In laboratory tests performed on bones collected from the upper and medial orbital wall (examination on fresh corpses), the Young's modulus was determined for these bones. Based on the CT image, a numerical model of the eye orbit was created. The damage zones within the eye socket were assessed after a blow (dynamic model) to the inferior and lateral walls, and only to the inferior wall. Comparative clinical material were 9 patients with orbital blowout fracture treated at the Clinic of Otolaryngology Results. Experiment 1: the damage zone covered an area of 0.54cm2, and was located medially and laterally from the infraorbital nerve canal. Experiment 2: the damage zone was smaller - 0.38 cm2, and located medially to the infraorbital nerve canal. The results obtained in the experiment were compared with the CT image of the eye sockets of patients after injuries. On this basis, presumptions were made concerning the mechanism of the trauma. Conclusions. The finite element method is a good tool for assessing the pathomechanism of trauma, as well as for an attempt to determine the circumstances of the event. Based on analysis of the numerical and clinical images, the necessity for using protective measures which absorb the impact to the inferior wall and temporal areas should be emphasised, as well as the fact that using merely goggles is insufficient protection of the eye orbit. [ABSTRACT FROM AUTHOR]

Conclusion:By means of three-dimensional display of the critical measurements, the authors suggest a novel definition of ‘dangerous ethmoid’. Parallel to Keros type III, the proposed determining factors include: olfactory fossa width >6 mm, its distance to the medial nasal concha (turbinate) <20 mm and to the orbit interval of <10 mm. Clinical evaluation of these preliminary criteria based only on radiological data is required and underway. Objectives:Detailed pre-operative assessment of sinus computer tomography (CT) scans reduces the frequency of severe complications in patients undergoing endoscopic sinus surgery (ESS). The authors aimed to identify a sub-set of anatomical features pre-disposing to major post-operative complications. Method:Sinus computer tomography (CT) scans of patients of a single institution qualified for ESS were examined. Besides the Keros classification, authors focused on the anatomic measurements as follows: the olfactory fossa depth, width, and its distance from the medial nasal concha and the medial wall of the orbit (referred to as ‘critical measurements’). The sample comprised 120 consecutive CT exams, without clinical validation. Results:Keros type I, II, and III was noted in 9.2%, 75.8%, and 15.0% of cases, respectively. Despite some statistically significant correlations, it was not possible to identify the patient age, sex, and side of body clearly correlating with the critical measurements. [ABSTRACT FROM PUBLISHER]

Orbital emphysema is a common symptom accompanying orbital fracture. The pathomechanism is still not recognized and the usually assumed cause, elevated pressure in the upper airways connected with sneezing or coughing, does not always contribute to the occurrence of this type of fracture. Observations based on the finite model (simulating blowout type fracture) of the deformations of the inferior orbital wall after a strike in its lower rim. Authors created a computer numeric model of the orbit with specified features--thickness and resilience modulus. During simulation an evenly spread 14400 N force was applied to the nodular points in the inferior rim (the maximal value not causing cracking of the outer rim, but only ruptures in the inferior wall). The observation was made from 1 · 10-3 to 1 · 10-2 second after a strike. Right after a strike dislocations of the inferior orbital wall toward the maxillary sinus were observed. Afterwards a retrograde wave of the dislocation of the inferior wall toward the orbit was noticed. Overall dislocation amplitude reached about 6 mm. Based on a numeric model of the orbit submitted to a strike in the inferior wall an existence of a retrograde shock wave causing orbital emphysema has been found. [ABSTRACT FROM AUTHOR]

We aimed to develop a model to quantitatively assess the potential effectiveness of face shield (visor) in reducing airborne transmission risk of the novel coronavirus SARS-CoV-2 during the current COVID-19 pandemic using the computational fluid dynamics (CFD) method. The studies with and without face shield in both an infected and healthy person have been considered in indoor environment simulation. In addition to the influence of the face shield and the synchronization of the breathing process while using the device, we also simulated the effect of small air movements on the SARS-CoV-2 infection rate (outdoor environment simulation). The contact with infectious particles in the case without a face shield was 12–20 s (s), in the presence of at least one person who was positive for SARS-CoV-2. If the infected person wore a face shield, no contact with contaminated air was observed during the entire simulation time (80 s). The time of contact with contaminated air (infection time) decreases to about 11 s when the surrounding air is still and begins to move at a low speed. Qualitative differences between simulations performed on the patients with and without the face shield are clearly visible. The maximum prevention of contagion is probably a consequence of wearing a face shield by an infected person. Our results suggest that it is possible to determine contact with air contaminated by SARS-CoV-2 using the CFD method under realistic conditions for virtually any situation and configuration. The proposed method is probably the fastest and most reliable among those based on CFD-based techniques. • It is possible to determine contact with infectious particles using the CFD. • A face shield allow to decrease a risk of SARS-CoV-2 infection. • Wearing a face shield by an infected person allows for maximum prevention. • An airflow towards a healthy person increases the time of infection. • The proposed method is the fastest among based on CFD-based techniques. [ABSTRACT FROM AUTHOR]