Symmetry recovery in zygomaticomaxillary complex fractures compared to normal unfractured population: A new reliable 3D evaluation.

OBJECTIVE: This study aims to quantify the facial symmetry of surgically treated zygomaticomaxillary complex (ZMC) fractures through a new reliable three-dimensional evaluation method, which is crucial for improving post-operative aesthetic and functional outcomes. MATERIAL AND METHODS: Healthy patients and patients with surgically treated ZMC fractures were retrospectively reviewed. Using Brainlab Elements® the zygomatic bone and the orbit of each patient was segmented and mirrored. Subsequently, the mirrored side was matched with the other side via volume-based registration, using the segmented orbit as reference. Volumetric asymmetry was measured using 3-matic software, and a surface-based matching technique was used to calculate the mean absolute differences (MAD) between the surfaces of the two sides of the ZMC. The reliability of this novel method using volume-based registration was tested, and the intra-class correlation coefficient was assessed. RESULTS: The MAD between the surfaces of the left and right sides in the control group was 0.51 mm (±0.09). As for the ZMC fracture group, MAD was 0.78 mm (±0.20) and 0.72 mm (±0.15) pre- and post-operatively, respectively. The MAD showed statistically significant differences between pre- and post-operative groups (p = 0.005) and between control and post-operative groups (p < 0.001). The intra-class correlation coefficient was high (≥0.99). CONCLUSIONS: This evaluation method using mirroring and volume-based registration to determine the symmetrical position of the ZMC is reliable. The surface-based measurements revealed an improved symmetry after surgery. However, the symmetry of the treated patients remained lower than the control group.

A cross-sectional study of the impact of the COVID-19 lockdown on domestic violence-related oral and maxillofacial injuries.

BACKGROUND: During the COVID-19 lockdown, more domestic violence-related traumas were reported. In this study, we investigated and compared the incidence of domestic violence-related injuries-in particular oral and maxillofacial injuries-in Ulaanbaatar, Mongolia, before and during the COVID-19 lockdown. MATERIALS AND METHODS: We conducted a cross-sectional study based on 3974 domestic violence cases registered at the Public Health Department, National Traumatology and Orthopedics Research Center of Mongolia between 2018 and 2022. Descriptive and binary logistic regression analyses were conducted. The victims were categorized according to their age (child, adult, and elderly). RESULTS: The mean age of the victims was children 9.7 ± 5.4 years, adults 34.8 ± 8.3 years, and elderly 64.3 ± 8.7 years. Binary logistic regression analysis (no/yes) showed that oral and maxillofacial injuries during the lockdown increased 1.3 times (OR = 1.3; CI 95% = 1.0-1.6; p = .003) in adults and 2.5 times in children (OR = 2.5; CI 95% = 1.7-3.9; p = .001). Additionally, injuries to upper limbs increased 4.6 times (OR = 4.6; CI 95% = 3.5-6.1; p = .001) in adults and 5.2 times in elderly patients (OR = 5.2; CI 95% = 1.8-16.2; p = .01). Additionally, thorax injury in children increased 3.1 times (OR = 3.1; CI 95% = 1.7-5.7; p = .001). CONCLUSIONS: During the lockdown, injury to oral and maxillofacial regions increased in adult and child victims of domestic violence.

Epidemiology of maxillofacial injury among adults in sub-Saharan Africa: a scoping review.

BACKGROUND: Injuries remain one of the leading causes of death globally. These disproportionately affect young adults and are particularly prevalent in sub-Saharan Africa (SSA). Maxillofacial injuries (MI) pose significant challenges to public health systems. However, much remains unknown regarding the epidemiology and extent of the financial burden in resource-limited areas, such as SSA, further necessitating more research and support. This scoping review aims to investigate the mechanism, distribution, and financial impact of MI in adults aged ≥ 18 years in SSA. MAIN BODY: The scoping review was guided by the methodological frameworks of Arksey and O'Malley and Levac. An electronic literature search for English-published articles on maxillofacial injuries in adults ≥ 18 years was conducted in Scopus, Medline, PubMed, Science Direct, CINAHL, Health Source: Nursing/Academic Edition, and grey literature. The PRISMA chart was used to document database searches and screening outcomes while reporting was guided by PRISMA-ScR. The data extraction process revolved around the predefined study outcomes, which encompassed the study characteristics and epidemiological parameters. The review used a narrative approach to report findings and evaluate publication quality using the STROBE checklist. The database search yielded 8246 studies, of which 30 met the inclusion criteria. A total of 7317 participants were included, 79.3% of whom were males. The peak age range for incidence was between 18 and 40 years. Road traffic collision (RTC) was the leading cause of MI, 59% of which resulted from motorcycle collisions. Assault/interpersonal violence ranked as the second leading cause of MI. The mandible was MI's most frequently affected hard tissue, followed by the midface. Factors such as alcohol/illicit drug use, poor knowledge of traffic regulations, and non-observance of these regulations were associated with MI. In our study, the cost range for mandibular fractures was $200-$468.6, borne by victims and their families. CONCLUSIONS: Maxillofacial injuries are predominantly caused by road traffic collisions and assaults in SSA. The findings can provide valuable insights into policy decisions and prevention strategies aimed at reducing injury burden. Further research is warranted to explore the psychological impact of MI, including PTSD, for tailored support and intervention. Scoping Review Registration The protocol has been registered on the Open Science Framework. Registration DOI: https://doi.org/10.17605/OSF.IO/BWVDK .

Comparison of characteristics of kick- and electric-scooter-related dental and maxillofacial injuries: A retrospective study.

BACKGROUND/AIM: Owing to the nearly three-year-long COVID-19 pandemic, small personal transportation devices that allow for greater freedom of movement within the cities have gained attention. Therefore, the number of people using kick or electric scooters has increased. This study aimed to compare the characteristics of kick and electric scooter-related dental and maxillofacial trauma and provide helpful information for preventing scooter accidents, appropriate treatment of patients with scooter-related trauma, and policy establishment. MATERIALS AND METHODS: This retrospective observational study analysed the medical records of 310 patients who visited the emergency room of Ajou University Dental Hospital for kick and electric scooter-related oral and maxillofacial injuries between 1 January 2017 and 31 December 2022. Sex, age, scooter type, time, and mechanism of the accident, helmet use, alcohol consumption, dental and maxillofacial injury types, and treatment were analysed. RESULTS: The average age in the kick-scooter group (5.71 ± 4.25) was lower than that in the electric-scooter group (28.24 ± 10.02) (p < .0001). There were more males in both groups. The helmet usage rates of the two groups were 2.80% and 7.88%, respectively. In the kick-scooter group, periodontal damage was more common than pulp injury, while in the electric-scooter group, pulp injury was more common than periodontal injury. There was no significant difference in soft-tissue damage between the two groups; however, bone fractures occurred significantly more frequently in the electric-scooter group (p < .0001). CONCLUSIONS: Electric scooters cause more crown and bone fractures than kick scooters and require more active treatment of dental and maxillofacial injuries. Riders should use protective equipment to prevent dental and maxillofacial injury. Although there are regulations related to scooters, the effectiveness of both kick- and electric-scooter related laws needs to be evaluated.

Characteristics of E-Scooter-Related Maxillofacial Injuries over 2019-2022-Retrospective Study from Poznan, Poland.

Recently, there has been a considerable rise in the popularity and use of electric scooters. Because of this, the number of accidents involving them has also risen. Head and neck injuries are the most common. The aim of the study was to determine the most frequent craniofacial injuries resulting from accidents involving electric scooters, and to identify the risk factors directly related to their placement and severity. The study carried out a retrospective analysis of the medical records of patients of the Clinic of Maxillofacial Surgery over 2019-2022, in terms of craniofacial injuries suffered as a result of e-scooter-related accidents. In the study population (31 cases), of which 61.3% were men, the median age was 27 years. At the time of the accident, 32.3% patients were under the influence of alcohol. Accidents were most common in the 21-30 age group; more often than not, they occurred during warm months and on weekends. The study identified a total of 40 fractures in the patients. The most common craniofacial injuries were mandibular fractures (37.5%), zygomatic-orbital fractures (20%) and frontal bone fractures (10%). A multidimensional correspondence analysis was also performed, which showed that at an age of under 30, alcohol consumption and female gender were associated with a higher likelihood of mandibular fracture. Proper education on the risks associated with the use of e-scooters is essential, with particular emphasis on the impact of alcohol on the driver. It is important to develop diagnostic and therapeutic algorithms for doctors, both in ED and in specialised departments.

Epidemiology of Blindness From Facial Trauma: A Multi-Centre Nigerian Study.

Study Design: This is a multi-centre retrospective study. Objective: To determine the prevalence of blindness and pattern of facial trauma associated with blindness among Nigerians. Methods: A multi-centre retrospective study of all patients with facial trauma resulting in blindness, that were co-managed by maxillofacial surgeons and ophthalmologists in 4 Nigerian public tertiary hospitals between January 2010 and December 2019 was undertaken. Data was analysed by IBM SPSS Statistics (version 21.0 for windows, IBM© Inc, Chicago, IL). Results: Of 2070 patients who presented with major facial injuries during the study period, 61 eyes of 56 (2.7%) patients were blind. Blindness was bilateral and unilateral in 5 (8.9%) and 51 (92.1%) patients, respectively. The mean age (SD) at presentation was 36.2 (16.6) years, and 47 (83.9%) of these patients were males. Road traffic accident (n = 27; 48%) was the commonest mechanism of facial trauma, the cheek (n = 18; 40.9%) was the commonest site of associated soft tissue injury and zygomatic complex fracture (n = 19; 24.1%) was the commonest related fracture. Globe rupture (n = 34; 55.7%) was the leading cause of blindness. Enucleation (n = 7; 13.2%) and evisceration (n = 22; 41.5%) were performed on 29 eyes of which 12 (41.4%) patients had ocular prosthesis post-operatively. Conclusions: Blindness was recorded in 2.7% of Nigerians with facial trauma. The commonest mechanism of trauma and cause of blindness in at least one eye were road traffic accident and globe rupture, respectively. Eye removal surgery was necessary in about half of the blind eyes.

Mapping Evidence on the Epidemiology and Cost Associated with Maxillofacial Injury among Adults in Sub-Saharan Africa: A Scoping Review Protocol.

(1) Background: Maxillofacial injury (MI) occurs universally, for it disregards preference for age, gender, and geographical region. The global incidence and prevalence of facial fractures rose by 39.45% and 54.39%, respectively, between the years 1990 to 2017. Projections indicate that the burden of injuries will persist in sub-Saharan Africa (SSA) in the next twenty years. This scoping review aims to map the literature on MI epidemiology and the economic burden on society in SSA. (2) Methods: The methodology presented by Arksey and O'Malley and extended by Levac and colleagues will be employed in the scoping review. The researcher will report the proposed review through the Preferred Reporting Items for Systematic Review, and Meta-Analysis extension for scoping reviews (PRISMA-ScR). The review will include studies encompassing MI in sub-Saharan African adults 18 years and above. (3) Results: This will be presented as a thematic analysis of the data extracted from the included studies, and the Nvivo version 12 will be employed. (4) Discussion: We anticipate searching for related literature on the prevalence, incidence, risk factors, mortality, and cost associated with MI in the adult population of SSA. The conclusion from the review will assist in ascertaining research gaps, informing policy, planning, authorizing upcoming research, and prioritizing funding for injury prevention and management.

Psychiatric symptoms and pain in maxillofacial injury following motor vehicle accidents: A comparative study.

BACKGROUND/AIM: Post-traumatic stress disorders, depression, and pain are rarely discussed in the literature on maxillofacial injuries, and psychiatric symptoms and pain are not identified and managed in such patients. The aim of this study was to determine the symptoms of post-traumatic stress disorders, depression, and pain in people with maxillofacial injuries following motor vehicle accidents. MATERIAL AND METHODS: In this cross-sectional study, people injured in motor vehicle accidents from March to September 2015 who were referred to a medical educational center in the northern part of Iran for treatment follow-up were sampled. The existing symptoms of post-traumatic stress disorder by PSS, depression by BDI-II, and pain by NRS were assessed. SPSS software version 21 was used for analysis. RESULTS: Maxillofacial injured patients had significant differences in terms of post-traumatic stress disorder (p = .006), depression (p = .001), pain (p = .001), and length of hospital stay (p = .002) than patients without maxillofacial injuries. CONCLUSIONS: Motor vehicle accident victims with maxillofacial injuries suffered significantly more from post-traumatic stress disorders and depression, pain and length of hospital stay than patients with other injuries.

Traumatic maxillofacial injuries: Patterns, outcomes, and long-term follow-up of a military cohort.

BACKGROUND/AIMS: Maxillofacial trauma poses a distinct challenge on the modern battlefield, and data on its long-term implications are scarce. The aim of this study was to investigate maxillofacial injury characteristics, outcomes, and complications along the continuum of care among hospitalized military personnel from the pre-hospital setting through long-term rehabilitation. MATERIALS AND METHODS: A registry-based study was undertaken of three national trauma and rehabilitation registries: The Israel Defense Forces Trauma Registry (IDF-TR), which records pre-hospital data. The Israeli National Trauma Registry for in-hospital data and the Israel Ministry of Defense Rehabilitation Department (MOD-RD) registry contain long-term disability data. The cohort comprised IDF soldiers who suffered maxillofacial injuries between 1997 and 2020. RESULTS: A total of 672 patients with maxillofacial injuries were included in the study, and 6.4% of all trauma admissions were related to maxillofacial injuries. Of these, 366 (54%) were injured in non-military (NMC) circumstances, and 306 (46%) were wounded in military circumstances (MC). The mechanisms of injury were mainly traffic-related among the NMC group compared with an explosion in the MC group. Maxillofacial fractures were frequently associated with traumatic brain injuries with higher rates in the NMC group than in the MC group (55% vs. 30%, p < .001). In a multivariate analysis, zygomatic and orbital fractures were associated with higher odds of concomitant head injury. The most common categories of long-term disability included central nervous system disorders, skull injuries, epilepsy, hearing impairment, ophthalmologic conditions, and post-traumatic stress disorder. CONCLUSIONS: Maxillofacial injuries are often associated with concomitant traumatic brain injury. Long-term disabilities associated with these injuries included the central nervous system, hearing, ophthalmologic impairments, and post-traumatic stress disorder.

Traumatic hemifacial avulsion and degloving injury: a case report.

Gross maxillofacial injuries are challenging to manage because they can be complicated by airway obstruction, injuries to the cervical spine, and cranial structures. Deformities from such injuries have lasting psychological effects which if not addressed can be devastating. We present a 21-year-old male motorcyclist who was involved in a motor traffic collision and sustained avulsion and degloving of the forehead skin, left eyebrow, left upper and lower eyelids, the nose, the left cheek and part of the right cheek, upper and lower lips, and the skin overlying the chin. His airway was compromised; hence rapid sequence intubation was done to secure it. Thereafter single-stage primary reconstruction and repair were done. A multidisciplinary team approach involving different specialties yielded good outcomes for this patient's condition.

Prevalence and patterns of maxillofacial trauma: a retrospective descriptive study.

INTRODUCTION: We aimed to describe the prevalence and pattern of maxillofacial trauma in Qatar. METHODS: This is a retrospective study of trauma registry data at Hamad General Hospital during the period from January 2011 to December 2014. The study included all traumatic maxillofacial patients who underwent CT scan and were admitted during the study period. RESULTS: A total of 1187 patients with maxillofacial injuries were included in the study and 18.5% of all trauma admissions were related to maxillofacial injuries. Young age and males were predominantly affected. Mechanisms of injury were mainly traffic-related and fall. Orbital injuries were the commonest followed by maxillary injuries. The median and range face abbreviated injury score (AIS) was 2 [1-3] with 66% had a score of 2. Maxillofacial fractures were frequently associated with traumatic brain injuries. One out of five patients was managed with surgery and had median length of stays in ICU and hospital 5 and 7 days, respectively. Overall, in-hospital mortality was 8.3%. Mortality in isolated maxillofacial was low (0.3%) in comparison to 15% in polytrauma patients (p = 0.001). Multivariable regression analysis showed that Injury Severity Score, face AIS and Glasgow Coma Scale were predictors of mortality with age-adjusted odd ratio of 1.15, 2.48 and 0.82; respectively. CONCLUSIONS: Maxillofacial trauma requiring admission is not uncommon in our trauma center and mostly it is mild to moderate in severity. Associated injuries are present in most of the maxillofacial injured patients and further diagnostic investigations should be part of the assessment in maxillofacial injuries.

Association between type of fixation and a length of stay amongst maxillofacial fracture patients: A retrospective charts review.

We aimed to explore the predictors of hospital length of stay for patients admitted and with maxillofacial injuries. Patients presenting with maxillofacial trauma were included. Poly-trauma involving neurosurgery and/ or needing orthopaedics intervention were excluded. Logistic regression was applied to explore the predictors associated with the hospital stay of > 4 days. There were 241 patients with mean age 29.35 ± 12.5 years (age range 12-80 years). Mandibular fracture was the commonest observation 121(50.2%), followed by maxillary 48(19.9%), and zygomatic bone fracture 9 (3.7%). Road traffic accident 196 (81.3%) appears to be the most common etiology of maxillofacial injuries in the studied sample. The mean length of hospital stay among bone plating patients was 5.96 ±6.8 days compared to 4.15±6.2 days for ones treated without bone plating; p-value 0.05. It was concluded that longer length of stay is required in patients with more complex management including bone plates.

Mandibular Fractures: Diagnosis and Management.

Accurate evaluation, diagnosis, and management of mandibular fractures is essential to effectively restore an individual's facial esthetics and function. Understanding of surgical anatomy, fracture fixation principles, and the nuances of specific fractures with respect to various patient populations can aid in adequately avoiding complications such as malocclusion, non-union, paresthesia, and revision procedures. This article reviews comprehensive mandibular fracture assessment, mandibular surgical anatomy, fracture fixation principles, management considerations, and commonly encountered complications. In addition, this article reviews emerging literature examining 3-dimensional printing and intraoperative imaging.

Three-dimensional intraoperative computed tomography imaging for zygomatic fracture repair.

OBJECTIVES: Zygomatic complex (ZMC) fractures comprise up to 40% of all facial fractures. Misaligned bone fragments and misplaced fixation hardware traditionally detected postoperatively on plain radiographs of the skull might require re-operation. The intraoperative O-Arm (Medtronic, USA) is a three-dimensional (3D) computed tomographic imaging system. MATERIALS AND METHODS: This retrospective single-center study evaluated the utility of O-Arm scanning during corrective surgeries for ZMC and zygomatic arch (ZA) fractures from 2018 to 2020. Three females and 16 males (mean age, 31.52 years; range, 22-48 years) were included. Fracture instability (n=6) and facial deformity (n=15) were the most frequent indications for intraoperative 3D O-Arm scan. RESULTS: The images demonstrated that all fracture lines were properly reduced and fixed. Another scan performed at the end of the fixation or reduction stage, however, revealed suboptimal results in five of the 19 cases, and further reduction and fixation of the fracture lines were required. CONCLUSION: Implementation of an intraoperative O-Arm system in ZMC and ZA fracture surgeries assists in obtaining predictable and accurate results and obviates the need for revision surgeries. The device should be considered for precise operations such as ZMC fracture repairs.

The impact of helmet use on oral and maxillofacial injuries associated with electric-powered bikes or powered scooter: a retrospective cross-sectional study.

BACKGROUND: Electric bikes (E-bikes) and powered scooters (P-scooters) have become increasingly popular modes of public transportation, but they have been associated with injuries of all kinds, including dental trauma. Helmet use is promoted as a means of reducing injuries in accidents involving motorized and unmotorized vehicles. The aim of the study was to evaluate the impact of helmet use on the number and severity of oral and maxillofacial injuries caused by E-bikes and P-scooters. METHODS: A retrospective cross-sectional study design was used. The cohort included all patients referred to the emergency department of a tertiary medical center in 2014-2020 with oral and maxillofacial injuries involving E-bikes or P-scooters. Data were collected from the medical files on demographics, types of injuries, circumstances of occurrence, work-up, treatment, and outcome. Use of a helmet was recorded in each case. RESULTS: Of the total 1417 patients referred to the emergency department for E-bike and P-scooter-related trauma, 62 had oral and maxillofacial injuries, including 57 riders and 5 pedestrians. All had hard- or soft-tissue injuries; 20 (32.2%) had head injuries and 22 (35.5%) had dentoalveolar injuries. Eleven riders had worn a helmet at the time of injury (17.7%). Helmet use was associated with time of injury (weekday/weekend, daytime/night-time), type of motorized vehicle (E-bike or P-scooter), head injury, and number of bone fractures. Head injuries occurred more often on the weekend (57.9%) than during the week (20.9%) and were more likely to occur in riders who were not protected by a helmet (37.3% vs 18.2%). Patients who used helmets also had a lower rate of fractured bones (18.2%) and dentoalveolar injuries (23.7%) than patients who did not (68.8 and 37.3%, respectively). Interestingly, helmet use had no protective effect on soft-tissue injuries. CONCLUSIONS: Helmet use by E-bike and P-scooter riders decreased the probability of head injury and of hard tissue and dentoalveolar injuries. These results may provide guidance for effective legislation and regulation of helmet use and improved treatment protocols for general and dental physicians.

Numerical simulation and analysis of midfacial impacts and traumatic brain injuries.

BACKGROUNDS: The maxillofacial region is the exposed part of the human body and is susceptible to injury due to the limited protective equipment. Due to anatomic proximity of the maxillofacial skeleton and cranium, the force can be transmitted directly to the brain in case of maxillofacial impact, maxillofacial injuries are often accompanied with craniocerebral trauma. Therefore, it is necessary to study the biomechanical response mechanism of trauma to improve prevention of traumatic brain injury (TBI). METHODS: To investigate the biomechanical mechanism between the two injuries, a finite element (FE) head model including skull, midfacial bones and detailed anatomical intracranial features was successfully developed based on CT/MRI data. The model was validated by comparing it with one classical cadaver experiment. During the simulations, three different load forces were used to simulate common causes of injury seen in the clinic including boxing-type impact injury and car accident-type impact injury, and four locations on the model were considered as common injury sites in the midface. RESULTS: Twelve common impact scenarios were reproduced by FE simulation successfully. Simulations showed that there was a linear relationship between the severity of TBI and the collision energy. The location of TBI was directly related to the location of the impact site, and a lateral impact was more injurious to the brain than an anterior-posterior impact. The relative movement between the skull and brain could cause physical damage to the brain. The study indicated that the midfacial bones acted as a structure capable of absorbing energy and protecting the brain from impact. CONCLUSIONS: This biomechanical information may assist surgeons better understand and diagnose brain injuries accompanied by midfacial fractures.

Characteristics of Otorhinolaryngological Emergencies in the Elderly.

OBJECTIVE: This study was designed to characterize the distribution of otorhinolaryngological emergencies seen in the geriatric population in one year. In this article we present our results and discuss the differences between our results and those reported in the current literature. METHODS: The study was carried out in a tertiary care university hospital. All patients aged 65 years or over that were referred by the general emergency department (ED) to the otorhinolaryngology emergency room in a one-year period were retrospectively reviewed. Demographic characteristics (age, gender), findings of physical examination, accompanying systemic diseases, diagnosis, and treatment methods were documented. Hospitalization and referral needs were also analyzed. RESULTS: In the one-year period from April 2017 to April 2018, a total of 12,780 patients aged 65 or older presented to the ED and the otorhinolaryngology physician was consulted for 195 (1.5%) of these patients. The age range of the patients was 65-96 years, with a mean age of 75 years. The most common cause for presenting to the ED was maxillofacial trauma (31.7%), followed by epistaxis (18.7%). Dyspnea (9.7%) and peripheral facial paralysis (9.7%) were the third most frequent causes. The outcome analysis revealed that 9.7% of the patients were hospitalized. CONCLUSION: Identifying the characteristics of the geriatric patients presenting to EDs is important for developing proper management algorithms. Maxillofacial traumas were the most frequently seen ORL emergencies in our cohort of geriatric patients, followed by epistaxis. The distribution and the prevalence of the cases could differ according to the institutional protocols.

Evaluation of bite force recovery in patients with maxillofacial fracture.

The aim of this study was to measure the maximum voluntary bite force and recovery time in patients treated for different types of the maxillofacial fracture. Patients aged between 18 and 60 years, who received surgical treatment for a single isolated fracture of the maxillofacial structure, were included in this study. Healthy individuals without any maxillofacial abnormality were selected as the control group. Bite force (in kg) was measured at the first incisor tooth, bilaterally, prior to surgery and 2 weeks, 6 weeks, 3 months, and 6 months after surgery. Of 120 patients, 89 (74.17%) were male and 31 (25.83%) were female. Mean patient age (±SD) was 31.21 (±11.64) years. Bite forces relating to fractures of the zygomaticomaxillary complex (ZMC) with involvement of the arch and zygomaticofrontal suture reached normal levels after 6 weeks (from 3.89 (±1.11) to 10.82 (±1.29); p = 0.296 and from 4.20 (±0.93) to 10.70 (±1.70); p = 0.192, respectively). Bite force returned to normal after 3 months in fractures of the symphysis (from 2.05 (±0.97) to 12.18 (±0.77); p = 0.222), body (from 2.21 (±1.26) to 11.9 (±0.73); p = 0.750), angle (from 2.45 (±1.24) to 11.89 (±0.76); p = 0.769), condyle (from 2.45 (±1.27) to 11.25 (±0.82); p = 0.968), and ZMC with and without infraorbital rim involvement (from 3.83 (±0.93) to 11.92 (±0.84); p = 0.724 and from 3.7 (±1.21) to 12.03 (±0.82); p = 0.482, respectively). Patients with ZMC fracture involving the arch and zygomaticofrontal suture require fewer follow-ups in comparison with those with other maxillofacial fractures. Measurement of maximal bite force can help to evaluate dentofacial deformities before and after surgical treatment.

Helmet chinstrap protective role in maxillofacial blast injury.

BACKGROUND: The protective role of helmet accessories in moderating stress load generated by explosion shock waves of explosive devices is usually neglected. OBJECTIVE: In the presented study, the protective role of the helmet chinstrap against the impulse and overpressure experienced by the maxillofacial region were examined. METHODS: The explosion shock wave and skull interaction were investigated under three different configurations: (1) unprotected skull, (2) skull with helmet (3) skull with helmet and chinstrap. For this purpose, a 3D finite element model (FEM) was constructed to mimic the investigated biomechanics module. Three working conditions were set according to different explosive charges and distances to represent different load conditions. Case 1: 500 mg explosive trinitrotoluene (TNT), 3 cm, case 2: 1000 mg TNT, 3 cm, and case 3: 1000 mg TNT and 6 cm distance to the studied object. The explosion effect was discussed by examining the shock wave stress flow pattern. Three points were selected on the skull and the stress curve of each point position were illustrated for each case study. RESULTS: The results showed that the helmet chinstrap can reduce the explosive injuries and plays a protective role in the maxillofacial region, especially for the mandible.