Pediatric maxillofacial fractures are uncommon compared with adults. The incidence of pediatric facial fractures ranged between 1% - 15% of all facial fractures    The variations in the structural anatomy, the flexibility of the pediatric skeleton, the large quantities of facial soft tissues, and the lack of paranasal sinus pneumatization contribute to reduced frequency of pediatric fractures     . The protected environments under parental supervision also make them less likely to be exposed to major trauma as are adults  
The etiology of maxillofacial injuries in children varies according to social, cultural, and environmental factors, however, the main causes worldwide are traffic accidents, falls, altercations, and sports-related accidents, while interpersonal violence is rare    . Despite advancements in child safety, trauma remains the most common cause of pediatric morbidity and mortality . A survey in the United Kingdom has shown that trauma remains the mean cause of morbidity and mortality in children and affects one in three annually  .
Studies in this age group have reported mandibular fractures to be the most common with condylar and para-symphyseal fractures are reported to be more frequent   .
Epidemiological data on pediatric maxillofacial trauma is important as it has obvious implications for improving care by its use in clinical audit, service management, planning of future services, and effective targeting of preventive measures . Social, cultural, and environmental factors vary from one country to another and influence the incidence and etiology of facial trauma    - .
To the best of our knowledge, there is no study so far evaluated the epidemiological data of pediatric maxillofacial fractures in Yemen. Therefore, our aim is to report the prevalence, socio-demographics, causes, and pattern of maxillofacial fractures in children and adolescents in a sample of the Yemeni population.
2. Patients and Methods
This was a retrospective study that included pediatric and adolescent patients with maxillofacial fractures. The protocol was approved by the ethics committee of the faculty of dentistry, Thamar University. We retrospectively examined the records of patients treated at three mean medical hospitals (Almusali, Lebanon and Alsaidah) in Dhamar city, Yemen, from June 2017 to October 2020. To be included in the study, patients had to be aged 18 years or less at the time of initial admission. They were assigned to three age groups, preschool (0 - 6 years), primary school (7 - 12 years), and teenage (13 - 18 years).
The patient records were reviewed, and data including gender, age, mechanism of injury, site of the fracture, and type of fracture were recorded. The mechanism of trauma included road traffic accidents (RTA), falls, and violence. The fractures were categorized into those of the mandible, maxillae, nasal bone, zygomatic bone, and orbital bone. The classifications of the fractures were based on conventional radiographic study and computed tomographic examinations. Sites of mandibular fractures included symphysis and parasymphysis, body, angle, ramus, and condyle.
Data analyzed by using statistical software SPSS version 20 (SPSS Inc., Chicago, IL, USA). Chi-square test was performed and significance level set at p < 0.05. Descriptive analyses: proportions, percentages, and frequency distribution were performed.
A total of 483 cases of oral and maxillofacial fracture were reviewed. Seventy-one were cases involving children and adolescents who are 18 years or younger giving a prevalence of 14.6%. The age ranged from 3 years to 18 years with a mean of 12.1 ± 4.9. There were 50 boys (70.4%) and 21 girls (29.6%), in a ratio of 2.38:1.
The age group with the lowest proportion was that of children under 6 years of age, accountable for 18.3% of the cases, and the most frequent age range was that of patients between 13 - 18 years of age, presenting 50.7% of the cases. The male-to-female ratio in patients aged 0 - 6 years was 2.2:1. This ratio decreased to 1.4:1 in patients who were 7 - 12 years, while it increased in patients who were 13 - 18 years old to 3.5:1 (Table 1).
3.1. Mechanism of Injury
The primary mechanism of fractures was RTA (67.6%), followed by falls (26.8%) and then violence (5.6%).
Mechanism of fractures was associated with patient age. Fall was the most common etiology in children aged ≤ 6 years (69.2%), while in patients aged ≥ 7 years, the primary etiology was RTA. There was a significant difference between the 1st and 3rd age groups for RTA, fall, and violence (P < 0.05) (Table 2).
3.2. Location and Type of Fracture
A total of 87 fractures were recorded. Isolated fractures were found in 63.4% of study patients while 36.6% of patients sustained multiple fractures. Mandibular
Table 1. Distribution of patients according to different age groups.
Table 2. Frequency of etiology of facial fractures in relation to gender and age group.
fractures had the highest frequency of occurrence 55.2%, followed by nasal fractures (18.4%), zygoma (14.9%), maxilla (8.0%), and orbit (3.4%) (Table 3). In mandible, 56 fractures in 45 patients were observed. The most common site of mandibular fractures was condyle (39.3%), followed by symphysis and parasymphysis (35.7%), angle (16.1%), and body (8.9%) (Table 4).
Many of the unique features of pediatric facial trauma are directly related to the underdevelopment and continuing growth of the facial skeleton . The variations seen in the types of facial injuries that occur between children and adults are related to the variations in the structural anatomy. As children age and their facial structure begin to grow downward and outward, their injury patterns begin to mirror those of adults  .
In this study 14.6% of the patients presenting with facial fractures were children. This figure is consistent with other studies from different parts of the world, where facial fractures in the pediatric population were reported to be less than 15% of all facial fractures    . Hill, et al.  reported a higher rate (30%) of maxillofacial injuries in children, probably because their study was done in a specialist trauma center with a high referral rate.
Previously published work showed a higher incidence rate of maxillofacial fractures in males, with male-to-female ratios ranging from 1.5:1 to 2.8:1    - , n our study, the male-to-female ratio was 2.38:1, which was consistent with previous figures. Daniels, et al.  reported a male to female ratio of 16.6:1
Table 3. Distribution of facial fracture location according to gender and age group.
Table 4. Distribution of mandibular fractures according to gender and age group.
which is extremely high. They attributed this high ratio rate to the local culture where females spend more time at home with little or no outdoor activities.
Published data from different studies on the etiology and incidence of maxillofacial fractures tend to vary from one country to another, perhaps because of the differences in social, cultural, and environmental factors      . Our results showed an increase of maxillofacial fractures according to age, with a high frequency in the adolescent group. Similar findings were also presented in many studies in the world     . In contrast to the finding of the current study, other studies found the primary school age group to have the highest prevalence among other groups   . This contrast may be owing to the fact that they did not include patients older than 15 years in their studies.
It has been found that, despite individual variation in the reported prevalence that ranged from 30% to 70%, RTA was the most common cause of pediatric maxillofacial fractures       . Other studies showed that falls were the most frequent cause of pediatric facial fractures     . It is worth mentioning that teenagers are not included in those studies that reported fall as the main trauma etiology. A study from South Africa , oddly, found that violence is still a leading cause of facial fractures in a group of patients less than 18 years of age. In the present study, RTA was responsible for 67.6% of facial fractures in all patients. Among individual age groups, fall was prevalent in preschool groups, while RTA was the most common etiology among school and teenage groups. These results could be related to bad unrepaired roads and also due to the rising number of teenagers who are working on motor bicycles.
Many studies         showed that the mandible was the most commonly involved bone in facial fractures with an incidence range of 32% - 89%. This was also shown in our study; mandibular fractures were noted to account for 55.2% of pediatric facial fractures. Unexpected pattern of fractures found by Van As, et al.  in their study on a group of South African children where orbital fracture was the most common site of facial fractures.
The second most frequently fractured facial bone in our study was the nasal bone. Similarly, some studies   supported this finding. In contrast to our results, Daniels, et al.  found maxilla to be the second most commonly affected bone. Notably, they excluded nasal bone fractures from their study.
In the present study, the condyle was the most frequently involved part of the mandible within preschool and primary school age groups with an incidence of 54.5%, 41.2% respectively. However, within the teenage group, the symphysis was the most commonly fractured site (42.9%). Most of the published studies showed that condyle is the most frequently fractured part of the mandible        , While other studies    found that mandibular symphysis was the most commonly affected. These differences could be related to the degree of force, the direction and the point of application of the force and to the cross-sectional area of the agent or object struck  .
In conclusion, the findings of this study have shown that pediatric facial fractures constitute 14.6% of the total facial fractures. RTA was the principal cause of maxillofacial fractures and the peak incidence occurred in the teenage group (50.7%). The predominant site of fracture was the mandible (55.2%), in which 39.3% of the fractures were found in the condylar region.
The current study is limited by its retrospective nature which is an inherent weakness. Also, the sample size was limited to the local community so it may not represent the true situation in Yemen.
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