Incidence and etiology of maxillofacial trauma: a retrospective analysis of King Chulalongkorn Memorial Hospital in the past decade

The cause of maxillofacial injuries varies because of socioeconomic, cultural, and environmental factors. In our study, motorcycle accident (506 [40%] cases) was the most common cause of injuries, which is similar to that seen in other studies [7, 8]. This may be a result of a societal shift from agricultural to industrial dependency, resulting in more traffic that might consequently cause more facial injuries from motorcycle accident. Apart from the low cost of motorcycles, Bangkok has some of the most severe traffic congestion in the world, encouraging the use of motorcycles in many situations. These data correlate with the World Health Organization’s report that the leading cause of death in the age group of 15–29 years is road traffic accidents, mostly involving male victims, and the proportion is double in developing countries compared with developed countries.

By contrast, a multicenter and prospective study from the European Maxillofacial Trauma project in 2015 found that assault and falling are the most common causes of maxillofacial injuries with rates of 39% and 31%, respectively. However, road traffic accidents cause maxillofacial injuries in only 11% of people [9]. The decrease in road traffic accidents in Europe is attributed mainly to the implementation of strictly enforced traffic rules and regulations with best practice on seat belts, drink driving, speed limits, motorcycle helmets, and child restraints [10].

In patients older than 70 years, falling is the most common cause of injury (24 of 49 [49%] cases). Manodh et al. [11] and Al-Qamachi et al. [12] reported that 66.6% and 83% of maxillofacial trauma in elderly people, respectively, is a consequence of falls. The incidence of falling increases by age and mostly occurs at home because of senility, osteoporosis, and systemic complications such as diabetes.

Associated injuries were found in 28.9% of patients with maxillofacial fracture (368 of 1,275 cases) and comprised head injury in 58% of patients, thoracic injury in 24%, abdominal injury in 8%, pelvic injury in 6%, and C-spine injury in 4%, as shown in Figure 2, corresponding to the studies of Chalya et al. [3] and Gadre et al. [4] who found that head injuries occurred in 53.1% and 56% of patients with maxillofacial trauma, respectively. Head injuries are the most commonly associated injuries because the forces that can cause facial bone fractures might also cause brain injuries. Another study showed the most common associated injury was to the extremities (51.3%), followed by skull injury (27.6%) [13].

The most important associated injury is the C-spine injury, which occurred in 4% of the patients. The incidence of C-spine injuries varies from 0% to 8% in maxillofacial injuries. Mukherjee et al. [14] found that patients with mixed mandibular and nonmandibular fractures had a higher incidence of C-spine injuries than those with mandibular fracture only and nonmandibular fracture only, with the rates of 12.8%, 1.8%, and 1.5%, respectively [14]. Vital transportation, e.g. by ambulance, and primary care of patients with maxillofacial injuries using C-spine protection to avoid spinal cord injuries is necessary, especially in patients with combined mandibular and nonmandibular fractures who have a higher risk of C-spine injuries.

The variation in the patterns of facial bone fracture depends on variation in geographic, cultural, and socioeconomic environments of the countries in which studies are conducted. In the present study, the most common facial fracture is ZMC fracture (38.6%), followed by mandibular fracture (21.8%) and nasal bone fracture (17.8%). The direction of the injury-producing force determines the pattern of fractures, and the ZMC has the most prominent anatomical position in the Asian face [15, 16]. Therefore, it is not surprising that the most common fracture in the present study is the ZMC fracture. The finding reported here is in contrast with that reported by Manodh et al. [11] who found that the most common maxillofacial fracture is mandibular fracture (59.2%). They implied that the patients usually, as a reflex, turn to their side when there is a sudden impact directed to the face. Therefore, the mandible is the first bone that encounters the injury force, especially when the victim wears an open-type helmet. By contrast, the incidence of nasal bone fracture is quite low, compared with that in other studies [17, 18]. It appears likely that in these other studies, the patients have more prominent nasal bones and lack soft tissue coverage, making the nasal bone the most fragile facial bone. By contrast, in the Asian faces in the present study, the malar bone is more prominent and the nasal dorsum is flatter [15, 16].

In the case of mandibular fractures, we found that 204 (61.5%) cases had single fracture. Parasymphysis is the most common fracture site, as reported by Manodh et al. [11]. This may result in this area being anatomically the weakest point. Usually, the canine roots are longer than other roots, resulting in less bone and a higher tendency to fracture [17]. We found that 128 (38.5%) cases had combined fracture, which is consistent with the study of Sirimaharaj and Pyungtanasup [5] and Park and Lim [6] who reported the incidence of combined fracture to be 41.4% and 36.7%, respectively. The most common combined fracture was parasymphysis and angle (15.4%), followed by parasymphysis and condyle (12.6%), which is consistent with the report of Park and Lim [6], while the study from Parkland Memorial Hospital found that the most common combined fracture was parasymphysis and condyle (15%), followed by parasymphysis and angle (8%) [19]. This might be the result of different causes of injuries. The main cause of injury in the present study was road traffic accidents, which resulted in more impact force directed to the mandible. By contrast, the causes of injury in patients at Parkland Memorial Hospital were falling and assault. With these injuries, the impact force might be directed to the primary fracture site and then transmitted to the condyle, which is the thinnest part of mandible.

At KCMH, Neurosurgery Unit is mainly responsible for frontal bone fracture and the Plastic Surgery Unit is responsible only for the anterior table of frontal sinus. We did not include frontal bone fracture in the present study because it was beyond our scope.

The main goal of treatment for facial fractures is to rearrange bone pieces in the same place (anatomical reduction) for good cosmetic results and function, especially occlusion [1]. Most patients therefore underwent open reduction and internal fixation with plates and screws (58.9%). In cases where fractures occurred in both upper and lower jaws, patients underwent intermaxillary fixation for 1–3 weeks. However, patients with nasal fracture usually underwent either closed reduction or conservative treatment, owing to the small and slim Asian nasal bone, in which fracture might not be readily observed.

In reference to the United Nation’s policy of “improving global road safety” from the Moscow Declaration, urgent action is needed to achieve the ambitious target for road safety reflected in the newly adopted 2030 agenda for sustainable development, which will half the number of deaths and injuries from road traffic crashes globally by 2020. The Thai government needs to enforce the laws with best practice on seat belts, drink driving, speed limits, motorcycle helmets, and child restraints. While there has been progress toward improving road safety legislation and in making vehicles safer, the present study shows that the pace of change is too slow. A study by Jiwattanakulpaisarn et al. [20] reported that only 60% of drivers and only 28% of passengers wore a motorcycle helmet. Nearly half of patients (583 patients, (47.5%) reported having consumed alcohol, 315 patients (24.7%) denied consumption, and approximately 30% did not indicate.

Surprisingly, after the policy launch, not only the incidence of maxillofacial injury increased by 14% (years 2006–2010, 597 cases vs years 2011–2015, 678 cases) but also the severity of injuries increased. The authors evaluated severity increase by comparing combined and multiple fractures with single fracture. We conclude that the Thai government needs to strictly enforce laws to promote risk reduction [20], and in further studies, we suggest that a prevention program and a supportive technology should be developed.

In addition to the force impact from the trauma, prevention of facial and maxillofacial injuries with helmets is very important to protect the victim from the direct force affecting the facial bones. Two types of helmets are used: closed and open. The closed type is available in a specific head size, but some motorcyclists use an improper size. As a result, protection might not be adequate. Some motorcyclists do not fasten the chin straps in the open type of helmets. If an accident occurs, the helmet cannot protect the facial bones effectively. Cooter and David [21] found that the use of a helmet significantly decreased neurotrauma in patients with facial fractures who wore an energy-absorbing helmet. Similarly, Harvey et al. [22] found that accident victims who did not wear helmets are more likely to sustain facial bone fractures and are more likely to require hospital admission than helmeted victims.

Because this was a retrospective observational study, some data were not collected. For example, for patients who sustained maxillofacial fractures from motorcycle accidents, the use of helmets and alcohol consumption were not indicated in the records of approximately 30% of the cases. We recommend that for prospective studies such indicators need to be added to the medical record form and outpatient department and inpatient department record cards, so that the data can be analyzed and generalizations involving law enforcement can be made in order to reduce the risk factors in the long term. Because this was a single-center study, it may not represent the true situation in Bangkok.