The effect of a blast on the mandible and teeth: transverse fractures and their management

Bones heal, teeth don't! The involvement of dentists in the acute and long-term management of patients injured in the Manchester Arena Bomb

This paper outlines the involvement of dentists in the treatment of patients following the terror attack at Manchester Arena on 22 May 2017. It predominantly describes the role of the authors - a paediatric dental consultant and maxillofacial surgery dental core trainee (DCT). As a result of the incident a number of patients suffered oro-facial injuries, with many treated at Central Manchester Foundation Trust Hospitals' Manchester Royal Infirmary and Royal Manchester Children's Hospital. The major incident response of the trust is discussed, as are the presentation of blast injuries and corresponding NHS guidance. Two paediatric cases present the role of the paediatric dental consultant in the acute, intermediate and long-term management of these patients. The presentation of unique dento-alveolar injuries in the context of other trauma and their subsequent treatment demanded true multidisciplinary management. The importance of teeth and oral health to physical and psycho-social wellbeing and recovery was clear and recognised by other teams involved in the patients' management. The experience reinforced the overall impact dental health has on physical and psycho-social health, and how a holistic approach is integral to treatment of major trauma.

Mandibular fractures in iraq: an epidemiological study

The purpose of this study was to evaluate the epidemiological characteristics of the mandibular fractures relating to gender, age, the etiology of injury, and the rendered treatment modalities and complications. The data of the patients who sustained mandibular fractures were retrieved and were analyzed retrospectively, and based on these data a descriptive analysis was conducted. A total of 112 patients were included in this study; the most common cause was road traffic accidents (RTAs) followed by assaults and missile injuries. The most frequently involved age group was 11 to 20 years, treatment modalities included conservative, closed reduction and indirect fixation, and open reduction and internal fixation (ORIF) in 11.6, 79.5, and 8.9% of the cases, respectively. Most of the major complications were injury related. This study showed RTAs to be the most frequent cause followed by assaults, it also showed that a high percentage of assault victims were females mainly of low socioeconomic status. Another distinguishing feature in this study was the high incidence of missile injuries in the form of bullets and blasts. Closed reduction still has an important role in the treatment of fractures of mandible especially when the necessary equipments for ORIF are not readily available. A higher complication rate was observed in patients diagnosed with multiple and comminuted fractures as well as those caused by violence in the form of missile and assault injuries.

Development of a finite element model for blast injuries to the pig mandible and a preliminary biomechanical analysis

BACKGROUND

Explosive damages to the maxillofacial bones exhibit complex dynamic response processes; the current traditional model and methods for blast wounds are unable to meet research needs. The finite element (FE) method has obvious advantages in complex biomechanical analysis. The objective of this study was to develop an FE model for blast injuries to the pig mandible and investigate the feasibility of using FE method as an ideal research tool for mandible blast wounds.

METHODS

A hexahedral FE model of a pig mandible was established to simulate explosive damage in air by using MIMICS and ANSA software. Then, the FE model was imported into LS-DYNA for computation. Finally, the LS-POST was used for the analysis and the measurements. At the same time, an experimental study was performed by measuring biomechanical data (strains and accelerations) and wound patterns from fresh pig mandibles to validate our FE model and simulation result.

RESULTS

The FE model and the dynamic processes of blast injuries to the pig mandible were developed and simulated successfully, and most of the biomechanical data and wound patterns displayed no significant differences with experimental results. Stress distribution in the mandible was relatively uniform; high-intensity strain was mainly concentrated in the mandibular angle and ramus, especially along the location of the fracture line.

CONCLUSION

The FE model and method of this experiment will be helpful for investigations in the biomechanical mechanisms of mandibular blast injuries and the subsequent human maxillofacial blast injury simulation.

Blast injuries to the human mandible: development of a finite element model and a preliminary finite element analysis

OBJECTIVE

In an attempt to explore new tools for constructing a model of blast injuries to the human mandible, a finite element method was used. This model allowed us to perform dynamic simulations and analyse the injury processes and severity of trauma to the human mandible from an explosion striking at the middle mandibular angle.

METHODS

A 3D finite element model of the human mandible was created using digitally visualised CT scanning data of the human mandible. It was used to dynamically simulate the complete injury process of a blast event to a human mandible (at the middle mandibular angle) under the injury conditions of a 600 mg TNT explosion. The model was also used to elucidate the subsequent mandibular damage and the dynamic distribution of several biomechanical indices (e.g., stress, and strain). The resulting data were subjected to a comparative analysis.

RESULTS

Simulation was successfully conducted for injury events in which 600 mg of TNT exploded at 3 cm, 5 cm and 10 cm from the middle mandibular angle of a human mandible; specifically, the simulation included the dynamic injury processes and the distribution of stress and strain in various parts of the damaged mandible. A comparison of the simulation data revealed that different blast distances resulted in considerable variation in the severity and biological indices of the mandibular injury.

CONCLUSION

The finite element model was able to dynamically simulate the blast-initiated trauma processes to a human mandible, which allowed for investigation of the severity of damage to the mandible under different injury conditions. This model and the simulation method are conducive for applications in basic studies and clinical investigations of blast-initiated injury mechanisms of bone tissues.

A summary of trauma and trauma-related papers published in BJOMS during 2008-2009

This paper provides a summary of the 49 trauma and related papers published in British Journal of Oral and Maxillofacial Surgery during the period January 2008 to December 2009. 16/49 (32%) of these publications were full length articles, which covered areas such as epidemiology, service provision, materials and operative surgery. In addition there were other articles including short communications, technical notes, letters to the editor and interesting cases. Whilst fewer full length articles were published compared to the other sub-specialties, it was reassuring to see that the studies represent all aspects of trauma. More basic science and randomized control studies relating to trauma need to be encouraged.

Maxillofacial air-containing cavities, blast implosion injuries, and management

PURPOSE

Distinctive mechanisms of primary blast effects have produced a transitional era of facial trauma. Implosion mechanism damage is one of these. Implosion mechanism damage results in injury limited to the gas-containing structures of the auditory canal, paranasal sinuses, gastrointestinal tract, and lungs. Worldwide, the victims of explosive detonations have increased and advanced dramatically. The outcome is greater mortality and morbidity and new types of injuries, especially in the maxillofacial region. Thus, the knowledge of, and experience with, their management should be shared globally by colleagues through publications.

MATERIALS AND METHODS

The implosion and mini re-explosion of compressed air sinuses leads to skeletal crush injury to the nasal-orbital-ethmoidal, maxillary sinuses, and nasal bones. A variety of surgical approaches were used successfully under conditions of war. The assessment of the associated injuries to the lung and/or brain is the initial priority to any life-threatening blast injury. This article describes the biophysical results of blast injuries to the middle third facial skeleton and associated injuries and details the management and protection of crushed air containing paranasal spaces.

RESULTS

Easy, simple, and fast treatment and management were used successfully on the pulverized, fragmented skeletal architecture of the facial middle part without increasing morbidity and with the avoidance of unnecessary surgical trauma.

CONCLUSIONS

Injuries in one of the most difficult esthetic, physiologic, and anatomic regions of the body is best treated with an understanding of the biophysical effects of the implosion mechanism on air-containing spaces in the maxillofacial region. The introduction of new methods for the management of severe destruction of hard and soft tissue will decrease the incidence of complications and the operative time.