3D assessment of damaged bicycle helmets and corresponding craniomaxillo-mandibular skull injuries: A feasibility study.

OBJECTIVES: In the Netherlands, cyclists continue to outnumber other road users in injuries and deaths. The wearing of bicycle helmets is not mandatory in the Netherlands even though research has shown that wearing bicycle helmets can reduce head and brain injuries by up to 88%. Therefore, the aim of this study was to assess the feasibility of using 3D technology to evaluate bicycle-related head injuries and helmet protection. METHODS: Three patients who had been involved in a bicycle accident while wearing a helmet were subjected to multi-detector row computed tomography (MDCT) imaging after trauma. The helmets were separately scanned using the same MDCT scanner with tube voltages ranging from 80kVp to 140kVp and tube currents ranging from 10mAs to 300mAs in order to determine the best image acquisition parameters for helmets. The acquired helmet images were converted into virtual 3D surface hence Standard Tessellation Language (STL) models and merged with MDCT-derived STL models of the patients' skulls. Finally, all skull fractures and corresponding helmet damage were visualized and related. RESULTS: Imaging bicycle helmets on an MDCT scanner proved to be feasible using a tube voltage of 120kVp and a tube current of 120mAs. Merging the resulting STL models of the patients' skull and helmet allowed the overall damage sustained by both skull and helmet to be related. CONCLUSION: Our proposed 3D method of assessing bicycle helmet damage and corresponding head injuries could offer valuable information for the development and design of safer bicycle helmets.

Epidemiología de las fracturas mandibulares tratadas quirúrgicamente en el Instituto Traumatológico de Santiago (Chile): 10 años de revisión / Epidemiology of surgically treated jaw fractures in the Traumatology Institute of Santiago (Chile): a 10-year review

Los traumatismos en Chile son la tercera causa de muerte en la población general y la primera entre jóvenes. Se ha reportado una epidemiología variable alrededor del mundo asociada a diferencias demográficas y socioculturales, con escasos estudios en Latinoamérica. Objetivo. Conocer la epidemiología de las fracturas mandibulares en el Instituto Traumatológico de Santiago, Chile. Material y método. Estudio retrospectivo descriptivo de tipo cuantitativo en el Servicio de Cirugía Maxilofacial del IT, consistente en la recolección de datos mediante revisión de fichas clínicas de pacientes operados por fracturas mandibulares entre enero de 2001 y diciembre de 2010. Los datos fueron recopilados utilizando una base de datos Microsoft Access 2007 y luego tabulados y graficados con Microsoft Excel 2007. Resultados. De un universo de 783 fracturas faciales, 240 fichas de fracturas mandibulares operadas estuvieron disponibles para su análisis. La proporción hombres:mujeres fue de 5,9:1 y el grupo etario más afectado fue aquel entre 20 y 29 años. Las agresiones por terceros fueron su causa más frecuente. La mayoría de los pacientes fueron tratados en un promedio de 8,6 días desde su ingreso. En conclusión, estos resultados en general son concordantes con la literatura, salvo asociaciones entre sitio anatómico afectado y etiología (AU)

The traumatic injuries in Chile are the third cause of death in the general population and the first in young people. Their epidemiology varies around the world, and is linked to demographic and sociocultural differences, with few studies in Latin America. Objective. To determine epidemiological profile of the jaw bone fractures in the Traumatology Institute (IT) of Santiago, Chile. Material and method. Retrospective descriptive and quantitative study was conducted in the Maxillofacial Surgery Department of the IT, developed by recording data from a review of clinical records of patients with surgicaly treated jaw fractures. Data were collected between January-2001 and December-2010 using Microsoft Access 2007© and then tabulated and plotted using Microsoft Excel 2007©. Results. Out of a total of 783 facial fractures, 240 clinical files of surgically treated jaw fractures were available for analysis. The male:female ratio was 5.9:1, and the most afected age group was between 20 and 29 years old. The most frequent cause of the fracture was aggressions. Most patients were treated in an average of 8.6 days from admission. In conclusion, these results are consistent with the literature, except for the associations between the affected anatomical site and etiology (AU)

Novel method for comparing coverage by future methods of ballistic facial protection.

The wearing of eye protection by United Kingdom soldiers in Afghanistan has reduced the morbidity caused by explosive fragments. However, the remaining face remains uncovered because there is a lack of evidence to substantiate the procurement of methods to protect it. Using a new computerised tool we entered details of the entry sites of surface wounds caused by explosive fragments in all UK soldiers who were injured in the face between 1 January 2010 and 31 December 2011. We compared clinical and predicted immediate and long term outcomes (as defined by the Abbreviated Injury Score (AIS) and the Functional Capacity Index (pFCI), respectively). We also used the tool to predict how additional protection in the form of a visor and mandible guard would affect outcomes. A soldier wearing eye protection was 9 times (1.03/0.12) less likely to sustain an eye injury than one without. However, 38% of soldiers in this series were not wearing eye protection at the time of injury. There was no significant difference between the AIS and pFCI scores predicted by the tool and those found clinically. There is limited evidence to support the use of a mandible guard; its greatest asset is better protection of the nose, but a visor would be expected to reduce long-term morbidity more than eye protection alone, and we recommend future trials to assess its acceptability to users. We think that use of this novel tool can help in the selection of future methods of ballistic facial protection.

The impact of CBCT imaging when placing dental implants in the anterior edentulous mandible: a before-after study.

OBJECTIVES: To evaluate the impact of CBCT imaging when placing dental implants in the anterior edentulous mandible, using a "before-after" study design. METHODS: Eight dental practitioners, who regularly place dental implants in independent dental practice in the North West of England, were presented with realistic simulations of four edentulous cases. The practitioners were asked to assess case difficulty, select implants and then drill osteotomies in preparation for dental implants in the lower canine regions to support a complete overdenture. In the "before" part of the study, a panoramic and a trans-symphyseal view were available. In the "after" part of the study, a CBCT image was added. Perception of case difficulty, implant selection and the incidence of perforations or "near miss perforations" of the lingual cortical plate were recorded. Two cases were regarded as "regular" and two as "challenging". RESULTS: In challenging cases, the availability of CBCT led practitioners to select narrower implants and to assess cases as more difficult. In the challenging cases only, there were fewer perforations of the lingual cortical plate after the availability of CBCT, but this difference was not statistically significant. There were no perforations in the regular cases either before or after the availability of CBCT. CONCLUSIONS: Perception of case difficulty and implant selection are of importance only if they change the outcome for the patient. This study provided weak evidence that CBCT is helpful in avoiding perforations in challenging cases. The availability of CBCT had no impact in regular cases.

Biomechanics of the weakened mandible: use of image correlation analysis.

Uninterrupted resection of mandibular bone is often necessary during maxillofacial operations for cancer. This weakens the mandible, and increases the risk of fracture. To our knowledge no biomechanical analysis has been made of deformations and strains that occur during chewing if this happens, so we have made such an analysis of the weakened mandible using a new technique: image correlation. Five fresh explanted human mandibles were prepared with black and white lacquer, and placed in a loading device that allowed replication of a physiological biting exercise. Calibrated pieces of bone were resected from the right body of each mandible. Images of the mandibular surface were recorded by 2 cameras and analysed with an algorithm to correlate them, which allowed us to confirm the distribution of strain on the body of the mandible, and to focus on the weak points. Before the bone was resected, we noted tensile strains on the alveolar border of the body, and compressive strains on the basilar border. The intensity of the strains in the posterior angle of the resected bony area then increased, with reduction in the height of the bone until fracture. The orientation of the fracture line started at the lower posterior angle of the resection area and spread in a lower posterior direction until it reached the basilar border of the mandible. Image correlation is a new technique for the study of mandibular biomechanics that provides accurate measurements on a wide bony surface with high definition images and without modification of the structure. Its application to weakened mandible provided reliable images of modifications to strains during simulated biting exercises.

Assessment of the risk of perforation of the mandibular canal by implant drill using density and thickness parameters.

OBJECTIVE: The objective of this study was to investigate whether the resistance of the bone surrounding the mandibular canal had sufficient density and thickness to avoid perforation by drills when preparing the bed of the implant. BACKGROUND: Damage to the inferior alveolar nerve (IAN) is more common than expected. This injury may lead to serious complications ranging from mild paresthesia to total anaesthesia of the lower jaw. MATERIALS AND METHODS: The CT images of 99 patients, whose ages ranged between 20 and 79years, and who applied for an implant application to the posterior aspect of the mandible were included in this study. RESULTS: The overall average bone thickness in the premolar and molar regions was 0.8717±0.1818 and 0.8556±0.1756mm, respectively, whereas the bone density in the premolar and molar regions was 649.18±241.42 and 584.44±222.73 Hounsfield Units (HU), respectively (p<0.001). CONCLUSION: It was determined that the average density and thickness of the bone that surrounds the mandibular canal was not sufficient to resist the implant drill. It can be concluded that the risk of injury to the IAN may be minimised by accurately determining the bone mass on the canal prior to the implant procedure, and avoiding excessive force when approaching the canal.

Evaluation of different rotary devices on bone repair in rabbits.

In oral surgery, the quality of bone repair may be influenced by several factors that can increase the morbidity of the procedure. The type of equipment used for ostectomy can directly affect bone healing. The aim of this study was to evaluate bone repair of mandible bone defects prepared in rabbits using three different rotary devices. Fifteen New Zealand rabbits were randomly assigned to 3 groups (n=5) according to type of rotary device used to create bone defects: I--pneumatic low-speed rotation engine, II--pneumatic high-speed rotation engine, and III--electric low-speed rotation engine. The anatomic pieces were surgically obtained after 2, 7 and 30 days and submitted to histological and morphometric analysis. The morphometric results were expressed as the total area of bone remodeling matrix using an image analysis system. Increases in the bone remodeling matrix were noticed with time along the course of the experiment. No statistically significant differences (p>0.05) were observed among the groups at the three sacrificing time points considering the total area of bone mineralized matrix, although the histological analysis showed a slightly advanced bone repair in group III compared to the other two groups. The findings of the present study suggest that the type of rotary device used in oral and maxillofacial surgery does not interfere with the bone repair process.

Evaluation of different rotary devices on bone repair in rabbits

In oral surgery, the quality of bone repair may be influenced by several factors that can increase the morbidity of the procedure. The type of equipment used for ostectomy can directly affect bone healing. The aim of this study was to evaluate bone repair of mandible bone defects prepared in rabbits using three different rotary devices. Fifteen New Zealand rabbits were randomly assigned to 3 groups (n=5) according to type of rotary device used to create bone defects: I - pneumatic low-speed rotation engine, II - pneumatic high-speed rotation engine, and III - electric low-speed rotation engine. The anatomic pieces were surgically obtained after 2, 7 and 30 days and submitted to histological and morphometric analysis. The morphometric results were expressed as the total area of bone remodeling matrix using an image analysis system. Increases in the bone remodeling matrix were noticed with time along the course of the experiment. No statistically significant differences (p>0.05) were observed among the groups at the three sacrificing time points considering the total area of bone mineralized matrix, although the histological analysis showed a slightly advanced bone repair in group III compared to the other two groups. The findings of the present study suggest that the type of rotary device used in oral and maxillofacial surgery does not interfere with the bone repair process.

A ostectomia é uma manobra cirúrgica fundamental que pode afetar a reparação tecidual de modo a aumentar a morbidade do procedimento. O tipo de equipamento e/ou instrumental utilizado para a ostectomia pode influenciar diretamente no reparo ósseo. O objetivo deste trabalho foi analisar o processo de reparação óssea em defeitos realizados em mandíbula de coelho com três diferentes equipamentos. Quinze coelhos foram aleatoriamente divididos em 3 grupos (n=5) de acordo com o equipamento usado para preparacão de 3 cavidades ósseas com brocas padronizadas: I) motor de baixa rotação pneumático, II) motor de alta rotação pneumático e III) motor de baixa rotação elétrico, todos com refrigeração constante. Após os períodos experimentais de 2, 7e 30 dias, as peças anatômicas foram removidas e submetidas a análises microscópica e histomorfométrica. Não houve diferença estatisticamente significante (p>0,05) entre os grupos nos 3 períodos experimentais, considerando-se a área total de matriz óssea mineralizada, embora a análise microscópica tenha revelado uma tendência a um processo de reparação óssea um pouco mais adiantado no grupo III, quando comparado aos demais grupos. Os resultados deste estudo sugerem que o tipo de equipamento rotatório utilizado em cirurgia bucomaxilofacial não interfere no reparo ósseo.

Fundamentos en odontología del deporte / Foundations in odontology of the sport

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Facial trauma: a recurrent disease? The potential role of disease prevention.

PURPOSE: The objectives of this investigation were to determine a profile of facial trauma patients presenting to the emergency department of University Hospital, University of Medicine and Dentistry of New Jersey, Newark, NJ, and to assess patient interest in violence or stress reduction programs. MATERIALS AND METHODS: A prospective study of the patients was conducted with the aid of a data collection form generated specifically for the purpose of this study. Data regarding patient age, race, gender, various aspects of social history, mechanism, and nature of injury were collected over a period of 1 year. In addition, all patients were asked to respond to 4 health promotion questions. All patients for whom the oral maxillofacial surgery service was consulted were included in the study. Descriptive statistical analysis of the data was used. RESULTS: A total of 92 patients were enrolled, of whom 80% were males. The mean age of patients enrolled was 30.5 years with the peak incidence of injury occurring in the 20- to 30-year-old age group (n = 30). The most frequent etiology was assault (75%), followed by motor vehicle accidents (18.5%). The most frequently occurring injury was mandible fracture (46.7%), followed by lacerations (42.4%). Within the study sample, 42.4% had previous injuries. Patients with facial injuries were 1.5 times more likely to have experienced previous interpersonal violence. This patient group also expressed an overwhelming willingness to change their behavior patterns (91.3%). CONCLUSIONS: The findings of this investigation indicated that most facial trauma patients are between the ages of 20 and 30 years and male. Assault is the most common etiologic agent resulting in facial trauma. Mandible fractures and lacerations are the most likely injuries in the facial trauma patient. Patients experiencing recurrent trauma due to assault are more responsive to violence reduction programs than those experiencing only 1 assault.

Prevention of oral injuries.

The importance of protection during various types of sports activities cannot be overemphasized. The use of mouth guards has been instrumental in preventing dental injuries. Dentists, however, must be knowledgeable in the pitfalls of these various types of protective devices.

The bimaxillary mouthguard.

The bimaxillary mouthguard provides enhanced protection for the participation in contact sports. This article describes the bimaxillary mouthguard and outlines construction techniques.

Orofacial injuries and the use of mouthguards by the 1984 Great Britain Rugby League touring team.

Mouthguards are considered by most authorities to be an essential part of equipment for players in any body-contact sports, especially the combative type e.g. Rugby Union, Rugby League, American Football (gridiron), boxing, etc. (Turner, 1977). The qualities provided by the mouthguard are dental protection, especially of the upper anterior teeth, soft tissue protection around the mouth, a reduction in the risk of fracture of the mandible, and a reduction in the concussion force from a blow to the mandible (Clegg, 1969; Upson, 1982; Davies et al, 1977). Of the 28 players interviewed, only 7 (25%) wore mouthguards, the commonest reason for not using a mouthguard being difficulty with breathing, a finding in common with other similar surveys (Davies et al, 1977). In view of the fact that 17 (60.7%) had sustained oral injuries - dental and jaw injuries, intra-oral and circumoral lacerations, in the past, it was a surprising response to find that only 2 (7.2%) stated that mouthguards should be compulsory when playing Rugby League football.