Are open mandibular fractures still an emergency?

INTRODUCTION: Early surgical management is often advocated for fractures of the tooth-bearing portion of the mandible. A 6-hour delay has been mentioned for the fixation of these fractures. Our aim was to bring this paradigm into question. METHODS: All patients referred to our department from September 2012 to May 2014 for fractures of the tooth-bearing portion of the mandible were retrospectively included. For each patient, age, gender, aetiology of the fracture, and characteristics of the fractures were recorded. Tobacco and/or alcohol addictions, diabetes and mandibular dental condition were taken into account. We also noticed the preoperative delay and the occurrence of complications such as: haematoma, infection, wound dehiscence, osteosynthesis failure and pseudarthrosis. RESULTS: Among the 47 patients referred, 36 were treated with a delay of more than 6 hours (76.6%). In 88.8% of the cases, the reason for this delay was unavoidable. The mean delay time from trauma to surgery was 52 hours (range: 7-312). Forty-nine percent of the patients had comorbidities. Complications occurred in 6 patients leading to an overall complication rate of 16.67%. A statistically significant higher complication rate was observed among smokers (P=0.006). No statistical relationship was found between the delay and the occurrence of complications (P=0.994). This study suggests that fractures of the tooth-bearing portion of the mandible should no longer be considered as an emergency that must be treated within a 6-hour delay.

[3D planning in maxillofacial surgery]. / Planification 3D en chirurgie maxi to-faciale.

The development of new technologies such as three-dimensional (3D) planning has changed the everyday practice in maxillofacial surgery. Rapid prototyping associated with the 3D planning has also enabled the creation of patient specific surgical tools, such as cutting guides. As with all new technologies, uses, practicalities, cost effectiveness and especially benefits for the patients have to be carefully evaluated. In this paper, several examples of 3D planning that have been used in our institution are presented. The advantages such as the accuracy of the reconstructive surgery and decreased operating time, as well as the difficulties have also been addressed.

The use of 3D planning in facial surgery: preliminary observations.

Three-dimensional (3D) planning is becoming a more commonly used tool in maxillofacial surgery. At first used only virtually, 3D planning now also enables the creation of useful intraoperative aids such as cutting guides, which decrease the operative difficulty. In our center, we have used 3D planning in various domains of facial surgery and have investigated the advantages of this technique. We have also addressed the difficulties associated with its use. 3D planning increases the accuracy of reconstructive surgery, decreases operating time, whilst maintaining excellent esthetic results. However, its use is restricted to osseous reconstruction at this stage and once planning has been undertaken, it cannot be reversed or altered intraoperatively. Despite the attractive nature of this new tool, its uses and practicalities must be further evaluated. In particular, cost-effectiveness, hospital stay, and patient perceived benefits must be assessed.

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.