Development Background

The motivation behind the research is the need to include oral surgery as part of the basic dental curriculum requirements in dentistry. The Swedish Dental Association has conducted studies on the quality of dental education quality by surveying a group of graduate dentists which showed that former students are in general satisfied with their education but a large and increasing number of students have expressed their wish to have more training in surgical practice.

The current curriculum at Karolinska Institute includes theory and group observations of real time surgery but lacks hands-on practice due to the high costs involved in personnel, operating room and specialist resources. A suggested solution to the problem could be a simulator where students get to practice the necessary procedures, especially in the area of surgical extraction of wisdom teeth, in a computer-based virtual environment. Prior work in the area of medical simulation, such as that of Agus (2004), proves that such environment can be created, where the user gets an immersive hands-on experience through stereo vision and force feedback, which allows users to touch and modify virtual objects.

The use of touch in combination with motor behaviours to identify objects is called haptic sensing. (Appelle, 1991) 

The integration of audio and haptic input and output techniques can increase the bandwidth for information perception. Now emerging media space technologies like three-dimensional haptic interfaces makes it possible to interact physically in haptic object spaces. In a haptic user interface it is possible to feel the shape, weight, texture, friction and stiffness of an object and for example collisions between objects.

In the oral surgery simulator project, important results have already been achieved by leveraging on the collaboration between Royal Institute of Technology, KTH, and Karolinska Institute, KI, in a development process known as User Centered Design. The method used is based on the specifications of the ISO 13407 standard, describing the process as an iterative cycle of four distinctive steps:

1. In the first phase, the researchers with engineering and human computer interaction background conducted a contextual inquiry where they were introduced to the detailed procedure as well as formulate the most important part of the procedure by surgery observation, interviews and experiments at the Dep. of Oral Surgery at the Karolinska Institute.

2. The outcome of the first field studies resulted in design specification and considerations for a prototype simulator. The design considerations were updated with feedback from surgeons. 

3. A first version of the prototype was developed. The design work involved implementing haptic algorithms for drilling on teeth and generating a head model with inserted real time volume rendering from a CT-scanned jaw. 

4. The oral surgery simulator has also been evaluated by surgeons in a process called Cooperative Evaluation. The procedure is proven to be easily performed by professional users and the application received very positive feedback from them.

Previous studies conducted for example by Felländer-Tsai and Wredmark (2004) shows that training in a medical simulator for visiospatial coordination significantly improves the performance of the new surgeon. It has also been shown that the perceived discomfort of the patient is reduced if surgeon student is trained in simulator prior to procedure. Medical simulation can also reduce the learning curve of trainees and thus lowers the cost of education. Trainees are able to practice different procedures until they are proficient and would be more prepared for actual patient cases. There is also the possibility of pre-surgery preparations that would allow surgeons to analyse and evaluate patient cases and plan the necessary procedures before the actual surgery takes place.