Haptics in periodontics

Abstract

Throughout history, education has evolved, and new teaching/learning methods have been developed. These methods have helped us come a long way in understanding the pathogenesis, diagnosis, and treatment of diseases of the oral cavity. However, there is still no one good way to render a student/clinician the tactile sense for detecting calculus/caries or placing the incisions or detecting the smoothness of a restoration or any treatment procedures before entering the clinics. In the education field, to improve the tactile sensation, the sense of touch and force-feedback can offer great improvements to the existing learning methods, thus enhancing the quality of education procedures. The concept of Haptics, which is extensively in use and indispensable in other fields like aviation, telecommunication etc., is now making its way into dentistry. Against this background, the following write-up intends to provide a glimpse of the coming wave of Haptics - A virtual reality system in dental education and discusses the strengths and weak points of this system.

INTRODUCTION

Dental and medical education has utilized technology increasingly over the past few years for learning as well as training. Medical simulation has become a valuable tool for learning and acquiring skills. Acquiring abilities and skills to perform dental procedures is essential for dental students and clinicians. It takes more than only observing patients, diagnosing and managing the disease but also needs a practical experience of the tactile information to gain surgical expertise. Till date, these are gained in the laboratories of the dental faculties in two stages. Firstly, dental students are trained on artificial teeth, placed within a manikin head, using real dental instruments, like burs, etc., Practicing on manikins reduces the risk to some extent but is less effective considering the cost, availability, and lack of rare real-world cases (cannot provide the level of detail and material properties of real life teeth and procedures). In the second stage, the students perform dental procedures on real patients under the close supervision of their professors. So, the students/clinicians go through a trial and error process by working on real patients before achieving better and more consistent experience and safe performance of dental and medical procedures.

Although the conventional techniques have their own importance in training but to practice on live patients, students/clinicians must know how to use the tools and the material properties of the organs (e.g. before taking up surgeries on real patients, we need to have a feel of soft tissues and bone texture, which is not possible in a conventional setup). Hence, a system, which simulates real dental procedures graphically and haptically, will be a better option to increase students’ knowledge/experience level and to perform mock surgeries before they actually practice them on live patients. Hence, introduction of haptic technology can bring about better outcomes with less error. It is a technology of tactile feedback that makes use of a user's sense of touch by applying vibrations, forces or motions to the user.[1]

BACKGROUND AND PRINCIPLES

Haptics-based simulators employ a haptic device and a platform to facilitate dental practicing (virtual models of a human tooth or mouth). The trainee holds the stylus of haptic device instead of real dental instruments and can manipulate the instruments, shown on the screen, which in turn reproduces clinical sensations in the hand of the operator through tactile feedback.

It works on the principles of creating virtual environment, which replaces the reality, and user can interact to perform various motor and perceptual tasks. It can help one to be mentally transported and immersed in virtual worlds through various computer softwares.

Hardware includes:

• Monitor and speakers

• Haptic interface device (stylus)

• Glasses and helmets for visualizing 2D video display as 3D

• Gloves to feel the sensations.

Application

Differentiating between pathological and normal conditions, diagnosing and treat periodontal diseases requires skill which can be achieved by employing one of the two visuo-haptic systems: PerioSim and a periodontal simulator.[2,3]

Periosim and periodontal simulator were developed by university of Illinois at Chicago. The application simulates three dental instruments: A periodontal probe, a scaler, and an explorer, which can be used for training students in various aspects of periodontology.

Diagnosis: Diagnosing the periodontal disease mainly depends on probing and measuring the clinical attachment loss. Probing depth measurement vary from examiner to examiner because of variation in angulation, pressure, force etc., and thus virtual periodontal probe could be used to teach the correct probing technique, which will help in determining the health and severity of disease of periodontal tissue and thus the correct diagnosis.

Treatment : Main etiological factors of periodontal disease are plaque and calculus, and thus the treatment of periodontal disease revolves around complete elimination of these etiological factors.

Supragingival calculus which is easily seen can be removed effectively using scalers, but the problem arises in completely removing the sub-gingival calculus, which mainly depends on tactile sensation, which can be achieved using a haptic technology while learning.

A virtual periodontal scaler with two models of gingiva, transparent and opaque, could be used for this purpose. With the opaque model where the tooth surface is covered by gingiva, the haptic device will provide the tactile sensation to evaluate virtual calculus present on the root surface, and with the transparent gingiva, calculus can be concomitantly seen under the gum line. Further virtual explorer can be used to evaluate that the calculus has been completely removed, which could be performed with both a transparent and an opaque gingiva.

Advantages

• Reinforcement of learned dental concepts

• Correct use of dental instruments

• Correct ergonomic positioning: Incorrect operator or patient positioning can result in blocking the camera from reading the LED sensors and prevents the user from continuing by warning signals. This encourages the students to practice good ergonomic habits

• Good psychomotor skills[4]

• Self-evaluation: Students have immediate, unlimited, and objective access to detailed feedback of their work

• Standardized evaluation

• Faster acquisition of skills: Students attain a competency-based skill level at a faster rate than with traditional simulator units (phantom heads). This can result in changes in dental curriculum and earlier entrance into the pre-doctoral clinic

• Positive student perception.[5]

Disadvantages

• Virtual of augmented reality dental simulators are at an early or experimental stage

• A system limitation with the current design: The tactile perception for gingiva is not very real

• The initial cost of this advanced technology simulation can be substantial. Difficult equipment to maintain and repair: Technology-based systems require faculty/engineering staff to be available for training and supervision of the laboratory.

CONCLUSION

Virtual reality is the next step in dental education. The technologies of virtual reality innovate how clinical training takes place. Unlike existing systems for clinical courses, virtual reality systems overcome the limitations of phantom head systems and provide standardized case, objective assessment, and interactivity. They encourage a self-assessment process to identify self-directed learning and should become an integral part of any student training program.