Application of MI sensor-aided motion control system to prosthetic dentistry

Y.ishida, T.ichikawa

Department of Oral & Maxillofacial Prosthodontics, Institute of Health Biosciences, The University of Tokushima Graduate School

INTRODUCTION

MI sensor aided to Magneto-inductive effect¹⁾ in amorphous wires is able to recognize 0.1mG. Motion control sensor (AMI601, Aichiseikou) constructed with a geomagnetism-sensor and an acceleration-sensor can measure the posture angles of pitching, yawing and rolling of the object as all directional angle analysis of the three dimensions. In clinical treatments of prosthetic dentistry, there are not a few procedures to be required to measure the angels or the parallelisms for the examination of condyle paths and occlusal planes, the preparations of abutment teeth, the formations of implant cavity and the arrangements of artificial teeth. Furthermore for the denture movement, the abutment tooth movement and the laxity of temporomandiblar joint, this sensor may be expected a useful equipment as a clinical tester.

OBJECTIVE

The purpose of this study was to report a summary of this system and to assess the possibility of applications of prosthetic treatment.

Materials and Methods

This system constructed with the detecting elements and the sensor of IC (Fig.1). The detecting element had an USB connecter, so the measured date could be handled on PC. Any objects were not restricted to measure when the sensor and the detecting elements were contacted by wireless.

We developed the software (α version) for this system as dental use.

In case of using this system, at first, we measure the posture of the object using with this sensor. This basic posture is regarded as the one of the standard axis. Next, measuring the some postures of the object, we can monitor the pitching, yawing and rolling of postures by comparing with the standard axis. Further, this system can warn the operator by sound in the case of exceeding the permissive angles input beforehand.

We assessed this system for prosthetic treatment by the following:

1. Navigation of the preparation of abutment tooth and the formation of implant fossa

The sensor was put at the head of the dental micromotor in order for the correspondence of the axis between the sensor and the head of the micromoter. After performing the preparations of teeth and the formations of implant fossae using this micromoter, we examined the angles of preparations and assessed the parallelisms of implant fossae.

2. Evaluation of the occlusal plane

We evaluated the parallelism of an occlusal rim to a Camper's plane using this system.

3. Evaluation of A systemic joint laxity

We evaluated the hyperextention of the little finger and the elbow using this system, and assessed by comparing with the conventional method of the systemic joint laxity reported by Hada²⁾.

Results

We measured the angles of abutment teeth and implant fossae using by this system. The results were showed in Table 1. As for examining the parallelism of the occlusal plane and a systemic joint laxity, this system facilitated to evaluate more easily and more objectively than conventional system.

Table.1 Formation and evaluation by this sensor (n=5)

Conclusions

This study suggested that MI sensor-aided motion control system might be an effective system for requiring the evaluations of the angles through the treatment in prosthetic dentistry.

References

1. Mohri, K. Kawashima, T. Kohzawa, et.al. Magneto-inductive effect in amorphous wires, IEEE Trans. Magn 28: 3150-3152, 1992.

2. Hada, M. Hoteiya, K. Saiga, A. et.al. Relationship of a temporomandibular arthrosis and a systemic joint laxity. Journal of the Japanese Society for the temporomandibular Joint 8:68-79, 1996.

Discussion Board