Reproducibility of a magnet-based jaw motion analysis system

Area of Science:

• Dental Technology
• Biomechanics
• Medical Device Evaluation

Background:

• The Dental Motion Decoder system (DMS-System) utilizes magnetic field technology to record mandible movements.
• Recorded data can be used for articulator programming or direct computer-aided design (CAD) processing.

Purpose of the Study:

• To assess the in vitro and in vivo reproducibility of the Dental Motion Decoder system (DMS-System).

Main Methods:

• Simulated protrusive and laterotrusive jaw movements in vitro (Group M) and in vivo (Group P).
• Measurements were taken with single or multiple reference point initializations.
• Evaluated reproducibility using standard deviations of sagittal condylar path inclination angle (sCPIA) and Bennett angle (BA).

Main Results:

• In vitro measurements (M1, M2) demonstrated significantly higher reproducibility (lower SDs) for sCPIA and BA compared to in vivo measurements (P1, P2).
• In vitro sCPIA SDs ranged from 0.08 to 0.26 degrees; BA SDs ranged from 0.06 to 0.11 degrees.
• In vivo sCPIA SDs ranged from 0.61 to 1.4 degrees; BA SDs ranged from 0.45 to 0.65 degrees.

Conclusions:

• The in vitro deviation of the DMS-System is smaller than the in vivo biologic variance.
• Reliable measurements using the DMS-System under clinical conditions can be assumed.