Design of a Stereophotogrammetric Axiopantography

Written by Fábián Zoltán oh.

Axiographic analysis of condylar pathways of the temporomandibular joint (TMJ) is considered by some to be a standard procedure when used for diagnostic and prosthetic reconstruction purposes. This is confirmed by some practitioners’ statement regarding odontiatrogenic TMJ dysfunction. This paper deals with the presentation of the preliminary results of an optoelectronic axiograph, by means of which we could eliminate the difficulties of the classical condylar tracing, difficulties that could be the main cause of the low permeation of this method in daily practice. This motion-capture-based method uses infrared LEDs and video cameras connected to a computer. Triangulation algorithms were used to determine the 3D coordinates of the tracking markers mounted on the articulator. A set of measurements was carried out by incrementally changing the sagittal condylar inclination by 5° from 15° to 60°. The articulator had no cast mounted, and was hand-manipulated. Hinge axis location was computed during opening movements; sagittal condylar pathway was recorded during propulsion. In addition to propulsion lateropulsion and wide opening was carried out to collect data for Posselt diagrams. The resulted sagittal condyle inclination (SCI) values were lower than the protractor’s margin of error, and standard deviation was less than 0.325 degrees. In conclusion we can say that this method can be used for tracing Posselt diagrams, and for determining SCI, however there is a need for improvements for in vivo usage.


Keywords: axiography, optoelectronic, condylar pathway

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