View Full Version : 3d motion analysis for chewing

A. Van Der Bilt
12-01-1998, 10:38 PM
Dear all,

In our lab we study chewing movements already for quite some time.
We have an Optotrak 3D system (3010) since 1991 (the first one that was
sold in Europe).
We still use it and it works fine, we have done lots of motion studies with it.

However, for a new study on a large group of subjects we want to determine
the jaw movement during normal chewing. Attaching the markers on the skin
of the upper and lower jaw is too inaccurate because of rather large skin
movements during chewing. Optical markers, of course, cannot be used inside
the mouth. Dental 'devices' fixed to the front teeth of the upper and lower
jaw, supporting the markers outside the mouth will interfere too much with
'normal' chewing.

Therefore, we are looking for a motion analysis system that can measure 2
markers within the mouth
with an accuracy better than 0.5 millimeter during chewing. At the same
time we measure analogue signals like EMG. We know that motion tracking
systems exist that use magnetic markers. To that end I have been rereading
the discussion of Paul Treffner on this list about motion analysis systems
(30 may 1998, the Biomch-l archive works perfect!).

However, after reading that discussion I still have some questions:
- what system could do the job
- what would be the price of such a system
- there used to be a system made by Siemens: sirognathograph, especially
made for jaw movements. However, I could not find information on that
system on the internet (although I used 6 different search machines).

Thank you for your interest,

Andries van der Bilt

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Andries van der Bilt
Dept. Oral Physiology Telephone +31-30-2533096/2533540
Faculty of Medicine Fax +31-30-2535537
Utrecht University e-mail A.vanderBilt@med.uu.nl
P.O. Box 80.037 WWW http://www.med.uu.nl/BTHK/index.htm
3508 TA Utrecht Address Universiteitsweg 100
The Netherlands
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