Related Experiment Videos
Functional movements of putative jaw muscle insertions
T K Goto1, G E Langenbach, T W Korioth
1Department of Oral Biology, Faculty of Dentistry, University of British Columbia, Vancouver, Canada.
The Anatomical Record
|June 1, 1995
Summary
Jaw muscle insertions move differently in each person during jaw movements. Understanding these unique biomechanical behaviors requires direct measurement of visualized muscle parts for accurate predictions.
Area of Science:
- Biomechanics
- Craniomandibular function
- Musculoskeletal system
Background:
- Craniomandibular muscles are crucial for jaw position and forces.
- Limited understanding of their biomechanical behavior during dynamic jaw function.
Purpose of the Study:
- To determine how jaw muscle insertions change position during various jaw movements in living individuals.
Main Methods:
- Combined 3D reconstruction of MRI scans with jaw-tracking for six-degrees-of-freedom movement analysis.
- Recorded maximum mandibular opening, protrusive, and laterotrusive positions in four subjects.
- Measured translation and rotation of masseter, temporal, medial, and lateral pterygoid muscle insertions.
Main Results:
- Significant variation in attachment sizes, shapes, and displacement patterns among subjects and muscles.
- Observed distinct movements of superior and inferior masseter insertion sites during jaw closing.
- Identified the jaw's rotational center during jaw closing in three subjects.
Conclusions:
- Individual musculoskeletal form and jaw motion patterns necessitate direct measurement of muscle part motion for accurate prediction.
- The study demonstrates the feasibility of obtaining this crucial biomechanical data.