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Motion of the human mandibular condyle during mastication
S Miyawaki1, Y Tanimoto, T Kawakami
1Department of Orthodontics, Okayama University Dental School, Japan.
Journal of Dental Research
|May 3, 2001
Summary
Condylar displacement on the chewing side is greater than on the non-chewing side during jaw movements. This indicates the temporomandibular joint (TMJ) is positioned to prevent excessive loading in healthy adults.
Area of Science:
- Biomechanics
- Dental Science
- Human Physiology
Background:
- Mandibular loading during jaw closing influences condylar path direction.
- Understanding condylar displacement is crucial for temporomandibular joint (TMJ) health.
Purpose of the Study:
- To test the hypothesis that condyle displacement on the chewing side is greater than on the non-chewing side.
- To investigate condylar motion during mastication in healthy adults.
Main Methods:
- Utilized a six-degrees-of-freedom jaw movement recording system.
- Recorded condylar motion in 12 healthy adults without temporomandibular disorders (TMD).
- Subjects chewed a large, hard gummy jelly to simulate functional loading.
Main Results:
- Maximum condylar displacements on the chewing side were significantly larger in superior, medial, and posterior directions compared to the non-chewing side.
- Specific displacements: superior (0.5 mm), medial (0.5 mm), and posterior (0.6 mm) on the chewing side versus minimal displacement on the non-chewing side.
- These findings were observed from the maximum intercuspation (CO) position.
Conclusions:
- In healthy adults, condylar positions at maximum intercuspation are adapted to accommodate significant displacements during chewing.
- The temporomandibular joint (TMJ) appears to be positioned to avoid excessive load despite these condylar movements.
- This study provides insights into the functional adaptation of the TMJ during mastication.