Related Experiment Video
Updated: Aug 9, 2026
10:42
A Postoperative Evaluation Guideline for Computer-Assisted Reconstruction of the Mandible
Published on: January 28, 2020
A three-dimensional comparison of condylar position changes between centric relation and centric occlusion using the
T W Utt1, C E Meyers, T F Wierzba
1U.S. Army Dental Corp., Stuttgart, Germany.
Summary
Nearly all patients exhibit condylar position differences between centric relation (CR) and centric occlusion (CO). These changes, measured by the mandibular position indicator (MPI), are not predictable by patient age, gender, or malocclusion class.
Area of Science:
- Orthodontics and Dental Biomechanics
- Craniofacial Morphology and Function
Background:
- Understanding the positional differences between centric relation (CR) and centric occlusion (CO) is crucial for diagnosing and treating malocclusions.
- The mandibular position indicator (MPI) is a tool used to quantify condylar position changes.
Purpose of the Study:
- To compare condylar position between CR and CO using the MPI in a cohort of orthodontic patients.
- To analyze the frequency, direction, and magnitude of CO-CR differences.
- To investigate potential correlations between CO-CR changes and Angle classification, ANB angle, age, or gender.
Main Methods:
- The mandibular position indicator (MPI) was employed to measure condylar positions in 107 patients prior to orthodontic treatment.
- MPI data were analyzed for differences in three spatial planes (sagittal, transverse, superoinferior/anteroposterior).
- Statistical analysis explored correlations between CO-CR changes and patient demographics and cephalometric measurements.
Main Results:
- A measurable CO-CR difference was observed in 99.1% of patients.
- Superoinferior (SI) or anteroposterior (AP) displacements of at least 2.0 mm occurred in 18.7% of patients.
- Transverse shifts of 0.5 mm or greater were noted in 15.9% of patients.
- No significant differences in CO-CR changes were found between Class I and Class II malocclusions.
- SI displacement (mean 0.84 mm) was greater than AP displacement (mean 0.61 mm).
- Weak correlations were observed between right and left condyle movements.
- Patient age, ANB angle, gender, and Angle classification did not predict the frequency, magnitude, or direction of CO-CR changes.
Conclusions:
- Condylar position differences between CR and CO are highly prevalent in orthodontic patients.
- The magnitude and direction of these positional changes are not reliably predicted by common diagnostic parameters like Angle classification, ANB angle, age, or gender.
- Further research may be needed to understand the clinical implications and management of these common CO-CR discrepancies.
More Related Videos
Related Concept Videos
01:25Relative Motion Analysis using Rotating Axes
Consider a component AB undergoing a linear motion. Along with a linear motion, point B also rotates around point A. To comprehend this complex movement, position vectors for both points A and B are established using a stationary reference frame.
However, to express the relative position of point B relative to point A, an additional frame of reference, denoted as x'y', is necessary. This additional frame not only translates but also rotates relative to the fixed frame, making it instrumental in...
However, to express the relative position of point B relative to point A, an additional frame of reference, denoted as x'y', is necessary. This additional frame not only translates but also rotates relative to the fixed frame, making it instrumental in...
01:20Moment of Inertia about an Arbitrary Axis
The moment of inertia is typically associated with principal axes, but it can also be computed for any random axis. When an arbitrary axis is under consideration, the moment of inertia is determined by integrating the mass distribution of the object along that specific axis. It is crucial in applications like the design of machinery, where components rotate about various axes, and balance and stability are essential.
In this scenario, the perpendicular distance between the chosen arbitrary axis...
In this scenario, the perpendicular distance between the chosen arbitrary axis...