Understanding Centric Stops and Terminal Contact Functional Quality
DIAGNOSTICS: Centric Stops (Terminal Contacts)
QUESTION: Can posterior centric stops be the correct centric stops if a TMD pain patient is able to close on their occlusal appliances to the existing centric stops reproducibly and precisely, but having lots of muscles pain with joint clicking?
- Not all good centric stops are pain free centric stops even if they are balanced and look good.
- TMJ/TMD patients must recognize that mandibular location and positioning makes a significant difference when the dentist adjusts the appliance with articulating marks.
- Balanced centric stops does not imply comfort or health.
- Centric stops “hold” the jaw from further closure. The jaw may or may not be in the correct position. Lateral excursive movements should be free of occlusal interferences.
Every discipline argues correctness about their approach and method. Only one philosophy and approach measures CMS jaw positioning, muscle resting and functional EMG activity before and after treatment with TENS. This approach quantifies whether the approach was really physiologically healthy and optimal. Other approaches may say their approach was “successful” – subjective.
Positional measurements combined with functional and resting EMG measurements does not leave much room for here say. Data that indicates the patients level of functional success can be quantified.
Example: Patient presents with severe myofacial TMD pain. Computerized mandibular scanning (jaw tracking) that measured open and closing movements in the sagittal and frontal planes with velocity is able to help dentists visualize quality of terminal contact mandibular responses.
- Guarded occlusion (dysfunction) – Terminal velocity is < 200-250 mm/sec.
- Balanced occlusion (healthy) – Terminal velocity is > 250 mm/sec.
The ability for a patients mandible to open and close to a terminal contact (centric stop) should be free of occlusal interferences with good velocity (no slow downs) after any occlusal therapy.
Below K7 Scan 2 Jaw Tracking Traces compare before habitual occlusion vs. after GNM Orthotic (Sagittal, frontal movements and Velocity of closure).
BEFORE: K7 Open and closing cycles (left jaw tracking Scan 2) are correlated with habitual vs. physiologic isotonic (muscle rested) position and optimal myo-trajectory (sagittal and frontal). Guarded slow down velocity is show at this terminal contact position indicating dysfunction and impairment.
AFTER: K7 Open and closing cycles (left jaw tracking Scan 2) are correlated with habitual vs. physiologic isotonic (muscle rested) position and optimal myo-trajectory (sagittal and frontal). Improved velocity with no guarding (balanced) is achieved with mandible closing on the optimal myo-trajectory (isotonic path).
K7 technology and measurements allows the dentist to see the quality of his/her patients jaw closing ability to the terminal contact (centric stop) position as well as correlate the centric stop adjustments to a proper optimal myo-trajectory.
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Read more: What Does the K7 Technology Measure?
