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Mandibular movements/(function), temporomandibular joint function and muscle activity that does not operate to standards of physiologic health are considered dysfunctional or impaired.
There are standards and parameters to which one can identify physiologic functional health or dysfunction of the muscles, the joints and jaw movements. Resting and functional modes can be determined. The quality of functional movement and quality of resting ability can also be measured to determine whether a patients ability is working to those health standards or not.
Research and understanding starts with data and documentation of evidence. By recording before, mid and after treatment data the treating clinician can better learn what physiologic responses of his patient are working and what parts are not working. The prudent dentist will then further his study and treatment in a direction that respectfully addresses these responses to the masticatory system positively that will improve the patient’s health rather than by randomly and subjectively assuming certain procedures and modes of treatment he/she provides to the patient is OK. MEASUREMENTS TELL ALL.
There are specific parameters for muscle health, mandibular movement ability and joint functional ability that help establish health vs unhealth.
Let’s start with masticatory muscles. Neuromuscular science has well established that healthy resting muscles can be measured using electromyography (EMG). EMG has been well established in the medical and dental literature as valid aids in monitoring resting and functional muscle activity. Muscle activity can be measured in microvolts (mV). High levels are not as good, super lower EMG levels are also not so good, but normal EMG levels for various muscle groups have been determined from research.
Normative EMG values based on clinical studies and published research have been established and can be used to by dentists to determine whether a patients resting muscle activity are normal or not. Just as within the medical community we can measure blood pressure, pulse rate and or heart rates, the field of medicine as established physiologic normative parameters of what is considered “normal” vs abnormal whether the values would be too high or values too low.
Normal resting EMG activity for the following muscles are:
* Temporalis anterior group ~2.3mV,
* Masseter ~1.3 mV,
* Cervical group ~ 2.2 mV and
* Suprahyoid/digastrics ~ 1.7 mV
What this means is that muscles of the jaw regions can be quantified before, mid and after treatment to determine of a TMD patients muscle activity status is normal or abnormal when the mandible is at rest.
This also would mean that muscle status can be measured quantitatively after any forms of therapy, whether it is splints therapy, occlusal oriented treatment, orthodontic, restorative, etc and the dentists can measure to see if the therapy rendered is allowing the patients muscles to come into a normalized range.
If the EMGs are above or way below these normative values neuromuscular science has recognized that these resting muscle values would be abnormal. We would consider that pathologic, or nor healthy.
Something everyone on this forum can consider as specific measurable and quantifiable parameters of physiologic healthy vs. unhealthy.