The left window of 4 ESG recordings shows late closing joint sounds occurring in the right joint (blue) before orthotic treatment.
The right window of 4 ESG recordings show improved later closing recipricol joint sounds after GNM orthotic treatment.
Four consecutive open closing cycles are recorded using K7 ESG (electrosonography, Myotronics, Inc., Kent, WA). These joint sound recordings distinguish specific left and right temporomandibular joints sounds and characteristic signature patterns. Velocity, timing, amplitude, duration and frequency are accurately documented and used to detect and distinguish high and low frequency as well as high and low amplitude signature sound patterns. Severe degenerative joint (DJD) patterns are distinguished by low amplitude high frequency patterns (bone grating on bone).
Recording of joint sounds is part of a recommended screening examination for TMD patients and is the “standard of care” during examination of TMD patients. Standards for the history, examination, diagnosis and treatment of temporomandibular distorders (TMD) published by the American Academy of Head and Neck and Facial Pain indicates (1990), “Digital Sonography may be used to record and analyze temporomandibular joint sounds providing the doctor with valuable information for diagnosis and treatment planning”.